summaryrefslogtreecommitdiffstats
path: root/src/boost/tools/auto_index
diff options
context:
space:
mode:
Diffstat (limited to 'src/boost/tools/auto_index')
-rw-r--r--src/boost/tools/auto_index/build/Jamfile.v235
-rw-r--r--src/boost/tools/auto_index/include/auto_index_helpers.qbk19
-rw-r--r--src/boost/tools/auto_index/index.html15
-rw-r--r--src/boost/tools/auto_index/src/auto_index.cpp783
-rw-r--r--src/boost/tools/auto_index/src/auto_index.hpp137
-rw-r--r--src/boost/tools/auto_index/src/file_scanning.cpp495
-rw-r--r--src/boost/tools/auto_index/src/index_generator.cpp327
-rw-r--r--src/boost/tools/auto_index/src/tiny_xml.cpp257
-rw-r--r--src/boost/tools/auto_index/src/tiny_xml.hpp83
-rw-r--r--src/boost/tools/auto_index/test/Jamfile.v262
-rw-r--r--src/boost/tools/auto_index/test/index.idx26
-rw-r--r--src/boost/tools/auto_index/test/test1.gold6671
-rw-r--r--src/boost/tools/auto_index/test/test2.gold6671
-rw-r--r--src/boost/tools/auto_index/test/test3.gold6671
-rw-r--r--src/boost/tools/auto_index/test/type_traits.docbook6673
15 files changed, 28925 insertions, 0 deletions
diff --git a/src/boost/tools/auto_index/build/Jamfile.v2 b/src/boost/tools/auto_index/build/Jamfile.v2
new file mode 100644
index 00000000..2e622773
--- /dev/null
+++ b/src/boost/tools/auto_index/build/Jamfile.v2
@@ -0,0 +1,35 @@
+#==============================================================================
+# Copyright (c) 2015 Rene Rivera
+#
+# Use, modification and distribution is subject to the Boost Software
+# License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+#==============================================================================
+
+import quickbook ;
+import modules ;
+import boostcpp ;
+import path ;
+import option ;
+
+local DIST_DIR = [ option.get distdir ] ;
+DIST_DIR ?= [ option.get build-dir ] ;
+DIST_DIR ?= [ path.join $(BOOST_ROOT) dist ] ;
+DIST_DIR = [ path.root [ path.make $(DIST_DIR) ] [ path.pwd ] ] ;
+local DIST_BIN = [ path.join $(DIST_DIR) bin ] ;
+
+exe auto_index :
+ ../src/auto_index.cpp
+ ../src/file_scanning.cpp
+ ../src/index_generator.cpp
+ ../src/tiny_xml.cpp
+ /boost//regex
+ /boost//filesystem
+ /boost//system
+ /boost//program_options
+: <define>BOOST_ALL_NO_LIB=1 <link>static release ;
+
+install aii : auto_index : <location>. ;
+explicit aii ;
+
+install i : auto_index : <location>$(DIST_BIN) ;
diff --git a/src/boost/tools/auto_index/include/auto_index_helpers.qbk b/src/boost/tools/auto_index/include/auto_index_helpers.qbk
new file mode 100644
index 00000000..086c9163
--- /dev/null
+++ b/src/boost/tools/auto_index/include/auto_index_helpers.qbk
@@ -0,0 +1,19 @@
+
+
+[template index[]
+'''<index/>'''
+]
+
+[template named_index[type title]
+'''<index type="'''[type]'''"><title>'''[title]'''</title></index>'''
+]
+
+[template AutoIndex [Args] '''<?BoostAutoIndex ''' [Args]'''?>''']
+
+[template indexterm1 [primary] '''<indexterm><primary>'''[primary]'''</primary></indexterm>''']
+[template indexterm2 [primary secondary] '''<indexterm><primary>'''[primary]'''</primary><secondary>'''[secondary]'''</secondary></indexterm>''']
+[template indexterm3 [primary secondary tertiary] '''<indexterm><primary>'''[primary]'''</primary><secondary>'''[secondary]'''</secondary><tertiary>'''[tertiary]'''</tertiary></indexterm>''']
+
+[template typed_indexterm1 [type primary] '''<indexterm type="'''[type]'''"><primary>'''[primary]'''</primary></indexterm>''']
+[template typed_indexterm2 [type primary secondary] '''<indexterm type="'''[type]'''"><primary>'''[primary]'''</primary><secondary>'''[secondary]'''</secondary></indexterm>''']
+[template typed_indexterm3 [type primary secondary tertiary] '''<indexterm type="'''[type]'''"><primary>'''[primary]'''</primary><secondary>'''[secondary]'''</secondary><tertiary>'''[tertiary]'''</tertiary></indexterm>''']
diff --git a/src/boost/tools/auto_index/index.html b/src/boost/tools/auto_index/index.html
new file mode 100644
index 00000000..df7430bd
--- /dev/null
+++ b/src/boost/tools/auto_index/index.html
@@ -0,0 +1,15 @@
+<html>
+ <head>
+ <meta http-equiv="refresh" content="0; URL=doc/html/index.html">
+ </head>
+ <body>
+ <P>
+ Automatic redirection failed, please go to <a href="doc/html/index.html">doc/html/index.html</a>.
+ </P>
+ <P>Copyright&nbsp;John Maddock 2001</P>
+ <P>Distributed under the Boost Software License, Version 1.0. (See accompanying file <A href="../../LICENSE_1_0.txt">
+ LICENSE_1_0.txt</A> or copy at <A href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</A>).</P>
+ </body>
+</html>
+
+
diff --git a/src/boost/tools/auto_index/src/auto_index.cpp b/src/boost/tools/auto_index/src/auto_index.cpp
new file mode 100644
index 00000000..e8d5db20
--- /dev/null
+++ b/src/boost/tools/auto_index/src/auto_index.cpp
@@ -0,0 +1,783 @@
+// Copyright 2008 John Maddock
+//
+// Use, modification and distribution are subject to the
+// Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include <set>
+#include <cstring>
+#include <boost/array.hpp>
+#include <boost/exception/all.hpp>
+#include <boost/program_options.hpp>
+#include "auto_index.hpp"
+
+std::string infile, outfile, prefix, last_primary, last_secondary, last_tertiary;
+std::set<index_info> index_terms;
+std::set<std::pair<std::string, std::string> > found_terms;
+bool no_duplicates = false;
+bool verbose = false;
+bool use_section_names = true;
+index_entry_set index_entries;
+boost::tiny_xml::element_list indexes;
+std::list<id_rewrite_rule> id_rewrite_list;
+bool internal_indexes = false;
+std::string internal_index_type = "section";
+boost::regex debug;
+file_scanner_set_type file_scanner_set;
+
+int help()
+{
+ std::cout << "Please refer to the documentation for the correct command line syntax" << std::endl;
+ return 1;
+}
+
+void eat_block(std::string& result, std::istream & is)
+{
+ //
+ // everything until we get to a closing '>':
+ //
+ char c;
+ while(is.get(c) && c != '>')
+ {
+ result += c;
+ if(c == '\\')
+ {
+ is.get(c);
+ result += c;
+ }
+ }
+ result += c;
+}
+
+std::string get_header(std::istream & is)
+{
+ //
+ // We need to get any leading <? and <! elements:
+ //
+ std::string result;
+ is >> std::ws;
+ if(is.get() != '<')
+ throw std::runtime_error("Invalid leading markup in XML file found");
+ char c = is.peek();
+ while((c == '?') || (c == '!'))
+ {
+ std::string temp;
+ std::getline(is, temp, '>');
+ result += '<' + temp + '>';
+ is >> std::ws;
+ if(is.get() != '<')
+ throw std::runtime_error("Invalid leading markup in XML file found");
+ c = is.peek();
+ result += '\n';
+ }
+ return result;
+}
+//
+// Find attribute named "name" in node "node":
+//
+const std::string* find_attr(boost::tiny_xml::element_ptr node, const char* name)
+{
+ for(boost::tiny_xml::attribute_list::const_iterator i = node->attributes.begin();
+ i != node->attributes.end(); ++i)
+ {
+ if(i->name == name)
+ return &(i->value);
+ }
+ return 0;
+}
+//
+// Get the ID of the current block scope, basically
+// move up the XML tree until we find a valid ID:
+//
+const std::string* get_current_block_id(node_id const* id)
+{
+ while((id->id == 0) && (id->prev))
+ id = id->prev;
+ if(!id->id)
+ BOOST_THROW_EXCEPTION(std::runtime_error("Current XML block has no enclosing ID: XML is not valid Boostbook?"));
+ return id->id;
+}
+//
+// Get the title of the current block scope, basically
+// move up the XML tree until we find a valid title:
+//
+const std::string& get_current_block_title(title_info const* id)
+{
+ while((id->title.size() == 0) && (id->prev))
+ id = id->prev;
+ return id->title;
+}
+//
+// Get all the content under this node, with any inline XML
+// stripped out:
+//
+std::string get_consolidated_content(boost::tiny_xml::element_ptr node)
+{
+ std::string result(node->content);
+ for(boost::tiny_xml::element_list::const_iterator i = node->elements.begin();
+ i != node->elements.end(); ++i)
+ {
+ result += " ";
+ result += get_consolidated_content(*i);
+ }
+ static const boost::regex e("(^[[:space:]]+)|([[:space:]]+)|([[:space:]]+$)");
+ return regex_replace(result, e, "(?2 )", boost::regex_constants::format_all);
+}
+//
+// Rewrite a title based on any rewrite rules we may have:
+//
+std::string rewrite_title(const std::string& title, const std::string& id)
+{
+ for(std::list<id_rewrite_rule>::const_iterator i = id_rewrite_list.begin(); i != id_rewrite_list.end(); ++i)
+ {
+ if(i->base_on_id)
+ {
+ if(regex_match(id, i->id))
+ return i->new_name;
+ }
+ else
+ {
+ if(regex_match(title, i->id))
+ return regex_replace(title, i->id, i->new_name);
+ }
+ }
+ return title;
+}
+
+struct string_cmp
+{
+ bool operator()(const char* a, const char* b)const
+ {
+ return std::strcmp(a, b) < 0;
+ }
+};
+//
+// Discover whether this node can contain a <title> or not, if not
+// we don't want to link to it, or the XSL HTML stylesheets may do strange
+// things, and at least emit copious messages. See https://sourceforge.net/tracker/?func=detail&aid=3325153&group_id=21935&atid=373747
+//
+bool can_contain_title(const char* name)
+{
+ static const boost::array<const char*, 103> names =
+ { {
+ "abstract", "appendix", "appendixinfo", "article", "articleinfo", "authorblurb", "bibliodiv", "biblioentry", "bibliography",
+ "bibliographyinfo", "bibliolist", "bibliomixed", "bibliomset", "biblioset", "blockinfo", "blockquote", "book", "bookinfo",
+ "calloutlist", "caution", "chapter", "chapterinfo", "colophon", "constraintdef", "dedication", "equation", "example", "figure",
+ "formalpara", "glossary", "glossaryinfo", "glossdiv", "glosslist", "important", "index", "indexdiv", "indexinfo", "itemizedlist",
+ "legalnotice", "lot", "msg", "msgexplan", "msgmain", "msgrel", "msgset", "msgsub", "note", "objectinfo", "orderedlist", "part",
+ "partinfo", "partintro", "personblurb", "preface", "prefaceinfo", "procedure", "productionset", "qandadiv", "qandaset",
+ "refentryinfo", "reference", "referenceinfo", "refsect1", "refsect1info", "refsect2", "refsect2info", "refsect3", "refsect3info",
+ "refsection", "refsectioninfo", "refsynopsisdiv", "refsynopsisdivinfo", "sect1", "sect1info", "sect2", "sect2info", "sect3",
+ "sect3info", "sect4", "sect4info", "sect5", "sect5info", "section", "sectioninfo", "segmentedlist", "set", "setindex",
+ "setindexinfo", "setinfo", "sidebar", "sidebarinfo", "simplesect", "step", "table", "task", "taskprerequisites",
+ "taskrelated", "tasksummary", "tip", "toc", "variablelist", "warning", "refentry"
+ } };
+ static std::set<const char*, string_cmp> permitted;
+
+ if(permitted.empty())
+ permitted.insert(names.begin(), names.end());
+
+ return 0 != permitted.count(name);
+}
+//
+// Determine whether this node can contain an indexterm or not:
+//
+bool can_contain_indexterm(const char* name)
+{
+ static const boost::array<const char*, 257> names =
+ { {
+ "abbrev", "accel", "ackno", "acronym", "action", "answer", "appendix", "appendixinfo", "application",
+ "article", "articleinfo", "artpagenums", "attribution", "authorinitials", "bibliocoverage", "bibliodiv",
+ "biblioentry", "bibliography", "bibliographyinfo", "biblioid", "bibliomisc", "bibliomixed", "bibliomset",
+ "bibliorelation", "biblioset", "bibliosource", "blockinfo", "blockquote", "bookinfo", "bridgehead", "callout",
+ "caution", "chapter", "chapterinfo", "citation", "citebiblioid", "citetitle", "city", "classname", "classsynopsisinfo",
+ "code", "collabname", "command", "computeroutput", "confdates", "confnum", "confsponsor", "conftitle", "constant",
+ "constraintdef", "contractnum", "contractsponsor", "contrib", "corpauthor", "corpcredit", "corpname", "country",
+ "database", "date", "dedication", "edition", "email", "emphasis", "entry", "envar", "errorcode", "errorname", "errortext",
+ "errortype", "example", "exceptionname", "fax", "figure", "filename", "firstname", "firstterm", "foreignphrase",
+ "formalpara", "funcparams", "funcsynopsisinfo", "function", "glossary", "glossaryinfo", "glossdef", "glossdiv",
+ "glossentry", "glosssee", "glossseealso", "glossterm", "guibutton", "guiicon", "guilabel", "guimenu", "guimenuitem",
+ "guisubmenu", "hardware", "highlights", "holder", "honorific", "important", "index", "indexinfo", "informalexample",
+ "informalfigure", "initializer", "interface", "interfacename", "invpartnumber", "isbn", "issn", "issuenum", "itemizedlist",
+ "itermset", "jobtitle", "keycap", "keycode", "keysym", "label", "legalnotice", "lineage", "lineannotation",
+ /*"link", */"listitem", "literal", "literallayout", "lotentry", "manvolnum", "markup", "medialabel", "member",
+ "methodname", "modespec", "modifier", "mousebutton", "msgaud", "msgexplan", "msglevel", "msgorig", "msgtext", "note",
+ "objectinfo", "olink", "option", "optional", "orderedlist", "orgdiv", "orgname", "otheraddr", "othername", "package",
+ "pagenums", "para", "parameter", "partinfo", "partintro", "phone", "phrase", "pob", "postcode", "preface", "prefaceinfo",
+ "procedure", "productname", "productnumber", "programlisting", "prompt", "property", "pubdate", "publishername",
+ "pubsnumber", "qandadiv", "qandaset", "question", "quote", "refentry", "refentryinfo", "refentrytitle", "referenceinfo",
+ "refmeta", "refmiscinfo", "refpurpose", "refsect1", "refsect1info", "refsect2", "refsect2info", "refsect3", "refsect3info",
+ "refsection", "refsectioninfo", "refsynopsisdiv", "refsynopsisdivinfo", "releaseinfo", "remark", "returnvalue",
+ "revdescription", "revnumber", "revremark", "screen", "screeninfo", "sect1", "sect1info", "sect2", "sect2info", "sect3",
+ "sect3info", "sect4", "sect4info", "sect5", "sect5info", "section", "sectioninfo", "seg", "segtitle", "seriesvolnums",
+ "setindex", "setindexinfo", "setinfo", "sgmltag", "shortaffil", "sidebar", "sidebarinfo", "simpara", "simplesect",
+ "state", "step", "street", "structfield", "structname", "subtitle", "surname", "symbol", "synopsis", "systemitem",
+ "table", "task", "taskprerequisites", "taskrelated", "tasksummary", "td", "term", "termdef", "th", "tip", /*"title",*/
+ "titleabbrev", "tocback", "tocentry", "tocfront", "token", "type", "ulink", "uri", "userinput", "variablelist",
+ "varname", "volumenum", "warning", "wordasword", "year"
+ } };
+ static std::set<const char*, string_cmp> permitted;
+
+ if(permitted.empty())
+ permitted.insert(names.begin(), names.end());
+
+ return 0 != permitted.count(name);
+}
+//
+// Decide whether to flatten this node for searching purposes:
+//
+bool should_flatten_node(const char* name)
+{
+ //
+ // The list of nodes to flatten is basically the list of elements that
+ // can appear inside a <section> - see http://www.docbook.org/tdg/en/html/section.html.
+ // In other words basically anything at the level of a paragraph/table/listing etc.
+ //
+ static const boost::array<const char*, 57> names =
+ { {
+ "title", "subtitle", "titleabbrev",
+ "toc", "lot", "glossary", "bibliography",
+ /*"calloutlist", "glosslist", "bibliolist", "itemizedlist", "orderedlist",
+ "segmentedlist", "simplelist", "variablelist",*/ "caution", "important", "note",
+ "tip", "warning", "literallayout", "programlisting", "programlistingco",
+ "screen", "screenco", "screenshot", "synopsis", "cmdsynopsis", "funcsynopsis",
+ "classsynopsis", "fieldsynopsis", "constructorsynopsis",
+ "destructorsynopsis", "methodsynopsis", "formalpara", "para", "simpara",
+ "address", "blockquote", "graphic", "graphicco", "mediaobject",
+ "mediaobjectco", "informalequation", "informalexample", "informalfigure",
+ "informaltable", "equation", "example", "figure", "table", "msgset", "procedure",
+ "sidebar", "qandaset", "task", "productionset", "constraintdef", "anchor",
+ "bridgehead", "remark", "highlights", "abstract", "authorblurb", "epigraph"
+ /*"biblioentry", "bibliomixed", "callout", "glossentry", "listitem", "seg", "seglistitem", "member",
+ "term", */
+ } };
+ static std::set<const char*, string_cmp> terminals;
+
+ if(terminals.empty())
+ terminals.insert(names.begin(), names.end());
+ return 0 != terminals.count(name);
+}
+std::string unescape_xml(const std::string& s)
+{
+ boost::regex e("&(?:(quot)|(amp)|(apos)|(lt)|(gt));");
+ return regex_replace(s, e, "(?1\")(?2&)(?3\')(?4<)(?5>)", boost::regex_constants::format_all);
+}
+//
+// Exception classes to propagate processing instruction info:
+//
+struct ignore_section{};
+struct ignore_block{};
+//
+// Check if we're in a section (or chapter etc) or not:
+//
+bool is_section(const std::string& name)
+{
+ static const boost::array<const char*, 19> data =
+ {{
+ "dedication", "toc", "lot", "glossary", "bibliography", "preface", "chapter",
+ "reference", "part", "article", "appendix", "index", "setindex", "colophon",
+ "sect1", "refentry", "simplesect", "section", "partintro"
+ }};
+ std::set<std::string> names;
+ if(names.empty())
+ names.insert(data.begin(), data.end());
+ return 0 != names.count(name);
+}
+//
+// Check if we're in a block/paragraph or not:
+//
+bool is_block(const std::string& name)
+{
+ static const boost::array<const char*, 58> data =
+ {{
+ "calloutlist", "glosslist", "bibliolist", "itemizedlist", "orderedlist",
+ "segmentedlist", "simplelist", "variablelist", "caution", "important", "note",
+ "tip", "warning", "literallayout", "programlisting", "programlistingco",
+ "screen", "screenco", "screenshot", "synopsis", "cmdsynopsis", "funcsynopsis",
+ "classsynopsis", "fieldsynopsis", "constructorsynopsis",
+ "destructorsynopsis", "methodsynopsis", "formalpara", "para", "simpara",
+ "address", "blockquote", "graphic", "graphicco", "mediaobject",
+ "mediaobjectco", "informalequation", "informalexample", "informalfigure",
+ "informaltable", "equation", "example", "figure", "table", "msgset", "procedure",
+ "sidebar", "qandaset", "task", "productionset", "constraintdef", "anchor",
+ "bridgehead", "remark", "highlights", "abstract", "authorblurb", "epigraph"
+ }};
+ std::set<std::string> names;
+ if(names.empty())
+ names.insert(data.begin(), data.end());
+ return 0 != names.count(name);
+}
+//
+// Helper proc to recurse through children:
+//
+void process_node(boost::tiny_xml::element_ptr node, node_id* prev, title_info* pt, bool seen);
+bool recurse_through_children(boost::tiny_xml::element_ptr node, node_id* id, title_info* pt, bool seen)
+{
+ try
+ {
+ for(boost::tiny_xml::element_list::const_iterator i = node->elements.begin();
+ i != node->elements.end(); ++i)
+ {
+ process_node(*i, id, pt, seen);
+ }
+ }
+ catch(const ignore_section&)
+ {
+ if(is_section(node->name))
+ return false;
+ else
+ throw;
+ }
+ catch(const ignore_block&)
+ {
+ if(is_block(node->name) || is_section(node->name))
+ return false;
+ else
+ throw;
+ }
+ return true;
+}
+//
+// This does most of the work: process the node pointed to, and any children
+// that it may have:
+//
+void process_node(boost::tiny_xml::element_ptr node, node_id* prev, title_info* pt, bool seen = false)
+{
+ //
+ // Store the current ID and title as nested scoped objects:
+ //
+ node_id id = { 0, prev };
+ if(can_contain_title(node->name.c_str()))
+ {
+ // Only set the ID to link to if the block can contain a title, see
+ // can_contain_title above for rationale.
+ id.id = find_attr(node, "id");
+ }
+ title_info title = { "", pt};
+ bool flatten = should_flatten_node(node->name.c_str());
+
+ if(node->name.size() && node->name[0] == '?')
+ {
+ if(node->name == "?BoostAutoIndex")
+ {
+ if(node->content == "IgnoreSection")
+ {
+ throw ignore_section();
+ }
+ else if(node->content == "IgnoreBlock")
+ {
+ throw ignore_block();
+ }
+ }
+ return; // Ignore processing instructions
+ }
+ else if((node->name == "title") && (id.prev->id))
+ {
+ //
+ // This actually sets the title of the enclosing scope,
+ // not this tag itself:
+ //
+ title.prev->title = get_consolidated_content(node);
+ if(verbose)
+ std::cout << "Indexing section: " << title.prev->title << std::endl;
+ }
+ else if((node->name == "refentrytitle") && (id.prev->prev->id))
+ {
+ //
+ // This actually sets the title of the enclosing refentry scope,
+ // not this tag itself:
+ //
+ title.prev->prev->title = get_consolidated_content(node);
+ if(verbose)
+ std::cout << "Indexing refentry: " << title.prev->prev->title << std::endl;
+ }
+ if(node->name == "anchor")
+ {
+ if(node->parent.lock()->name == "title")
+ {
+ // We have a title with a nested anchor ID, change the ID of our parents parent to match:
+ id.prev->prev->id = id.id;
+ }
+ }
+ else if(node->name == "index")
+ {
+ // Keep track of all the indexes we see:
+ indexes.push_back(node);
+ if(node->parent.lock()->name == "para")
+ node->parent.lock()->name = "";
+ }
+ else if(node->name == "primary")
+ {
+ last_primary = get_consolidated_content(node);
+ }
+ else if(node->name == "secondary")
+ {
+ last_secondary = get_consolidated_content(node);
+ }
+ else if(node->name == "tertiary")
+ {
+ last_tertiary = get_consolidated_content(node);
+ }
+ else if((node->name == "see") && internal_indexes)
+ {
+ std::cerr << "WARNING: <see> in XML source will be ignored for the index generation" << std::endl;
+ }
+ else if((node->name == "seealso") && internal_indexes)
+ {
+ std::cerr << "WARNING: <seealso> in XML source will be ignored for the index generation" << std::endl;
+ }
+
+ std::string flattenned_text;
+ const std::string* ptext;
+ if(flatten)
+ {
+ flattenned_text = unescape_xml(get_consolidated_content(node));
+ ptext = &flattenned_text;
+ //
+ // Recurse through children here if we're going to flatten the text, that way we see any processing instructions first:
+ //
+ if(!recurse_through_children(node, &id, &title, flatten || seen))
+ return;
+ }
+ else
+ {
+ ptext = &(node->content);
+ }
+
+ //
+ // Search content for items: we only search if the content is not empty,
+ // and the content is not whitespace alone, and we haven't already searched this
+ // text in one of our parent nodes that got flattened.
+ //
+ static const boost::regex space_re("[[:space:]]+");
+ if(!seen && ptext->size() && !regex_match(*ptext, space_re))
+ {
+ // Save block ID and title in case we find some hits:
+ const std::string* pid = get_current_block_id(&id);
+ const std::string& rtitle = get_current_block_title(&title);
+ const std::string simple_title = rewrite_title(rtitle, *pid);
+ // Scan for each index term:
+ for(std::set<index_info>::const_iterator i = index_terms.begin();
+ i != index_terms.end(); ++i)
+ {
+ if(regex_search(*ptext, i->search_text))
+ {
+ //
+ // We need to check to see if this term has already been indexed
+ // in this zone, in order to prevent duplicate entries, also check
+ // that any constrait placed on the term's ID is satisfied:
+ //
+ std::pair<std::string, std::string> item_index(*pid, i->term);
+ if(((no_duplicates == false) || (0 == found_terms.count(item_index)))
+ && (i->search_id.empty() || regex_match(*pid, i->search_id)))
+ {
+ // We have something to index!
+ found_terms.insert(item_index);
+
+ if(!debug.empty() && (regex_match(i->term, debug) || regex_match(rtitle, debug) || regex_match(simple_title, debug)))
+ {
+ std::cout << "Debug term found, in block with ID: " << *pid << std::endl;
+ std::cout << "Current section title is: " << rtitle << std::endl;
+ std::cout << "The main index entry will be : " << simple_title << std::endl;
+ std::cout << "The indexed term is: " << i->term << std::endl;
+ std::cout << "The search regex is: " << i->search_text << std::endl;
+ std::cout << "The section constraint is: " << i->search_id << std::endl;
+ std::cout << "The index type for this entry is: " << i->category << std::endl;
+ }
+
+ if(use_section_names && (simple_title != i->term))
+ {
+ //
+ // First off insert index entry with primary term
+ // consisting of the section title, and secondary term the
+ // actual index term, this gets skipped if the title and index
+ // term are the same:
+ //
+ if(internal_indexes == false)
+ {
+ // Insert an <indexterm> into the XML:
+ boost::tiny_xml::element_ptr p(new boost::tiny_xml::element());
+ p->name = "indexterm";
+ boost::tiny_xml::element_ptr prim(new boost::tiny_xml::element());
+ prim->name = "primary";
+ prim->elements.push_front(boost::tiny_xml::element_ptr(new boost::tiny_xml::element()));
+ prim->elements.front()->content = simple_title;
+ p->elements.push_front(prim);
+
+ boost::tiny_xml::element_ptr sec(new boost::tiny_xml::element());
+ sec->name = "secondary";
+ sec->elements.push_front(boost::tiny_xml::element_ptr(new boost::tiny_xml::element()));
+ sec->elements.front()->content = i->term;
+ p->elements.push_back(sec);
+ try{
+ // Insert the Indexterm:
+ boost::tiny_xml::element_ptr parent(node->parent);
+ while(!can_contain_indexterm(parent->name.c_str()))
+ parent = parent->parent.lock();
+ parent->elements.push_front(p);
+ }
+ catch(const std::exception&)
+ {
+ std::cerr << "Unable to find location to insert <indexterm>" << std::endl;
+ }
+ }
+ // Track the entry in our internal index:
+ index_entry_ptr item1(new index_entry(simple_title));
+ index_entry_ptr item2(new index_entry(i->term, *pid));
+ index_entry_set::iterator pos = index_entries.insert(item1).first;
+ (**pos).sub_keys.insert(item2);
+ }
+ //
+ // Now insert another index entry with the index term
+ // as the primary key, and the section title as the
+ // secondary key, this one gets assigned to the
+ // appropriate index category if there is one:
+ //
+ bool preferred_term = false;
+ if(internal_indexes == false)
+ {
+ // Insert <indexterm> into the XML:
+ boost::tiny_xml::element_ptr p2(new boost::tiny_xml::element());
+ p2->name = "indexterm";
+ if(i->category.size())
+ {
+ p2->attributes.push_back(boost::tiny_xml::attribute("type", i->category));
+ }
+ boost::tiny_xml::element_ptr prim2(new boost::tiny_xml::element());
+ prim2->name = "primary";
+ prim2->elements.push_front(boost::tiny_xml::element_ptr(new boost::tiny_xml::element()));
+ prim2->elements.front()->content = i->term;
+ p2->elements.push_front(prim2);
+
+ boost::tiny_xml::element_ptr sec2(new boost::tiny_xml::element());
+ sec2->name = "secondary";
+ sec2->elements.push_front(boost::tiny_xml::element_ptr(new boost::tiny_xml::element()));
+ sec2->elements.front()->content = rtitle;
+ p2->elements.push_back(sec2);
+ try{
+ // Insert the Indexterm:
+ boost::tiny_xml::element_ptr parent(node->parent);
+ while(!can_contain_indexterm(parent->name.c_str()))
+ {
+ // If the search text was found in a title then make it a preferred term:
+ if(parent->name == "title")
+ preferred_term = true;
+ parent = parent->parent.lock();
+ }
+ if(preferred_term)
+ {
+ boost::tiny_xml::attribute a("significance", "preferred");
+ p2->attributes.push_back(a);
+ }
+ parent->elements.push_front(p2);
+ }
+ catch(const std::exception&)
+ {
+ std::cerr << "Unable to find location to insert <indexterm>" << std::endl;
+ }
+ }
+
+ // Track the entry in our internal index:
+ try{
+ // figure out if it's preferred or not:
+ boost::tiny_xml::element_ptr parent(node->parent);
+ while(!can_contain_indexterm(parent->name.c_str()))
+ {
+ // If the search text was found in a title then make it a preferred term:
+ if(parent->name == "title")
+ {
+ preferred_term = true;
+ }
+ parent = parent->parent.lock();
+ if(!parent)
+ break;
+ }
+ }
+ catch(const std::exception&){}
+
+ index_entry_ptr item3(new index_entry(i->term));
+ if(i->category.size())
+ item3->category = i->category;
+ index_entry_ptr item4(new index_entry(rtitle, *pid));
+ item4->preferred = preferred_term;
+ index_entry_set::iterator pos = index_entries.insert(item3).first;
+ (**pos).sub_keys.insert(item4);
+ }
+ }
+ }
+ }
+ //
+ // Recurse through children, if not done already:
+ //
+ if(!flatten)
+ recurse_through_children(node, &id, &title, flatten || seen);
+ //
+ // Process manual index entries last of all:
+ //
+ if(node->name == "indexterm")
+ {
+ // Track the entry in our internal index:
+ const std::string* pid = get_current_block_id(&id);
+ const std::string* attr = find_attr(node, "type");
+ const std::string& rtitle = get_current_block_title(&title);
+ const std::string simple_title = rewrite_title(rtitle, *pid);
+ index_entry_ptr item1(new index_entry(last_primary, "", attr ? *attr : ""));
+ index_entry_set* parent = &((*index_entries.insert(item1).first)->sub_keys);
+
+ if(last_secondary.size())
+ {
+ item1.reset(new index_entry(last_secondary, "", attr ? *attr : ""));
+ parent = &((*parent->insert(item1).first)->sub_keys);
+ }
+ if(last_tertiary.size())
+ {
+ item1.reset(new index_entry(last_tertiary, "", attr ? *attr : ""));
+ parent = &((*parent->insert(item1).first)->sub_keys);
+ }
+ item1.reset(new index_entry(simple_title, *pid, attr ? *attr : ""));
+ parent->insert(item1);
+
+ last_primary = "";
+ last_secondary = "";
+ last_tertiary = "";
+ }
+}
+
+void process_nodes(boost::tiny_xml::element_ptr node)
+{
+ node_id id = { 0, };
+ title_info t = { "", 0 };
+ process_node(node, &id, &t);
+}
+
+int main(int argc, char* argv[])
+{
+ try{
+
+ namespace po = boost::program_options;
+ po::options_description desc("AutoIndex Allowed Options");
+ desc.add_options()
+ ("help", "Print help message")
+ ("in", po::value<std::string>(), "Set the input XML file.")
+ ("out", po::value<std::string>(), "Set output input XML file.")
+ ("scan", po::value<std::string>(), "Scan the specified file for terms to try and index.")
+ ("script", po::value<std::string>(), "Specifies the script file to use.")
+ ("no-duplicates", "Prevents duplicate index entries within the same section.")
+ ("no-section-names", "Suppresses use of section names as index entries.")
+ ("internal-index", "Causes AutoIndex to generate the index itself, rather than relying on the XSL stylesheets.")
+ ("verbose", "Turns on verbose mode.")
+ ("prefix", po::value<std::string>(), "Sets the prefix to be prepended to all file names and paths in the script file.")
+ ("index-type", po::value<std::string>(), "Sets the XML container type to use the index.")
+ ;
+
+ po::variables_map vm;
+ po::store(po::parse_command_line(argc, argv, desc), vm);
+ po::notify(vm);
+
+ //
+ // Process arguments:
+ //
+ if(vm.count("help"))
+ {
+ std::cout << desc;
+ return 0;
+ }
+ if(vm.count("in"))
+ {
+ infile = vm["in"].as<std::string>();
+ }
+ else
+ {
+ std::cerr << "No input XML file specified" << std::endl;
+ return 1;
+ }
+ if(vm.count("out"))
+ {
+ outfile = vm["out"].as<std::string>();
+ }
+ else
+ {
+ std::cerr << "No output XML file specified" << std::endl;
+ return 1;
+ }
+ if(vm.count("verbose"))
+ {
+ verbose = true;
+ }
+ if(vm.count("prefix"))
+ {
+ prefix = vm["prefix"].as<std::string>();
+ }
+ if(vm.count("scan"))
+ {
+ std::string f = vm["scan"].as<std::string>();
+ if(!exists(boost::filesystem::path(f)))
+ throw std::runtime_error("Error the file requested for scanning does not exist: " + f);
+ scan_file(f);
+ }
+ if(vm.count("script"))
+ {
+ process_script(vm["script"].as<std::string>());
+ }
+ if(vm.count("no-duplicates"))
+ {
+ no_duplicates = true;
+ }
+ if(vm.count("no-section-names"))
+ {
+ use_section_names = false;
+ }
+ if(vm.count("internal-index"))
+ {
+ internal_indexes = true;
+ }
+ if(vm.count("index-type"))
+ {
+ internal_index_type = vm["index-type"].as<std::string>();
+ }
+
+ std::ifstream is(infile.c_str());
+ if((0 == is.peek()) || !is.good())
+ {
+ std::cerr << "Unable to open XML data file " << argv[1] << std::endl;
+ return 1;
+ }
+ //
+ // We need to skip any leading <? and <! elements:
+ //
+ std::string header = get_header(is);
+ boost::tiny_xml::element_ptr xml = boost::tiny_xml::parse(is, "");
+ is.close();
+
+ std::cout << "Indexing " << index_terms.size() << " terms..." << std::endl;
+
+ process_nodes(xml);
+
+ if(internal_indexes)
+ generate_indexes();
+
+ std::ofstream os(outfile.c_str());
+ os << header << std::endl;
+ boost::tiny_xml::write(*xml, os);
+ std::cout << index_entries.size() << " Index entries were created." << std::endl;
+
+ }
+ catch(boost::exception& e)
+ {
+ std::cerr << diagnostic_information(e);
+ return 1;
+ }
+ catch(const std::exception& e)
+ {
+ std::cerr << e.what() << std::endl;
+ return 1;
+ }
+ catch(const std::string& s)
+ {
+ std::cerr << s << std::endl;
+ return 1;
+ }
+
+ return 0;
+}
diff --git a/src/boost/tools/auto_index/src/auto_index.hpp b/src/boost/tools/auto_index/src/auto_index.hpp
new file mode 100644
index 00000000..255b8575
--- /dev/null
+++ b/src/boost/tools/auto_index/src/auto_index.hpp
@@ -0,0 +1,137 @@
+// Copyright 2008 John Maddock
+//
+// Use, modification and distribution are subject to the
+// Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_AUTO_INDEX_HPP
+#define BOOST_AUTO_INDEX_HPP
+
+#include <boost/version.hpp>
+
+#if BOOST_VERSION < 104400
+# error "This tool requires Boost 1.44 or later to build."
+#endif
+
+#define BOOST_FILESYSTEM_VERSION 3
+
+#include "tiny_xml.hpp"
+#include <boost/regex.hpp>
+#include <boost/filesystem.hpp>
+#include <boost/algorithm/string/case_conv.hpp>
+#include <fstream>
+#include <cctype>
+#include <map>
+#include <set>
+#include <sstream>
+
+struct index_info
+{
+ std::string term; // The term goes in the index entry
+ boost::regex search_text; // What to search for when indexing the term.
+ boost::regex search_id; // What id's this term may be indexed in.
+ std::string category; // Index category (function, class, macro etc).
+};
+inline bool operator < (const index_info& a, const index_info& b)
+{
+ return (a.term != b.term) ? (a.term < b.term) : (a.category < b.category);
+}
+
+
+struct index_entry;
+typedef boost::shared_ptr<index_entry> index_entry_ptr;
+bool operator < (const index_entry_ptr& a, const index_entry_ptr& b);
+typedef std::set<index_entry_ptr> index_entry_set;
+
+struct index_entry
+{
+ std::string key; // The index term.
+ std::string sort_key; // upper case version of term used for sorting.
+ std::string id; // The id of the block that we will link to.
+ std::string category; // The category of this entry (function, class, macro etc).
+ index_entry_set sub_keys; // All our sub-keys.
+ bool preferred; // This entry is the preferred one for this key
+
+ index_entry() : preferred(false) {}
+ index_entry(const std::string& k) : key(k), sort_key(k), preferred(false) { boost::to_upper(sort_key); }
+ index_entry(const std::string& k, const std::string& i) : key(k), sort_key(k), id(i), preferred(false) { boost::to_upper(sort_key); }
+ index_entry(const std::string& k, const std::string& i, const std::string& c) : key(k), sort_key(k), id(i), category(c), preferred(false) { boost::to_upper(sort_key); }
+};
+
+
+inline bool operator < (const index_entry_ptr& a, const index_entry_ptr& b)
+{
+ return ((a->sort_key != b->sort_key) ? (a->sort_key < b->sort_key) : (a->category < b->category));
+}
+
+struct id_rewrite_rule
+{
+ bool base_on_id; // rewrite the title if "id" matches the section id, otherwise rewrite if title matches "id".
+ boost::regex id; // regex for the id or title to match
+ std::string new_name; // either literal string or format string for the new name.
+
+ id_rewrite_rule(const std::string& i, const std::string& n, bool b)
+ : base_on_id(b), id(i), new_name(n) {}
+};
+
+struct node_id
+{
+ const std::string* id;
+ node_id* prev;
+};
+
+struct title_info
+{
+ std::string title;
+ title_info* prev;
+};
+
+struct file_scanner
+{
+ boost::regex scanner, file_name_filter, section_filter;
+ std::string format_string, type, term_formatter;
+};
+
+inline bool operator < (const file_scanner & a, const file_scanner& b)
+{
+ return a.type < b.type;
+}
+
+typedef std::multiset<file_scanner> file_scanner_set_type;
+
+void process_script(const std::string& script);
+void scan_dir(const std::string& dir, const std::string& mask, bool recurse);
+void scan_file(const std::string& file);
+void generate_indexes();
+const std::string* find_attr(boost::tiny_xml::element_ptr node, const char* name);
+
+extern file_scanner_set_type file_scanner_set;
+
+inline void add_file_scanner(const std::string& type, const std::string& scanner, const std::string& format, const std::string& term_formatter, const std::string& id_filter, const std::string& file_filter)
+{
+ file_scanner s;
+ s.type = type;
+ s.scanner = scanner;
+ s.format_string = format;
+ s.term_formatter = term_formatter;
+ if(file_filter.size())
+ s.file_name_filter = file_filter;
+ if(id_filter.size())
+ s.section_filter = id_filter;
+ file_scanner_set.insert(s);
+}
+
+extern std::set<index_info> index_terms;
+extern std::set<std::pair<std::string, std::string> > found_terms;
+extern bool no_duplicates;
+extern bool verbose;
+extern index_entry_set index_entries;
+extern boost::tiny_xml::element_list indexes;
+extern std::list<id_rewrite_rule> id_rewrite_list;
+extern bool internal_indexes;
+extern std::string prefix;
+extern std::string internal_index_type;
+extern boost::regex debug;
+
+#endif
diff --git a/src/boost/tools/auto_index/src/file_scanning.cpp b/src/boost/tools/auto_index/src/file_scanning.cpp
new file mode 100644
index 00000000..f6c2209c
--- /dev/null
+++ b/src/boost/tools/auto_index/src/file_scanning.cpp
@@ -0,0 +1,495 @@
+// Copyright 2008 John Maddock
+//
+// Use, modification and distribution are subject to the
+// Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include "auto_index.hpp"
+
+bool need_defaults = true;
+
+void install_default_scanners()
+{
+ need_defaults = false;
+ //
+ // Set the default scanners if they're not defined already:
+ //
+ file_scanner s;
+ s.type = "class_name";
+ if(file_scanner_set.find(s) == file_scanner_set.end())
+ {
+ add_file_scanner(
+ "class_name", // Index type
+ // Header file scanner regex:
+ // possibly leading whitespace:
+ "^[[:space:]]*"
+ // possible template declaration:
+ "(template[[:space:]]*<[^;:{]+>[[:space:]]*)?"
+ // class or struct:
+ "(class|struct)[[:space:]]*"
+ // leading declspec macros etc:
+ "("
+ "\\<\\w+\\>"
+ "("
+ "[[:blank:]]*\\([^)]*\\)"
+ ")?"
+ "[[:space:]]*"
+ ")*"
+ // the class name
+ "(\\<\\w*\\>)[[:space:]]*"
+ // template specialisation parameters
+ "(<[^;:{]+>)?[[:space:]]*"
+ // terminate in { or :
+ "(\\{|:[^;\\{()]*\\{)",
+
+ "(?:class|struct)[^;{]+\\\\<\\5\\\\>[^;{]+\\\\{", // Format string to create indexing regex.
+ "\\5", // Format string to create index term.
+ "", // Filter regex for section id's.
+ "" // Filter regex for filenames.
+ );
+ }
+
+ s.type = "typedef_name";
+ if(file_scanner_set.find(s) == file_scanner_set.end())
+ {
+ add_file_scanner(
+ "typedef_name", // Index type
+ "typedef[^;{}#]+?(\\w+)\\s*;", // scanner regex
+ "typedef[^;]+\\\\<\\1\\\\>\\\\s*;", // Format string to create indexing regex.
+ "\\1", // Format string to create index term.
+ "", // Filter regex for section id's.
+ "" // Filter regex for filenames.
+ );
+ }
+
+ s.type = "macro_name";
+ if(file_scanner_set.find(s) == file_scanner_set.end())
+ {
+ add_file_scanner(
+ "macro_name", // Index type
+ "^\\s*#\\s*define\\s+(\\w+)", // scanner regex
+ "\\\\<\\1\\\\>", // Format string to create indexing regex.
+ "\\1", // Format string to create index term.
+ "", // Filter regex for section id's.
+ "" // Filter regex for filenames.
+ );
+ }
+
+ s.type = "function_name";
+ if(file_scanner_set.find(s) == file_scanner_set.end())
+ {
+ add_file_scanner(
+ "function_name", // Index type
+ "\\w++(?:\\s*+<[^>]++>)?[\\s&*]+?(\\w+)\\s*(?:BOOST_[[:upper:]_]+\\s*)?\\([^;{}]*\\)\\s*[;{]", // scanner regex
+ "\\\\<\\\\w+\\\\>(?:\\\\s+<[^>]*>)*[\\\\s&*]+\\\\<\\1\\\\>\\\\s*\\\\([^;{]*\\\\)", // Format string to create indexing regex.
+ "\\1", // Format string to create index term.
+ "", // Filter regex for section id's.
+ "" // Filter regex for filenames.
+ );
+ }
+}
+
+//
+// Helper to dump file contents into a std::string:
+//
+void load_file(std::string& s, std::istream& is)
+{
+ s.erase();
+ if(is.bad()) return;
+ s.reserve(is.rdbuf()->in_avail());
+ char c;
+ while(is.get(c))
+ {
+ if(s.capacity() == s.size())
+ s.reserve(s.capacity() * 3);
+ s.append(1, c);
+ }
+}
+//
+// Helper to convert string from external source into valid XML:
+//
+std::string escape_to_xml(const std::string& in)
+{
+ std::string result;
+ for(std::string::size_type i = 0; i < in.size(); ++i)
+ {
+ switch(in[i])
+ {
+ case '&':
+ result.append("&amp;");
+ break;
+ case '<':
+ result.append("&lt;");
+ break;
+ case '>':
+ result.append("&gt;");
+ break;
+ case '"':
+ result.append("&quot;");
+ break;
+ default:
+ result.append(1, in[i]);
+ }
+ }
+ return result;
+}
+//
+// Scan a source file for things to index:
+//
+void scan_file(const std::string& file)
+{
+ if(need_defaults)
+ install_default_scanners();
+ if(verbose)
+ std::cout << "Scanning file... " << file << std::endl;
+ std::string text;
+ std::ifstream is(file.c_str());
+ if(!is.peek() || !is.good())
+ throw std::runtime_error(std::string("Unable to read from file: ") + file);
+ load_file(text, is);
+
+ for(file_scanner_set_type::iterator pscan = file_scanner_set.begin(); pscan != file_scanner_set.end(); ++pscan)
+ {
+ bool need_debug = false;
+ if(!debug.empty() && regex_match(pscan->type, ::debug))
+ {
+ need_debug = true;
+ std::cout << "Processing scanner " << pscan->type << " on file " << file << std::endl;
+ std::cout << "Scanner regex:" << pscan->scanner << std::endl;
+ std::cout << "Scanner formatter (search regex):" << pscan->format_string << std::endl;
+ std::cout << "Scanner formatter (index term):" << pscan->term_formatter << std::endl;
+ std::cout << "Scanner file name filter:" << pscan->file_name_filter << std::endl;
+ std::cout << "Scanner section id filter:" << pscan->section_filter << std::endl;
+ }
+ if(!pscan->file_name_filter.empty())
+ {
+ if(!regex_match(file, pscan->file_name_filter))
+ {
+ if(need_debug)
+ {
+ std::cout << "File failed to match file name filter, this file will be skipped..." << std::endl;
+ }
+ continue; // skip this file
+ }
+ }
+ if(verbose && !need_debug)
+ std::cout << "Scanning for type \"" << (*pscan).type << "\" ... " << std::endl;
+ boost::sregex_iterator i(text.begin(), text.end(), (*pscan).scanner), j;
+ while(i != j)
+ {
+ try
+ {
+ index_info info;
+ info.term = escape_to_xml(i->format(pscan->term_formatter));
+ info.search_text = i->format(pscan->format_string);
+ info.category = pscan->type;
+ if(!pscan->section_filter.empty())
+ info.search_id = pscan->section_filter;
+ std::pair<std::set<index_info>::iterator, bool> pos = index_terms.insert(info);
+ if(pos.second)
+ {
+ if(verbose || need_debug)
+ std::cout << "Indexing " << info.term << " as type " << info.category << std::endl;
+ if(need_debug)
+ std::cout << "Search regex will be: \"" << info.search_text << "\"" <<
+ " ID constraint is: \"" << info.search_id << "\""
+ << "Found text was: " << i->str() << std::endl;
+ if(pos.first->search_text != info.search_text)
+ {
+ //
+ // Merge the search terms:
+ //
+ const_cast<boost::regex&>(pos.first->search_text) =
+ "(?:" + pos.first->search_text.str() + ")|(?:" + info.search_text.str() + ")";
+ }
+ if(pos.first->search_id != info.search_id)
+ {
+ //
+ // Merge the ID constraints:
+ //
+ const_cast<boost::regex&>(pos.first->search_id) =
+ "(?:" + pos.first->search_id.str() + ")|(?:" + info.search_id.str() + ")";
+ }
+ }
+ }
+ catch(const boost::regex_error& e)
+ {
+ std::cerr << "Unable to create regular expression from found index term:\""
+ << i->format(pscan->term_formatter) << "\" In file " << file << std::endl;
+ std::cerr << e.what() << std::endl;
+ }
+ catch(const std::exception& e)
+ {
+ std::cerr << "Unable to create index term:\""
+ << i->format(pscan->term_formatter) << "\" In file " << file << std::endl;
+ std::cerr << e.what() << std::endl;
+ throw;
+ }
+ ++i;
+ }
+ }
+}
+//
+// Scan a whole directory for files to search:
+//
+void scan_dir(const std::string& dir, const std::string& mask, bool recurse)
+{
+ using namespace boost::filesystem;
+ boost::regex e(mask);
+ directory_iterator i(dir), j;
+
+ while(i != j)
+ {
+ if(regex_match(i->path().filename().string(), e))
+ {
+ scan_file(i->path().string());
+ }
+ else if(recurse && is_directory(i->status()))
+ {
+ scan_dir(i->path().string(), mask, recurse);
+ }
+ ++i;
+ }
+}
+//
+// Remove quotes from a string:
+//
+std::string unquote(const std::string& s)
+{
+ std::string result(s);
+ if((s.size() >= 2) && (*s.begin() == '\"') && (*s.rbegin() == '\"'))
+ {
+ result.erase(result.begin());
+ result.erase(result.end() - 1);
+ }
+ return result;
+}
+//
+// Load and process a script file:
+//
+void process_script(const std::string& script)
+{
+ static const boost::regex comment_parser(
+ "\\s*(?:#.*)?$"
+ );
+ static const boost::regex scan_parser(
+ "!scan[[:space:]]+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")\\s*"
+ );
+ static const boost::regex scan_dir_parser(
+ "!scan-path[[:space:]]+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")"
+ "[[:space:]]+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")"
+ "(?:"
+ "[[:space:]]+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")"
+ ")?\\s*"
+ );
+ static const boost::regex entry_parser(
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")"
+ "(?:"
+ "[[:space:]]+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)*\")"
+ "(?:"
+ "[[:space:]]+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)*\")"
+ "(?:"
+ "[[:space:]]+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)*\")"
+ ")?"
+ ")?"
+ ")?"
+ "[[:space:]]*");
+ static const boost::regex rewrite_parser(
+ "!(rewrite-name|rewrite-id)\\s+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")\\s+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")\\s*"
+ );
+ static const boost::regex debug_parser(
+ "!debug\\s+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")\\s*"
+ );
+ static const boost::regex define_scanner_parser(
+ "!define-scanner\\s+"
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")\\s+" // type, index 1
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")\\s+" // scanner regex, index 2
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")\\s+" // format string, index 3
+ "([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")" // format string for name, index 4
+ "(?:"
+ "\\s+([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")" // id-filter, index 5
+ "(?:"
+ "\\s+([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")" // filename-filter, index 6
+ ")?"
+ ")?"
+ "\\s*"
+ );
+ static const boost::regex error_parser("!.*");
+
+ if(verbose)
+ std::cout << "Processing script " << script << std::endl;
+ boost::smatch what;
+ std::string line;
+ std::ifstream is(script.c_str());
+ if(is.bad() || !exists(boost::filesystem::path(script)))
+ {
+ throw std::runtime_error(std::string("Could not open script file: ") + script);
+ }
+ while(std::getline(is, line).good())
+ {
+ if(regex_match(line, what, comment_parser))
+ {
+ // Nothing to do here...
+ }
+ else if(regex_match(line, what, scan_parser))
+ {
+ std::string f = unquote(what[1].str());
+ if(!boost::filesystem::path(f).is_complete())
+ {
+ if(prefix.size())
+ {
+ boost::filesystem::path base(prefix);
+ base /= f;
+ f = base.string();
+ }
+ else
+ {
+ boost::filesystem::path base(script);
+ base.remove_filename();
+ base /= f;
+ f = base.string();
+ }
+ }
+ if(!exists(boost::filesystem::path(f)))
+ throw std::runtime_error("Error the file requested for scanning does not exist: " + f);
+ scan_file(f);
+ }
+ else if(regex_match(line, what, debug_parser))
+ {
+ debug = unquote(what[1].str());
+ }
+ else if(regex_match(line, what, define_scanner_parser))
+ {
+ add_file_scanner(unquote(what.str(1)), unquote(what.str(2)), unquote(what.str(3)),
+ unquote(what.str(4)), unquote(what.str(5)), unquote(what.str(6)));
+ }
+ else if(regex_match(line, what, scan_dir_parser))
+ {
+ std::string d = unquote(what[1].str());
+ std::string m = unquote(what[2].str());
+ bool r = unquote(what[3].str()) == "true";
+ if(!boost::filesystem::path(d).is_complete())
+ {
+ if(prefix.size())
+ {
+ boost::filesystem::path base(prefix);
+ base /= d;
+ d = base.string();
+ }
+ else
+ {
+ boost::filesystem::path base(script);
+ base.remove_filename();
+ base /= d;
+ d = base.string();
+ }
+ }
+ if(verbose)
+ std::cout << "Scanning directory " << d << std::endl;
+ if(!exists(boost::filesystem::path(d)))
+ throw std::runtime_error("Error the path requested for scanning does not exist: " + d);
+ scan_dir(d, m, r);
+ }
+ else if(regex_match(line, what, rewrite_parser))
+ {
+ bool id = what[1] == "rewrite-id";
+ std::string a = unquote(what[2].str());
+ std::string b = unquote(what[3].str());
+ id_rewrite_list.push_back(id_rewrite_rule(a, b, id));
+ }
+ else if(line.compare(0, 9, "!exclude ") == 0)
+ {
+ static const boost::regex delim("([^\"[:space:]]+|\"(?:[^\"\\\\]|\\\\.)+\")");
+ boost::sregex_token_iterator i(line.begin() + 9, line.end(), delim, 0), j;
+ while(i != j)
+ {
+ index_info info;
+ info.term = escape_to_xml(unquote(*i));
+ // Erase all entries that have a category in our scanner set,
+ // plus any entry with no category at all:
+ index_terms.erase(info);
+ for(file_scanner_set_type::iterator pscan = file_scanner_set.begin(); pscan != file_scanner_set.end(); ++pscan)
+ {
+ info.category = (*pscan).type;
+ index_terms.erase(info);
+ }
+ ++i;
+ }
+ }
+ else if(regex_match(line, error_parser))
+ {
+ std::cerr << "Error: Unable to process line: " << line << std::endl;
+ }
+ else if(regex_match(line, what, entry_parser))
+ {
+ try{
+ // what[1] is the Index entry
+ // what[2] is the regex to search for (optional)
+ // what[3] is a section id that must be matched
+ // in order for the term to be indexed (optional)
+ // what[4] is the index category to place the term in (optional).
+ index_info info;
+ info.term = escape_to_xml(unquote(what.str(1)));
+ std::string s = unquote(what.str(2));
+ if(s.size())
+ info.search_text = boost::regex(s, boost::regex::icase|boost::regex::perl);
+ else
+ info.search_text = boost::regex("\\<" + what.str(1) + "\\>", boost::regex::icase|boost::regex::perl);
+
+ s = unquote(what.str(3));
+ if(s.size())
+ info.search_id = s;
+ if(what[4].matched)
+ info.category = unquote(what.str(4));
+ std::pair<std::set<index_info>::iterator, bool> pos = index_terms.insert(info);
+ if(pos.second)
+ {
+ if(pos.first->search_text != info.search_text)
+ {
+ //
+ // Merge the search terms:
+ //
+ const_cast<boost::regex&>(pos.first->search_text) =
+ "(?:" + pos.first->search_text.str() + ")|(?:" + info.search_text.str() + ")";
+ }
+ if(pos.first->search_id != info.search_id)
+ {
+ //
+ // Merge the ID constraints:
+ //
+ const_cast<boost::regex&>(pos.first->search_id) =
+ "(?:" + pos.first->search_id.str() + ")|(?:" + info.search_id.str() + ")";
+ }
+ }
+ }
+ catch(const boost::regex_error&)
+ {
+ std::cerr << "Unable to process regular expression in script line:\n \""
+ << line << "\"" << std::endl;
+ throw;
+ }
+ catch(const std::exception&)
+ {
+ std::cerr << "Unable to process script line:\n \""
+ << line << "\"" << std::endl;
+ throw;
+ }
+ }
+ else
+ {
+ std::cerr << "Error: Unable to process line: " << line << std::endl;
+ }
+ }
+}
+
diff --git a/src/boost/tools/auto_index/src/index_generator.cpp b/src/boost/tools/auto_index/src/index_generator.cpp
new file mode 100644
index 00000000..1b65f63c
--- /dev/null
+++ b/src/boost/tools/auto_index/src/index_generator.cpp
@@ -0,0 +1,327 @@
+// Copyright 2008 John Maddock
+//
+// Use, modification and distribution are subject to the
+// Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include "auto_index.hpp"
+#include <boost/range.hpp>
+#include <boost/format.hpp>
+
+//
+// Get a numerical ID for the next item:
+//
+std::string get_next_index_id()
+{
+ static int index_id_count = 0;
+ std::stringstream s;
+ s << "idx_id_" << index_id_count;
+ ++index_id_count;
+ return s.str();
+}
+
+void raise_invalid_xml(const std::string& parent, const std::string& child)
+{
+ throw std::runtime_error("Error: element " + child + " can not appear inside the container " + parent + ": try using a different value for property \"auto-index-type\".");
+}
+//
+// Validate that the container for the Index is in a valid place:
+//
+void check_index_type_and_placement(const std::string& parent, const std::string& container)
+{
+ if(container == "section")
+ {
+ if((parent != "appendix")
+ && (parent != "article")
+ && (parent != "chapter")
+ && (parent != "partintro")
+ && (parent != "preface")
+ && (parent != "section"))
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "appendix")
+ {
+ if((parent != "article")
+ && (parent != "book")
+ && (parent != "part"))
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "index")
+ {
+ if((parent != "appendix")
+ && (parent != "article")
+ && (parent != "book")
+ && (parent != "chapter")
+ && (parent != "part")
+ && (parent != "preface")
+ && (parent != "sect1")
+ && (parent != "sect2")
+ && (parent != "sect3")
+ && (parent != "sect4")
+ && (parent != "sect5")
+ && (parent != "section")
+ )
+ raise_invalid_xml(parent, container);
+ }
+ else if((container == "article") || (container == "chapter") || (container == "reference"))
+ {
+ if((parent != "book")
+ && (parent != "part"))
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "part")
+ {
+ if(parent != "book")
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "refsect1")
+ {
+ if(parent != "refentry")
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "refsect2")
+ {
+ if(parent != "refsect1")
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "refsect3")
+ {
+ if(parent != "refsect2")
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "refsection")
+ {
+ if((parent != "refsection") && (parent != "refentry"))
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "sect1")
+ {
+ if((parent != "appendix")
+ && (parent != "article")
+ && (parent != "chapter")
+ && (parent != "partintro")
+ && (parent != "preface")
+ )
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "sect2")
+ {
+ if(parent != "sect1")
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "sect3")
+ {
+ if(parent != "sect2")
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "sect4")
+ {
+ if(parent != "sect3")
+ raise_invalid_xml(parent, container);
+ }
+ else if(container == "sect5")
+ {
+ if(parent != "sect4")
+ raise_invalid_xml(parent, container);
+ }
+ else
+ {
+ throw std::runtime_error("Error: element " + container + " is unknown, and can not be used as a container for an index: try using a different value for property \"auto-index-type\".");
+ }
+}
+
+boost::tiny_xml::element_ptr make_element(const std::string& name)
+{
+ boost::tiny_xml::element_ptr result(new boost::tiny_xml::element);
+ result->name = name;
+ return result;
+}
+
+boost::tiny_xml::element_ptr add_attribute(boost::tiny_xml::element_ptr ptr, const std::string& name, const std::string& value)
+{
+ boost::tiny_xml::attribute attr;
+ attr.name = name;
+ attr.value = value;
+ ptr->attributes.push_back(attr);
+ return ptr;
+}
+
+boost::regex make_primary_key_matcher(const std::string& s)
+{
+ static const boost::regex e("[-_[:space:]]+|([.\\[{}()\\*+?|^$])");
+ static const char* format = "(?1\\\\$1:[-_[:space:]]+)";
+ return boost::regex(regex_replace(s, e, format, boost::regex_constants::format_all), boost::regex::icase|boost::regex::perl);
+}
+
+//
+// Generate an index entry using our own internal method:
+//
+template <class Range>
+boost::tiny_xml::element_ptr generate_entry(const Range& range, const std::string* pcategory, int level = 0, const boost::regex* primary_key = 0)
+{
+ boost::tiny_xml::element_ptr list = add_attribute(add_attribute(::add_attribute(make_element("itemizedlist"), "mark", "none"), "spacing", "compact"), "role", "index");
+
+ for(typename boost::range_iterator<Range>::type i = boost::begin(range); i != boost::end(range);)
+ {
+ std::string key = (*i)->key;
+ index_entry_set entries;
+ bool preferred = false;
+ std::string id;
+ bool collapse = false;
+
+ //
+ // Create a regular expression for comparing key to other key's:
+ //
+ boost::regex key_regex;
+ if(level == 0)
+ {
+ key_regex = make_primary_key_matcher(key);
+ primary_key = &key_regex;
+ }
+ //
+ // Begin by consolidating entries with identical keys but possibly different categories:
+ //
+ while((i != boost::end(range)) && ((*i)->key == key))
+ {
+ if((0 == pcategory) || (pcategory->size() == 0) || (pcategory && (**i).category == *pcategory))
+ {
+ entries.insert((*i)->sub_keys.begin(), (*i)->sub_keys.end());
+ if((*i)->preferred)
+ preferred = true;
+ if((*i)->id.size())
+ {
+ if(id.size())
+ {
+ std::cerr << "WARNING: two identical index terms have different link destinations!!" << std::endl;
+ }
+ id = (*i)->id;
+ }
+ }
+ ++i;
+ }
+ //
+ // Only actually generate content if we have anything in the entries set:
+ //
+ if(entries.size() || id.size())
+ {
+ //
+ // See if we can collapse any sub-entries into this one:
+ //
+ if(entries.size() == 1)
+ {
+ if((regex_match((*entries.begin())->key, *primary_key) || ((*entries.begin())->key == key))
+ && ((*entries.begin())->id.size())
+ && ((*entries.begin())->id != id))
+ {
+ collapse = true;
+ id = (*entries.begin())->id;
+ }
+ }
+ //
+ // See if this key is the same as the primary key, if it is then make it prefered:
+ //
+ if(level && regex_match(key, *primary_key))
+ {
+ preferred = true;
+ }
+ boost::tiny_xml::element_ptr item = make_element("listitem");
+ boost::tiny_xml::element_ptr para = make_element("para");
+ item->elements.push_back(para);
+ list->elements.push_back(item);
+ if(preferred)
+ {
+ para->elements.push_back(add_attribute(make_element("emphasis"), "role", "bold"));
+ para = para->elements.back();
+ }
+ if(id.size())
+ {
+ boost::tiny_xml::element_ptr link = add_attribute(make_element("link"), "linkend", id);
+ para->elements.push_back(link);
+ para = link;
+ }
+ std::string classname = (boost::format("index-entry-level-%1%") % level).str();
+ para->elements.push_back(add_attribute(make_element("phrase"), "role", classname));
+ para = para->elements.back();
+ para->content = key;
+ if(!collapse && entries.size())
+ {
+ std::pair<index_entry_set::const_iterator, index_entry_set::const_iterator> subrange(entries.begin(), entries.end());
+ item->elements.push_back(generate_entry(subrange, 0, level+1, primary_key));
+ }
+ }
+ }
+ return list;
+}
+//
+// Generate indexes using our own internal method:
+//
+void generate_indexes()
+{
+ for(boost::tiny_xml::element_list::const_iterator i = indexes.begin(); i != indexes.end(); ++i)
+ {
+ boost::tiny_xml::element_ptr node = *i;
+ const std::string* category = find_attr(node, "type");
+ bool has_title = false;
+
+ for(boost::tiny_xml::element_list::const_iterator k = (*i)->elements.begin(); k != (*i)->elements.end(); ++k)
+ {
+ if((**k).name == "title")
+ {
+ has_title = true;
+ break;
+ }
+ }
+
+ boost::tiny_xml::element_ptr navbar = make_element("para");
+ node->elements.push_back(navbar);
+
+ index_entry_set::const_iterator m = index_entries.begin();
+ index_entry_set::const_iterator n = m;
+ boost::tiny_xml::element_ptr vlist = make_element("variablelist");
+ node->elements.push_back(vlist);
+ while(n != index_entries.end())
+ {
+ char current_letter = std::toupper((*n)->key[0]);
+ std::string id_name = get_next_index_id();
+ boost::tiny_xml::element_ptr entry = add_attribute(make_element("varlistentry"), "id", id_name);
+ boost::tiny_xml::element_ptr term = make_element("term");
+ term->content = std::string(1, current_letter);
+ entry->elements.push_back(term);
+ boost::tiny_xml::element_ptr item = make_element("listitem");
+ entry->elements.push_back(item);
+ while((n != index_entries.end()) && (std::toupper((*n)->key[0]) == current_letter))
+ ++n;
+ std::pair<index_entry_set::const_iterator, index_entry_set::const_iterator> range(m, n);
+ item->elements.push_back(generate_entry(range, category));
+ if(item->elements.size() && (*item->elements.begin())->elements.size())
+ {
+ vlist->elements.push_back(entry);
+ boost::tiny_xml::element_ptr p = make_element("");
+ p->content = " ";
+ if(navbar->elements.size())
+ {
+ navbar->elements.push_back(p);
+ }
+ p = add_attribute(make_element("link"), "linkend", id_name);
+ p->content = current_letter;
+ navbar->elements.push_back(p);
+ }
+ m = n;
+ }
+
+ node->name = internal_index_type;
+ boost::tiny_xml::element_ptr p(node->parent);
+ while(p->name.empty())
+ p = boost::tiny_xml::element_ptr(p->parent);
+ check_index_type_and_placement(p->name, node->name);
+ node->attributes.clear();
+ if(!has_title)
+ {
+ boost::tiny_xml::element_ptr t = make_element("title");
+ t->content = "Index";
+ node->elements.push_front(t);
+ }
+ }
+}
+
diff --git a/src/boost/tools/auto_index/src/tiny_xml.cpp b/src/boost/tools/auto_index/src/tiny_xml.cpp
new file mode 100644
index 00000000..81b3b26d
--- /dev/null
+++ b/src/boost/tools/auto_index/src/tiny_xml.cpp
@@ -0,0 +1,257 @@
+// tiny XML sub-set tools implementation -----------------------------------//
+
+// (C) Copyright Beman Dawes 2002. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include "tiny_xml.hpp"
+#include <cassert>
+#include <cstring>
+
+namespace
+{
+
+ inline void eat_whitespace( char & c, std::istream & in )
+ {
+ while ( c == ' ' || c == '\r' || c == '\n' || c == '\t' )
+ in.get( c );
+ }
+
+ void eat_comment( char & c, std::istream & in )
+ {
+ in.get(c);
+ if(c != '-')
+ throw std::string("Invalid comment in XML");
+ in.get(c);
+ if(c != '-')
+ throw std::string("Invalid comment in XML");
+ do{
+ while(in.get(c) && (c != '-'));
+ in.get(c);
+ if(c != '-')
+ continue;
+ in.get(c);
+ if(c != '>')
+ continue;
+ else
+ break;
+ }
+ while(true);
+ }
+
+ std::string get_name( char & c, std::istream & in )
+ {
+ std::string result;
+ eat_whitespace( c, in );
+ while ( std::strchr(
+ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-.:", c )
+ != 0 )
+ {
+ result += c;
+ if(!in.get( c ))
+ throw std::string("xml: unexpected eof");
+ }
+ return result;
+ }
+
+ void eat_delim( char & c, std::istream & in,
+ char delim, const std::string & msg )
+ {
+ eat_whitespace( c, in );
+ if ( c != delim )
+ throw std::string("xml syntax error, expected ") + delim
+ + " (" + msg + ")";
+ in.get( c );
+ }
+
+ std::string get_value( char & c, std::istream & in )
+ {
+ std::string result;
+ while ( c != '\"' )
+ {
+ result += c;
+ in.get( c );
+ }
+ in.get( c );
+ return result;
+ }
+
+}
+
+namespace boost
+{
+ namespace tiny_xml
+ {
+
+ // parse -----------------------------------------------------------------//
+
+ element_ptr parse( std::istream & in, const std::string & msg )
+ {
+ char c = 0; // current character
+ element_ptr e( new element );
+
+ if(!in.get( c ))
+ throw std::string("xml: unexpected eof");
+ if ( c == '<' )
+ if(!in.get( c ))
+ throw std::string("xml: unexpected eof");
+
+ if(c == '!')
+ {
+ eat_comment(c, in);
+ return e;
+ }
+ if(c == '?')
+ {
+ // XML processing instruction.
+ e->name += c;
+ if(!in.get( c )) // next char
+ throw std::string("xml: unexpected eof");
+ e->name += get_name(c, in);
+ in >> std::ws;
+ if(!in.get( c )) // next char
+ throw std::string("xml: unexpected eof");
+ while(c != '?')
+ {
+ e->content += c;
+ if(!in.get( c )) // next char
+ throw std::string("xml: unexpected eof");
+ }
+ if(!in.get( c )) // next char
+ throw std::string("xml: unexpected eof");
+ if(c != '>')
+ throw std::string("Invalid XML processing instruction.");
+ return e;
+ }
+
+ e->name = get_name( c, in );
+ eat_whitespace( c, in );
+
+ // attributes
+ while ( (c != '>') && (c != '/') )
+ {
+ attribute a;
+ a.name = get_name( c, in );
+
+ eat_delim( c, in, '=', msg );
+ eat_delim( c, in, '\"', msg );
+
+ a.value = get_value( c, in );
+
+ e->attributes.push_back( a );
+ eat_whitespace( c, in );
+ }
+ if(c == '/')
+ {
+ if(!in.get( c )) // next after '/'
+ throw std::string("xml: unexpected eof");
+ eat_whitespace( c, in );
+ if(c != '>')
+ throw std::string("xml: unexpected /");
+ return e;
+ }
+ if(!in.get( c )) // next after '>'
+ throw std::string("xml: unexpected eof");
+
+ //eat_whitespace( c, in );
+
+ do{
+ // sub-elements
+ while ( c == '<' )
+ {
+ if ( in.peek() == '/' )
+ break;
+ element_ptr child(parse( in, msg ));
+ child->parent = e;
+ e->elements.push_back(child);
+ in.get( c ); // next after '>'
+ //eat_whitespace( c, in );
+ }
+ if (( in.peek() == '/' ) && (c == '<'))
+ break;
+
+ // content
+ if ( (c != '<') )
+ {
+ element_ptr sub( new element );
+ while ( c != '<' )
+ {
+ sub->content += c;
+ if(!in.get( c ))
+ throw std::string("xml: unexpected eof");
+ }
+ sub->parent = e;
+ e->elements.push_back( sub );
+ }
+
+ assert( c == '<' );
+ if( in.peek() == '/' )
+ break;
+ }while(true);
+
+ in.get(c);
+ eat_delim( c, in, '/', msg );
+ std::string end_name( get_name( c, in ) );
+ if ( e->name != end_name )
+ throw std::string("xml syntax error: beginning name ")
+ + e->name + " did not match end name " + end_name
+ + " (" + msg + ")";
+
+ eat_delim( c, in, '>', msg );
+ if(c != '>')
+ {
+ // we've eaten one character past the >, put it back:
+ if(!in.putback(c))
+ throw std::string("Unable to put back character");
+ }
+ return e;
+ }
+
+ // write ---------------------------------------------------------------//
+
+ void write( const element & e, std::ostream & out )
+ {
+ if(e.name.size())
+ {
+ out << "<" << e.name;
+ if ( !e.attributes.empty() )
+ {
+ for( attribute_list::const_iterator itr = e.attributes.begin();
+ itr != e.attributes.end(); ++itr )
+ {
+ out << " " << itr->name << "=\"" << itr->value << "\"";
+ }
+ }
+ if(e.name[0] == '?')
+ {
+ out << " " << e.content << "?>";
+ return;
+ }
+ if(e.elements.empty() && e.content.empty())
+ {
+ out << "/>";
+ return;
+ }
+ out << ">";
+ }
+ if ( !e.elements.empty() )
+ {
+ for( element_list::const_iterator itr = e.elements.begin();
+ itr != e.elements.end(); ++itr )
+ {
+ write( **itr, out );
+ }
+ }
+ if ( !e.content.empty() )
+ {
+ out << e.content;
+ }
+ if(e.name.size() && (e.name[0] != '?'))
+ {
+ out << "</" << e.name << ">";
+ }
+ }
+
+ } // namespace tiny_xml
+} // namespace boost
+
diff --git a/src/boost/tools/auto_index/src/tiny_xml.hpp b/src/boost/tools/auto_index/src/tiny_xml.hpp
new file mode 100644
index 00000000..5ecbd4ce
--- /dev/null
+++ b/src/boost/tools/auto_index/src/tiny_xml.hpp
@@ -0,0 +1,83 @@
+// tiny XML sub-set tools --------------------------------------------------//
+
+// (C) Copyright Beman Dawes 2002. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// Provides self-contained tools for this XML sub-set:
+//
+// element ::= { "<" name { name "=" "\"" value "\"" } ">"
+// {element} [contents] "</" name ">" }
+//
+// The point of "self-contained" is to minimize tool-chain dependencies.
+
+#ifndef BOOST_TINY_XML_H
+#define BOOST_TINY_XML_H
+
+#include "boost/smart_ptr.hpp" // for shared_ptr
+#include "boost/utility.hpp" // for noncopyable
+#include <list>
+#include <iostream>
+#include <string>
+
+namespace boost
+{
+ namespace tiny_xml
+ {
+ class element;
+ struct attribute
+ {
+ std::string name;
+ std::string value;
+
+ attribute(){}
+ attribute( const std::string & name, const std::string & value )
+ : name(name), value(value) {}
+ };
+ typedef boost::shared_ptr< element > element_ptr;
+ typedef boost::weak_ptr< element > weak_element_ptr;
+ typedef std::list< element_ptr > element_list;
+ typedef std::list< attribute > attribute_list;
+
+ class element
+ : private boost::noncopyable // because deep copy semantics would be required
+ {
+ public:
+ // The name of the XML element, or "" if this is inline content,
+ // or begins with '?' if this is a processing instruction.
+ std::string name;
+ // List of attributes applied to this element
+ attribute_list attributes;
+ // List of sub-elements, this will be empty if the name is empty
+ // or starts with a '?'. Plain text content will be inside
+ // anonymous elements in this list - this preserves the order of
+ // plain text mixed with true XML <elements>.
+ element_list elements;
+ // The plain text content of this element, only present if the name is ""
+ // or if this is a processing instruction in which case it is the content
+ // after the name of the instruction.
+ std::string content;
+ // Pointer to our parent
+ weak_element_ptr parent;
+
+ element() {}
+ explicit element( const std::string & name ) : name(name) {}
+ };
+
+ // Precondition: stream positioned at either the initial "<"
+ // or the first character after the initial "<".
+ // Postcondition: stream positioned at the first character after final
+ // ">" (or eof).
+ // Returns: an element_ptr to an element representing the parsed stream.
+ // Throws: std::string on syntax error. msg appended to what() string.
+ element_ptr parse( std::istream & in, const std::string & msg );
+
+ void write( const element & e, std::ostream & out );
+
+ }
+}
+
+#endif // BOOST_TINY_XML_H
+
+
+
diff --git a/src/boost/tools/auto_index/test/Jamfile.v2 b/src/boost/tools/auto_index/test/Jamfile.v2
new file mode 100644
index 00000000..4b1e60b5
--- /dev/null
+++ b/src/boost/tools/auto_index/test/Jamfile.v2
@@ -0,0 +1,62 @@
+
+import feature ;
+import generators ;
+import modules ;
+import project ;
+import targets ;
+import testing ;
+import toolset ;
+import type ;
+
+alias line_compare_tool : ../../quickbook/test/src//line-compare-tool ;
+
+rule auto-index-test ( target-name : input-file : output-file ? : options * )
+{
+ local project = [ project.current ] ;
+
+ local t =
+ [ targets.create-typed-target RUN
+ : $(project)
+ : $(target-name)
+ : [ alias autoindex : ../build//auto_index : release ]
+ : $(requirements)
+ <location-prefix>$(target-name).test
+ <testing.arg>--prefix=../../..
+ <testing.arg>$(options)
+ <testing.arg>--in=$(input-file)
+ <testing.arg>--out=$(target-name).out
+ <preserve-test-targets>on
+ <dependency>Jamfile.v2
+ <dependency>$(input-file)
+ ]
+ ;
+
+ t +=
+ [ targets.create-typed-target RUN
+ : $(project)
+ : $(target-name)_check
+ : .//line_compare_tool
+ : $(requirements)
+ <location-prefix>$(target-name).test
+ <testing.arg>$(target-name).out
+ <testing.arg>$(target-name).gold
+ <preserve-test-targets>on
+ <dependency>$(target_name)
+ <implicit-dependency>$(target_name)
+ <dependency>Jamfile.v2
+ <dependency>$(input-file)
+ ]
+ ;
+
+ modules.poke testing : .all-tests : \$\(all-tests\) $(t) ;
+
+ return $(t) ;
+}
+
+auto-index-test test1 : type_traits.docbook : : --script=index.idx ;
+auto-index-test test2 : type_traits.docbook : : --internal-index --script=index.idx ;
+auto-index-test test3 : type_traits.docbook : : --internal-index --index-type=index --script=index.idx ;
+
+
+
+
diff --git a/src/boost/tools/auto_index/test/index.idx b/src/boost/tools/auto_index/test/index.idx
new file mode 100644
index 00000000..52507c28
--- /dev/null
+++ b/src/boost/tools/auto_index/test/index.idx
@@ -0,0 +1,26 @@
+
+!define-scanner class_name "BOOST_TT_AUX_TYPE_TRAIT_DEF\d\s*\(\s*(\w+)\s*[,)]" "(?:class|struct)[^;{]+\\<\1\\>[^;{]+\\{" \1
+!define-scanner class_name "BOOST_TT_AUX_BOOL_TRAIT_DEF\d\s*\(\s*(\w+)\s*[,)]" "(?:class|struct)[^;{]+\\<\1\\>[^;{]+\\{" \1
+!define-scanner class_name "BOOST_TT_AUX_SIZE_T_TRAIT_DEF\d\s*\(\s*(\w+)\s*[,)]" "(?:class|struct)[^;{]+\\<\1\\>[^;{]+\\{" \1
+
+!define-scanner class_name "^[[:space:]]*(template[[:space:]]*<[^;:{]+>[[:space:]]*)?(class|struct)[[:space:]]*(\<\w+\>([[:blank:]]*\([^)]*\))?[[:space:]]*)*(\<\w*\>)[[:space:]]*(<[^;:{]+>)?[[:space:]]*(\{|:[^;\{()]*\{)" "(?:class|struct)[^;{]+\\<\5\\>[^;{]+\\{" \5
+!define-scanner typedef_name "typedef[^;{}#]+?(\w+)\s*;" "typedef[^;]+\\<\1\\>\\s*;" "\1"
+!define-scanner "macro_name" "^\s*#\s*define\s+(\w+)" "\\<\1\\>" "\1"
+!define-scanner "function_name" "\w+\s+(\w+)\s*\([^\)]*\)\s*[;{]" "\\<\\w+\\>\\s+\\<\1\\>\\s*\\([^;{]*\\)\\s*[;{]" "\1"
+
+!scan-path boost/type_traits .*\.hpp true
+!scan boost/aligned_storage.hpp
+!scan boost/type_traits.hpp
+
+!exclude type arg1_type arg2_type arg3_type arg4_type arg5_type B D
+!exclude result
+
+!rewrite-name "(?:A|An|The)\s+(.*)" "\1"
+
+"Constrained Index Term" add_const "boost_typetraits\.reference.*" class_name
+"This term should not appear anywhere because of the ID constraint" strlen "(?!boost_typetraits.background).*" function_name
+
+
+type-traits "" ".*.intro" test_index_1
+type-traits "" ".*.background" test_index_2
+
diff --git a/src/boost/tools/auto_index/test/test1.gold b/src/boost/tools/auto_index/test/test1.gold
new file mode 100644
index 00000000..ec051ab9
--- /dev/null
+++ b/src/boost/tools/auto_index/test/test1.gold
@@ -0,0 +1,6671 @@
+<?xml version="1.0"?>
+<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!--
+
+This file is based upon the type traits docs, but has had additional XML elements added to it
+to ensure complete testing.
+
+-->
+
+<chapter xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" id="boost_typetraits" rev:last-revision="$Date: 2008-11-28 12:41:45 +0000 (Fri, 28 Nov 2008) $">
+ <chapterinfo><author>
+ <firstname>various</firstname> <surname>authors</surname>
+ </author><copyright>
+ <year>2000</year> <year>2006</year> <holder>Adobe Systems Inc, David Abrahams,
+ Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant, Jesse Jones, Mat
+ Marcus, Itay Maman, John Maddock, Alexander Nasonov, Thorsten Ottosen, Robert
+ Ramey and Jeremy Siek</holder>
+ </copyright><legalnotice>
+ <para>
+ Distributed under the Boost Software License, Version 1.0. (See accompanying
+ file LICENSE_1_0.txt or copy at <ulink url="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</ulink>)
+ </para>
+ </legalnotice></chapterinfo>
+ <title>Boost.TypeTraits</title>
+ <para>
+ A printer-friendly <ulink url="http://svn.boost.org/svn/boost/sandbox/pdf/type_traits/release/type_traits.pdf">PDF
+ version of this manual is also available</ulink>.
+ </para>
+ <section id="boost_typetraits.intro"><indexterm type="test_index_1"><primary>type-traits</primary><secondary>Introduction</secondary></indexterm><indexterm><primary>Introduction</primary><secondary>type-traits</secondary></indexterm><indexterm type="test_index_1"><primary>type-traits</primary><secondary>Introduction</secondary></indexterm><indexterm><primary>Introduction</primary><secondary>type-traits</secondary></indexterm><indexterm type="test_index_1"><primary>type-traits</primary><secondary>Introduction</secondary></indexterm><indexterm><primary>Introduction</primary><secondary>type-traits</secondary></indexterm>
+ <title><link linkend="boost_typetraits.intro"> Introduction</link></title>
+ <para>
+ The Boost type-traits library contains a set of very specific traits classes,
+ each of which encapsulate a single trait from the C++ type system; for example,
+ is a type a pointer or a reference type? Or does a type have a trivial constructor,
+ or a const-qualifier?
+ </para>
+ <para>
+ The type-traits classes share a unified design: each class inherits from a
+ the type <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the type has the specified property and inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ otherwise.
+ </para>
+ <para>
+ The type-traits library also contains a set of classes that perform a specific
+ transformation on a type; for example, they can remove a top-level const or
+ volatile qualifier from a type. Each class that performs a transformation defines
+ a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of the transformation.
+ </para>
+ </section>
+ <section id="boost_typetraits.background"><indexterm type="test_index_2"><primary>type-traits</primary><secondary>Background and Tutorial</secondary></indexterm><indexterm><primary>Background and Tutorial</primary><secondary>type-traits</secondary></indexterm><indexterm type="test_index_2"><primary>type-traits</primary><secondary>Background and Tutorial</secondary></indexterm><indexterm><primary>Background and Tutorial</primary><secondary>type-traits</secondary></indexterm><indexterm type="class_name"><primary>remove_extent</primary><secondary>Background and Tutorial</secondary></indexterm><indexterm><primary>Background and Tutorial</primary><secondary>remove_extent</secondary></indexterm><indexterm type="class_name"><primary>is_pointer</primary><secondary>Background and Tutorial</secondary></indexterm><indexterm><primary>Background and Tutorial</primary><secondary>is_pointer</secondary></indexterm><indexterm type="class_name"><primary>is_void</primary><secondary>Background and Tutorial</secondary></indexterm><indexterm><primary>Background and Tutorial</primary><secondary>is_void</secondary></indexterm><indexterm type="test_index_2"><primary>type-traits</primary><secondary>Background and Tutorial</secondary></indexterm><indexterm><primary>Background and Tutorial</primary><secondary>type-traits</secondary></indexterm><indexterm type="test_index_2"><primary>type-traits</primary><secondary>Background and Tutorial</secondary></indexterm><indexterm><primary>Background and Tutorial</primary><secondary>type-traits</secondary></indexterm><indexterm type="test_index_2"><primary>type-traits</primary><secondary>Background and Tutorial</secondary></indexterm><indexterm><primary>Background and Tutorial</primary><secondary>type-traits</secondary></indexterm>
+ <title><link linkend="boost_typetraits.background"> Background and Tutorial</link></title>
+ <para>
+ The following is an updated version of the article "C++ Type traits"
+ by John Maddock and Steve Cleary that appeared in the October 2000 issue of
+ <ulink url="http://www.ddj.com">Dr Dobb's Journal</ulink>.
+ </para>
+ <para>
+ Generic programming (writing code which works with any data type meeting a
+ set of requirements) has become the method of choice for providing reusable
+ code. However, there are times in generic programming when "generic"
+ just isn't good enough - sometimes the differences between types are too large
+ for an efficient generic implementation. This is when the traits technique
+ becomes important - by encapsulating those properties that need to be considered
+ on a type by type basis inside a traits class, we can minimize the amount of
+ code that has to differ from one type to another, and maximize the amount of
+ generic code.
+ </para>
+ <?dbfo keep-together="auto" ?>
+ <para>
+ <indexterm>
+ <primary>Foo1</primary>
+ </indexterm>
+ Consider an example: when working with character strings, one common operation
+ is to determine the length of a null terminated string. Clearly it's possible
+ to write generic code that can do this, but it turns out that there are much
+ more efficient methods available: for example, the C library functions <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">strlen</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">wcslen</phrase></computeroutput>
+ are usually written in assembler, and with suitable hardware support can be
+ considerably faster than a generic version written in C++. The authors of the
+ C++ standard library realized this, and abstracted the properties of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">wchar_t</phrase></computeroutput>
+ into the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput>.
+ Generic code that works with character strings can simply use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase><phrase role="special">&lt;&gt;::</phrase><phrase role="identifier">length</phrase></computeroutput> to determine the length of a null
+ terminated string, safe in the knowledge that specializations of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput> will use the most appropriate
+ method available to them.
+ </para>
+ <anchor id="boost_typetraits.background.type_traits"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.type_traits">Type Traits</link>
+ </bridgehead>
+ <para>
+ Class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput> is a classic
+ example of a collection of type specific properties wrapped up in a single
+ class - what Nathan Myers termed a <emphasis>baggage class</emphasis><link linkend="background.references">[1]</link>. In the Boost type-traits library,
+ we<link linkend="background.references">[2]</link> have written a set of very
+ specific traits classes, each of which encapsulate a single trait from the
+ C++ type system; for example, is a type a pointer or a reference type? Or does
+ a type have a trivial constructor, or a const-qualifier? The type-traits classes
+ share a unified design: each class inherits from a the type <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the type has the specified property and inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ otherwise. As we will show, these classes can be used in generic programming
+ to determine the properties of a given type and introduce optimizations that
+ are appropriate for that case.
+ </para>
+ <para>
+ The type-traits library also contains a set of classes that perform a specific
+ transformation on a type; for example, they can remove a top-level const or
+ volatile qualifier from a type. Each class that performs a transformation defines
+ a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of the transformation. All of the type-traits classes are
+ defined inside namespace <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase></computeroutput>;
+ for brevity, namespace-qualification is omitted in most of the code samples
+ given.
+ </para>
+ <anchor id="boost_typetraits.background.implementation"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.implementation">Implementation</link>
+ </bridgehead>
+ <para>
+ There are far too many separate classes contained in the type-traits library
+ to give a full implementation here - see the source code in the Boost library
+ for the full details - however, most of the implementation is fairly repetitive
+ anyway, so here we will just give you a flavor for how some of the classes
+ are implemented. Beginning with possibly the simplest class in the library,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits
+ from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ only if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>.
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ Here we define a primary version of the template class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_void">is_void</link></computeroutput>,
+ and provide a full-specialization when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>. While full specialization
+ of a template class is an important technique, sometimes we need a solution
+ that is halfway between a fully generic solution, and a full specialization.
+ This is exactly the situation for which the standards committee defined partial
+ template-class specialization. As an example, consider the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput>:
+ here we needed a primary version that handles all the cases where T is not
+ a pointer, and a partial specialization to handle all the cases where T is
+ a pointer:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">*&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ The syntax for partial specialization is somewhat arcane and could easily occupy
+ an article in its own right; like full specialization, in order to write a
+ partial specialization for a class, you must first declare the primary template.
+ The partial specialization contains an extra &lt;...&gt; after the class name
+ that contains the partial specialization parameters; these define the types
+ that will bind to that partial specialization rather than the default template.
+ The rules for what can appear in a partial specialization are somewhat convoluted,
+ but as a rule of thumb if you can legally write two function overloads of the
+ form:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">foo</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">);</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">foo</phrase><phrase role="special">(</phrase><phrase role="identifier">U</phrase><phrase role="special">);</phrase>
+</programlisting>
+ <para>
+ Then you can also write a partial specialization of the form:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">class</phrase> <phrase role="identifier">c</phrase><phrase role="special">{</phrase> <phrase role="comment">/*details*/</phrase> <phrase role="special">};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">class</phrase> <phrase role="identifier">c</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;{</phrase> <phrase role="comment">/*details*/</phrase> <phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ This rule is by no means foolproof, but it is reasonably simple to remember
+ and close enough to the actual rule to be useful for everyday use.
+ </para>
+ <para>
+ As a more complex example of partial specialization consider the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput>. This
+ class defines a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the same type as T but with any top-level array bounds removed; this
+ is an example of a traits class that performs a transformation on a type:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link>
+<phrase role="special">{</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">N</phrase><phrase role="special">]&gt;</phrase>
+<phrase role="special">{</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ The aim of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.remove_extent">remove_extent</link></computeroutput>
+ is this: imagine a generic algorithm that is passed an array type as a template
+ parameter, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.remove_extent">remove_extent</link></computeroutput>
+ provides a means of determining the underlying type of the array. For example
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">][</phrase><phrase role="number">5</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> would evaluate to the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">5</phrase><phrase role="special">]</phrase></computeroutput>. This example also shows that the number of
+ template parameters in a partial specialization does not have to match the
+ number in the default template. However, the number of parameters that appear
+ after the class name do have to match the number and type of the parameters
+ in the default template.
+ </para>
+ <anchor id="boost_typetraits.background.optimized_copy"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.optimized_copy">Optimized copy</link>
+ </bridgehead>
+ <para>
+ As an example of how the type traits classes can be used, consider the standard
+ library algorithm copy:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iter1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Iter2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">Iter2</phrase> <phrase role="identifier">copy</phrase><phrase role="special">(</phrase><phrase role="identifier">Iter1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter2</phrase> <phrase role="identifier">out</phrase><phrase role="special">);</phrase>
+</programlisting>
+ <para>
+ Obviously, there's no problem writing a generic version of copy that works
+ for all iterator types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput>; however, there are
+ some circumstances when the copy operation can best be performed by a call
+ to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>. In order to implement
+ copy in terms of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput> all
+ of the following conditions need to be met:
+ </para>
+ <itemizedlist>
+ <listitem>
+ Both of the iterator types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput> must be pointers.
+ </listitem>
+ <listitem>
+ Both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput> must point to the same type - excluding
+ const and volatile-qualifiers.
+ </listitem>
+ <listitem>
+ The type pointed to by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ must have a trivial assignment operator.
+ </listitem>
+ </itemizedlist>
+ <para>
+ By trivial assignment operator we mean that the type is either a scalar type<link linkend="background.references">[3]</link> or:
+ </para>
+ <itemizedlist>
+ <listitem>
+ The type has no user defined assignment operator.
+ </listitem>
+ <listitem>
+ The type does not have any data members that are references.
+ </listitem>
+ <listitem>
+ All base classes, and all data member objects must have trivial assignment
+ operators.
+ </listitem>
+ </itemizedlist>
+ <para>
+ If all these conditions are met then a type can be copied using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput> rather than using a compiler generated
+ assignment operator. The type-traits library provides a class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>,
+ such that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is true only if T has a trivial assignment
+ operator. This class "just works" for scalar types, but has to be
+ explicitly specialised for class/struct types that also happen to have a trivial
+ assignment operator. In other words if <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link>
+ gives the wrong answer, it will give the "safe" wrong answer - that
+ trivial assignment is not allowable.
+ </para>
+ <para>
+ The code for an optimized version of copy that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>
+ where appropriate is given in <link linkend="boost_typetraits.examples.copy">the
+ examples</link>. The code begins by defining a template function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">do_copy</phrase></computeroutput> that performs a "slow but safe"
+ copy. The last parameter passed to this function may be either a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ or a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">false_type</link></computeroutput>.
+ Following that there is an overload of do<emphasis role="underline">copy that
+ uses `memcpy`: this time the iterators are required to actually be pointers
+ to the same type, and the final parameter must be a `</emphasis>_true_type<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase> <phrase role="identifier">Finally</phrase><phrase role="special">,</phrase> <phrase role="identifier">the</phrase> <phrase role="identifier">version</phrase>
+ <phrase role="identifier">of</phrase> </computeroutput>copy<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="identifier">calls</phrase>
+ </computeroutput>do<emphasis role="underline">copy`, passing `</emphasis>_has_trivial_assign&lt;value_type&gt;()`
+ as the final parameter: this will dispatch to the optimized version where appropriate,
+ otherwise it will call the "slow but safe version".
+ </para>
+ <anchor id="boost_typetraits.background.was_it_worth_it_"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.was_it_worth_it_">Was it worth it?</link>
+ </bridgehead>
+ <para>
+ It has often been repeated in these columns that "premature optimization
+ is the root of all evil" <link linkend="background.references">[4]</link>.
+ So the question must be asked: was our optimization premature? To put this
+ in perspective the timings for our version of copy compared a conventional
+ generic copy<link linkend="background.references">[5]</link> are shown in table
+ 1.
+ </para>
+ <para>
+ Clearly the optimization makes a difference in this case; but, to be fair,
+ the timings are loaded to exclude cache miss effects - without this accurate
+ comparison between algorithms becomes difficult. However, perhaps we can add
+ a couple of caveats to the premature optimization rule:
+ </para>
+ <itemizedlist>
+ <listitem>
+ If you use the right algorithm for the job in the first place then optimization
+ will not be required; in some cases, memcpy is the right algorithm.
+ </listitem>
+ <listitem>
+ If a component is going to be reused in many places by many people then optimizations
+ may well be worthwhile where they would not be so for a single case - in
+ other words, the likelihood that the optimization will be absolutely necessary
+ somewhere, sometime is that much higher. Just as importantly the perceived
+ value of the stock implementation will be higher: there is no point standardizing
+ an algorithm if users reject it on the grounds that there are better, more
+ heavily optimized versions available.
+ </listitem>
+ </itemizedlist>
+ <table frame="all"> <title>Time taken to copy 1000 elements using `copy&lt;const
+ T*, T*&gt;` (times in micro-seconds)</title>
+ <tgroup cols="3">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Version
+ </para>
+ </entry><entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ Time
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ "Optimized" copy
+ </para>
+ </entry><entry>
+ <para>
+ char
+ </para>
+ </entry><entry>
+ <para>
+ 0.99
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ Conventional copy
+ </para>
+ </entry><entry>
+ <para>
+ char
+ </para>
+ </entry><entry>
+ <para>
+ 8.07
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ "Optimized" copy
+ </para>
+ </entry><entry>
+ <para>
+ int
+ </para>
+ </entry><entry>
+ <para>
+ 2.52
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ Conventional copy
+ </para>
+ </entry><entry>
+ <para>
+ int
+ </para>
+ </entry><entry>
+ <para>
+ 8.02
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table> <anchor id="boost_typetraits.background.pair_of_references"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.pair_of_references">Pair of References</link>
+ </bridgehead>
+ <para>
+ The optimized copy example shows how type traits may be used to perform optimization
+ decisions at compile-time. Another important usage of type traits is to allow
+ code to compile that otherwise would not do so unless excessive partial specialization
+ is used. This is possible by delegating partial specialization to the type
+ traits classes. Our example for this form of usage is a pair that can hold
+ references <link linkend="background.references">[6]</link>.
+ </para>
+ <para>
+ First, let us examine the definition of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">pair</phrase></computeroutput>, omitting
+ the comparison operators, default constructor, and template copy constructor
+ for simplicity:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">pair</phrase>
+<phrase role="special">{</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T1</phrase> <phrase role="identifier">first_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T2</phrase> <phrase role="identifier">second_type</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">T1</phrase> <phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+<phrase role="identifier">T2</phrase> <phrase role="identifier">second</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">pair</phrase><phrase role="special">(</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">nfirst</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T2</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase>
+<phrase role="special">:</phrase><phrase role="identifier">first</phrase><phrase role="special">(</phrase><phrase role="identifier">nfirst</phrase><phrase role="special">),</phrase> <phrase role="identifier">second</phrase><phrase role="special">(</phrase><phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">}</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ Now, this "pair" cannot hold references as it currently stands, because
+ the constructor would require taking a reference to a reference, which is currently
+ illegal <link linkend="background.references">[7]</link>. Let us consider what
+ the constructor's parameters would have to be in order to allow "pair"
+ to hold non-reference types, references, and constant references:
+ </para>
+ <table frame="all"> <title>Required Constructor Argument Types</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of parameter to initializing constructor
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ A little familiarity with the type traits classes allows us to construct a
+ single mapping that allows us to determine the type of parameter from the type
+ of the contained class. The type traits classes provide a transformation <link linkend="boost_typetraits.reference.add_reference">add_reference</link>, which
+ adds a reference to its type, unless it is already a reference.
+ </para>
+ <table frame="all"> <title>Using add_reference to synthesize the correct constructor
+ type</title>
+ <tgroup cols="3">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ const T
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ T &amp; [8]
+ </para>
+ </entry><entry>
+ <para>
+ T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ This allows us to build a primary template definition for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput>
+ that can contain non-reference types, reference types, and constant reference
+ types:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">pair</phrase>
+<phrase role="special">{</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T1</phrase> <phrase role="identifier">first_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T2</phrase> <phrase role="identifier">second_type</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">T1</phrase> <phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+<phrase role="identifier">T2</phrase> <phrase role="identifier">second</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">pair</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">nfirst</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase>
+<phrase role="special">:</phrase><phrase role="identifier">first</phrase><phrase role="special">(</phrase><phrase role="identifier">nfirst</phrase><phrase role="special">),</phrase> <phrase role="identifier">second</phrase><phrase role="special">(</phrase><phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">}</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ Add back in the standard comparison operators, default constructor, and template
+ copy constructor (which are all the same), and you have a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">pair</phrase></computeroutput> that
+ can hold reference types!
+ </para>
+ <para>
+ This same extension could have been done using partial template specialization
+ of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput>, but to specialize
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput> in this way would require
+ three partial specializations, plus the primary template. Type traits allows
+ us to define a single primary template that adjusts itself auto-magically to
+ any of these partial specializations, instead of a brute-force partial specialization
+ approach. Using type traits in this fashion allows programmers to delegate
+ partial specialization to the type traits classes, resulting in code that is
+ easier to maintain and easier to understand.
+ </para>
+ <anchor id="boost_typetraits.background.conclusion"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.conclusion">Conclusion</link>
+ </bridgehead>
+ <para>
+ We hope that in this article we have been able to give you some idea of what
+ type-traits are all about. A more complete listing of the available classes
+ are in the boost documentation, along with further examples using type traits.
+ Templates have enabled C++ uses to take the advantage of the code reuse that
+ generic programming brings; hopefully this article has shown that generic programming
+ does not have to sink to the lowest common denominator, and that templates
+ can be optimal as well as generic.
+ </para>
+ <anchor id="boost_typetraits.background.acknowledgements"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.acknowledgements">Acknowledgements</link>
+ </bridgehead>
+ <para>
+ The authors would like to thank Beman Dawes and Howard Hinnant for their helpful
+ comments when preparing this article.
+ </para>
+ <anchor id="background.references"/> <anchor id="boost_typetraits.background.references"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.references">References</link>
+ </bridgehead>
+ <orderedlist inheritnum="ignore" continuation="restarts">
+ <listitem>
+ Nathan C. Myers, C++ Report, June 1995.
+ </listitem>
+ <listitem>
+ The type traits library is based upon contributions by Steve Cleary, Beman
+ Dawes, Howard Hinnant and John Maddock: it can be found at www.boost.org.
+ </listitem>
+ <listitem>
+ A scalar type is an arithmetic type (i.e. a built-in integer or floating
+ point type), an enumeration type, a pointer, a pointer to member, or a const-
+ or volatile-qualified version of one of these types.
+ </listitem>
+ <listitem>
+ This quote is from Donald Knuth, ACM Computing Surveys, December 1974, pg
+ 268.
+ </listitem>
+ <listitem>
+ The test code is available as part of the boost utility library (see algo_opt_examples.cpp),
+ the code was compiled with gcc 2.95 with all optimisations turned on, tests
+ were conducted on a 400MHz Pentium II machine running Microsoft Windows 98.
+ </listitem>
+ <listitem>
+ John Maddock and Howard Hinnant have submitted a "compressed_pair"
+ library to Boost, which uses a technique similar to the one described here
+ to hold references. Their pair also uses type traits to determine if any
+ of the types are empty, and will derive instead of contain to conserve space
+ -- hence the name "compressed".
+ </listitem>
+ <listitem>
+ This is actually an issue with the C++ Core Language Working Group (issue
+ #106), submitted by Bjarne Stroustrup. The tentative resolution is to allow
+ a "reference to a reference to T" to mean the same thing as a "reference
+ to T", but only in template instantiation, in a method similar to multiple
+ cv-qualifiers.
+ </listitem>
+ <listitem>
+ For those of you who are wondering why this shouldn't be const-qualified,
+ remember that references are always implicitly constant (for example, you
+ can't re-assign a reference). Remember also that "const T &amp;"
+ is something completely different. For this reason, cv-qualifiers on template
+ type arguments that are references are ignored.
+ </listitem>
+ </orderedlist>
+ </section>
+ <section id="boost_typetraits.category">
+ <title><link linkend="boost_typetraits.category"> Type Traits by Category</link></title>
+ <section id="boost_typetraits.category.value_traits">
+ <title><link linkend="boost_typetraits.category.value_traits"> Type Traits
+ that Describe the Properties of a Type</link></title>
+ <para>
+ <indexterm>
+ <primary>Foo2</primary>
+ <secondary>Bar2</secondary>
+ </indexterm>
+ These traits are all <emphasis>value traits</emphasis>, which is to say the
+ traits classes all inherit from <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link>,
+ and are used to access some numerical property of a type. Often this is a
+ simple true or false Boolean value, but in a few cases may be some other
+ integer value (for example when dealing with type alignments, or array bounds:
+ see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.alignment_of">alignment_of</link></computeroutput>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.rank">rank</link></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.extent">extent</link></computeroutput>).
+ </para>
+ <section id="boost_typetraits.category.value_traits.primary">
+ <title><link linkend="boost_typetraits.category.value_traits.primary"> Categorizing
+ a Type</link></title>
+ <para>
+ These traits identify what "kind" of type some type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is. These are split into two groups:
+ primary traits which are all mutually exclusive, and composite traits that
+ are compositions of one or more primary traits.
+ </para>
+ <para>
+ For any given type, exactly one primary type trait will inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ and all the others will inherit from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>,
+ in other words these traits are mutually exclusive.
+ </para>
+ <para>
+ This means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_integral">is_integral</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ will only ever be true for built-in types; if you want to check for a user-defined
+ class type that behaves "as if" it is an integral or floating
+ point type, then use the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase>
+ <phrase role="keyword">template</phrase></computeroutput> instead.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_array">is_array</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_class">is_class</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_complex">is_complex</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_enum">is_enum</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_function">is_function</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_integral">is_integral</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_object_pointer">is_member_object_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_union">is_union</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ The following traits are made up of the union of one or more type categorizations.
+ A type may belong to more than one of these categories, in addition to
+ one of the primary categories.
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_arithmetic">is_arithmetic</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_compound">is_compound</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_fundamental">is_fundamental</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_object">is_object</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_scalar">is_scalar</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.value_traits.properties">
+ <title><link linkend="boost_typetraits.category.value_traits.properties">
+ General Type Properties</link></title>
+ <para>
+ The following templates describe the general properties of a type.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.alignment_of">alignment_of</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_assign">has_nothrow_assign</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_default_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_default_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_virtual_destructor">has_virtual_destructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_abstract">is_abstract</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_const">is_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_empty">is_empty</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_stateless">is_stateless</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_signed">is_signed</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_unsigned">is_unsigned</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_volatile">is_volatile</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.extent">extent</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.rank">rank</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.value_traits.relate">
+ <title><link linkend="boost_typetraits.category.value_traits.relate"> Relationships
+ Between Two Types</link></title>
+ <para>
+ These templates determine the whether there is a relationship between two
+ types:
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_base_of">is_base_of</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_same">is_same</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.category.transform"><indexterm type="macro_name"><primary>BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</primary><secondary>Type Traits that Transform One Type to Another</secondary></indexterm><indexterm><primary>Type Traits that Transform One Type to Another</primary><secondary>BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</primary><secondary>Type Traits that Transform One Type to Another</secondary></indexterm><indexterm><primary>Type Traits that Transform One Type to Another</primary><secondary>BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</secondary></indexterm>
+ <title><link linkend="boost_typetraits.category.transform"> Type Traits that
+ Transform One Type to Another</link></title>
+ <para>
+ The following templates transform one type to another, based upon some well-defined
+ rule. Each template has a single member called <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of applying the transformation to the template argument
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_const">add_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_cv">add_cv</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_pointer">add_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_volatile">add_volatile</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.decay">decay</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.floating_point_promotion">floating_point_promotion</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.integral_promotion">integral_promotion</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.make_signed">make_signed</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.make_unsigned">make_unsigned</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.promote">promote</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_all_extents">remove_all_extents</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_const">remove_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_cv">remove_cv</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_reference">remove_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_volatile">remove_volatile</link><phrase role="special">;</phrase>
+</programlisting>
+ <anchor id="boost_typetraits.category.transform.broken_compiler_workarounds_"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">Broken
+ Compiler Workarounds:</link>
+ </bridgehead>
+ <para>
+ For all of these templates support for partial specialization of class templates
+ is required to correctly implement the transformation. On the other hand,
+ practice shows that many of the templates from this category are very useful,
+ and often essential for implementing some generic libraries. Lack of these
+ templates is often one of the major limiting factors in porting those libraries
+ to compilers that do not yet support this language feature. As some of these
+ compilers are going to be around for a while, and at least one of them is
+ very wide-spread, it was decided that the library should provide workarounds
+ where possible.
+ </para>
+ <para>
+ The basic idea behind the workaround is to manually define full specializations
+ of all type transformation templates for all fundamental types, and all their
+ 1st and 2nd rank cv-[un]qualified derivative pointer types, and to provide
+ a user-level macro that will define all the explicit specializations needed
+ for any user-defined type T.
+ </para>
+ <para>
+ The first part guarantees the successful compilation of something like this:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="special">...</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+</programlisting>
+ <para>
+ and the second part provides the library's users with a mechanism to make
+ the above code work not only for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput> or other built-in type,
+ but for their own types as well:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">myspace</phrase><phrase role="special">{</phrase>
+ <phrase role="keyword">struct</phrase> <phrase role="identifier">MyClass</phrase> <phrase role="special">{};</phrase>
+<phrase role="special">}</phrase>
+<phrase role="comment">// declare this at global scope:
+</phrase><phrase role="identifier">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase><phrase role="special">(</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">)</phrase>
+<phrase role="comment">// transformations on myspace::MyClass now work:
+</phrase><phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="comment">// etc.
+</phrase></programlisting>
+ <para>
+ Note that the macro BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION evaluates
+ to nothing on those compilers that <emphasis role="bold">do</emphasis> support
+ partial specialization.
+ </para>
+ </section>
+ <section id="boost_typetraits.category.alignment">
+ <title><link linkend="boost_typetraits.category.alignment"> Synthesizing Types
+ with Specific Alignments</link></title>
+ <para>
+ Some low level memory management routines need to synthesize a POD type with
+ specific alignment properties. The template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.type_with_alignment">type_with_alignment</link></computeroutput>
+ finds the smallest type with a specified alignment, while template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.aligned_storage">aligned_storage</link></computeroutput>
+ creates a type with a specific size and alignment.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.type_with_alignment">type_with_alignment</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Size</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.aligned_storage">aligned_storage</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.function">
+ <title><link linkend="boost_typetraits.category.function"> Decomposing Function
+ Types</link></title>
+ <para>
+ The class template <link linkend="boost_typetraits.reference.function_traits">function_traits</link>
+ extracts information from function types (see also <link linkend="boost_typetraits.reference.is_function">is_function</link>).
+ This traits class allows you to tell how many arguments a function takes,
+ what those argument types are, and what the return type is.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.function_traits">function_traits</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.user_defined"><indexterm type="class_name"><primary>is_union</primary><secondary>User Defined Specializations</secondary></indexterm><indexterm><primary>User Defined Specializations</primary><secondary>is_union</secondary></indexterm><indexterm type="class_name"><primary>is_class</primary><secondary>User Defined Specializations</secondary></indexterm><indexterm><primary>User Defined Specializations</primary><secondary>is_class</secondary></indexterm>
+ <title><link linkend="boost_typetraits.user_defined"> User Defined Specializations</link></title>
+ <para>
+ Occationally the end user may need to provide their own specialization for
+ one of the type traits - typically where intrinsic compiler support is required
+ to implement a specific trait fully. These specializations should derive from
+ boost::<link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ or boost::<link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ as appropriate:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pod</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+<phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_class</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+<phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_union</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+
+<phrase role="keyword">struct</phrase> <phrase role="identifier">my_pod</phrase><phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">my_union</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">char</phrase> <phrase role="identifier">c</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_pod</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_union">is_union</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_class">is_class</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.intrinsics"><indexterm type="macro_name"><primary>BOOST_IS_UNION</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_IS_UNION</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_IS_POLYMORPHIC</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_IS_POLYMORPHIC</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_IS_POD</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_IS_POD</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_IS_ENUM</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_IS_ENUM</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_IS_EMPTY</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_IS_EMPTY</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_IS_CONVERTIBLE</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_IS_CONVERTIBLE</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_IS_CLASS</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_IS_CLASS</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_IS_BASE_OF</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_IS_BASE_OF</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_IS_ABSTRACT</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_IS_ABSTRACT</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_HAS_VIRTUAL_DESTRUCTOR</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_HAS_VIRTUAL_DESTRUCTOR</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_HAS_TRIVIAL_DESTRUCTOR</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_HAS_TRIVIAL_DESTRUCTOR</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_HAS_TRIVIAL_COPY</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_HAS_TRIVIAL_COPY</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_HAS_TRIVIAL_CONSTRUCTOR</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_HAS_TRIVIAL_CONSTRUCTOR</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_HAS_TRIVIAL_ASSIGN</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_HAS_TRIVIAL_ASSIGN</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_HAS_NOTHROW_COPY</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_HAS_NOTHROW_COPY</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_HAS_NOTHROW_CONSTRUCTOR</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_HAS_NOTHROW_CONSTRUCTOR</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_HAS_NOTHROW_ASSIGN</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_HAS_NOTHROW_ASSIGN</secondary></indexterm><indexterm type="macro_name"><primary>BOOST_ALIGNMENT_OF</primary><secondary>Support for Compiler Intrinsics</secondary></indexterm><indexterm><primary>Support for Compiler Intrinsics</primary><secondary>BOOST_ALIGNMENT_OF</secondary></indexterm>
+ <title><link linkend="boost_typetraits.intrinsics"> Support for Compiler Intrinsics</link></title>
+ <para>
+ There are some traits that can not be implemented within the current C++ language:
+ to make these traits "just work" with user defined types, some kind
+ of additional help from the compiler is required. Currently (April 2008) Visual
+ C++ 8 and 9, GNU GCC 4.3 and MWCW 9 provide the necessary intrinsics, and other
+ compilers will no doubt follow in due course.
+ </para>
+ <para>
+ The Following traits classes always need compiler support to do the right thing
+ for all types (but all have safe fallback positions if this support is unavailable):
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_union">is_union</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_pod">is_pod</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_assign">has_nothrow_assign</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_virtual_destructor">has_virtual_destructor</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The following traits classes can't be portably implemented in the C++ language,
+ although in practice, the implementations do in fact do the right thing on
+ all the compilers we know about:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_empty">is_empty</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The following traits classes are dependent on one or more of the above:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_class">is_class</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_stateless">is_stateless</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The hooks for compiler-intrinsic support are defined in <ulink url="../../../../boost/type_traits/intrinsics.hpp">boost/type_traits/intrinsics.hpp</ulink>,
+ adding support for new compilers is simply a matter of defining one of more
+ of the following macros:
+ </para>
+ <table frame="all"> <title>Macros for Compiler Intrinsics</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_UNION(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a union type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_POD(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a POD type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_EMPTY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is an empty struct or union
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_CONSTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if the default constructor for T is trivial (i.e.
+ has no effect)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_COPY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial copy constructor (and can
+ therefore be replaced by a call to memcpy)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_ASSIGN(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial assignment operator (and can
+ therefore be replaced by a call to memcpy)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_DESTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial destructor (i.e. ~T() has
+ no effect)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_CONSTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="identifier">x</phrase><phrase role="special">;</phrase></computeroutput>
+ can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_COPY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase><phrase role="special">(</phrase><phrase role="identifier">t</phrase><phrase role="special">)</phrase></computeroutput> can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_ASSIGN(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="identifier">t</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">u</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">t</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">u</phrase></computeroutput> can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_VIRTUAL_DESTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true T has a virtual destructor
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_ABSTRACT(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is an abstract type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_BASE_OF(T,U)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a base class of U
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_CLASS(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a class type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_CONVERTIBLE(T,U)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is convertible to U
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_ENUM(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true is T is an enum
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_POLYMORPHIC(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a polymorphic type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_ALIGNMENT_OF(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to the alignment requirements of type T.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.mpl">
+ <title><link linkend="boost_typetraits.mpl"> MPL Interoperability</link></title>
+ <para>
+ All the value based traits in this library conform to MPL's requirements for
+ an <ulink url="../../../../libs/mpl/doc/refmanual/integral-constant.html">Integral
+ Constant type</ulink>: that includes a number of rather intrusive workarounds
+ for broken compilers.
+ </para>
+ <para>
+ Purely as an implementation detail, this means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/bool.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">true_</phrase></computeroutput></ulink>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">false_type</link></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/bool.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">false_</phrase></computeroutput></ulink>,
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">v</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/integral-c.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">integral_c</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">v</phrase><phrase role="special">&gt;</phrase></computeroutput></ulink>
+ (provided <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>)
+ </para>
+ </section>
+ <section id="boost_typetraits.examples">
+ <title><link linkend="boost_typetraits.examples"> Examples</link></title>
+ <section id="boost_typetraits.examples.copy"><indexterm type="typedef_name"><primary>value_type</primary><secondary>An Optimized Version of std::copy</secondary></indexterm><indexterm><primary>Optimized Version of std::copy</primary><secondary>value_type</secondary></indexterm>
+ <title><link linkend="boost_typetraits.examples.copy"> An Optimized Version
+ of std::copy</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">copy</phrase></computeroutput>
+ that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>
+ to determine whether to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>
+ to optimise the copy operation (see <ulink url="../../examples/copy_example.cpp">copy_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// opt::copy
+</phrase><phrase role="comment">// same semantics as std::copy
+</phrase><phrase role="comment">// calls memcpy where appropriate.
+</phrase><phrase role="comment">//
+</phrase>
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">I2</phrase> <phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">out</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">out</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">out</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">memcpy</phrase><phrase role="special">(</phrase><phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="special">(</phrase><phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">)*</phrase><phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">));</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">out</phrase><phrase role="special">+(</phrase><phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">copy</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">out</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// We can copy with memcpy if T has a trivial assignment operator,
+</phrase> <phrase role="comment">// and if the iterator arguments are actually pointers (this last
+</phrase> <phrase role="comment">// requirement we detect with overload resolution):
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">&lt;</phrase><phrase role="identifier">value_type</phrase><phrase role="special">&gt;());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.fill">
+ <title><link linkend="boost_typetraits.examples.fill"> An Optimised Version
+ of std::fill</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">fill</phrase></computeroutput>
+ that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>
+ to determine whether to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memset</phrase></computeroutput>
+ to optimise the fill operation (see <ulink url="../../examples/fill_example.cpp">fill_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// fill
+</phrase><phrase role="comment">// same as std::fill, but uses memset where appropriate
+</phrase><phrase role="comment">//
+</phrase><phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">first</phrase> <phrase role="special">=</phrase> <phrase role="identifier">val</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">memset</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">I</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">fill</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// We can do an optimised fill if T has a trivial assignment
+</phrase> <phrase role="comment">// operator and if it's size is one:
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase>
+ <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="special">(</phrase><phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">)&gt;</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.destruct">
+ <title><link linkend="boost_typetraits.examples.destruct"> An Example that
+ Omits Destructor Calls For Types with Trivial Destructors</link></title>
+ <para>
+ Demonstrates a simple algorithm that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">__has_trivial_destruct</phrase></computeroutput>
+ to determine whether to destructors need to be called (see <ulink url="../../examples/trivial_destructor_example.cpp">trivial_destructor_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// algorithm destroy_array:
+</phrase><phrase role="comment">// The reverse of std::unitialized_copy, takes a block of
+</phrase><phrase role="comment">// initialized memory and calls destructors on all objects therein.
+</phrase><phrase role="comment">//
+</phrase>
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="identifier">first</phrase><phrase role="special">-&gt;~</phrase><phrase role="identifier">T</phrase><phrase role="special">();</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase> <phrase role="comment">// namespace detail
+</phrase>
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">p1</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">p2</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">p1</phrase><phrase role="special">,</phrase> <phrase role="identifier">p2</phrase><phrase role="special">,</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.iter">
+ <title><link linkend="boost_typetraits.examples.iter"> An improved Version
+ of std::iter_swap</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iter_swap</phrase></computeroutput>
+ that use type traits to determine whether an it's arguments are proxying
+ iterators or not, if they're not then it just does a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">swap</phrase></computeroutput>
+ of it's dereferenced arguments (the same as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iter_swap</phrase></computeroutput>
+ does), however if they are proxying iterators then takes special care over
+ the swap to ensure that the algorithm works correctly for both proxying iterators,
+ and even iterators of different types (see <ulink url="../../examples/iter_swap_example.cpp">iter_swap_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// iter_swap:
+</phrase><phrase role="comment">// tests whether iterator is a proxying iterator or not, and
+</phrase><phrase role="comment">// uses optimal form accordingly:
+</phrase><phrase role="comment">//
+</phrase><phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">v_t</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">v_t</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">one</phrase><phrase role="special">;</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">one</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">two</phrase><phrase role="special">;</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">two</phrase> <phrase role="special">=</phrase> <phrase role="identifier">v</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">using</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">swap</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">swap</phrase><phrase role="special">(*</phrase><phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="special">*</phrase><phrase role="identifier">two</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">iter_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">two</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// See is both arguments are non-proxying iterators,
+</phrase> <phrase role="comment">// and if both iterator the same type:
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">r1_t</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I2</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">r2_t</phrase><phrase role="special">;</phrase>
+
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase>
+ <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">&lt;</phrase><phrase role="identifier">r1_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">&lt;</phrase><phrase role="identifier">r2_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_same">is_same</link><phrase role="special">&lt;</phrase><phrase role="identifier">r1_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">r2_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">;</phrase>
+
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.to_double">
+ <title><link linkend="boost_typetraits.examples.to_double"> Convert Numeric
+ Types and Enums to double</link></title>
+ <para>
+ Demonstrates a conversion of <ulink url="../../../../libs/numeric/conversion/doc/html/boost_numericconversion/definitions.html#boost_numericconversion.definitions.numeric_types">Numeric
+ Types</ulink> and enum types to double:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">double</phrase> <phrase role="identifier">to_double</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">promoted</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric</phrase><phrase role="special">::</phrase><phrase role="identifier">converter</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase><phrase role="identifier">promoted</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">convert</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.reference">
+ <title><link linkend="boost_typetraits.reference"> Alphabetical Reference</link></title>
+ <section id="boost_typetraits.reference.add_const"><indexterm type="class_name"><primary>Constrained Index Term</primary><secondary>add_const</secondary></indexterm><indexterm><primary>add_const</primary><secondary>Constrained Index Term</secondary></indexterm><indexterm type="class_name"><primary>Constrained Index Term</primary><secondary>add_const</secondary></indexterm><indexterm><primary>add_const</primary><secondary>Constrained Index Term</secondary></indexterm><indexterm type="class_name"><primary>add_const</primary><secondary>add_const</secondary></indexterm><indexterm type="class_name"><primary>Constrained Index Term</primary><secondary>add_const</secondary></indexterm><indexterm><primary>add_const</primary><secondary>Constrained Index Term</secondary></indexterm><indexterm type="class_name"><primary>Constrained Index Term</primary><secondary>add_const</secondary></indexterm><indexterm><primary>add_const</primary><secondary>Constrained Index Term</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.add_const"> add_const</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ <secondary>two</secondary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">const</phrase></computeroutput> for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_cv"><indexterm type="class_name"><primary>add_cv</primary><secondary>add_cv</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.add_cv"> add_cv</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ <secondary>two</secondary>
+ <tertiary>three</tertiary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_cv</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_cv</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_pointer"><indexterm type="class_name"><primary>add_pointer</primary><secondary>add_pointer</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.add_pointer"> add_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_pointer</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">*</phrase></computeroutput>.
+ </para>
+ <para>
+ The rationale for this template is that it produces the same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">TYPEOF</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">t</phrase><phrase role="special">)</phrase></computeroutput>, where
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t</phrase></computeroutput> is an object of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">**</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">**</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_reference"><indexterm type="class_name"><primary>add_reference</primary><secondary>add_reference</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.add_reference"> add_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_reference</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is not a reference type then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase></computeroutput>, otherwise <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_volatile"><indexterm type="class_name"><primary>add_volatile</primary><secondary>add_volatile</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.add_volatile"> add_volatile</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput> for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.aligned_storage"><indexterm type="class_name"><primary>aligned_storage</primary><secondary>aligned_storage</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.aligned_storage"> aligned_storage</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Size</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">aligned_storage</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> a built-in or POD type with size
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Size</phrase></computeroutput> and an alignment that
+ is a multiple of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Align</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">aligned_storage</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.alignment_of"><indexterm type="class_name"><primary>integral_constant</primary><secondary>alignment_of</secondary></indexterm><indexterm><primary>alignment_of</primary><secondary>integral_constant</secondary></indexterm><indexterm type="class_name"><primary>alignment_of</primary><secondary>alignment_of</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.alignment_of"> alignment_of</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">alignment_of</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template alignment<emphasis role="underline">of inherits from `</emphasis>_integral_constant&lt;std::size_t,
+ ALIGNOF(T)&gt;<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">,</phrase> <phrase role="identifier">where</phrase>
+ </computeroutput>ALIGNOF(T)` is the alignment of type T.
+ </para>
+ <para>
+ <emphasis>Note: strictly speaking you should only rely on the value of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> being
+ a multiple of the true alignment of T, although in practice it does compute
+ the correct value in all the cases we know about.</emphasis>
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">alignment_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ with value <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.decay"><indexterm type="class_name"><primary>decay</primary><secondary>decay</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.decay"> decay</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">decay</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> Let <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>
+ be the result of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>, then if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>
+ is an array type, the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;*</phrase></computeroutput>,
+ otherwise if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput> is a function
+ type then the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase><phrase role="special">*</phrase></computeroutput>, otherwise the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">decay</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">(&amp;)[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">(&amp;)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.extent"><indexterm type="class_name"><primary>integral_constant</primary><secondary>extent</secondary></indexterm><indexterm><primary>extent</primary><secondary>integral_constant</secondary></indexterm><indexterm type="class_name"><primary>extent</primary><secondary>extent</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.extent"> extent</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">extent</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template extent inherits
+ from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)&gt;</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)</phrase></computeroutput> is the number of elements in the N'th array
+ dimention of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not an array type,
+ or if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">N</phrase> <phrase role="special">&gt;</phrase>
+ <link linkend="boost_typetraits.reference.rank">rank</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>, or if the N'th array bound is incomplete,
+ then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)</phrase></computeroutput> is zero.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">extent</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">],</phrase>
+ <phrase role="number">1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">3</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>4</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">],</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>2</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.floating_point_promotion"><indexterm type="class_name"><primary>floating_point_promotion</primary><secondary>floating_point_promotion</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.floating_point_promotion">
+ floating_point_promotion</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">floating_point_promotion</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If floating point promotion can be
+ applied to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ then applies floating point promotion to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">float</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.function_traits"><indexterm type="typedef_name"><primary>result_type</primary><secondary>function_traits</secondary></indexterm><indexterm><primary>function_traits</primary><secondary>result_type</secondary></indexterm><indexterm type="class_name"><primary>function_traits</primary><secondary>function_traits</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.function_traits"> function_traits</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">F</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">function_traits</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">static</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">arity</phrase> <phrase role="special">=</phrase> <replaceable>see-below</replaceable><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">result_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> arg<replaceable>N</replaceable>_type<phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ The class template function_traits will only compile if:
+ </para>
+ <itemizedlist>
+ <listitem>
+ The compiler supports partial specialization of class templates.
+ </listitem>
+ <listitem>
+ The template argument <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>
+ is a <emphasis>function type</emphasis>, note that this <emphasis><emphasis role="bold">is not</emphasis></emphasis> the same thing as a <emphasis>pointer
+ to a function</emphasis>.
+ </listitem>
+ </itemizedlist>
+ <tip>
+ <para>
+ function_traits is intended to introspect only C++ functions of the form
+ R (), R( A1 ), R ( A1, ... etc. ) and not function pointers or class member
+ functions. To convert a function pointer type to a suitable type use <link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link>.
+ </para>
+ </tip>
+ <table frame="all"> <title>Function Traits Members</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Member
+ </para>
+ </entry><entry>
+ <para>
+ Description
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that gives the number of arguments
+ accepted by the function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type returned by function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase>arg<replaceable>N</replaceable>_type</computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The <replaceable>N</replaceable>th argument type of function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase> <phrase role="special">&lt;=</phrase>
+ <phrase role="identifier">N</phrase> <phrase role="special">&lt;=</phrase>
+ <phrase role="identifier">arity</phrase></computeroutput> of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table> <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 0.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 1.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 4.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">long</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arg1_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arg4_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase><phrase role="special">*</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arg5_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A compiler error: there is no <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">arg5_type</phrase></computeroutput>
+ since there are only four arguments.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A compiler error: argument type is a <emphasis>function pointer</emphasis>,
+ and not a <emphasis>function type</emphasis>.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_assign"><indexterm type="class_name"><primary>has_nothrow_assign</primary><secondary>has_nothrow_assign</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.has_nothrow_assign"> has_nothrow_assign</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_assign</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing assignment-operator then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_assign</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing assignment-operator;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler support to ensure that this trait "just
+ works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_assign</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_constructor"><indexterm type="class_name"><primary>has_nothrow_default_constructor</primary><secondary>has_nothrow_constructor</secondary></indexterm><indexterm><primary>has_nothrow_constructor</primary><secondary>has_nothrow_default_constructor</secondary></indexterm><indexterm type="class_name"><primary>has_nothrow_constructor</primary><secondary>has_nothrow_constructor</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.has_nothrow_constructor">
+ has_nothrow_constructor</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_default_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing default-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_constructor</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing default-constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to ensure that this trait "just works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_constructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_copy"><indexterm type="class_name"><primary>has_nothrow_copy_constructor</primary><secondary>has_nothrow_copy</secondary></indexterm><indexterm><primary>has_nothrow_copy</primary><secondary>has_nothrow_copy_constructor</secondary></indexterm><indexterm type="class_name"><primary>has_nothrow_copy</primary><secondary>has_nothrow_copy</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.has_nothrow_copy"> has_nothrow_copy</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_copy</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_copy_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing copy-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_copy</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing copy-constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to ensure that this trait "just works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_copy</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_cp_cons">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_cp_cons"> has_nothrow_copy_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_no_throw_def_cons">
+ <title><link linkend="boost_typetraits.reference.has_no_throw_def_cons"> has_nothrow_default_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_assign"><indexterm type="class_name"><primary>has_trivial_assign</primary><secondary>has_trivial_assign</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.has_trivial_assign"> has_trivial_assign</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_assign</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial assignment-operator then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ If a type has a trivial assignment-operator then the operator has the same
+ effect as copying the bits of one object to the other: calls to the operator
+ can be safely replaced with a call to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_assign
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.8p11.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_constructor"><indexterm type="class_name"><primary>has_trivial_default_constructor</primary><secondary>has_trivial_constructor</secondary></indexterm><indexterm><primary>has_trivial_constructor</primary><secondary>has_trivial_default_constructor</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.has_trivial_constructor">
+ has_trivial_constructor</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_default_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial default-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ If a type has a trivial default-constructor then the constructor have no
+ effect: calls to the constructor can be safely omitted. Note that using meta-programming
+ to omit a call to a single trivial-constructor call is of no benefit whatsoever.
+ However, if loops and/or exception handling code can also be omitted, then
+ some benefit in terms of code size and speed can be obtained.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_constructor
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.1p6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_copy"><indexterm type="class_name"><primary>has_trivial_copy_constructor</primary><secondary>has_trivial_copy</secondary></indexterm><indexterm><primary>has_trivial_copy</primary><secondary>has_trivial_copy_constructor</secondary></indexterm><indexterm type="class_name"><primary>has_trivial_copy</primary><secondary>has_trivial_copy</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.has_trivial_copy"> has_trivial_copy</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_copy</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_copy_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial copy-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ If a type has a trivial copy-constructor then the constructor has the same
+ effect as copying the bits of one object to the other: calls to the constructor
+ can be safely replaced with a call to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_copy
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.8p6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_cp_cons">
+ <title><link linkend="boost_typetraits.reference.has_trivial_cp_cons"> has_trivial_copy_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_def_cons">
+ <title><link linkend="boost_typetraits.reference.has_trivial_def_cons"> has_trivial_default_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_destructor"><indexterm type="class_name"><primary>has_trivial_destructor</primary><secondary>has_trivial_destructor</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.has_trivial_destructor"> has_trivial_destructor</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_destructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial destructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ If a type has a trivial destructor then the destructor has no effect: calls
+ to the destructor can be safely omitted. Note that using meta-programming
+ to omit a call to a single trivial-constructor call is of no benefit whatsoever.
+ However, if loops and/or exception handling code can also be omitted, then
+ some benefit in terms of code size and speed can be obtained.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_destructor
+ will never report that a user-defined class or struct has a trivial destructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.4p3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_virtual_destructor"><indexterm type="class_name"><primary>has_virtual_destructor</primary><secondary>has_virtual_destructor</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.has_virtual_destructor"> has_virtual_destructor</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_virtual_destructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a virtual destructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> This trait is provided
+ for completeness, since it's part of the Technical Report on C++ Library
+ Extensions. However, there is currently no way to portably implement this
+ trait. The default version provided always inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>,
+ and has to be explicitly specialized for types with virtual destructors unless
+ the compiler used has compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ that enable the trait to do the right thing: currently (May 2005) only Visual
+ C++ 8 and GCC-4.3 have the necessary <link linkend="boost_typetraits.intrinsics">intrinsics</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.4.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_virtual_destructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.integral_constant"><indexterm type="typedef_name"><primary>value_type</primary><secondary>integral_constant</secondary></indexterm><indexterm><primary>integral_constant</primary><secondary>value_type</secondary></indexterm><indexterm type="typedef_name"><primary>true_type</primary><secondary>integral_constant</secondary></indexterm><indexterm><primary>integral_constant</primary><secondary>true_type</secondary></indexterm><indexterm type="class_name"><primary>integral_constant</primary><secondary>integral_constant</secondary></indexterm><indexterm type="typedef_name"><primary>false_type</primary><secondary>integral_constant</secondary></indexterm><indexterm><primary>integral_constant</primary><secondary>false_type</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.integral_constant"> integral_constant</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">val</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">integral_constant</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">static</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">val</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="keyword">true</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">true_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="keyword">false</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">false_type</phrase><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ Class template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_constant</phrase></computeroutput>
+ is the common base class for all the value-based type traits. The two typedef's
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">true_type</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">false_type</phrase></computeroutput> are provided for convenience:
+ most of the value traits are Boolean properties and so will inherit from
+ one of these.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.integral_promotion"><indexterm type="class_name"><primary>integral_promotion</primary><secondary>integral_promotion</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.integral_promotion"> integral_promotion</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">integral_promotion</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If integral promotion can be applied
+ to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>, then
+ applies integral promotion to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.5 except 4.5/3
+ (integral bit-field).
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">integral_promotion</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">enum</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">float_round_style</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.is_abstract"><indexterm type="class_name"><primary>is_abstract</primary><secondary>is_abstract</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_abstract"> is_abstract</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_abstract</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ abstract type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_abstract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> The compiler must
+ support DR337 (as of April 2005: GCC 3.4, VC++ 7.1 (and later), Intel C++
+ 7 (and later), and Comeau 4.3.2). Otherwise behaves the same as <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link>;
+ this is the "safe fallback position" for which polymorphic types
+ are always regarded as potentially abstract. The macro BOOST_NO_IS_ABSTRACT
+ is used to signify that the implementation is buggy, users should check for
+ this in their own code if the "safe fallback" is not suitable for
+ their particular use-case.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">abc</phrase><phrase role="special">{</phrase> <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">abc</phrase><phrase role="special">()</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_arithmetic"><indexterm type="class_name"><primary>is_arithmetic</primary><secondary>is_arithmetic</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_arithmetic"> is_arithmetic</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_arithmetic</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ arithmetic type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Arithmetic types include integral and floating point types (see also <link linkend="boost_typetraits.reference.is_integral">is_integral</link> and
+ <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link>).
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p8.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_arithmetic</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_array"><indexterm type="class_name"><primary>is_array</primary><secondary>is_array</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_array"> is_array</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_array</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ array type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_array</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can give the wrong result with function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_base_of"><indexterm type="class_name"><primary>is_base_of</primary><secondary>is_base_of</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_base_of"> is_base_of</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_base_of</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If Base is base class of type
+ Derived or if both types are the same then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ This template will detect non-public base classes, and ambiguous base classes.
+ </para>
+ <para>
+ Note that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">X</phrase><phrase role="special">,</phrase><phrase role="identifier">X</phrase><phrase role="special">&gt;</phrase></computeroutput> will always inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>.
+ <emphasis role="bold">This is the case even if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">X</phrase></computeroutput>
+ is not a class type</emphasis>. This is a change in behaviour from Boost-1.33
+ in order to track the Technical Report on C++ Library Extensions.
+ </para>
+ <para>
+ Types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput> must not be incomplete types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_base_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types. There are some older compilers which
+ will produce compiler errors if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput>
+ is a private base class of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput>,
+ or if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput> is an ambiguous
+ base of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput>. These compilers
+ include Borland C++, older versions of Sun Forte C++, Digital Mars C++, and
+ older versions of EDG based compilers.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">{};</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase> <phrase role="special">:</phrase>
+ <phrase role="keyword">public</phrase> <phrase role="identifier">Base</phrase><phrase role="special">{};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Base</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>: a class is regarded as it's
+ own base.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_class"><indexterm type="class_name"><primary>is_class</primary><secondary>is_class</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_class"> is_class</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_class</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ class type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 9.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_class</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Without (some as
+ yet unspecified) help from the compiler, we cannot distinguish between union
+ and class types, as a result this type will erroneously inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link> for
+ union types. See also <link linkend="boost_typetraits.reference.is_union">is_union</link>.
+ Currently (May 2005) only Visual C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to correctly identify union types, and therefore make is_class function correctly.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">MyClass</phrase><phrase role="special">;</phrase></computeroutput> then:
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_complex"><indexterm type="class_name"><primary>is_complex</primary><secondary>is_complex</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_complex"> is_complex</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_complex</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is a complex number type then true (of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">complex</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ for some type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>), otherwise
+ false.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 26.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_complex</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.is_compound"><indexterm type="class_name"><primary>is_compound</primary><secondary>is_compound</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_compound"> is_compound</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_compound</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ compound type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Any type that is not a fundamental type is a compound type (see also <link linkend="boost_typetraits.reference.is_fundamental">is_fundamental</link>).
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_compound</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyEnum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_const"><indexterm type="class_name"><primary>is_const</primary><secondary>is_const</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_const"> is_const</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_const</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (top level) const-qualified
+ type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the const-qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the const-qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_convertible"><indexterm type="class_name"><primary>is_convertible</primary><secondary>is_convertible</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_convertible"> is_convertible</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_convertible</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If an imaginary lvalue of type
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">From</phrase></computeroutput> is convertible to type
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput> then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ Type From must not be an incomplete type.
+ </para>
+ <para>
+ Type To must not be an incomplete, or function type.
+ </para>
+ <para>
+ No types are considered to be convertible to array types or abstract-class
+ types.
+ </para>
+ <para>
+ This template can not detect whether a converting-constructor is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput> or not: if type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput>
+ has a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput> converting constructor
+ from type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">From</phrase></computeroutput> then instantiating
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ will produce a compiler error. For this reason <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase></computeroutput>
+ can not be used to determine whether a type has a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
+ copy-constructor or not.
+ </para>
+ <para>
+ This template will also produce compiler errors if the conversion is ambiguous,
+ for example:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">B</phrase> <phrase role="special">:</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">C</phrase> <phrase role="special">:</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">D</phrase> <phrase role="special">:</phrase> <phrase role="identifier">B</phrase><phrase role="special">,</phrase> <phrase role="identifier">C</phrase> <phrase role="special">{};</phrase>
+<phrase role="comment">// This produces a compiler error, the conversion is ambiguous:
+</phrase><phrase role="keyword">bool</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">y</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">D</phrase><phrase role="special">*,</phrase><phrase role="identifier">A</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4 and 8.5.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> This template is
+ currently broken with Borland C++ Builder 5 (and earlier), for constructor-based
+ conversions, and for the Metrowerks 7 (and earlier) compiler in all cases.
+ If the compiler does not support <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_abstract">is_abstract</link></computeroutput>,
+ then the template parameter <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput>
+ must not be an abstract type.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_convertible</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*,</phrase> <phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the conversion would require a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const_cast</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;,</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_empty"><indexterm type="class_name"><primary>is_empty</primary><secondary>is_empty</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_empty"> is_empty</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_empty</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an empty class type then
+ inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10p5.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> In order to correctly
+ detect empty classes this trait relies on either:
+ </para>
+ <itemizedlist>
+ <listitem>
+ the compiler implementing zero sized empty base classes, or
+ </listitem>
+ <listitem>
+ the compiler providing <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect empty classes.
+ </listitem>
+ </itemizedlist>
+ <para>
+ Can not be used with incomplete types.
+ </para>
+ <para>
+ Can not be used with union types, until is_union can be made to work.
+ </para>
+ <para>
+ If the compiler does not support partial-specialization of class templates,
+ then this template can not be used with abstract types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">empty_class</phrase>
+ <phrase role="special">{};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_enum"><indexterm type="class_name"><primary>is_enum</primary><secondary>is_enum</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_enum"> is_enum</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_enum</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ enum type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_enum</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Requires a correctly
+ functioning <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link>
+ template; this means that is_enum is currently broken under Borland C++ Builder
+ 5, and for the Metrowerks compiler prior to version 8, other compilers should
+ handle this template just fine.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">enum</phrase> <phrase role="identifier">my_enum</phrase>
+ <phrase role="special">{</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">two</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_floating_point"><indexterm type="class_name"><primary>is_floating_point</primary><secondary>is_floating_point</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_floating_point"> is_floating_point</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_floating_point</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ floating point type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p8.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_floating_point</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_function"><indexterm type="class_name"><primary>is_function</primary><secondary>is_function</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_function"> is_function</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_function</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ function type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Note that this template does not detect <emphasis>pointers to functions</emphasis>,
+ or <emphasis>references to functions</emphasis>, these are detected by <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link> and <link linkend="boost_typetraits.reference.is_reference">is_reference</link> respectively:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">f1</phrase><phrase role="special">();</phrase> <phrase role="comment">// f1 is of function type.
+</phrase><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">f2</phrase><phrase role="special">*)();</phrase> <phrase role="comment">// f2 is a pointer to a function.
+</phrase><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">f3</phrase><phrase role="special">&amp;)();</phrase> <phrase role="comment">// f3 is a reference to a function.
+</phrase></programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2p1 and 8.3.5.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_function</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a pointer type, not a function type.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(&amp;)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a reference to a function, not a function type.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a pointer to a member function.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <tip>
+ <para>
+ Don't confuse function-types with pointers to functions:
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">);</phrase></computeroutput>
+ </para>
+ <para>
+ defines a function type,
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase> <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ declares a prototype for a function of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase></computeroutput>,
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase><phrase role="special">*</phrase>
+ <phrase role="identifier">pf</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase><phrase role="special">&amp;</phrase>
+ <phrase role="identifier">fr</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ declares a pointer and a reference to the function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">foo</phrase></computeroutput>.
+ </para>
+ <para>
+ If you want to detect whether some type is a pointer-to-function then use:
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_function">is_function</link><phrase role="special">&lt;</phrase><link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ </para>
+ <para>
+ or for pointers to member functions you can just use <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link>
+ directly.
+ </para>
+ </tip>
+ </section>
+ <section id="boost_typetraits.reference.is_fundamental"><indexterm type="class_name"><primary>is_fundamental</primary><secondary>is_fundamental</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_fundamental"> is_fundamental</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_fundamental</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ fundamental type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Fundamental types include integral, floating point and void types (see also
+ <link linkend="boost_typetraits.reference.is_integral">is_integral</link>,
+ <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link>
+ and <link linkend="boost_typetraits.reference.is_void">is_void</link>)
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_fundamental</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_integral"><indexterm type="class_name"><primary>is_integral</primary><secondary>is_integral</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_integral"> is_integral</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_integral</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ integral type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p7.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_integral</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_function_pointer"><indexterm type="class_name"><primary>is_member_function_pointer</primary><secondary>is_member_function_pointer</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_member_function_pointer">
+ is_member_function_pointer</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_function_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member function then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the argument in this case is a pointer to a data member and not a member
+ function, see <link linkend="boost_typetraits.reference.is_member_object_pointer">is_member_object_pointer</link>
+ and <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_object_pointer"><indexterm type="class_name"><primary>is_member_object_pointer</primary><secondary>is_member_object_pointer</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_member_object_pointer">
+ is_member_object_pointer</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_object_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member object (a data member) then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the argument in this case is a pointer to a member function and not a
+ member object, see <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link>
+ and <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_pointer"><indexterm type="class_name"><primary>is_member_pointer</primary><secondary>is_member_pointer</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_member_pointer"> is_member_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member (either a function or a data member) then inherits from
+ <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_object"><indexterm type="class_name"><primary>is_object</primary><secondary>is_object</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_object"> is_object</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_object</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ object type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ All types are object types except references, void, and function types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p9.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_object</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: reference types are not
+ objects
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: function types are not
+ objects
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ void is not an object type
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_pod">
+ <title><link linkend="boost_typetraits.reference.is_pod"> is_pod</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_pod</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ POD type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ POD stands for "Plain old data". Arithmetic types, and enumeration
+ types, a pointers and pointer to members are all PODs. Classes and unions
+ can also be POD's if they have no non-static data members that are of reference
+ or non-POD type, no user defined constructors, no user defined assignment
+ operators, no private or protected non-static data members, no virtual functions
+ and no base classes. Finally, a cv-qualified POD is still a POD, as is an
+ array of PODs.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10 and 9p4 (Note
+ that POD's are also aggregates, see 8.5.1).
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, is<emphasis role="underline">pod
+ will never report that a class or struct is a POD; this is always safe, if
+ possibly sub-optimal. Currently (May 2005) only MWCW 9 and Visual C++ 8 have
+ the necessary compiler-</emphasis>_intrinsics.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pod</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_pointer"><indexterm type="class_name"><primary>is_pointer</primary><secondary>is_pointer</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_pointer"> is_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer type (includes function pointers, but excludes pointers to members)
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2p2 and 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <important>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase></computeroutput> detects "real"
+ pointer types only, and <emphasis>not</emphasis> smart pointers. Users
+ should not specialise <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase></computeroutput>
+ for smart pointer types, as doing so may cause Boost (and other third party)
+ code to fail to function correctly. Users wanting a trait to detect smart
+ pointers should create their own. However, note that there is no way in
+ general to auto-magically detect smart pointer types, so such a trait would
+ have to be partially specialised for each supported smart pointer type.
+ </para>
+ </important>
+ </section>
+ <section id="boost_typetraits.reference.is_polymorphic"><indexterm type="class_name"><primary>is_polymorphic</primary><secondary>is_polymorphic</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_polymorphic"> is_polymorphic</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_polymorphic</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ polymorphic type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> The implementation
+ requires some knowledge of the compilers ABI, it does actually seem to work
+ with the majority of compilers though.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_polymorphic</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">poly</phrase><phrase role="special">{</phrase> <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">poly</phrase><phrase role="special">();</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_same"><indexterm type="class_name"><primary>is_same</primary><secondary>is_same</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_same"> is_same</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_same</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T and U are the same types
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_same</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with abstract, incomplete or function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_scalar"><indexterm type="class_name"><primary>is_scalar</primary><secondary>is_scalar</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_scalar"> is_scalar</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_scalar</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ scalar type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Scalar types include integral, floating point, enumeration, pointer, and
+ pointer-to-member types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_scalar</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_signed"><indexterm type="class_name"><primary>is_signed</primary><secondary>is_signed</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_signed"> is_signed</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_signed</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an signed integer type
+ or an enumerated type with an underlying signed integer type, then inherits
+ from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1, 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_signed</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myclass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ whose value depends upon the signedness of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_stateless">
+ <title><link linkend="boost_typetraits.reference.is_stateless"> is_stateless</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_stateless</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Ff T is a stateless type then
+ inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ Type T must be a complete type.
+ </para>
+ <para>
+ A stateless type is a type that has no storage and whose constructors and
+ destructors are trivial. That means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_stateless</phrase></computeroutput>
+ only inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the following expression is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput>:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_stateless</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, is_stateless will
+ never report that a class or struct is stateless; this is always safe, if
+ possibly sub-optimal. Currently (May 2005) only MWCW 9 and Visual C++ 8 have
+ the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to make this template work automatically.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.is_reference"><indexterm type="class_name"><primary>is_reference</primary><secondary>is_reference</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_reference"> is_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_reference</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a reference pointer type
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ may report the wrong result for function types, and for types that are both
+ const and volatile qualified.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(&amp;)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis> (the argument in this case
+ is a reference to a function).
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_union"><indexterm type="class_name"><primary>is_union</primary><secondary>is_union</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_union"> is_union</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_union</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ union type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Currently requires some kind of compiler support, otherwise unions are identified
+ as classes.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 9.5.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Without (some as
+ yet unspecified) help from the compiler, we cannot distinguish between union
+ and class types using only standard C++, as a result this type will never
+ inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ unless the user explicitly specializes the template for their user-defined
+ union types, or unless the compiler supplies some unspecified intrinsic that
+ implements this functionality. Currently (May 2005) only Visual C++ 8 has
+ the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to make this trait "just work" without user intervention.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_union</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_unsigned"><indexterm type="class_name"><primary>is_unsigned</primary><secondary>is_unsigned</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_unsigned"> is_unsigned</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_unsigned</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an unsigned integer type
+ or an enumerated type with an underlying unsigned integer type, then inherits
+ from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1, 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_unsigned</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myclass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ whose value depends upon the signedness of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">long</phrase>
+ <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_void"><indexterm type="class_name"><primary>is_void</primary><secondary>is_void</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_void"> is_void</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_void</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ void type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p9.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_void</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_volatile"><indexterm type="class_name"><primary>is_volatile</primary><secondary>is_volatile</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.is_volatile"> is_volatile</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_volatile</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (top level) volatile-qualified
+ type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">volatile</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase>
+ <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the volatile qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.make_signed"><indexterm type="class_name"><primary>make_signed</primary><secondary>make_signed</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.make_signed"> make_signed</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">make_signed</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If T is a signed integer type then
+ the same type as T, if T is an unsigned integer type then the corresponding
+ signed type. Otherwise if T is an enumerated or character type (char or wchar_t)
+ then a signed integer type with the same width as T.
+ </para>
+ <para>
+ If T has any cv-qualifiers then these are also present on the result type.
+ </para>
+ <para>
+ <emphasis role="bold">Requires:</emphasis> T must be an integer or enumerated
+ type, and must not be the type bool.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">make_signed</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">long</phrase>
+ <phrase role="keyword">long</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A signed integer type with the same width as the enum.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">wchar_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A signed integer type with the same width as wchar_t.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.make_unsigned"><indexterm type="class_name"><primary>make_unsigned</primary><secondary>make_unsigned</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.make_unsigned"> make_unsigned</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">make_unsigned</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If T is a unsigned integer type then
+ the same type as T, if T is an signed integer type then the corresponding
+ unsigned type. Otherwise if T is an enumerated or character type (char or
+ wchar_t) then an unsigned integer type with the same width as T.
+ </para>
+ <para>
+ If T has any cv-qualifiers then these are also present on the result type.
+ </para>
+ <para>
+ <emphasis role="bold">Requires:</emphasis> T must be an integer or enumerated
+ type, and must not be the type bool.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">make_unsigned</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An unsigned integer type with the same width as the enum.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">wchar_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An unsigned integer type with the same width as wchar_t.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.promote"><indexterm type="class_name"><primary>promote</primary><secondary>promote</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.promote"> promote</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">promote</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If integral or floating point promotion
+ can be applied to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ then applies integral and floating point promotions to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ See also <link linkend="boost_typetraits.reference.integral_promotion">integral_promotion</link>
+ and <link linkend="boost_typetraits.reference.floating_point_promotion">floating_point_promotion</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.5 except 4.5/3
+ (integral bit-field) and 4.6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">promote</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.rank"><indexterm type="class_name"><primary>integral_constant</primary><secondary>rank</secondary></indexterm><indexterm><primary>rank</primary><secondary>integral_constant</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.rank"> rank</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">rank</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template rank inherits from
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> is the
+ number of array dimensions in type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not an array type,
+ then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> is zero.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">rank</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[]&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">3</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>1</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>2</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.remove_all_extents"><indexterm type="class_name"><primary>remove_all_extents</primary><secondary>remove_all_extents</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.remove_all_extents"> remove_all_extents</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_all_extents</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is an array type, then removes all of the array bounds on <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_all_extents</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_const"><indexterm type="class_name"><primary>remove_const</primary><secondary>remove_const</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.remove_const"> remove_const</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> const-qualifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_cv"><indexterm type="class_name"><primary>remove_cv</primary><secondary>remove_cv</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.remove_cv"> remove_cv</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_cv</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> cv-qualifiers removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_cv</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_extent"><indexterm type="class_name"><primary>remove_extent</primary><secondary>remove_extent</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.remove_extent"> remove_extent</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_extent</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is an array type, then removes the topmost array bound, otherwise leaves
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_extent</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">]</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_pointer"><indexterm type="class_name"><primary>remove_pointer</primary><secondary>remove_pointer</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.remove_pointer"> remove_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_pointer</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any pointer modifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">**&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_reference"><indexterm type="class_name"><primary>remove_reference</primary><secondary>remove_reference</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.remove_reference"> remove_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_reference</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any reference modifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_volatile"><indexterm type="class_name"><primary>remove_volatile</primary><secondary>remove_volatile</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.remove_volatile"> remove_volatile</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> volatile-qualifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.type_with_alignment"><indexterm type="class_name"><primary>type_with_alignment</primary><secondary>type_with_alignment</secondary></indexterm>
+ <title><link linkend="boost_typetraits.reference.type_with_alignment"> type_with_alignment</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">type_with_alignment</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> a built-in or POD type with an alignment
+ that is a multiple of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Align</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">type_with_alignment</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ </section>
+ <section id="boost_typetraits.credits">
+ <title><link linkend="boost_typetraits.credits"> Credits</link></title>
+ <para>
+ This documentation was pulled together by John Maddock, using <ulink url="../../../../doc/html/quickbook.html">Boost.Quickbook</ulink>
+ and <ulink url="../../../../doc/html/boostbook.html">Boost.DocBook</ulink>.
+ </para>
+ <para>
+ The original version of this library was created by Steve Cleary, Beman Dawes,
+ Howard Hinnant, and John Maddock. John Maddock is the current maintainer of
+ the library.
+ </para>
+ <para>
+ This version of type traits library is based on contributions by Adobe Systems
+ Inc, David Abrahams, Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant,
+ Jesse Jones, Mat Marcus, Itay Maman, John Maddock, Thorsten Ottosen, Robert
+ Ramey and Jeremy Siek.
+ </para>
+ <para>
+ Mat Marcus and Jesse Jones invented, and <ulink url="http://opensource.adobe.com/project4/project.shtml">published
+ a paper describing</ulink>, the partial specialization workarounds used in
+ this library.
+ </para>
+ <para>
+ Aleksey Gurtovoy added MPL integration to the library.
+ </para>
+ <para>
+ The <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link>
+ template is based on code originally devised by Andrei Alexandrescu, see "<ulink url="http://www.cuj.com/experts/1810/alexandr.htm?topic=experts">Generic&lt;Programming&gt;:
+ Mappings between Types and Values</ulink>".
+ </para>
+ <para>
+ The latest version of this library and documentation can be found at <ulink url="http://www.boost.org">www.boost.org</ulink>. Bugs, suggestions and discussion
+ should be directed to boost@lists.boost.org (see <ulink url="http://www.boost.org/more/mailing_lists.htm#main">www.boost.org/more/mailing_lists.htm#main</ulink>
+ for subscription details).
+ </para>
+ </section>
+
+ <section id="boost_typetraits.ignored_section">
+ <title>This section must not be indexed.</title>
+ <?BoostAutoIndex IgnoreSection?>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ </section>
+
+ <section id="boost_typetraits.ignored_block"><indexterm type="class_name"><primary>add_volatile</primary><secondary>This section contains one block that must not be indexed and one that should be.</secondary></indexterm><indexterm><primary>This section contains one block that must not be indexed and one that should be.</primary><secondary>add_volatile</secondary></indexterm>
+ <title>This section contains one block that must not be indexed and one that should be.</title>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">
+ <?BoostAutoIndex IgnoreBlock?>
+ template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">
+ template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ </section>
+
+
+ <index type="class_name">
+ <title>Class Index</title>
+ </index>
+ <index type="typedef_name">
+ <title>Typedef Index</title>
+ </index>
+ <index type="macro_name">
+ <title>Macro Index</title>
+ </index>
+ <index type="test_index_1">
+ <title>Index Test 1</title>
+ </index>
+ <index type="test_index_2">
+ <title>Index Test 2</title>
+ </index>
+ <index/>
+
+</chapter> \ No newline at end of file
diff --git a/src/boost/tools/auto_index/test/test2.gold b/src/boost/tools/auto_index/test/test2.gold
new file mode 100644
index 00000000..b4f7c4ea
--- /dev/null
+++ b/src/boost/tools/auto_index/test/test2.gold
@@ -0,0 +1,6671 @@
+<?xml version="1.0"?>
+<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!--
+
+This file is based upon the type traits docs, but has had additional XML elements added to it
+to ensure complete testing.
+
+-->
+
+<chapter xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" id="boost_typetraits" rev:last-revision="$Date: 2008-11-28 12:41:45 +0000 (Fri, 28 Nov 2008) $">
+ <chapterinfo><author>
+ <firstname>various</firstname> <surname>authors</surname>
+ </author><copyright>
+ <year>2000</year> <year>2006</year> <holder>Adobe Systems Inc, David Abrahams,
+ Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant, Jesse Jones, Mat
+ Marcus, Itay Maman, John Maddock, Alexander Nasonov, Thorsten Ottosen, Robert
+ Ramey and Jeremy Siek</holder>
+ </copyright><legalnotice>
+ <para>
+ Distributed under the Boost Software License, Version 1.0. (See accompanying
+ file LICENSE_1_0.txt or copy at <ulink url="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</ulink>)
+ </para>
+ </legalnotice></chapterinfo>
+ <title>Boost.TypeTraits</title>
+ <para>
+ A printer-friendly <ulink url="http://svn.boost.org/svn/boost/sandbox/pdf/type_traits/release/type_traits.pdf">PDF
+ version of this manual is also available</ulink>.
+ </para>
+ <section id="boost_typetraits.intro">
+ <title><link linkend="boost_typetraits.intro"> Introduction</link></title>
+ <para>
+ The Boost type-traits library contains a set of very specific traits classes,
+ each of which encapsulate a single trait from the C++ type system; for example,
+ is a type a pointer or a reference type? Or does a type have a trivial constructor,
+ or a const-qualifier?
+ </para>
+ <para>
+ The type-traits classes share a unified design: each class inherits from a
+ the type <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the type has the specified property and inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ otherwise.
+ </para>
+ <para>
+ The type-traits library also contains a set of classes that perform a specific
+ transformation on a type; for example, they can remove a top-level const or
+ volatile qualifier from a type. Each class that performs a transformation defines
+ a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of the transformation.
+ </para>
+ </section>
+ <section id="boost_typetraits.background">
+ <title><link linkend="boost_typetraits.background"> Background and Tutorial</link></title>
+ <para>
+ The following is an updated version of the article "C++ Type traits"
+ by John Maddock and Steve Cleary that appeared in the October 2000 issue of
+ <ulink url="http://www.ddj.com">Dr Dobb's Journal</ulink>.
+ </para>
+ <para>
+ Generic programming (writing code which works with any data type meeting a
+ set of requirements) has become the method of choice for providing reusable
+ code. However, there are times in generic programming when "generic"
+ just isn't good enough - sometimes the differences between types are too large
+ for an efficient generic implementation. This is when the traits technique
+ becomes important - by encapsulating those properties that need to be considered
+ on a type by type basis inside a traits class, we can minimize the amount of
+ code that has to differ from one type to another, and maximize the amount of
+ generic code.
+ </para>
+ <?dbfo keep-together="auto" ?>
+ <para>
+ <indexterm>
+ <primary>Foo1</primary>
+ </indexterm>
+ Consider an example: when working with character strings, one common operation
+ is to determine the length of a null terminated string. Clearly it's possible
+ to write generic code that can do this, but it turns out that there are much
+ more efficient methods available: for example, the C library functions <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">strlen</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">wcslen</phrase></computeroutput>
+ are usually written in assembler, and with suitable hardware support can be
+ considerably faster than a generic version written in C++. The authors of the
+ C++ standard library realized this, and abstracted the properties of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">wchar_t</phrase></computeroutput>
+ into the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput>.
+ Generic code that works with character strings can simply use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase><phrase role="special">&lt;&gt;::</phrase><phrase role="identifier">length</phrase></computeroutput> to determine the length of a null
+ terminated string, safe in the knowledge that specializations of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput> will use the most appropriate
+ method available to them.
+ </para>
+ <anchor id="boost_typetraits.background.type_traits"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.type_traits">Type Traits</link>
+ </bridgehead>
+ <para>
+ Class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput> is a classic
+ example of a collection of type specific properties wrapped up in a single
+ class - what Nathan Myers termed a <emphasis>baggage class</emphasis><link linkend="background.references">[1]</link>. In the Boost type-traits library,
+ we<link linkend="background.references">[2]</link> have written a set of very
+ specific traits classes, each of which encapsulate a single trait from the
+ C++ type system; for example, is a type a pointer or a reference type? Or does
+ a type have a trivial constructor, or a const-qualifier? The type-traits classes
+ share a unified design: each class inherits from a the type <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the type has the specified property and inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ otherwise. As we will show, these classes can be used in generic programming
+ to determine the properties of a given type and introduce optimizations that
+ are appropriate for that case.
+ </para>
+ <para>
+ The type-traits library also contains a set of classes that perform a specific
+ transformation on a type; for example, they can remove a top-level const or
+ volatile qualifier from a type. Each class that performs a transformation defines
+ a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of the transformation. All of the type-traits classes are
+ defined inside namespace <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase></computeroutput>;
+ for brevity, namespace-qualification is omitted in most of the code samples
+ given.
+ </para>
+ <anchor id="boost_typetraits.background.implementation"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.implementation">Implementation</link>
+ </bridgehead>
+ <para>
+ There are far too many separate classes contained in the type-traits library
+ to give a full implementation here - see the source code in the Boost library
+ for the full details - however, most of the implementation is fairly repetitive
+ anyway, so here we will just give you a flavor for how some of the classes
+ are implemented. Beginning with possibly the simplest class in the library,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits
+ from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ only if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>.
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ Here we define a primary version of the template class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_void">is_void</link></computeroutput>,
+ and provide a full-specialization when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>. While full specialization
+ of a template class is an important technique, sometimes we need a solution
+ that is halfway between a fully generic solution, and a full specialization.
+ This is exactly the situation for which the standards committee defined partial
+ template-class specialization. As an example, consider the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput>:
+ here we needed a primary version that handles all the cases where T is not
+ a pointer, and a partial specialization to handle all the cases where T is
+ a pointer:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">*&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ The syntax for partial specialization is somewhat arcane and could easily occupy
+ an article in its own right; like full specialization, in order to write a
+ partial specialization for a class, you must first declare the primary template.
+ The partial specialization contains an extra &lt;...&gt; after the class name
+ that contains the partial specialization parameters; these define the types
+ that will bind to that partial specialization rather than the default template.
+ The rules for what can appear in a partial specialization are somewhat convoluted,
+ but as a rule of thumb if you can legally write two function overloads of the
+ form:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">foo</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">);</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">foo</phrase><phrase role="special">(</phrase><phrase role="identifier">U</phrase><phrase role="special">);</phrase>
+</programlisting>
+ <para>
+ Then you can also write a partial specialization of the form:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">class</phrase> <phrase role="identifier">c</phrase><phrase role="special">{</phrase> <phrase role="comment">/*details*/</phrase> <phrase role="special">};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">class</phrase> <phrase role="identifier">c</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;{</phrase> <phrase role="comment">/*details*/</phrase> <phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ This rule is by no means foolproof, but it is reasonably simple to remember
+ and close enough to the actual rule to be useful for everyday use.
+ </para>
+ <para>
+ As a more complex example of partial specialization consider the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput>. This
+ class defines a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the same type as T but with any top-level array bounds removed; this
+ is an example of a traits class that performs a transformation on a type:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link>
+<phrase role="special">{</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">N</phrase><phrase role="special">]&gt;</phrase>
+<phrase role="special">{</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ The aim of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.remove_extent">remove_extent</link></computeroutput>
+ is this: imagine a generic algorithm that is passed an array type as a template
+ parameter, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.remove_extent">remove_extent</link></computeroutput>
+ provides a means of determining the underlying type of the array. For example
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">][</phrase><phrase role="number">5</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> would evaluate to the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">5</phrase><phrase role="special">]</phrase></computeroutput>. This example also shows that the number of
+ template parameters in a partial specialization does not have to match the
+ number in the default template. However, the number of parameters that appear
+ after the class name do have to match the number and type of the parameters
+ in the default template.
+ </para>
+ <anchor id="boost_typetraits.background.optimized_copy"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.optimized_copy">Optimized copy</link>
+ </bridgehead>
+ <para>
+ As an example of how the type traits classes can be used, consider the standard
+ library algorithm copy:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iter1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Iter2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">Iter2</phrase> <phrase role="identifier">copy</phrase><phrase role="special">(</phrase><phrase role="identifier">Iter1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter2</phrase> <phrase role="identifier">out</phrase><phrase role="special">);</phrase>
+</programlisting>
+ <para>
+ Obviously, there's no problem writing a generic version of copy that works
+ for all iterator types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput>; however, there are
+ some circumstances when the copy operation can best be performed by a call
+ to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>. In order to implement
+ copy in terms of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput> all
+ of the following conditions need to be met:
+ </para>
+ <itemizedlist>
+ <listitem>
+ Both of the iterator types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput> must be pointers.
+ </listitem>
+ <listitem>
+ Both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput> must point to the same type - excluding
+ const and volatile-qualifiers.
+ </listitem>
+ <listitem>
+ The type pointed to by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ must have a trivial assignment operator.
+ </listitem>
+ </itemizedlist>
+ <para>
+ By trivial assignment operator we mean that the type is either a scalar type<link linkend="background.references">[3]</link> or:
+ </para>
+ <itemizedlist>
+ <listitem>
+ The type has no user defined assignment operator.
+ </listitem>
+ <listitem>
+ The type does not have any data members that are references.
+ </listitem>
+ <listitem>
+ All base classes, and all data member objects must have trivial assignment
+ operators.
+ </listitem>
+ </itemizedlist>
+ <para>
+ If all these conditions are met then a type can be copied using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput> rather than using a compiler generated
+ assignment operator. The type-traits library provides a class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>,
+ such that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is true only if T has a trivial assignment
+ operator. This class "just works" for scalar types, but has to be
+ explicitly specialised for class/struct types that also happen to have a trivial
+ assignment operator. In other words if <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link>
+ gives the wrong answer, it will give the "safe" wrong answer - that
+ trivial assignment is not allowable.
+ </para>
+ <para>
+ The code for an optimized version of copy that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>
+ where appropriate is given in <link linkend="boost_typetraits.examples.copy">the
+ examples</link>. The code begins by defining a template function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">do_copy</phrase></computeroutput> that performs a "slow but safe"
+ copy. The last parameter passed to this function may be either a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ or a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">false_type</link></computeroutput>.
+ Following that there is an overload of do<emphasis role="underline">copy that
+ uses `memcpy`: this time the iterators are required to actually be pointers
+ to the same type, and the final parameter must be a `</emphasis>_true_type<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase> <phrase role="identifier">Finally</phrase><phrase role="special">,</phrase> <phrase role="identifier">the</phrase> <phrase role="identifier">version</phrase>
+ <phrase role="identifier">of</phrase> </computeroutput>copy<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="identifier">calls</phrase>
+ </computeroutput>do<emphasis role="underline">copy`, passing `</emphasis>_has_trivial_assign&lt;value_type&gt;()`
+ as the final parameter: this will dispatch to the optimized version where appropriate,
+ otherwise it will call the "slow but safe version".
+ </para>
+ <anchor id="boost_typetraits.background.was_it_worth_it_"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.was_it_worth_it_">Was it worth it?</link>
+ </bridgehead>
+ <para>
+ It has often been repeated in these columns that "premature optimization
+ is the root of all evil" <link linkend="background.references">[4]</link>.
+ So the question must be asked: was our optimization premature? To put this
+ in perspective the timings for our version of copy compared a conventional
+ generic copy<link linkend="background.references">[5]</link> are shown in table
+ 1.
+ </para>
+ <para>
+ Clearly the optimization makes a difference in this case; but, to be fair,
+ the timings are loaded to exclude cache miss effects - without this accurate
+ comparison between algorithms becomes difficult. However, perhaps we can add
+ a couple of caveats to the premature optimization rule:
+ </para>
+ <itemizedlist>
+ <listitem>
+ If you use the right algorithm for the job in the first place then optimization
+ will not be required; in some cases, memcpy is the right algorithm.
+ </listitem>
+ <listitem>
+ If a component is going to be reused in many places by many people then optimizations
+ may well be worthwhile where they would not be so for a single case - in
+ other words, the likelihood that the optimization will be absolutely necessary
+ somewhere, sometime is that much higher. Just as importantly the perceived
+ value of the stock implementation will be higher: there is no point standardizing
+ an algorithm if users reject it on the grounds that there are better, more
+ heavily optimized versions available.
+ </listitem>
+ </itemizedlist>
+ <table frame="all"> <title>Time taken to copy 1000 elements using `copy&lt;const
+ T*, T*&gt;` (times in micro-seconds)</title>
+ <tgroup cols="3">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Version
+ </para>
+ </entry><entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ Time
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ "Optimized" copy
+ </para>
+ </entry><entry>
+ <para>
+ char
+ </para>
+ </entry><entry>
+ <para>
+ 0.99
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ Conventional copy
+ </para>
+ </entry><entry>
+ <para>
+ char
+ </para>
+ </entry><entry>
+ <para>
+ 8.07
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ "Optimized" copy
+ </para>
+ </entry><entry>
+ <para>
+ int
+ </para>
+ </entry><entry>
+ <para>
+ 2.52
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ Conventional copy
+ </para>
+ </entry><entry>
+ <para>
+ int
+ </para>
+ </entry><entry>
+ <para>
+ 8.02
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table> <anchor id="boost_typetraits.background.pair_of_references"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.pair_of_references">Pair of References</link>
+ </bridgehead>
+ <para>
+ The optimized copy example shows how type traits may be used to perform optimization
+ decisions at compile-time. Another important usage of type traits is to allow
+ code to compile that otherwise would not do so unless excessive partial specialization
+ is used. This is possible by delegating partial specialization to the type
+ traits classes. Our example for this form of usage is a pair that can hold
+ references <link linkend="background.references">[6]</link>.
+ </para>
+ <para>
+ First, let us examine the definition of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">pair</phrase></computeroutput>, omitting
+ the comparison operators, default constructor, and template copy constructor
+ for simplicity:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">pair</phrase>
+<phrase role="special">{</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T1</phrase> <phrase role="identifier">first_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T2</phrase> <phrase role="identifier">second_type</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">T1</phrase> <phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+<phrase role="identifier">T2</phrase> <phrase role="identifier">second</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">pair</phrase><phrase role="special">(</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">nfirst</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T2</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase>
+<phrase role="special">:</phrase><phrase role="identifier">first</phrase><phrase role="special">(</phrase><phrase role="identifier">nfirst</phrase><phrase role="special">),</phrase> <phrase role="identifier">second</phrase><phrase role="special">(</phrase><phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">}</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ Now, this "pair" cannot hold references as it currently stands, because
+ the constructor would require taking a reference to a reference, which is currently
+ illegal <link linkend="background.references">[7]</link>. Let us consider what
+ the constructor's parameters would have to be in order to allow "pair"
+ to hold non-reference types, references, and constant references:
+ </para>
+ <table frame="all"> <title>Required Constructor Argument Types</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of parameter to initializing constructor
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ A little familiarity with the type traits classes allows us to construct a
+ single mapping that allows us to determine the type of parameter from the type
+ of the contained class. The type traits classes provide a transformation <link linkend="boost_typetraits.reference.add_reference">add_reference</link>, which
+ adds a reference to its type, unless it is already a reference.
+ </para>
+ <table frame="all"> <title>Using add_reference to synthesize the correct constructor
+ type</title>
+ <tgroup cols="3">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ const T
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ T &amp; [8]
+ </para>
+ </entry><entry>
+ <para>
+ T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ This allows us to build a primary template definition for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput>
+ that can contain non-reference types, reference types, and constant reference
+ types:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">pair</phrase>
+<phrase role="special">{</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T1</phrase> <phrase role="identifier">first_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T2</phrase> <phrase role="identifier">second_type</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">T1</phrase> <phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+<phrase role="identifier">T2</phrase> <phrase role="identifier">second</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">pair</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">nfirst</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase>
+<phrase role="special">:</phrase><phrase role="identifier">first</phrase><phrase role="special">(</phrase><phrase role="identifier">nfirst</phrase><phrase role="special">),</phrase> <phrase role="identifier">second</phrase><phrase role="special">(</phrase><phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">}</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ Add back in the standard comparison operators, default constructor, and template
+ copy constructor (which are all the same), and you have a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">pair</phrase></computeroutput> that
+ can hold reference types!
+ </para>
+ <para>
+ This same extension could have been done using partial template specialization
+ of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput>, but to specialize
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput> in this way would require
+ three partial specializations, plus the primary template. Type traits allows
+ us to define a single primary template that adjusts itself auto-magically to
+ any of these partial specializations, instead of a brute-force partial specialization
+ approach. Using type traits in this fashion allows programmers to delegate
+ partial specialization to the type traits classes, resulting in code that is
+ easier to maintain and easier to understand.
+ </para>
+ <anchor id="boost_typetraits.background.conclusion"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.conclusion">Conclusion</link>
+ </bridgehead>
+ <para>
+ We hope that in this article we have been able to give you some idea of what
+ type-traits are all about. A more complete listing of the available classes
+ are in the boost documentation, along with further examples using type traits.
+ Templates have enabled C++ uses to take the advantage of the code reuse that
+ generic programming brings; hopefully this article has shown that generic programming
+ does not have to sink to the lowest common denominator, and that templates
+ can be optimal as well as generic.
+ </para>
+ <anchor id="boost_typetraits.background.acknowledgements"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.acknowledgements">Acknowledgements</link>
+ </bridgehead>
+ <para>
+ The authors would like to thank Beman Dawes and Howard Hinnant for their helpful
+ comments when preparing this article.
+ </para>
+ <anchor id="background.references"/> <anchor id="boost_typetraits.background.references"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.references">References</link>
+ </bridgehead>
+ <orderedlist inheritnum="ignore" continuation="restarts">
+ <listitem>
+ Nathan C. Myers, C++ Report, June 1995.
+ </listitem>
+ <listitem>
+ The type traits library is based upon contributions by Steve Cleary, Beman
+ Dawes, Howard Hinnant and John Maddock: it can be found at www.boost.org.
+ </listitem>
+ <listitem>
+ A scalar type is an arithmetic type (i.e. a built-in integer or floating
+ point type), an enumeration type, a pointer, a pointer to member, or a const-
+ or volatile-qualified version of one of these types.
+ </listitem>
+ <listitem>
+ This quote is from Donald Knuth, ACM Computing Surveys, December 1974, pg
+ 268.
+ </listitem>
+ <listitem>
+ The test code is available as part of the boost utility library (see algo_opt_examples.cpp),
+ the code was compiled with gcc 2.95 with all optimisations turned on, tests
+ were conducted on a 400MHz Pentium II machine running Microsoft Windows 98.
+ </listitem>
+ <listitem>
+ John Maddock and Howard Hinnant have submitted a "compressed_pair"
+ library to Boost, which uses a technique similar to the one described here
+ to hold references. Their pair also uses type traits to determine if any
+ of the types are empty, and will derive instead of contain to conserve space
+ -- hence the name "compressed".
+ </listitem>
+ <listitem>
+ This is actually an issue with the C++ Core Language Working Group (issue
+ #106), submitted by Bjarne Stroustrup. The tentative resolution is to allow
+ a "reference to a reference to T" to mean the same thing as a "reference
+ to T", but only in template instantiation, in a method similar to multiple
+ cv-qualifiers.
+ </listitem>
+ <listitem>
+ For those of you who are wondering why this shouldn't be const-qualified,
+ remember that references are always implicitly constant (for example, you
+ can't re-assign a reference). Remember also that "const T &amp;"
+ is something completely different. For this reason, cv-qualifiers on template
+ type arguments that are references are ignored.
+ </listitem>
+ </orderedlist>
+ </section>
+ <section id="boost_typetraits.category">
+ <title><link linkend="boost_typetraits.category"> Type Traits by Category</link></title>
+ <section id="boost_typetraits.category.value_traits">
+ <title><link linkend="boost_typetraits.category.value_traits"> Type Traits
+ that Describe the Properties of a Type</link></title>
+ <para>
+ <indexterm>
+ <primary>Foo2</primary>
+ <secondary>Bar2</secondary>
+ </indexterm>
+ These traits are all <emphasis>value traits</emphasis>, which is to say the
+ traits classes all inherit from <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link>,
+ and are used to access some numerical property of a type. Often this is a
+ simple true or false Boolean value, but in a few cases may be some other
+ integer value (for example when dealing with type alignments, or array bounds:
+ see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.alignment_of">alignment_of</link></computeroutput>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.rank">rank</link></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.extent">extent</link></computeroutput>).
+ </para>
+ <section id="boost_typetraits.category.value_traits.primary">
+ <title><link linkend="boost_typetraits.category.value_traits.primary"> Categorizing
+ a Type</link></title>
+ <para>
+ These traits identify what "kind" of type some type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is. These are split into two groups:
+ primary traits which are all mutually exclusive, and composite traits that
+ are compositions of one or more primary traits.
+ </para>
+ <para>
+ For any given type, exactly one primary type trait will inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ and all the others will inherit from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>,
+ in other words these traits are mutually exclusive.
+ </para>
+ <para>
+ This means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_integral">is_integral</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ will only ever be true for built-in types; if you want to check for a user-defined
+ class type that behaves "as if" it is an integral or floating
+ point type, then use the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase>
+ <phrase role="keyword">template</phrase></computeroutput> instead.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_array">is_array</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_class">is_class</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_complex">is_complex</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_enum">is_enum</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_function">is_function</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_integral">is_integral</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_object_pointer">is_member_object_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_union">is_union</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ The following traits are made up of the union of one or more type categorizations.
+ A type may belong to more than one of these categories, in addition to
+ one of the primary categories.
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_arithmetic">is_arithmetic</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_compound">is_compound</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_fundamental">is_fundamental</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_object">is_object</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_scalar">is_scalar</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.value_traits.properties">
+ <title><link linkend="boost_typetraits.category.value_traits.properties">
+ General Type Properties</link></title>
+ <para>
+ The following templates describe the general properties of a type.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.alignment_of">alignment_of</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_assign">has_nothrow_assign</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_default_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_default_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_virtual_destructor">has_virtual_destructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_abstract">is_abstract</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_const">is_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_empty">is_empty</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_stateless">is_stateless</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_signed">is_signed</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_unsigned">is_unsigned</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_volatile">is_volatile</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.extent">extent</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.rank">rank</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.value_traits.relate">
+ <title><link linkend="boost_typetraits.category.value_traits.relate"> Relationships
+ Between Two Types</link></title>
+ <para>
+ These templates determine the whether there is a relationship between two
+ types:
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_base_of">is_base_of</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_same">is_same</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.category.transform">
+ <title><link linkend="boost_typetraits.category.transform"> Type Traits that
+ Transform One Type to Another</link></title>
+ <para>
+ The following templates transform one type to another, based upon some well-defined
+ rule. Each template has a single member called <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of applying the transformation to the template argument
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_const">add_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_cv">add_cv</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_pointer">add_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_volatile">add_volatile</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.decay">decay</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.floating_point_promotion">floating_point_promotion</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.integral_promotion">integral_promotion</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.make_signed">make_signed</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.make_unsigned">make_unsigned</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.promote">promote</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_all_extents">remove_all_extents</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_const">remove_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_cv">remove_cv</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_reference">remove_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_volatile">remove_volatile</link><phrase role="special">;</phrase>
+</programlisting>
+ <anchor id="boost_typetraits.category.transform.broken_compiler_workarounds_"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">Broken
+ Compiler Workarounds:</link>
+ </bridgehead>
+ <para>
+ For all of these templates support for partial specialization of class templates
+ is required to correctly implement the transformation. On the other hand,
+ practice shows that many of the templates from this category are very useful,
+ and often essential for implementing some generic libraries. Lack of these
+ templates is often one of the major limiting factors in porting those libraries
+ to compilers that do not yet support this language feature. As some of these
+ compilers are going to be around for a while, and at least one of them is
+ very wide-spread, it was decided that the library should provide workarounds
+ where possible.
+ </para>
+ <para>
+ The basic idea behind the workaround is to manually define full specializations
+ of all type transformation templates for all fundamental types, and all their
+ 1st and 2nd rank cv-[un]qualified derivative pointer types, and to provide
+ a user-level macro that will define all the explicit specializations needed
+ for any user-defined type T.
+ </para>
+ <para>
+ The first part guarantees the successful compilation of something like this:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="special">...</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+</programlisting>
+ <para>
+ and the second part provides the library's users with a mechanism to make
+ the above code work not only for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput> or other built-in type,
+ but for their own types as well:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">myspace</phrase><phrase role="special">{</phrase>
+ <phrase role="keyword">struct</phrase> <phrase role="identifier">MyClass</phrase> <phrase role="special">{};</phrase>
+<phrase role="special">}</phrase>
+<phrase role="comment">// declare this at global scope:
+</phrase><phrase role="identifier">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase><phrase role="special">(</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">)</phrase>
+<phrase role="comment">// transformations on myspace::MyClass now work:
+</phrase><phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="comment">// etc.
+</phrase></programlisting>
+ <para>
+ Note that the macro BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION evaluates
+ to nothing on those compilers that <emphasis role="bold">do</emphasis> support
+ partial specialization.
+ </para>
+ </section>
+ <section id="boost_typetraits.category.alignment">
+ <title><link linkend="boost_typetraits.category.alignment"> Synthesizing Types
+ with Specific Alignments</link></title>
+ <para>
+ Some low level memory management routines need to synthesize a POD type with
+ specific alignment properties. The template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.type_with_alignment">type_with_alignment</link></computeroutput>
+ finds the smallest type with a specified alignment, while template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.aligned_storage">aligned_storage</link></computeroutput>
+ creates a type with a specific size and alignment.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.type_with_alignment">type_with_alignment</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Size</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.aligned_storage">aligned_storage</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.function">
+ <title><link linkend="boost_typetraits.category.function"> Decomposing Function
+ Types</link></title>
+ <para>
+ The class template <link linkend="boost_typetraits.reference.function_traits">function_traits</link>
+ extracts information from function types (see also <link linkend="boost_typetraits.reference.is_function">is_function</link>).
+ This traits class allows you to tell how many arguments a function takes,
+ what those argument types are, and what the return type is.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.function_traits">function_traits</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.user_defined">
+ <title><link linkend="boost_typetraits.user_defined"> User Defined Specializations</link></title>
+ <para>
+ Occationally the end user may need to provide their own specialization for
+ one of the type traits - typically where intrinsic compiler support is required
+ to implement a specific trait fully. These specializations should derive from
+ boost::<link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ or boost::<link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ as appropriate:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pod</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+<phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_class</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+<phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_union</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+
+<phrase role="keyword">struct</phrase> <phrase role="identifier">my_pod</phrase><phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">my_union</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">char</phrase> <phrase role="identifier">c</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_pod</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_union">is_union</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_class">is_class</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.intrinsics">
+ <title><link linkend="boost_typetraits.intrinsics"> Support for Compiler Intrinsics</link></title>
+ <para>
+ There are some traits that can not be implemented within the current C++ language:
+ to make these traits "just work" with user defined types, some kind
+ of additional help from the compiler is required. Currently (April 2008) Visual
+ C++ 8 and 9, GNU GCC 4.3 and MWCW 9 provide the necessary intrinsics, and other
+ compilers will no doubt follow in due course.
+ </para>
+ <para>
+ The Following traits classes always need compiler support to do the right thing
+ for all types (but all have safe fallback positions if this support is unavailable):
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_union">is_union</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_pod">is_pod</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_assign">has_nothrow_assign</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_virtual_destructor">has_virtual_destructor</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The following traits classes can't be portably implemented in the C++ language,
+ although in practice, the implementations do in fact do the right thing on
+ all the compilers we know about:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_empty">is_empty</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The following traits classes are dependent on one or more of the above:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_class">is_class</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_stateless">is_stateless</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The hooks for compiler-intrinsic support are defined in <ulink url="../../../../boost/type_traits/intrinsics.hpp">boost/type_traits/intrinsics.hpp</ulink>,
+ adding support for new compilers is simply a matter of defining one of more
+ of the following macros:
+ </para>
+ <table frame="all"> <title>Macros for Compiler Intrinsics</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_UNION(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a union type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_POD(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a POD type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_EMPTY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is an empty struct or union
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_CONSTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if the default constructor for T is trivial (i.e.
+ has no effect)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_COPY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial copy constructor (and can
+ therefore be replaced by a call to memcpy)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_ASSIGN(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial assignment operator (and can
+ therefore be replaced by a call to memcpy)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_DESTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial destructor (i.e. ~T() has
+ no effect)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_CONSTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="identifier">x</phrase><phrase role="special">;</phrase></computeroutput>
+ can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_COPY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase><phrase role="special">(</phrase><phrase role="identifier">t</phrase><phrase role="special">)</phrase></computeroutput> can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_ASSIGN(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="identifier">t</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">u</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">t</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">u</phrase></computeroutput> can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_VIRTUAL_DESTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true T has a virtual destructor
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_ABSTRACT(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is an abstract type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_BASE_OF(T,U)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a base class of U
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_CLASS(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a class type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_CONVERTIBLE(T,U)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is convertible to U
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_ENUM(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true is T is an enum
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_POLYMORPHIC(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a polymorphic type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_ALIGNMENT_OF(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to the alignment requirements of type T.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.mpl">
+ <title><link linkend="boost_typetraits.mpl"> MPL Interoperability</link></title>
+ <para>
+ All the value based traits in this library conform to MPL's requirements for
+ an <ulink url="../../../../libs/mpl/doc/refmanual/integral-constant.html">Integral
+ Constant type</ulink>: that includes a number of rather intrusive workarounds
+ for broken compilers.
+ </para>
+ <para>
+ Purely as an implementation detail, this means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/bool.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">true_</phrase></computeroutput></ulink>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">false_type</link></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/bool.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">false_</phrase></computeroutput></ulink>,
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">v</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/integral-c.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">integral_c</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">v</phrase><phrase role="special">&gt;</phrase></computeroutput></ulink>
+ (provided <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>)
+ </para>
+ </section>
+ <section id="boost_typetraits.examples">
+ <title><link linkend="boost_typetraits.examples"> Examples</link></title>
+ <section id="boost_typetraits.examples.copy">
+ <title><link linkend="boost_typetraits.examples.copy"> An Optimized Version
+ of std::copy</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">copy</phrase></computeroutput>
+ that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>
+ to determine whether to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>
+ to optimise the copy operation (see <ulink url="../../examples/copy_example.cpp">copy_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// opt::copy
+</phrase><phrase role="comment">// same semantics as std::copy
+</phrase><phrase role="comment">// calls memcpy where appropriate.
+</phrase><phrase role="comment">//
+</phrase>
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">I2</phrase> <phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">out</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">out</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">out</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">memcpy</phrase><phrase role="special">(</phrase><phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="special">(</phrase><phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">)*</phrase><phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">));</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">out</phrase><phrase role="special">+(</phrase><phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">copy</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">out</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// We can copy with memcpy if T has a trivial assignment operator,
+</phrase> <phrase role="comment">// and if the iterator arguments are actually pointers (this last
+</phrase> <phrase role="comment">// requirement we detect with overload resolution):
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">&lt;</phrase><phrase role="identifier">value_type</phrase><phrase role="special">&gt;());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.fill">
+ <title><link linkend="boost_typetraits.examples.fill"> An Optimised Version
+ of std::fill</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">fill</phrase></computeroutput>
+ that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>
+ to determine whether to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memset</phrase></computeroutput>
+ to optimise the fill operation (see <ulink url="../../examples/fill_example.cpp">fill_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// fill
+</phrase><phrase role="comment">// same as std::fill, but uses memset where appropriate
+</phrase><phrase role="comment">//
+</phrase><phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">first</phrase> <phrase role="special">=</phrase> <phrase role="identifier">val</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">memset</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">I</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">fill</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// We can do an optimised fill if T has a trivial assignment
+</phrase> <phrase role="comment">// operator and if it's size is one:
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase>
+ <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="special">(</phrase><phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">)&gt;</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.destruct">
+ <title><link linkend="boost_typetraits.examples.destruct"> An Example that
+ Omits Destructor Calls For Types with Trivial Destructors</link></title>
+ <para>
+ Demonstrates a simple algorithm that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">__has_trivial_destruct</phrase></computeroutput>
+ to determine whether to destructors need to be called (see <ulink url="../../examples/trivial_destructor_example.cpp">trivial_destructor_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// algorithm destroy_array:
+</phrase><phrase role="comment">// The reverse of std::unitialized_copy, takes a block of
+</phrase><phrase role="comment">// initialized memory and calls destructors on all objects therein.
+</phrase><phrase role="comment">//
+</phrase>
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="identifier">first</phrase><phrase role="special">-&gt;~</phrase><phrase role="identifier">T</phrase><phrase role="special">();</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase> <phrase role="comment">// namespace detail
+</phrase>
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">p1</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">p2</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">p1</phrase><phrase role="special">,</phrase> <phrase role="identifier">p2</phrase><phrase role="special">,</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.iter">
+ <title><link linkend="boost_typetraits.examples.iter"> An improved Version
+ of std::iter_swap</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iter_swap</phrase></computeroutput>
+ that use type traits to determine whether an it's arguments are proxying
+ iterators or not, if they're not then it just does a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">swap</phrase></computeroutput>
+ of it's dereferenced arguments (the same as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iter_swap</phrase></computeroutput>
+ does), however if they are proxying iterators then takes special care over
+ the swap to ensure that the algorithm works correctly for both proxying iterators,
+ and even iterators of different types (see <ulink url="../../examples/iter_swap_example.cpp">iter_swap_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// iter_swap:
+</phrase><phrase role="comment">// tests whether iterator is a proxying iterator or not, and
+</phrase><phrase role="comment">// uses optimal form accordingly:
+</phrase><phrase role="comment">//
+</phrase><phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">v_t</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">v_t</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">one</phrase><phrase role="special">;</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">one</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">two</phrase><phrase role="special">;</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">two</phrase> <phrase role="special">=</phrase> <phrase role="identifier">v</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">using</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">swap</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">swap</phrase><phrase role="special">(*</phrase><phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="special">*</phrase><phrase role="identifier">two</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">iter_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">two</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// See is both arguments are non-proxying iterators,
+</phrase> <phrase role="comment">// and if both iterator the same type:
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">r1_t</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I2</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">r2_t</phrase><phrase role="special">;</phrase>
+
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase>
+ <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">&lt;</phrase><phrase role="identifier">r1_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">&lt;</phrase><phrase role="identifier">r2_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_same">is_same</link><phrase role="special">&lt;</phrase><phrase role="identifier">r1_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">r2_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">;</phrase>
+
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.to_double">
+ <title><link linkend="boost_typetraits.examples.to_double"> Convert Numeric
+ Types and Enums to double</link></title>
+ <para>
+ Demonstrates a conversion of <ulink url="../../../../libs/numeric/conversion/doc/html/boost_numericconversion/definitions.html#boost_numericconversion.definitions.numeric_types">Numeric
+ Types</ulink> and enum types to double:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">double</phrase> <phrase role="identifier">to_double</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">promoted</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric</phrase><phrase role="special">::</phrase><phrase role="identifier">converter</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase><phrase role="identifier">promoted</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">convert</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.reference">
+ <title><link linkend="boost_typetraits.reference"> Alphabetical Reference</link></title>
+ <section id="boost_typetraits.reference.add_const">
+ <title><link linkend="boost_typetraits.reference.add_const"> add_const</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ <secondary>two</secondary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">const</phrase></computeroutput> for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_cv">
+ <title><link linkend="boost_typetraits.reference.add_cv"> add_cv</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ <secondary>two</secondary>
+ <tertiary>three</tertiary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_cv</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_cv</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_pointer">
+ <title><link linkend="boost_typetraits.reference.add_pointer"> add_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_pointer</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">*</phrase></computeroutput>.
+ </para>
+ <para>
+ The rationale for this template is that it produces the same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">TYPEOF</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">t</phrase><phrase role="special">)</phrase></computeroutput>, where
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t</phrase></computeroutput> is an object of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">**</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">**</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_reference">
+ <title><link linkend="boost_typetraits.reference.add_reference"> add_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_reference</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is not a reference type then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase></computeroutput>, otherwise <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_volatile">
+ <title><link linkend="boost_typetraits.reference.add_volatile"> add_volatile</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput> for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.aligned_storage">
+ <title><link linkend="boost_typetraits.reference.aligned_storage"> aligned_storage</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Size</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">aligned_storage</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> a built-in or POD type with size
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Size</phrase></computeroutput> and an alignment that
+ is a multiple of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Align</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">aligned_storage</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.alignment_of">
+ <title><link linkend="boost_typetraits.reference.alignment_of"> alignment_of</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">alignment_of</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template alignment<emphasis role="underline">of inherits from `</emphasis>_integral_constant&lt;std::size_t,
+ ALIGNOF(T)&gt;<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">,</phrase> <phrase role="identifier">where</phrase>
+ </computeroutput>ALIGNOF(T)` is the alignment of type T.
+ </para>
+ <para>
+ <emphasis>Note: strictly speaking you should only rely on the value of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> being
+ a multiple of the true alignment of T, although in practice it does compute
+ the correct value in all the cases we know about.</emphasis>
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">alignment_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ with value <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.decay">
+ <title><link linkend="boost_typetraits.reference.decay"> decay</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">decay</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> Let <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>
+ be the result of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>, then if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>
+ is an array type, the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;*</phrase></computeroutput>,
+ otherwise if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput> is a function
+ type then the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase><phrase role="special">*</phrase></computeroutput>, otherwise the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">decay</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">(&amp;)[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">(&amp;)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.extent">
+ <title><link linkend="boost_typetraits.reference.extent"> extent</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">extent</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template extent inherits
+ from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)&gt;</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)</phrase></computeroutput> is the number of elements in the N'th array
+ dimention of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not an array type,
+ or if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">N</phrase> <phrase role="special">&gt;</phrase>
+ <link linkend="boost_typetraits.reference.rank">rank</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>, or if the N'th array bound is incomplete,
+ then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)</phrase></computeroutput> is zero.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">extent</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">],</phrase>
+ <phrase role="number">1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">3</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>4</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">],</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>2</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.floating_point_promotion">
+ <title><link linkend="boost_typetraits.reference.floating_point_promotion">
+ floating_point_promotion</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">floating_point_promotion</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If floating point promotion can be
+ applied to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ then applies floating point promotion to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">float</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.function_traits">
+ <title><link linkend="boost_typetraits.reference.function_traits"> function_traits</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">F</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">function_traits</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">static</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">arity</phrase> <phrase role="special">=</phrase> <replaceable>see-below</replaceable><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">result_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> arg<replaceable>N</replaceable>_type<phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ The class template function_traits will only compile if:
+ </para>
+ <itemizedlist>
+ <listitem>
+ The compiler supports partial specialization of class templates.
+ </listitem>
+ <listitem>
+ The template argument <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>
+ is a <emphasis>function type</emphasis>, note that this <emphasis><emphasis role="bold">is not</emphasis></emphasis> the same thing as a <emphasis>pointer
+ to a function</emphasis>.
+ </listitem>
+ </itemizedlist>
+ <tip>
+ <para>
+ function_traits is intended to introspect only C++ functions of the form
+ R (), R( A1 ), R ( A1, ... etc. ) and not function pointers or class member
+ functions. To convert a function pointer type to a suitable type use <link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link>.
+ </para>
+ </tip>
+ <table frame="all"> <title>Function Traits Members</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Member
+ </para>
+ </entry><entry>
+ <para>
+ Description
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that gives the number of arguments
+ accepted by the function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type returned by function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase>arg<replaceable>N</replaceable>_type</computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The <replaceable>N</replaceable>th argument type of function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase> <phrase role="special">&lt;=</phrase>
+ <phrase role="identifier">N</phrase> <phrase role="special">&lt;=</phrase>
+ <phrase role="identifier">arity</phrase></computeroutput> of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table> <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 0.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 1.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 4.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">long</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arg1_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arg4_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase><phrase role="special">*</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arg5_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A compiler error: there is no <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">arg5_type</phrase></computeroutput>
+ since there are only four arguments.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A compiler error: argument type is a <emphasis>function pointer</emphasis>,
+ and not a <emphasis>function type</emphasis>.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_assign">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_assign"> has_nothrow_assign</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_assign</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing assignment-operator then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_assign</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing assignment-operator;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler support to ensure that this trait "just
+ works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_assign</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_constructor">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_constructor">
+ has_nothrow_constructor</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_default_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing default-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_constructor</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing default-constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to ensure that this trait "just works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_constructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_copy">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_copy"> has_nothrow_copy</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_copy</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_copy_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing copy-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_copy</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing copy-constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to ensure that this trait "just works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_copy</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_cp_cons">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_cp_cons"> has_nothrow_copy_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_no_throw_def_cons">
+ <title><link linkend="boost_typetraits.reference.has_no_throw_def_cons"> has_nothrow_default_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_assign">
+ <title><link linkend="boost_typetraits.reference.has_trivial_assign"> has_trivial_assign</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_assign</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial assignment-operator then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ If a type has a trivial assignment-operator then the operator has the same
+ effect as copying the bits of one object to the other: calls to the operator
+ can be safely replaced with a call to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_assign
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.8p11.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_constructor">
+ <title><link linkend="boost_typetraits.reference.has_trivial_constructor">
+ has_trivial_constructor</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_default_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial default-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ If a type has a trivial default-constructor then the constructor have no
+ effect: calls to the constructor can be safely omitted. Note that using meta-programming
+ to omit a call to a single trivial-constructor call is of no benefit whatsoever.
+ However, if loops and/or exception handling code can also be omitted, then
+ some benefit in terms of code size and speed can be obtained.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_constructor
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.1p6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_copy">
+ <title><link linkend="boost_typetraits.reference.has_trivial_copy"> has_trivial_copy</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_copy</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_copy_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial copy-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ If a type has a trivial copy-constructor then the constructor has the same
+ effect as copying the bits of one object to the other: calls to the constructor
+ can be safely replaced with a call to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_copy
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.8p6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_cp_cons">
+ <title><link linkend="boost_typetraits.reference.has_trivial_cp_cons"> has_trivial_copy_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_def_cons">
+ <title><link linkend="boost_typetraits.reference.has_trivial_def_cons"> has_trivial_default_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_destructor">
+ <title><link linkend="boost_typetraits.reference.has_trivial_destructor"> has_trivial_destructor</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_destructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial destructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ If a type has a trivial destructor then the destructor has no effect: calls
+ to the destructor can be safely omitted. Note that using meta-programming
+ to omit a call to a single trivial-constructor call is of no benefit whatsoever.
+ However, if loops and/or exception handling code can also be omitted, then
+ some benefit in terms of code size and speed can be obtained.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_destructor
+ will never report that a user-defined class or struct has a trivial destructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.4p3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_virtual_destructor">
+ <title><link linkend="boost_typetraits.reference.has_virtual_destructor"> has_virtual_destructor</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_virtual_destructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a virtual destructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> This trait is provided
+ for completeness, since it's part of the Technical Report on C++ Library
+ Extensions. However, there is currently no way to portably implement this
+ trait. The default version provided always inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>,
+ and has to be explicitly specialized for types with virtual destructors unless
+ the compiler used has compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ that enable the trait to do the right thing: currently (May 2005) only Visual
+ C++ 8 and GCC-4.3 have the necessary <link linkend="boost_typetraits.intrinsics">intrinsics</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.4.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_virtual_destructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.integral_constant">
+ <title><link linkend="boost_typetraits.reference.integral_constant"> integral_constant</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">val</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">integral_constant</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">static</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">val</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="keyword">true</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">true_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="keyword">false</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">false_type</phrase><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ Class template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_constant</phrase></computeroutput>
+ is the common base class for all the value-based type traits. The two typedef's
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">true_type</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">false_type</phrase></computeroutput> are provided for convenience:
+ most of the value traits are Boolean properties and so will inherit from
+ one of these.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.integral_promotion">
+ <title><link linkend="boost_typetraits.reference.integral_promotion"> integral_promotion</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">integral_promotion</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If integral promotion can be applied
+ to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>, then
+ applies integral promotion to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.5 except 4.5/3
+ (integral bit-field).
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">integral_promotion</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">enum</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">float_round_style</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.is_abstract">
+ <title><link linkend="boost_typetraits.reference.is_abstract"> is_abstract</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_abstract</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ abstract type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_abstract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> The compiler must
+ support DR337 (as of April 2005: GCC 3.4, VC++ 7.1 (and later), Intel C++
+ 7 (and later), and Comeau 4.3.2). Otherwise behaves the same as <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link>;
+ this is the "safe fallback position" for which polymorphic types
+ are always regarded as potentially abstract. The macro BOOST_NO_IS_ABSTRACT
+ is used to signify that the implementation is buggy, users should check for
+ this in their own code if the "safe fallback" is not suitable for
+ their particular use-case.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">abc</phrase><phrase role="special">{</phrase> <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">abc</phrase><phrase role="special">()</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_arithmetic">
+ <title><link linkend="boost_typetraits.reference.is_arithmetic"> is_arithmetic</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_arithmetic</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ arithmetic type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Arithmetic types include integral and floating point types (see also <link linkend="boost_typetraits.reference.is_integral">is_integral</link> and
+ <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link>).
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p8.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_arithmetic</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_array">
+ <title><link linkend="boost_typetraits.reference.is_array"> is_array</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_array</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ array type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_array</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can give the wrong result with function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_base_of">
+ <title><link linkend="boost_typetraits.reference.is_base_of"> is_base_of</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_base_of</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If Base is base class of type
+ Derived or if both types are the same then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ This template will detect non-public base classes, and ambiguous base classes.
+ </para>
+ <para>
+ Note that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">X</phrase><phrase role="special">,</phrase><phrase role="identifier">X</phrase><phrase role="special">&gt;</phrase></computeroutput> will always inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>.
+ <emphasis role="bold">This is the case even if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">X</phrase></computeroutput>
+ is not a class type</emphasis>. This is a change in behaviour from Boost-1.33
+ in order to track the Technical Report on C++ Library Extensions.
+ </para>
+ <para>
+ Types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput> must not be incomplete types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_base_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types. There are some older compilers which
+ will produce compiler errors if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput>
+ is a private base class of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput>,
+ or if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput> is an ambiguous
+ base of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput>. These compilers
+ include Borland C++, older versions of Sun Forte C++, Digital Mars C++, and
+ older versions of EDG based compilers.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">{};</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase> <phrase role="special">:</phrase>
+ <phrase role="keyword">public</phrase> <phrase role="identifier">Base</phrase><phrase role="special">{};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Base</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>: a class is regarded as it's
+ own base.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_class">
+ <title><link linkend="boost_typetraits.reference.is_class"> is_class</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_class</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ class type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 9.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_class</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Without (some as
+ yet unspecified) help from the compiler, we cannot distinguish between union
+ and class types, as a result this type will erroneously inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link> for
+ union types. See also <link linkend="boost_typetraits.reference.is_union">is_union</link>.
+ Currently (May 2005) only Visual C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to correctly identify union types, and therefore make is_class function correctly.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">MyClass</phrase><phrase role="special">;</phrase></computeroutput> then:
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_complex">
+ <title><link linkend="boost_typetraits.reference.is_complex"> is_complex</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_complex</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is a complex number type then true (of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">complex</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ for some type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>), otherwise
+ false.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 26.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_complex</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.is_compound">
+ <title><link linkend="boost_typetraits.reference.is_compound"> is_compound</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_compound</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ compound type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Any type that is not a fundamental type is a compound type (see also <link linkend="boost_typetraits.reference.is_fundamental">is_fundamental</link>).
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_compound</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyEnum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_const">
+ <title><link linkend="boost_typetraits.reference.is_const"> is_const</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_const</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (top level) const-qualified
+ type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the const-qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the const-qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_convertible">
+ <title><link linkend="boost_typetraits.reference.is_convertible"> is_convertible</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_convertible</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If an imaginary lvalue of type
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">From</phrase></computeroutput> is convertible to type
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput> then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ Type From must not be an incomplete type.
+ </para>
+ <para>
+ Type To must not be an incomplete, or function type.
+ </para>
+ <para>
+ No types are considered to be convertible to array types or abstract-class
+ types.
+ </para>
+ <para>
+ This template can not detect whether a converting-constructor is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput> or not: if type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput>
+ has a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput> converting constructor
+ from type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">From</phrase></computeroutput> then instantiating
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ will produce a compiler error. For this reason <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase></computeroutput>
+ can not be used to determine whether a type has a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
+ copy-constructor or not.
+ </para>
+ <para>
+ This template will also produce compiler errors if the conversion is ambiguous,
+ for example:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">B</phrase> <phrase role="special">:</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">C</phrase> <phrase role="special">:</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">D</phrase> <phrase role="special">:</phrase> <phrase role="identifier">B</phrase><phrase role="special">,</phrase> <phrase role="identifier">C</phrase> <phrase role="special">{};</phrase>
+<phrase role="comment">// This produces a compiler error, the conversion is ambiguous:
+</phrase><phrase role="keyword">bool</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">y</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">D</phrase><phrase role="special">*,</phrase><phrase role="identifier">A</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4 and 8.5.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> This template is
+ currently broken with Borland C++ Builder 5 (and earlier), for constructor-based
+ conversions, and for the Metrowerks 7 (and earlier) compiler in all cases.
+ If the compiler does not support <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_abstract">is_abstract</link></computeroutput>,
+ then the template parameter <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput>
+ must not be an abstract type.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_convertible</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*,</phrase> <phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the conversion would require a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const_cast</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;,</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_empty">
+ <title><link linkend="boost_typetraits.reference.is_empty"> is_empty</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_empty</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an empty class type then
+ inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10p5.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> In order to correctly
+ detect empty classes this trait relies on either:
+ </para>
+ <itemizedlist>
+ <listitem>
+ the compiler implementing zero sized empty base classes, or
+ </listitem>
+ <listitem>
+ the compiler providing <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect empty classes.
+ </listitem>
+ </itemizedlist>
+ <para>
+ Can not be used with incomplete types.
+ </para>
+ <para>
+ Can not be used with union types, until is_union can be made to work.
+ </para>
+ <para>
+ If the compiler does not support partial-specialization of class templates,
+ then this template can not be used with abstract types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">empty_class</phrase>
+ <phrase role="special">{};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_enum">
+ <title><link linkend="boost_typetraits.reference.is_enum"> is_enum</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_enum</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ enum type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_enum</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Requires a correctly
+ functioning <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link>
+ template; this means that is_enum is currently broken under Borland C++ Builder
+ 5, and for the Metrowerks compiler prior to version 8, other compilers should
+ handle this template just fine.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">enum</phrase> <phrase role="identifier">my_enum</phrase>
+ <phrase role="special">{</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">two</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_floating_point">
+ <title><link linkend="boost_typetraits.reference.is_floating_point"> is_floating_point</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_floating_point</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ floating point type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p8.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_floating_point</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_function">
+ <title><link linkend="boost_typetraits.reference.is_function"> is_function</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_function</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ function type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Note that this template does not detect <emphasis>pointers to functions</emphasis>,
+ or <emphasis>references to functions</emphasis>, these are detected by <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link> and <link linkend="boost_typetraits.reference.is_reference">is_reference</link> respectively:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">f1</phrase><phrase role="special">();</phrase> <phrase role="comment">// f1 is of function type.
+</phrase><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">f2</phrase><phrase role="special">*)();</phrase> <phrase role="comment">// f2 is a pointer to a function.
+</phrase><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">f3</phrase><phrase role="special">&amp;)();</phrase> <phrase role="comment">// f3 is a reference to a function.
+</phrase></programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2p1 and 8.3.5.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_function</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a pointer type, not a function type.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(&amp;)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a reference to a function, not a function type.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a pointer to a member function.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <tip>
+ <para>
+ Don't confuse function-types with pointers to functions:
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">);</phrase></computeroutput>
+ </para>
+ <para>
+ defines a function type,
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase> <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ declares a prototype for a function of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase></computeroutput>,
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase><phrase role="special">*</phrase>
+ <phrase role="identifier">pf</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase><phrase role="special">&amp;</phrase>
+ <phrase role="identifier">fr</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ declares a pointer and a reference to the function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">foo</phrase></computeroutput>.
+ </para>
+ <para>
+ If you want to detect whether some type is a pointer-to-function then use:
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_function">is_function</link><phrase role="special">&lt;</phrase><link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ </para>
+ <para>
+ or for pointers to member functions you can just use <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link>
+ directly.
+ </para>
+ </tip>
+ </section>
+ <section id="boost_typetraits.reference.is_fundamental">
+ <title><link linkend="boost_typetraits.reference.is_fundamental"> is_fundamental</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_fundamental</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ fundamental type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Fundamental types include integral, floating point and void types (see also
+ <link linkend="boost_typetraits.reference.is_integral">is_integral</link>,
+ <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link>
+ and <link linkend="boost_typetraits.reference.is_void">is_void</link>)
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_fundamental</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_integral">
+ <title><link linkend="boost_typetraits.reference.is_integral"> is_integral</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_integral</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ integral type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p7.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_integral</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_function_pointer">
+ <title><link linkend="boost_typetraits.reference.is_member_function_pointer">
+ is_member_function_pointer</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_function_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member function then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the argument in this case is a pointer to a data member and not a member
+ function, see <link linkend="boost_typetraits.reference.is_member_object_pointer">is_member_object_pointer</link>
+ and <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_object_pointer">
+ <title><link linkend="boost_typetraits.reference.is_member_object_pointer">
+ is_member_object_pointer</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_object_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member object (a data member) then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the argument in this case is a pointer to a member function and not a
+ member object, see <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link>
+ and <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_pointer">
+ <title><link linkend="boost_typetraits.reference.is_member_pointer"> is_member_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member (either a function or a data member) then inherits from
+ <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_object">
+ <title><link linkend="boost_typetraits.reference.is_object"> is_object</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_object</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ object type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ All types are object types except references, void, and function types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p9.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_object</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: reference types are not
+ objects
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: function types are not
+ objects
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ void is not an object type
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_pod">
+ <title><link linkend="boost_typetraits.reference.is_pod"> is_pod</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_pod</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ POD type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ POD stands for "Plain old data". Arithmetic types, and enumeration
+ types, a pointers and pointer to members are all PODs. Classes and unions
+ can also be POD's if they have no non-static data members that are of reference
+ or non-POD type, no user defined constructors, no user defined assignment
+ operators, no private or protected non-static data members, no virtual functions
+ and no base classes. Finally, a cv-qualified POD is still a POD, as is an
+ array of PODs.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10 and 9p4 (Note
+ that POD's are also aggregates, see 8.5.1).
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, is<emphasis role="underline">pod
+ will never report that a class or struct is a POD; this is always safe, if
+ possibly sub-optimal. Currently (May 2005) only MWCW 9 and Visual C++ 8 have
+ the necessary compiler-</emphasis>_intrinsics.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pod</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_pointer">
+ <title><link linkend="boost_typetraits.reference.is_pointer"> is_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer type (includes function pointers, but excludes pointers to members)
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2p2 and 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <important>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase></computeroutput> detects "real"
+ pointer types only, and <emphasis>not</emphasis> smart pointers. Users
+ should not specialise <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase></computeroutput>
+ for smart pointer types, as doing so may cause Boost (and other third party)
+ code to fail to function correctly. Users wanting a trait to detect smart
+ pointers should create their own. However, note that there is no way in
+ general to auto-magically detect smart pointer types, so such a trait would
+ have to be partially specialised for each supported smart pointer type.
+ </para>
+ </important>
+ </section>
+ <section id="boost_typetraits.reference.is_polymorphic">
+ <title><link linkend="boost_typetraits.reference.is_polymorphic"> is_polymorphic</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_polymorphic</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ polymorphic type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> The implementation
+ requires some knowledge of the compilers ABI, it does actually seem to work
+ with the majority of compilers though.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_polymorphic</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">poly</phrase><phrase role="special">{</phrase> <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">poly</phrase><phrase role="special">();</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_same">
+ <title><link linkend="boost_typetraits.reference.is_same"> is_same</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_same</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T and U are the same types
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_same</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with abstract, incomplete or function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_scalar">
+ <title><link linkend="boost_typetraits.reference.is_scalar"> is_scalar</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_scalar</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ scalar type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Scalar types include integral, floating point, enumeration, pointer, and
+ pointer-to-member types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_scalar</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_signed">
+ <title><link linkend="boost_typetraits.reference.is_signed"> is_signed</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_signed</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an signed integer type
+ or an enumerated type with an underlying signed integer type, then inherits
+ from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1, 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_signed</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myclass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ whose value depends upon the signedness of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_stateless">
+ <title><link linkend="boost_typetraits.reference.is_stateless"> is_stateless</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_stateless</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Ff T is a stateless type then
+ inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ Type T must be a complete type.
+ </para>
+ <para>
+ A stateless type is a type that has no storage and whose constructors and
+ destructors are trivial. That means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_stateless</phrase></computeroutput>
+ only inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the following expression is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput>:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_stateless</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, is_stateless will
+ never report that a class or struct is stateless; this is always safe, if
+ possibly sub-optimal. Currently (May 2005) only MWCW 9 and Visual C++ 8 have
+ the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to make this template work automatically.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.is_reference">
+ <title><link linkend="boost_typetraits.reference.is_reference"> is_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_reference</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a reference pointer type
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ may report the wrong result for function types, and for types that are both
+ const and volatile qualified.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(&amp;)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis> (the argument in this case
+ is a reference to a function).
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_union">
+ <title><link linkend="boost_typetraits.reference.is_union"> is_union</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_union</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ union type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Currently requires some kind of compiler support, otherwise unions are identified
+ as classes.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 9.5.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Without (some as
+ yet unspecified) help from the compiler, we cannot distinguish between union
+ and class types using only standard C++, as a result this type will never
+ inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ unless the user explicitly specializes the template for their user-defined
+ union types, or unless the compiler supplies some unspecified intrinsic that
+ implements this functionality. Currently (May 2005) only Visual C++ 8 has
+ the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to make this trait "just work" without user intervention.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_union</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_unsigned">
+ <title><link linkend="boost_typetraits.reference.is_unsigned"> is_unsigned</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_unsigned</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an unsigned integer type
+ or an enumerated type with an underlying unsigned integer type, then inherits
+ from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1, 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_unsigned</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myclass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ whose value depends upon the signedness of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">long</phrase>
+ <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_void">
+ <title><link linkend="boost_typetraits.reference.is_void"> is_void</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_void</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ void type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p9.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_void</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_volatile">
+ <title><link linkend="boost_typetraits.reference.is_volatile"> is_volatile</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_volatile</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (top level) volatile-qualified
+ type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">volatile</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase>
+ <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the volatile qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.make_signed">
+ <title><link linkend="boost_typetraits.reference.make_signed"> make_signed</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">make_signed</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If T is a signed integer type then
+ the same type as T, if T is an unsigned integer type then the corresponding
+ signed type. Otherwise if T is an enumerated or character type (char or wchar_t)
+ then a signed integer type with the same width as T.
+ </para>
+ <para>
+ If T has any cv-qualifiers then these are also present on the result type.
+ </para>
+ <para>
+ <emphasis role="bold">Requires:</emphasis> T must be an integer or enumerated
+ type, and must not be the type bool.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">make_signed</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">long</phrase>
+ <phrase role="keyword">long</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A signed integer type with the same width as the enum.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">wchar_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A signed integer type with the same width as wchar_t.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.make_unsigned">
+ <title><link linkend="boost_typetraits.reference.make_unsigned"> make_unsigned</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">make_unsigned</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If T is a unsigned integer type then
+ the same type as T, if T is an signed integer type then the corresponding
+ unsigned type. Otherwise if T is an enumerated or character type (char or
+ wchar_t) then an unsigned integer type with the same width as T.
+ </para>
+ <para>
+ If T has any cv-qualifiers then these are also present on the result type.
+ </para>
+ <para>
+ <emphasis role="bold">Requires:</emphasis> T must be an integer or enumerated
+ type, and must not be the type bool.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">make_unsigned</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An unsigned integer type with the same width as the enum.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">wchar_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An unsigned integer type with the same width as wchar_t.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.promote">
+ <title><link linkend="boost_typetraits.reference.promote"> promote</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">promote</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If integral or floating point promotion
+ can be applied to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ then applies integral and floating point promotions to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ See also <link linkend="boost_typetraits.reference.integral_promotion">integral_promotion</link>
+ and <link linkend="boost_typetraits.reference.floating_point_promotion">floating_point_promotion</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.5 except 4.5/3
+ (integral bit-field) and 4.6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">promote</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.rank">
+ <title><link linkend="boost_typetraits.reference.rank"> rank</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">rank</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template rank inherits from
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> is the
+ number of array dimensions in type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not an array type,
+ then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> is zero.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">rank</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[]&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">3</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>1</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>2</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.remove_all_extents">
+ <title><link linkend="boost_typetraits.reference.remove_all_extents"> remove_all_extents</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_all_extents</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is an array type, then removes all of the array bounds on <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_all_extents</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_const">
+ <title><link linkend="boost_typetraits.reference.remove_const"> remove_const</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> const-qualifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_cv">
+ <title><link linkend="boost_typetraits.reference.remove_cv"> remove_cv</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_cv</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> cv-qualifiers removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_cv</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_extent">
+ <title><link linkend="boost_typetraits.reference.remove_extent"> remove_extent</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_extent</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is an array type, then removes the topmost array bound, otherwise leaves
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_extent</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">]</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_pointer">
+ <title><link linkend="boost_typetraits.reference.remove_pointer"> remove_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_pointer</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any pointer modifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">**&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_reference">
+ <title><link linkend="boost_typetraits.reference.remove_reference"> remove_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_reference</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any reference modifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_volatile">
+ <title><link linkend="boost_typetraits.reference.remove_volatile"> remove_volatile</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> volatile-qualifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.type_with_alignment">
+ <title><link linkend="boost_typetraits.reference.type_with_alignment"> type_with_alignment</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">type_with_alignment</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> a built-in or POD type with an alignment
+ that is a multiple of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Align</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">type_with_alignment</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ </section>
+ <section id="boost_typetraits.credits">
+ <title><link linkend="boost_typetraits.credits"> Credits</link></title>
+ <para>
+ This documentation was pulled together by John Maddock, using <ulink url="../../../../doc/html/quickbook.html">Boost.Quickbook</ulink>
+ and <ulink url="../../../../doc/html/boostbook.html">Boost.DocBook</ulink>.
+ </para>
+ <para>
+ The original version of this library was created by Steve Cleary, Beman Dawes,
+ Howard Hinnant, and John Maddock. John Maddock is the current maintainer of
+ the library.
+ </para>
+ <para>
+ This version of type traits library is based on contributions by Adobe Systems
+ Inc, David Abrahams, Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant,
+ Jesse Jones, Mat Marcus, Itay Maman, John Maddock, Thorsten Ottosen, Robert
+ Ramey and Jeremy Siek.
+ </para>
+ <para>
+ Mat Marcus and Jesse Jones invented, and <ulink url="http://opensource.adobe.com/project4/project.shtml">published
+ a paper describing</ulink>, the partial specialization workarounds used in
+ this library.
+ </para>
+ <para>
+ Aleksey Gurtovoy added MPL integration to the library.
+ </para>
+ <para>
+ The <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link>
+ template is based on code originally devised by Andrei Alexandrescu, see "<ulink url="http://www.cuj.com/experts/1810/alexandr.htm?topic=experts">Generic&lt;Programming&gt;:
+ Mappings between Types and Values</ulink>".
+ </para>
+ <para>
+ The latest version of this library and documentation can be found at <ulink url="http://www.boost.org">www.boost.org</ulink>. Bugs, suggestions and discussion
+ should be directed to boost@lists.boost.org (see <ulink url="http://www.boost.org/more/mailing_lists.htm#main">www.boost.org/more/mailing_lists.htm#main</ulink>
+ for subscription details).
+ </para>
+ </section>
+
+ <section id="boost_typetraits.ignored_section">
+ <title>This section must not be indexed.</title>
+ <?BoostAutoIndex IgnoreSection?>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ </section>
+
+ <section id="boost_typetraits.ignored_block">
+ <title>This section contains one block that must not be indexed and one that should be.</title>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">
+ <?BoostAutoIndex IgnoreBlock?>
+ template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">
+ template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ </section>
+
+
+ <section>
+ <title>Class Index</title>
+ <para><link linkend="idx_id_0">A</link> <link linkend="idx_id_2">C</link> <link linkend="idx_id_3">D</link> <link linkend="idx_id_4">E</link> <link linkend="idx_id_5">F</link> <link linkend="idx_id_6">H</link> <link linkend="idx_id_7">I</link> <link linkend="idx_id_8">M</link> <link linkend="idx_id_9">O</link> <link linkend="idx_id_10">P</link> <link linkend="idx_id_11">R</link> <link linkend="idx_id_13">T</link></para><variablelist><varlistentry id="idx_id_0"><term>A</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-0">add_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_cv"><phrase role="index-entry-level-0">add_cv</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_pointer"><phrase role="index-entry-level-0">add_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_reference"><phrase role="index-entry-level-0">add_reference</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">add_volatile</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.add_volatile"><phrase role="index-entry-level-1">add_volatile</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.ignored_block"><phrase role="index-entry-level-1">This section contains one block that must not be indexed and one that should be.</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.aligned_storage"><phrase role="index-entry-level-0">aligned_storage</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-0">alignment_of</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_2"><term>C</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">Constrained Index Term</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-1">add_const</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_3"><term>D</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.decay"><phrase role="index-entry-level-0">decay</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_4"><term>E</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-0">extent</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_5"><term>F</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.floating_point_promotion"><phrase role="index-entry-level-0">floating_point_promotion</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-0">function_traits</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_6"><term>H</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_assign"><phrase role="index-entry-level-0">has_nothrow_assign</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-0">has_nothrow_constructor</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-0">has_nothrow_copy</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_copy_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-1">has_nothrow_copy</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_default_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-1">has_nothrow_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_assign"><phrase role="index-entry-level-0">has_trivial_assign</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-0">has_trivial_copy</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_copy_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-1">has_trivial_copy</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_default_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_constructor"><phrase role="index-entry-level-1">has_trivial_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_destructor"><phrase role="index-entry-level-0">has_trivial_destructor</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_virtual_destructor"><phrase role="index-entry-level-0">has_virtual_destructor</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_7"><term>I</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">integral_constant</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-1">alignment_of</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-1">extent</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.rank"><phrase role="index-entry-level-1">rank</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_promotion"><phrase role="index-entry-level-0">integral_promotion</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_abstract"><phrase role="index-entry-level-0">is_abstract</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_arithmetic"><phrase role="index-entry-level-0">is_arithmetic</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_array"><phrase role="index-entry-level-0">is_array</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_base_of"><phrase role="index-entry-level-0">is_base_of</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_class</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_class"><phrase role="index-entry-level-1">is_class</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">User Defined Specializations</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_complex"><phrase role="index-entry-level-0">is_complex</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_compound"><phrase role="index-entry-level-0">is_compound</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_const"><phrase role="index-entry-level-0">is_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_convertible"><phrase role="index-entry-level-0">is_convertible</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_empty"><phrase role="index-entry-level-0">is_empty</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_enum"><phrase role="index-entry-level-0">is_enum</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_floating_point"><phrase role="index-entry-level-0">is_floating_point</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_function"><phrase role="index-entry-level-0">is_function</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_fundamental"><phrase role="index-entry-level-0">is_fundamental</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_integral"><phrase role="index-entry-level-0">is_integral</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_function_pointer"><phrase role="index-entry-level-0">is_member_function_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_object_pointer"><phrase role="index-entry-level-0">is_member_object_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_pointer"><phrase role="index-entry-level-0">is_member_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_object"><phrase role="index-entry-level-0">is_object</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_pointer</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_pointer"><phrase role="index-entry-level-1">is_pointer</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_polymorphic"><phrase role="index-entry-level-0">is_polymorphic</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_reference"><phrase role="index-entry-level-0">is_reference</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_same"><phrase role="index-entry-level-0">is_same</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_scalar"><phrase role="index-entry-level-0">is_scalar</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_signed"><phrase role="index-entry-level-0">is_signed</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_union</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_union"><phrase role="index-entry-level-1">is_union</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">User Defined Specializations</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_unsigned"><phrase role="index-entry-level-0">is_unsigned</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_void</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_void"><phrase role="index-entry-level-1">is_void</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_volatile"><phrase role="index-entry-level-0">is_volatile</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_8"><term>M</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.make_signed"><phrase role="index-entry-level-0">make_signed</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.make_unsigned"><phrase role="index-entry-level-0">make_unsigned</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_9"><term>O</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">one</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_volatile"><phrase role="index-entry-level-1">add_volatile</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-1">two</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-2">add_const</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-2">three</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_cv"><phrase role="index-entry-level-3">add_cv</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_10"><term>P</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.promote"><phrase role="index-entry-level-0">promote</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_11"><term>R</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.remove_all_extents"><phrase role="index-entry-level-0">remove_all_extents</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_const"><phrase role="index-entry-level-0">remove_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_cv"><phrase role="index-entry-level-0">remove_cv</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">remove_extent</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.remove_extent"><phrase role="index-entry-level-1">remove_extent</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_pointer"><phrase role="index-entry-level-0">remove_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_reference"><phrase role="index-entry-level-0">remove_reference</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_volatile"><phrase role="index-entry-level-0">remove_volatile</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_13"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.type_with_alignment"><phrase role="index-entry-level-0">type_with_alignment</phrase></link></para></listitem></itemizedlist></listitem></varlistentry></variablelist></section>
+ <section>
+ <title>Typedef Index</title>
+ <para><link linkend="idx_id_21">F</link> <link linkend="idx_id_27">R</link> <link linkend="idx_id_29">T</link> <link linkend="idx_id_31">V</link></para><variablelist><varlistentry id="idx_id_21"><term>F</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">false_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_27"><term>R</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">result_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-1">function_traits</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_29"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">true_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_31"><term>V</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">value_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.examples.copy"><phrase role="index-entry-level-1">An Optimized Version of std::copy</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></section>
+ <section>
+ <title>Macro Index</title>
+ <para><link linkend="idx_id_33">B</link></para><variablelist><varlistentry id="idx_id_33"><term>B</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">BOOST_ALIGNMENT_OF</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.category.transform"><phrase role="index-entry-level-1">Type Traits that Transform One Type to Another</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_ASSIGN</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_CONSTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_COPY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_ASSIGN</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_CONSTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_COPY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_DESTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_VIRTUAL_DESTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_ABSTRACT</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_BASE_OF</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_CLASS</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_CONVERTIBLE</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_EMPTY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_ENUM</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_POD</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_POLYMORPHIC</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_UNION</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></section>
+ <section>
+ <title>Index Test 1</title>
+ <para><link linkend="idx_id_61">T</link></para><variablelist><varlistentry id="idx_id_61"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">type-traits</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intro"><phrase role="index-entry-level-1">Introduction</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></section>
+ <section>
+ <title>Index Test 2</title>
+ <para><link linkend="idx_id_77">T</link></para><variablelist><varlistentry id="idx_id_77"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">type-traits</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></section>
+ <section><title>Index</title><para><link linkend="idx_id_80">A</link> <link linkend="idx_id_81">B</link> <link linkend="idx_id_82">C</link> <link linkend="idx_id_83">D</link> <link linkend="idx_id_84">E</link> <link linkend="idx_id_85">F</link> <link linkend="idx_id_86">H</link> <link linkend="idx_id_87">I</link> <link linkend="idx_id_88">M</link> <link linkend="idx_id_89">O</link> <link linkend="idx_id_90">P</link> <link linkend="idx_id_91">R</link> <link linkend="idx_id_92">S</link> <link linkend="idx_id_93">T</link> <link linkend="idx_id_94">U</link> <link linkend="idx_id_95">V</link></para><variablelist><varlistentry id="idx_id_80"><term>A</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">add_const</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-1">add_const</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-1">Constrained Index Term</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.add_cv"><phrase role="index-entry-level-0">add_cv</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_pointer"><phrase role="index-entry-level-0">add_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_reference"><phrase role="index-entry-level-0">add_reference</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">add_volatile</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.add_volatile"><phrase role="index-entry-level-1">add_volatile</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.ignored_block"><phrase role="index-entry-level-1">This section contains one block that must not be indexed and one that should be.</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.aligned_storage"><phrase role="index-entry-level-0">aligned_storage</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">alignment_of</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-1">alignment_of</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_81"><term>B</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">Background and Tutorial</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">is_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">is_void</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">remove_extent</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">type-traits</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_ALIGNMENT_OF</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.category.transform"><phrase role="index-entry-level-1">Type Traits that Transform One Type to Another</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_ASSIGN</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_CONSTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_COPY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_ASSIGN</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_CONSTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_COPY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_DESTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_VIRTUAL_DESTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_ABSTRACT</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_BASE_OF</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_CLASS</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_CONVERTIBLE</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_EMPTY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_ENUM</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_POD</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_POLYMORPHIC</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_UNION</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_82"><term>C</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">Constrained Index Term</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-1">add_const</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_83"><term>D</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.decay"><phrase role="index-entry-level-0">decay</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_84"><term>E</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">extent</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-1">extent</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_85"><term>F</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">false_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.floating_point_promotion"><phrase role="index-entry-level-0">floating_point_promotion</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">Foo1</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">Foo2</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-1">Bar2</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.category.value_traits"><phrase role="index-entry-level-2">Type Traits that Describe the Properties of a Type</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">function_traits</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-1">function_traits</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-1">result_type</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_86"><term>H</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_assign"><phrase role="index-entry-level-0">has_nothrow_assign</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-1">has_nothrow_constructor</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-1">has_nothrow_default_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_copy</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-1">has_nothrow_copy</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-1">has_nothrow_copy_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_copy_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-1">has_nothrow_copy</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_default_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-1">has_nothrow_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_assign"><phrase role="index-entry-level-0">has_trivial_assign</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_constructor"><phrase role="index-entry-level-1">has_trivial_default_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_copy</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-1">has_trivial_copy</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-1">has_trivial_copy_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_copy_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-1">has_trivial_copy</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_default_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_constructor"><phrase role="index-entry-level-1">has_trivial_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_destructor"><phrase role="index-entry-level-0">has_trivial_destructor</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_virtual_destructor"><phrase role="index-entry-level-0">has_virtual_destructor</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_87"><term>I</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">integral_constant</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-1">alignment_of</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-1">extent</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">false_type</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.rank"><phrase role="index-entry-level-1">rank</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">true_type</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">value_type</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_promotion"><phrase role="index-entry-level-0">integral_promotion</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">Introduction</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intro"><phrase role="index-entry-level-1">type-traits</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_abstract"><phrase role="index-entry-level-0">is_abstract</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_arithmetic"><phrase role="index-entry-level-0">is_arithmetic</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_array"><phrase role="index-entry-level-0">is_array</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_base_of"><phrase role="index-entry-level-0">is_base_of</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_class</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_class"><phrase role="index-entry-level-1">is_class</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">User Defined Specializations</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_complex"><phrase role="index-entry-level-0">is_complex</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_compound"><phrase role="index-entry-level-0">is_compound</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_const"><phrase role="index-entry-level-0">is_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_convertible"><phrase role="index-entry-level-0">is_convertible</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_empty"><phrase role="index-entry-level-0">is_empty</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_enum"><phrase role="index-entry-level-0">is_enum</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_floating_point"><phrase role="index-entry-level-0">is_floating_point</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_function"><phrase role="index-entry-level-0">is_function</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_fundamental"><phrase role="index-entry-level-0">is_fundamental</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_integral"><phrase role="index-entry-level-0">is_integral</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_function_pointer"><phrase role="index-entry-level-0">is_member_function_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_object_pointer"><phrase role="index-entry-level-0">is_member_object_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_pointer"><phrase role="index-entry-level-0">is_member_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_object"><phrase role="index-entry-level-0">is_object</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_pointer</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_pointer"><phrase role="index-entry-level-1">is_pointer</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_polymorphic"><phrase role="index-entry-level-0">is_polymorphic</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_reference"><phrase role="index-entry-level-0">is_reference</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_same"><phrase role="index-entry-level-0">is_same</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_scalar"><phrase role="index-entry-level-0">is_scalar</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_signed"><phrase role="index-entry-level-0">is_signed</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_union</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_union"><phrase role="index-entry-level-1">is_union</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">User Defined Specializations</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_unsigned"><phrase role="index-entry-level-0">is_unsigned</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_void</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_void"><phrase role="index-entry-level-1">is_void</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_volatile"><phrase role="index-entry-level-0">is_volatile</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_88"><term>M</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.make_signed"><phrase role="index-entry-level-0">make_signed</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.make_unsigned"><phrase role="index-entry-level-0">make_unsigned</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_89"><term>O</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">one</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_volatile"><phrase role="index-entry-level-1">add_volatile</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-1">two</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-2">add_const</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-2">three</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_cv"><phrase role="index-entry-level-3">add_cv</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">Optimized Version of std::copy</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.examples.copy"><phrase role="index-entry-level-1">value_type</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_90"><term>P</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.promote"><phrase role="index-entry-level-0">promote</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_91"><term>R</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">rank</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.rank"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_all_extents"><phrase role="index-entry-level-0">remove_all_extents</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_const"><phrase role="index-entry-level-0">remove_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_cv"><phrase role="index-entry-level-0">remove_cv</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">remove_extent</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.remove_extent"><phrase role="index-entry-level-1">remove_extent</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_pointer"><phrase role="index-entry-level-0">remove_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_reference"><phrase role="index-entry-level-0">remove_reference</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_volatile"><phrase role="index-entry-level-0">remove_volatile</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">result_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-1">function_traits</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_92"><term>S</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">Support for Compiler Intrinsics</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_ALIGNMENT_OF</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_NOTHROW_ASSIGN</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_NOTHROW_CONSTRUCTOR</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_NOTHROW_COPY</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_TRIVIAL_ASSIGN</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_TRIVIAL_CONSTRUCTOR</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_TRIVIAL_COPY</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_TRIVIAL_DESTRUCTOR</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_VIRTUAL_DESTRUCTOR</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_ABSTRACT</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_BASE_OF</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_CLASS</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_CONVERTIBLE</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_EMPTY</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_ENUM</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_POD</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_POLYMORPHIC</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_UNION</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_93"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">This section contains one block that must not be indexed and one that should be.</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.ignored_block"><phrase role="index-entry-level-1">add_volatile</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">true_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">Type Traits that Transform One Type to Another</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.category.transform"><phrase role="index-entry-level-1">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">type-traits</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intro"><phrase role="index-entry-level-1">Introduction</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.type_with_alignment"><phrase role="index-entry-level-0">type_with_alignment</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_94"><term>U</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">User Defined Specializations</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">is_class</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">is_union</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_95"><term>V</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">value_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.examples.copy"><phrase role="index-entry-level-1">An Optimized Version of std::copy</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></section>
+
+</chapter> \ No newline at end of file
diff --git a/src/boost/tools/auto_index/test/test3.gold b/src/boost/tools/auto_index/test/test3.gold
new file mode 100644
index 00000000..2da88c93
--- /dev/null
+++ b/src/boost/tools/auto_index/test/test3.gold
@@ -0,0 +1,6671 @@
+<?xml version="1.0"?>
+<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!--
+
+This file is based upon the type traits docs, but has had additional XML elements added to it
+to ensure complete testing.
+
+-->
+
+<chapter xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" id="boost_typetraits" rev:last-revision="$Date: 2008-11-28 12:41:45 +0000 (Fri, 28 Nov 2008) $">
+ <chapterinfo><author>
+ <firstname>various</firstname> <surname>authors</surname>
+ </author><copyright>
+ <year>2000</year> <year>2006</year> <holder>Adobe Systems Inc, David Abrahams,
+ Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant, Jesse Jones, Mat
+ Marcus, Itay Maman, John Maddock, Alexander Nasonov, Thorsten Ottosen, Robert
+ Ramey and Jeremy Siek</holder>
+ </copyright><legalnotice>
+ <para>
+ Distributed under the Boost Software License, Version 1.0. (See accompanying
+ file LICENSE_1_0.txt or copy at <ulink url="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</ulink>)
+ </para>
+ </legalnotice></chapterinfo>
+ <title>Boost.TypeTraits</title>
+ <para>
+ A printer-friendly <ulink url="http://svn.boost.org/svn/boost/sandbox/pdf/type_traits/release/type_traits.pdf">PDF
+ version of this manual is also available</ulink>.
+ </para>
+ <section id="boost_typetraits.intro">
+ <title><link linkend="boost_typetraits.intro"> Introduction</link></title>
+ <para>
+ The Boost type-traits library contains a set of very specific traits classes,
+ each of which encapsulate a single trait from the C++ type system; for example,
+ is a type a pointer or a reference type? Or does a type have a trivial constructor,
+ or a const-qualifier?
+ </para>
+ <para>
+ The type-traits classes share a unified design: each class inherits from a
+ the type <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the type has the specified property and inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ otherwise.
+ </para>
+ <para>
+ The type-traits library also contains a set of classes that perform a specific
+ transformation on a type; for example, they can remove a top-level const or
+ volatile qualifier from a type. Each class that performs a transformation defines
+ a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of the transformation.
+ </para>
+ </section>
+ <section id="boost_typetraits.background">
+ <title><link linkend="boost_typetraits.background"> Background and Tutorial</link></title>
+ <para>
+ The following is an updated version of the article "C++ Type traits"
+ by John Maddock and Steve Cleary that appeared in the October 2000 issue of
+ <ulink url="http://www.ddj.com">Dr Dobb's Journal</ulink>.
+ </para>
+ <para>
+ Generic programming (writing code which works with any data type meeting a
+ set of requirements) has become the method of choice for providing reusable
+ code. However, there are times in generic programming when "generic"
+ just isn't good enough - sometimes the differences between types are too large
+ for an efficient generic implementation. This is when the traits technique
+ becomes important - by encapsulating those properties that need to be considered
+ on a type by type basis inside a traits class, we can minimize the amount of
+ code that has to differ from one type to another, and maximize the amount of
+ generic code.
+ </para>
+ <?dbfo keep-together="auto" ?>
+ <para>
+ <indexterm>
+ <primary>Foo1</primary>
+ </indexterm>
+ Consider an example: when working with character strings, one common operation
+ is to determine the length of a null terminated string. Clearly it's possible
+ to write generic code that can do this, but it turns out that there are much
+ more efficient methods available: for example, the C library functions <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">strlen</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">wcslen</phrase></computeroutput>
+ are usually written in assembler, and with suitable hardware support can be
+ considerably faster than a generic version written in C++. The authors of the
+ C++ standard library realized this, and abstracted the properties of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">wchar_t</phrase></computeroutput>
+ into the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput>.
+ Generic code that works with character strings can simply use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase><phrase role="special">&lt;&gt;::</phrase><phrase role="identifier">length</phrase></computeroutput> to determine the length of a null
+ terminated string, safe in the knowledge that specializations of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput> will use the most appropriate
+ method available to them.
+ </para>
+ <anchor id="boost_typetraits.background.type_traits"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.type_traits">Type Traits</link>
+ </bridgehead>
+ <para>
+ Class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput> is a classic
+ example of a collection of type specific properties wrapped up in a single
+ class - what Nathan Myers termed a <emphasis>baggage class</emphasis><link linkend="background.references">[1]</link>. In the Boost type-traits library,
+ we<link linkend="background.references">[2]</link> have written a set of very
+ specific traits classes, each of which encapsulate a single trait from the
+ C++ type system; for example, is a type a pointer or a reference type? Or does
+ a type have a trivial constructor, or a const-qualifier? The type-traits classes
+ share a unified design: each class inherits from a the type <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the type has the specified property and inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ otherwise. As we will show, these classes can be used in generic programming
+ to determine the properties of a given type and introduce optimizations that
+ are appropriate for that case.
+ </para>
+ <para>
+ The type-traits library also contains a set of classes that perform a specific
+ transformation on a type; for example, they can remove a top-level const or
+ volatile qualifier from a type. Each class that performs a transformation defines
+ a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of the transformation. All of the type-traits classes are
+ defined inside namespace <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase></computeroutput>;
+ for brevity, namespace-qualification is omitted in most of the code samples
+ given.
+ </para>
+ <anchor id="boost_typetraits.background.implementation"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.implementation">Implementation</link>
+ </bridgehead>
+ <para>
+ There are far too many separate classes contained in the type-traits library
+ to give a full implementation here - see the source code in the Boost library
+ for the full details - however, most of the implementation is fairly repetitive
+ anyway, so here we will just give you a flavor for how some of the classes
+ are implemented. Beginning with possibly the simplest class in the library,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits
+ from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ only if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>.
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ Here we define a primary version of the template class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_void">is_void</link></computeroutput>,
+ and provide a full-specialization when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>. While full specialization
+ of a template class is an important technique, sometimes we need a solution
+ that is halfway between a fully generic solution, and a full specialization.
+ This is exactly the situation for which the standards committee defined partial
+ template-class specialization. As an example, consider the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput>:
+ here we needed a primary version that handles all the cases where T is not
+ a pointer, and a partial specialization to handle all the cases where T is
+ a pointer:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">*&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ The syntax for partial specialization is somewhat arcane and could easily occupy
+ an article in its own right; like full specialization, in order to write a
+ partial specialization for a class, you must first declare the primary template.
+ The partial specialization contains an extra &lt;...&gt; after the class name
+ that contains the partial specialization parameters; these define the types
+ that will bind to that partial specialization rather than the default template.
+ The rules for what can appear in a partial specialization are somewhat convoluted,
+ but as a rule of thumb if you can legally write two function overloads of the
+ form:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">foo</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">);</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">foo</phrase><phrase role="special">(</phrase><phrase role="identifier">U</phrase><phrase role="special">);</phrase>
+</programlisting>
+ <para>
+ Then you can also write a partial specialization of the form:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">class</phrase> <phrase role="identifier">c</phrase><phrase role="special">{</phrase> <phrase role="comment">/*details*/</phrase> <phrase role="special">};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">class</phrase> <phrase role="identifier">c</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;{</phrase> <phrase role="comment">/*details*/</phrase> <phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ This rule is by no means foolproof, but it is reasonably simple to remember
+ and close enough to the actual rule to be useful for everyday use.
+ </para>
+ <para>
+ As a more complex example of partial specialization consider the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput>. This
+ class defines a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the same type as T but with any top-level array bounds removed; this
+ is an example of a traits class that performs a transformation on a type:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link>
+<phrase role="special">{</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">N</phrase><phrase role="special">]&gt;</phrase>
+<phrase role="special">{</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ The aim of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.remove_extent">remove_extent</link></computeroutput>
+ is this: imagine a generic algorithm that is passed an array type as a template
+ parameter, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.remove_extent">remove_extent</link></computeroutput>
+ provides a means of determining the underlying type of the array. For example
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">][</phrase><phrase role="number">5</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> would evaluate to the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">5</phrase><phrase role="special">]</phrase></computeroutput>. This example also shows that the number of
+ template parameters in a partial specialization does not have to match the
+ number in the default template. However, the number of parameters that appear
+ after the class name do have to match the number and type of the parameters
+ in the default template.
+ </para>
+ <anchor id="boost_typetraits.background.optimized_copy"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.optimized_copy">Optimized copy</link>
+ </bridgehead>
+ <para>
+ As an example of how the type traits classes can be used, consider the standard
+ library algorithm copy:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iter1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Iter2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">Iter2</phrase> <phrase role="identifier">copy</phrase><phrase role="special">(</phrase><phrase role="identifier">Iter1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter2</phrase> <phrase role="identifier">out</phrase><phrase role="special">);</phrase>
+</programlisting>
+ <para>
+ Obviously, there's no problem writing a generic version of copy that works
+ for all iterator types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput>; however, there are
+ some circumstances when the copy operation can best be performed by a call
+ to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>. In order to implement
+ copy in terms of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput> all
+ of the following conditions need to be met:
+ </para>
+ <itemizedlist>
+ <listitem>
+ Both of the iterator types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput> must be pointers.
+ </listitem>
+ <listitem>
+ Both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput> must point to the same type - excluding
+ const and volatile-qualifiers.
+ </listitem>
+ <listitem>
+ The type pointed to by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ must have a trivial assignment operator.
+ </listitem>
+ </itemizedlist>
+ <para>
+ By trivial assignment operator we mean that the type is either a scalar type<link linkend="background.references">[3]</link> or:
+ </para>
+ <itemizedlist>
+ <listitem>
+ The type has no user defined assignment operator.
+ </listitem>
+ <listitem>
+ The type does not have any data members that are references.
+ </listitem>
+ <listitem>
+ All base classes, and all data member objects must have trivial assignment
+ operators.
+ </listitem>
+ </itemizedlist>
+ <para>
+ If all these conditions are met then a type can be copied using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput> rather than using a compiler generated
+ assignment operator. The type-traits library provides a class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>,
+ such that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is true only if T has a trivial assignment
+ operator. This class "just works" for scalar types, but has to be
+ explicitly specialised for class/struct types that also happen to have a trivial
+ assignment operator. In other words if <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link>
+ gives the wrong answer, it will give the "safe" wrong answer - that
+ trivial assignment is not allowable.
+ </para>
+ <para>
+ The code for an optimized version of copy that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>
+ where appropriate is given in <link linkend="boost_typetraits.examples.copy">the
+ examples</link>. The code begins by defining a template function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">do_copy</phrase></computeroutput> that performs a "slow but safe"
+ copy. The last parameter passed to this function may be either a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ or a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">false_type</link></computeroutput>.
+ Following that there is an overload of do<emphasis role="underline">copy that
+ uses `memcpy`: this time the iterators are required to actually be pointers
+ to the same type, and the final parameter must be a `</emphasis>_true_type<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase> <phrase role="identifier">Finally</phrase><phrase role="special">,</phrase> <phrase role="identifier">the</phrase> <phrase role="identifier">version</phrase>
+ <phrase role="identifier">of</phrase> </computeroutput>copy<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="identifier">calls</phrase>
+ </computeroutput>do<emphasis role="underline">copy`, passing `</emphasis>_has_trivial_assign&lt;value_type&gt;()`
+ as the final parameter: this will dispatch to the optimized version where appropriate,
+ otherwise it will call the "slow but safe version".
+ </para>
+ <anchor id="boost_typetraits.background.was_it_worth_it_"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.was_it_worth_it_">Was it worth it?</link>
+ </bridgehead>
+ <para>
+ It has often been repeated in these columns that "premature optimization
+ is the root of all evil" <link linkend="background.references">[4]</link>.
+ So the question must be asked: was our optimization premature? To put this
+ in perspective the timings for our version of copy compared a conventional
+ generic copy<link linkend="background.references">[5]</link> are shown in table
+ 1.
+ </para>
+ <para>
+ Clearly the optimization makes a difference in this case; but, to be fair,
+ the timings are loaded to exclude cache miss effects - without this accurate
+ comparison between algorithms becomes difficult. However, perhaps we can add
+ a couple of caveats to the premature optimization rule:
+ </para>
+ <itemizedlist>
+ <listitem>
+ If you use the right algorithm for the job in the first place then optimization
+ will not be required; in some cases, memcpy is the right algorithm.
+ </listitem>
+ <listitem>
+ If a component is going to be reused in many places by many people then optimizations
+ may well be worthwhile where they would not be so for a single case - in
+ other words, the likelihood that the optimization will be absolutely necessary
+ somewhere, sometime is that much higher. Just as importantly the perceived
+ value of the stock implementation will be higher: there is no point standardizing
+ an algorithm if users reject it on the grounds that there are better, more
+ heavily optimized versions available.
+ </listitem>
+ </itemizedlist>
+ <table frame="all"> <title>Time taken to copy 1000 elements using `copy&lt;const
+ T*, T*&gt;` (times in micro-seconds)</title>
+ <tgroup cols="3">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Version
+ </para>
+ </entry><entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ Time
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ "Optimized" copy
+ </para>
+ </entry><entry>
+ <para>
+ char
+ </para>
+ </entry><entry>
+ <para>
+ 0.99
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ Conventional copy
+ </para>
+ </entry><entry>
+ <para>
+ char
+ </para>
+ </entry><entry>
+ <para>
+ 8.07
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ "Optimized" copy
+ </para>
+ </entry><entry>
+ <para>
+ int
+ </para>
+ </entry><entry>
+ <para>
+ 2.52
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ Conventional copy
+ </para>
+ </entry><entry>
+ <para>
+ int
+ </para>
+ </entry><entry>
+ <para>
+ 8.02
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table> <anchor id="boost_typetraits.background.pair_of_references"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.pair_of_references">Pair of References</link>
+ </bridgehead>
+ <para>
+ The optimized copy example shows how type traits may be used to perform optimization
+ decisions at compile-time. Another important usage of type traits is to allow
+ code to compile that otherwise would not do so unless excessive partial specialization
+ is used. This is possible by delegating partial specialization to the type
+ traits classes. Our example for this form of usage is a pair that can hold
+ references <link linkend="background.references">[6]</link>.
+ </para>
+ <para>
+ First, let us examine the definition of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">pair</phrase></computeroutput>, omitting
+ the comparison operators, default constructor, and template copy constructor
+ for simplicity:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">pair</phrase>
+<phrase role="special">{</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T1</phrase> <phrase role="identifier">first_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T2</phrase> <phrase role="identifier">second_type</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">T1</phrase> <phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+<phrase role="identifier">T2</phrase> <phrase role="identifier">second</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">pair</phrase><phrase role="special">(</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">nfirst</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T2</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase>
+<phrase role="special">:</phrase><phrase role="identifier">first</phrase><phrase role="special">(</phrase><phrase role="identifier">nfirst</phrase><phrase role="special">),</phrase> <phrase role="identifier">second</phrase><phrase role="special">(</phrase><phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">}</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ Now, this "pair" cannot hold references as it currently stands, because
+ the constructor would require taking a reference to a reference, which is currently
+ illegal <link linkend="background.references">[7]</link>. Let us consider what
+ the constructor's parameters would have to be in order to allow "pair"
+ to hold non-reference types, references, and constant references:
+ </para>
+ <table frame="all"> <title>Required Constructor Argument Types</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of parameter to initializing constructor
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ A little familiarity with the type traits classes allows us to construct a
+ single mapping that allows us to determine the type of parameter from the type
+ of the contained class. The type traits classes provide a transformation <link linkend="boost_typetraits.reference.add_reference">add_reference</link>, which
+ adds a reference to its type, unless it is already a reference.
+ </para>
+ <table frame="all"> <title>Using add_reference to synthesize the correct constructor
+ type</title>
+ <tgroup cols="3">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ const T
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ T &amp; [8]
+ </para>
+ </entry><entry>
+ <para>
+ T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ This allows us to build a primary template definition for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput>
+ that can contain non-reference types, reference types, and constant reference
+ types:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">pair</phrase>
+<phrase role="special">{</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T1</phrase> <phrase role="identifier">first_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T2</phrase> <phrase role="identifier">second_type</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">T1</phrase> <phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+<phrase role="identifier">T2</phrase> <phrase role="identifier">second</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">pair</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">nfirst</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase>
+<phrase role="special">:</phrase><phrase role="identifier">first</phrase><phrase role="special">(</phrase><phrase role="identifier">nfirst</phrase><phrase role="special">),</phrase> <phrase role="identifier">second</phrase><phrase role="special">(</phrase><phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">}</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ Add back in the standard comparison operators, default constructor, and template
+ copy constructor (which are all the same), and you have a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">pair</phrase></computeroutput> that
+ can hold reference types!
+ </para>
+ <para>
+ This same extension could have been done using partial template specialization
+ of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput>, but to specialize
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput> in this way would require
+ three partial specializations, plus the primary template. Type traits allows
+ us to define a single primary template that adjusts itself auto-magically to
+ any of these partial specializations, instead of a brute-force partial specialization
+ approach. Using type traits in this fashion allows programmers to delegate
+ partial specialization to the type traits classes, resulting in code that is
+ easier to maintain and easier to understand.
+ </para>
+ <anchor id="boost_typetraits.background.conclusion"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.conclusion">Conclusion</link>
+ </bridgehead>
+ <para>
+ We hope that in this article we have been able to give you some idea of what
+ type-traits are all about. A more complete listing of the available classes
+ are in the boost documentation, along with further examples using type traits.
+ Templates have enabled C++ uses to take the advantage of the code reuse that
+ generic programming brings; hopefully this article has shown that generic programming
+ does not have to sink to the lowest common denominator, and that templates
+ can be optimal as well as generic.
+ </para>
+ <anchor id="boost_typetraits.background.acknowledgements"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.acknowledgements">Acknowledgements</link>
+ </bridgehead>
+ <para>
+ The authors would like to thank Beman Dawes and Howard Hinnant for their helpful
+ comments when preparing this article.
+ </para>
+ <anchor id="background.references"/> <anchor id="boost_typetraits.background.references"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.references">References</link>
+ </bridgehead>
+ <orderedlist inheritnum="ignore" continuation="restarts">
+ <listitem>
+ Nathan C. Myers, C++ Report, June 1995.
+ </listitem>
+ <listitem>
+ The type traits library is based upon contributions by Steve Cleary, Beman
+ Dawes, Howard Hinnant and John Maddock: it can be found at www.boost.org.
+ </listitem>
+ <listitem>
+ A scalar type is an arithmetic type (i.e. a built-in integer or floating
+ point type), an enumeration type, a pointer, a pointer to member, or a const-
+ or volatile-qualified version of one of these types.
+ </listitem>
+ <listitem>
+ This quote is from Donald Knuth, ACM Computing Surveys, December 1974, pg
+ 268.
+ </listitem>
+ <listitem>
+ The test code is available as part of the boost utility library (see algo_opt_examples.cpp),
+ the code was compiled with gcc 2.95 with all optimisations turned on, tests
+ were conducted on a 400MHz Pentium II machine running Microsoft Windows 98.
+ </listitem>
+ <listitem>
+ John Maddock and Howard Hinnant have submitted a "compressed_pair"
+ library to Boost, which uses a technique similar to the one described here
+ to hold references. Their pair also uses type traits to determine if any
+ of the types are empty, and will derive instead of contain to conserve space
+ -- hence the name "compressed".
+ </listitem>
+ <listitem>
+ This is actually an issue with the C++ Core Language Working Group (issue
+ #106), submitted by Bjarne Stroustrup. The tentative resolution is to allow
+ a "reference to a reference to T" to mean the same thing as a "reference
+ to T", but only in template instantiation, in a method similar to multiple
+ cv-qualifiers.
+ </listitem>
+ <listitem>
+ For those of you who are wondering why this shouldn't be const-qualified,
+ remember that references are always implicitly constant (for example, you
+ can't re-assign a reference). Remember also that "const T &amp;"
+ is something completely different. For this reason, cv-qualifiers on template
+ type arguments that are references are ignored.
+ </listitem>
+ </orderedlist>
+ </section>
+ <section id="boost_typetraits.category">
+ <title><link linkend="boost_typetraits.category"> Type Traits by Category</link></title>
+ <section id="boost_typetraits.category.value_traits">
+ <title><link linkend="boost_typetraits.category.value_traits"> Type Traits
+ that Describe the Properties of a Type</link></title>
+ <para>
+ <indexterm>
+ <primary>Foo2</primary>
+ <secondary>Bar2</secondary>
+ </indexterm>
+ These traits are all <emphasis>value traits</emphasis>, which is to say the
+ traits classes all inherit from <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link>,
+ and are used to access some numerical property of a type. Often this is a
+ simple true or false Boolean value, but in a few cases may be some other
+ integer value (for example when dealing with type alignments, or array bounds:
+ see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.alignment_of">alignment_of</link></computeroutput>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.rank">rank</link></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.extent">extent</link></computeroutput>).
+ </para>
+ <section id="boost_typetraits.category.value_traits.primary">
+ <title><link linkend="boost_typetraits.category.value_traits.primary"> Categorizing
+ a Type</link></title>
+ <para>
+ These traits identify what "kind" of type some type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is. These are split into two groups:
+ primary traits which are all mutually exclusive, and composite traits that
+ are compositions of one or more primary traits.
+ </para>
+ <para>
+ For any given type, exactly one primary type trait will inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ and all the others will inherit from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>,
+ in other words these traits are mutually exclusive.
+ </para>
+ <para>
+ This means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_integral">is_integral</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ will only ever be true for built-in types; if you want to check for a user-defined
+ class type that behaves "as if" it is an integral or floating
+ point type, then use the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase>
+ <phrase role="keyword">template</phrase></computeroutput> instead.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_array">is_array</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_class">is_class</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_complex">is_complex</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_enum">is_enum</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_function">is_function</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_integral">is_integral</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_object_pointer">is_member_object_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_union">is_union</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ The following traits are made up of the union of one or more type categorizations.
+ A type may belong to more than one of these categories, in addition to
+ one of the primary categories.
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_arithmetic">is_arithmetic</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_compound">is_compound</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_fundamental">is_fundamental</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_object">is_object</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_scalar">is_scalar</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.value_traits.properties">
+ <title><link linkend="boost_typetraits.category.value_traits.properties">
+ General Type Properties</link></title>
+ <para>
+ The following templates describe the general properties of a type.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.alignment_of">alignment_of</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_assign">has_nothrow_assign</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_default_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_default_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_virtual_destructor">has_virtual_destructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_abstract">is_abstract</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_const">is_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_empty">is_empty</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_stateless">is_stateless</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_signed">is_signed</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_unsigned">is_unsigned</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_volatile">is_volatile</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.extent">extent</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.rank">rank</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.value_traits.relate">
+ <title><link linkend="boost_typetraits.category.value_traits.relate"> Relationships
+ Between Two Types</link></title>
+ <para>
+ These templates determine the whether there is a relationship between two
+ types:
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_base_of">is_base_of</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_same">is_same</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.category.transform">
+ <title><link linkend="boost_typetraits.category.transform"> Type Traits that
+ Transform One Type to Another</link></title>
+ <para>
+ The following templates transform one type to another, based upon some well-defined
+ rule. Each template has a single member called <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of applying the transformation to the template argument
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_const">add_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_cv">add_cv</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_pointer">add_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_volatile">add_volatile</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.decay">decay</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.floating_point_promotion">floating_point_promotion</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.integral_promotion">integral_promotion</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.make_signed">make_signed</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.make_unsigned">make_unsigned</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.promote">promote</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_all_extents">remove_all_extents</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_const">remove_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_cv">remove_cv</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_reference">remove_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_volatile">remove_volatile</link><phrase role="special">;</phrase>
+</programlisting>
+ <anchor id="boost_typetraits.category.transform.broken_compiler_workarounds_"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">Broken
+ Compiler Workarounds:</link>
+ </bridgehead>
+ <para>
+ For all of these templates support for partial specialization of class templates
+ is required to correctly implement the transformation. On the other hand,
+ practice shows that many of the templates from this category are very useful,
+ and often essential for implementing some generic libraries. Lack of these
+ templates is often one of the major limiting factors in porting those libraries
+ to compilers that do not yet support this language feature. As some of these
+ compilers are going to be around for a while, and at least one of them is
+ very wide-spread, it was decided that the library should provide workarounds
+ where possible.
+ </para>
+ <para>
+ The basic idea behind the workaround is to manually define full specializations
+ of all type transformation templates for all fundamental types, and all their
+ 1st and 2nd rank cv-[un]qualified derivative pointer types, and to provide
+ a user-level macro that will define all the explicit specializations needed
+ for any user-defined type T.
+ </para>
+ <para>
+ The first part guarantees the successful compilation of something like this:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="special">...</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+</programlisting>
+ <para>
+ and the second part provides the library's users with a mechanism to make
+ the above code work not only for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput> or other built-in type,
+ but for their own types as well:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">myspace</phrase><phrase role="special">{</phrase>
+ <phrase role="keyword">struct</phrase> <phrase role="identifier">MyClass</phrase> <phrase role="special">{};</phrase>
+<phrase role="special">}</phrase>
+<phrase role="comment">// declare this at global scope:
+</phrase><phrase role="identifier">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase><phrase role="special">(</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">)</phrase>
+<phrase role="comment">// transformations on myspace::MyClass now work:
+</phrase><phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="comment">// etc.
+</phrase></programlisting>
+ <para>
+ Note that the macro BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION evaluates
+ to nothing on those compilers that <emphasis role="bold">do</emphasis> support
+ partial specialization.
+ </para>
+ </section>
+ <section id="boost_typetraits.category.alignment">
+ <title><link linkend="boost_typetraits.category.alignment"> Synthesizing Types
+ with Specific Alignments</link></title>
+ <para>
+ Some low level memory management routines need to synthesize a POD type with
+ specific alignment properties. The template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.type_with_alignment">type_with_alignment</link></computeroutput>
+ finds the smallest type with a specified alignment, while template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.aligned_storage">aligned_storage</link></computeroutput>
+ creates a type with a specific size and alignment.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.type_with_alignment">type_with_alignment</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Size</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.aligned_storage">aligned_storage</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.function">
+ <title><link linkend="boost_typetraits.category.function"> Decomposing Function
+ Types</link></title>
+ <para>
+ The class template <link linkend="boost_typetraits.reference.function_traits">function_traits</link>
+ extracts information from function types (see also <link linkend="boost_typetraits.reference.is_function">is_function</link>).
+ This traits class allows you to tell how many arguments a function takes,
+ what those argument types are, and what the return type is.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.function_traits">function_traits</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.user_defined">
+ <title><link linkend="boost_typetraits.user_defined"> User Defined Specializations</link></title>
+ <para>
+ Occationally the end user may need to provide their own specialization for
+ one of the type traits - typically where intrinsic compiler support is required
+ to implement a specific trait fully. These specializations should derive from
+ boost::<link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ or boost::<link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ as appropriate:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pod</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+<phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_class</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+<phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_union</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+
+<phrase role="keyword">struct</phrase> <phrase role="identifier">my_pod</phrase><phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">my_union</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">char</phrase> <phrase role="identifier">c</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_pod</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_union">is_union</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_class">is_class</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.intrinsics">
+ <title><link linkend="boost_typetraits.intrinsics"> Support for Compiler Intrinsics</link></title>
+ <para>
+ There are some traits that can not be implemented within the current C++ language:
+ to make these traits "just work" with user defined types, some kind
+ of additional help from the compiler is required. Currently (April 2008) Visual
+ C++ 8 and 9, GNU GCC 4.3 and MWCW 9 provide the necessary intrinsics, and other
+ compilers will no doubt follow in due course.
+ </para>
+ <para>
+ The Following traits classes always need compiler support to do the right thing
+ for all types (but all have safe fallback positions if this support is unavailable):
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_union">is_union</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_pod">is_pod</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_assign">has_nothrow_assign</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_virtual_destructor">has_virtual_destructor</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The following traits classes can't be portably implemented in the C++ language,
+ although in practice, the implementations do in fact do the right thing on
+ all the compilers we know about:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_empty">is_empty</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The following traits classes are dependent on one or more of the above:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_class">is_class</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_stateless">is_stateless</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The hooks for compiler-intrinsic support are defined in <ulink url="../../../../boost/type_traits/intrinsics.hpp">boost/type_traits/intrinsics.hpp</ulink>,
+ adding support for new compilers is simply a matter of defining one of more
+ of the following macros:
+ </para>
+ <table frame="all"> <title>Macros for Compiler Intrinsics</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_UNION(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a union type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_POD(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a POD type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_EMPTY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is an empty struct or union
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_CONSTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if the default constructor for T is trivial (i.e.
+ has no effect)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_COPY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial copy constructor (and can
+ therefore be replaced by a call to memcpy)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_ASSIGN(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial assignment operator (and can
+ therefore be replaced by a call to memcpy)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_DESTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial destructor (i.e. ~T() has
+ no effect)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_CONSTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="identifier">x</phrase><phrase role="special">;</phrase></computeroutput>
+ can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_COPY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase><phrase role="special">(</phrase><phrase role="identifier">t</phrase><phrase role="special">)</phrase></computeroutput> can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_ASSIGN(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="identifier">t</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">u</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">t</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">u</phrase></computeroutput> can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_VIRTUAL_DESTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true T has a virtual destructor
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_ABSTRACT(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is an abstract type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_BASE_OF(T,U)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a base class of U
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_CLASS(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a class type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_CONVERTIBLE(T,U)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is convertible to U
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_ENUM(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true is T is an enum
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_POLYMORPHIC(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a polymorphic type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_ALIGNMENT_OF(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to the alignment requirements of type T.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.mpl">
+ <title><link linkend="boost_typetraits.mpl"> MPL Interoperability</link></title>
+ <para>
+ All the value based traits in this library conform to MPL's requirements for
+ an <ulink url="../../../../libs/mpl/doc/refmanual/integral-constant.html">Integral
+ Constant type</ulink>: that includes a number of rather intrusive workarounds
+ for broken compilers.
+ </para>
+ <para>
+ Purely as an implementation detail, this means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/bool.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">true_</phrase></computeroutput></ulink>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">false_type</link></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/bool.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">false_</phrase></computeroutput></ulink>,
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">v</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/integral-c.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">integral_c</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">v</phrase><phrase role="special">&gt;</phrase></computeroutput></ulink>
+ (provided <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>)
+ </para>
+ </section>
+ <section id="boost_typetraits.examples">
+ <title><link linkend="boost_typetraits.examples"> Examples</link></title>
+ <section id="boost_typetraits.examples.copy">
+ <title><link linkend="boost_typetraits.examples.copy"> An Optimized Version
+ of std::copy</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">copy</phrase></computeroutput>
+ that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>
+ to determine whether to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>
+ to optimise the copy operation (see <ulink url="../../examples/copy_example.cpp">copy_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// opt::copy
+</phrase><phrase role="comment">// same semantics as std::copy
+</phrase><phrase role="comment">// calls memcpy where appropriate.
+</phrase><phrase role="comment">//
+</phrase>
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">I2</phrase> <phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">out</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">out</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">out</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">memcpy</phrase><phrase role="special">(</phrase><phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="special">(</phrase><phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">)*</phrase><phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">));</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">out</phrase><phrase role="special">+(</phrase><phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">copy</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">out</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// We can copy with memcpy if T has a trivial assignment operator,
+</phrase> <phrase role="comment">// and if the iterator arguments are actually pointers (this last
+</phrase> <phrase role="comment">// requirement we detect with overload resolution):
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">&lt;</phrase><phrase role="identifier">value_type</phrase><phrase role="special">&gt;());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.fill">
+ <title><link linkend="boost_typetraits.examples.fill"> An Optimised Version
+ of std::fill</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">fill</phrase></computeroutput>
+ that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>
+ to determine whether to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memset</phrase></computeroutput>
+ to optimise the fill operation (see <ulink url="../../examples/fill_example.cpp">fill_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// fill
+</phrase><phrase role="comment">// same as std::fill, but uses memset where appropriate
+</phrase><phrase role="comment">//
+</phrase><phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">first</phrase> <phrase role="special">=</phrase> <phrase role="identifier">val</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">memset</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">I</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">fill</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// We can do an optimised fill if T has a trivial assignment
+</phrase> <phrase role="comment">// operator and if it's size is one:
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase>
+ <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="special">(</phrase><phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">)&gt;</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.destruct">
+ <title><link linkend="boost_typetraits.examples.destruct"> An Example that
+ Omits Destructor Calls For Types with Trivial Destructors</link></title>
+ <para>
+ Demonstrates a simple algorithm that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">__has_trivial_destruct</phrase></computeroutput>
+ to determine whether to destructors need to be called (see <ulink url="../../examples/trivial_destructor_example.cpp">trivial_destructor_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// algorithm destroy_array:
+</phrase><phrase role="comment">// The reverse of std::unitialized_copy, takes a block of
+</phrase><phrase role="comment">// initialized memory and calls destructors on all objects therein.
+</phrase><phrase role="comment">//
+</phrase>
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="identifier">first</phrase><phrase role="special">-&gt;~</phrase><phrase role="identifier">T</phrase><phrase role="special">();</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase> <phrase role="comment">// namespace detail
+</phrase>
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">p1</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">p2</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">p1</phrase><phrase role="special">,</phrase> <phrase role="identifier">p2</phrase><phrase role="special">,</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.iter">
+ <title><link linkend="boost_typetraits.examples.iter"> An improved Version
+ of std::iter_swap</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iter_swap</phrase></computeroutput>
+ that use type traits to determine whether an it's arguments are proxying
+ iterators or not, if they're not then it just does a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">swap</phrase></computeroutput>
+ of it's dereferenced arguments (the same as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iter_swap</phrase></computeroutput>
+ does), however if they are proxying iterators then takes special care over
+ the swap to ensure that the algorithm works correctly for both proxying iterators,
+ and even iterators of different types (see <ulink url="../../examples/iter_swap_example.cpp">iter_swap_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// iter_swap:
+</phrase><phrase role="comment">// tests whether iterator is a proxying iterator or not, and
+</phrase><phrase role="comment">// uses optimal form accordingly:
+</phrase><phrase role="comment">//
+</phrase><phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">v_t</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">v_t</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">one</phrase><phrase role="special">;</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">one</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">two</phrase><phrase role="special">;</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">two</phrase> <phrase role="special">=</phrase> <phrase role="identifier">v</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">using</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">swap</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">swap</phrase><phrase role="special">(*</phrase><phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="special">*</phrase><phrase role="identifier">two</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">iter_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">two</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// See is both arguments are non-proxying iterators,
+</phrase> <phrase role="comment">// and if both iterator the same type:
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">r1_t</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I2</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">r2_t</phrase><phrase role="special">;</phrase>
+
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase>
+ <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">&lt;</phrase><phrase role="identifier">r1_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">&lt;</phrase><phrase role="identifier">r2_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_same">is_same</link><phrase role="special">&lt;</phrase><phrase role="identifier">r1_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">r2_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">;</phrase>
+
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.to_double">
+ <title><link linkend="boost_typetraits.examples.to_double"> Convert Numeric
+ Types and Enums to double</link></title>
+ <para>
+ Demonstrates a conversion of <ulink url="../../../../libs/numeric/conversion/doc/html/boost_numericconversion/definitions.html#boost_numericconversion.definitions.numeric_types">Numeric
+ Types</ulink> and enum types to double:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">double</phrase> <phrase role="identifier">to_double</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">promoted</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric</phrase><phrase role="special">::</phrase><phrase role="identifier">converter</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase><phrase role="identifier">promoted</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">convert</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.reference">
+ <title><link linkend="boost_typetraits.reference"> Alphabetical Reference</link></title>
+ <section id="boost_typetraits.reference.add_const">
+ <title><link linkend="boost_typetraits.reference.add_const"> add_const</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ <secondary>two</secondary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">const</phrase></computeroutput> for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_cv">
+ <title><link linkend="boost_typetraits.reference.add_cv"> add_cv</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ <secondary>two</secondary>
+ <tertiary>three</tertiary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_cv</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_cv</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_pointer">
+ <title><link linkend="boost_typetraits.reference.add_pointer"> add_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_pointer</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">*</phrase></computeroutput>.
+ </para>
+ <para>
+ The rationale for this template is that it produces the same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">TYPEOF</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">t</phrase><phrase role="special">)</phrase></computeroutput>, where
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t</phrase></computeroutput> is an object of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">**</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">**</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_reference">
+ <title><link linkend="boost_typetraits.reference.add_reference"> add_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_reference</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is not a reference type then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase></computeroutput>, otherwise <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_volatile">
+ <title><link linkend="boost_typetraits.reference.add_volatile"> add_volatile</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput> for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.aligned_storage">
+ <title><link linkend="boost_typetraits.reference.aligned_storage"> aligned_storage</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Size</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">aligned_storage</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> a built-in or POD type with size
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Size</phrase></computeroutput> and an alignment that
+ is a multiple of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Align</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">aligned_storage</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.alignment_of">
+ <title><link linkend="boost_typetraits.reference.alignment_of"> alignment_of</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">alignment_of</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template alignment<emphasis role="underline">of inherits from `</emphasis>_integral_constant&lt;std::size_t,
+ ALIGNOF(T)&gt;<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">,</phrase> <phrase role="identifier">where</phrase>
+ </computeroutput>ALIGNOF(T)` is the alignment of type T.
+ </para>
+ <para>
+ <emphasis>Note: strictly speaking you should only rely on the value of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> being
+ a multiple of the true alignment of T, although in practice it does compute
+ the correct value in all the cases we know about.</emphasis>
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">alignment_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ with value <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.decay">
+ <title><link linkend="boost_typetraits.reference.decay"> decay</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">decay</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> Let <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>
+ be the result of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>, then if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>
+ is an array type, the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;*</phrase></computeroutput>,
+ otherwise if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput> is a function
+ type then the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase><phrase role="special">*</phrase></computeroutput>, otherwise the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">decay</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">(&amp;)[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">(&amp;)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.extent">
+ <title><link linkend="boost_typetraits.reference.extent"> extent</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">extent</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template extent inherits
+ from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)&gt;</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)</phrase></computeroutput> is the number of elements in the N'th array
+ dimention of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not an array type,
+ or if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">N</phrase> <phrase role="special">&gt;</phrase>
+ <link linkend="boost_typetraits.reference.rank">rank</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>, or if the N'th array bound is incomplete,
+ then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)</phrase></computeroutput> is zero.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">extent</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">],</phrase>
+ <phrase role="number">1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">3</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>4</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">],</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>2</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.floating_point_promotion">
+ <title><link linkend="boost_typetraits.reference.floating_point_promotion">
+ floating_point_promotion</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">floating_point_promotion</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If floating point promotion can be
+ applied to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ then applies floating point promotion to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">float</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.function_traits">
+ <title><link linkend="boost_typetraits.reference.function_traits"> function_traits</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">F</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">function_traits</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">static</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">arity</phrase> <phrase role="special">=</phrase> <replaceable>see-below</replaceable><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">result_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> arg<replaceable>N</replaceable>_type<phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ The class template function_traits will only compile if:
+ </para>
+ <itemizedlist>
+ <listitem>
+ The compiler supports partial specialization of class templates.
+ </listitem>
+ <listitem>
+ The template argument <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>
+ is a <emphasis>function type</emphasis>, note that this <emphasis><emphasis role="bold">is not</emphasis></emphasis> the same thing as a <emphasis>pointer
+ to a function</emphasis>.
+ </listitem>
+ </itemizedlist>
+ <tip>
+ <para>
+ function_traits is intended to introspect only C++ functions of the form
+ R (), R( A1 ), R ( A1, ... etc. ) and not function pointers or class member
+ functions. To convert a function pointer type to a suitable type use <link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link>.
+ </para>
+ </tip>
+ <table frame="all"> <title>Function Traits Members</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Member
+ </para>
+ </entry><entry>
+ <para>
+ Description
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that gives the number of arguments
+ accepted by the function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type returned by function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase>arg<replaceable>N</replaceable>_type</computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The <replaceable>N</replaceable>th argument type of function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase> <phrase role="special">&lt;=</phrase>
+ <phrase role="identifier">N</phrase> <phrase role="special">&lt;=</phrase>
+ <phrase role="identifier">arity</phrase></computeroutput> of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table> <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 0.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 1.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 4.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">long</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arg1_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arg4_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase><phrase role="special">*</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arg5_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A compiler error: there is no <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">arg5_type</phrase></computeroutput>
+ since there are only four arguments.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A compiler error: argument type is a <emphasis>function pointer</emphasis>,
+ and not a <emphasis>function type</emphasis>.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_assign">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_assign"> has_nothrow_assign</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_assign</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing assignment-operator then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_assign</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing assignment-operator;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler support to ensure that this trait "just
+ works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_assign</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_constructor">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_constructor">
+ has_nothrow_constructor</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_default_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing default-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_constructor</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing default-constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to ensure that this trait "just works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_constructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_copy">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_copy"> has_nothrow_copy</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_copy</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_copy_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing copy-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_copy</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing copy-constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to ensure that this trait "just works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_copy</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_cp_cons">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_cp_cons"> has_nothrow_copy_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_no_throw_def_cons">
+ <title><link linkend="boost_typetraits.reference.has_no_throw_def_cons"> has_nothrow_default_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_assign">
+ <title><link linkend="boost_typetraits.reference.has_trivial_assign"> has_trivial_assign</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_assign</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial assignment-operator then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ If a type has a trivial assignment-operator then the operator has the same
+ effect as copying the bits of one object to the other: calls to the operator
+ can be safely replaced with a call to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_assign
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.8p11.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_constructor">
+ <title><link linkend="boost_typetraits.reference.has_trivial_constructor">
+ has_trivial_constructor</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_default_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial default-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ If a type has a trivial default-constructor then the constructor have no
+ effect: calls to the constructor can be safely omitted. Note that using meta-programming
+ to omit a call to a single trivial-constructor call is of no benefit whatsoever.
+ However, if loops and/or exception handling code can also be omitted, then
+ some benefit in terms of code size and speed can be obtained.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_constructor
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.1p6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_copy">
+ <title><link linkend="boost_typetraits.reference.has_trivial_copy"> has_trivial_copy</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_copy</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_copy_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial copy-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ If a type has a trivial copy-constructor then the constructor has the same
+ effect as copying the bits of one object to the other: calls to the constructor
+ can be safely replaced with a call to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_copy
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.8p6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_cp_cons">
+ <title><link linkend="boost_typetraits.reference.has_trivial_cp_cons"> has_trivial_copy_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_def_cons">
+ <title><link linkend="boost_typetraits.reference.has_trivial_def_cons"> has_trivial_default_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_destructor">
+ <title><link linkend="boost_typetraits.reference.has_trivial_destructor"> has_trivial_destructor</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_destructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial destructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ If a type has a trivial destructor then the destructor has no effect: calls
+ to the destructor can be safely omitted. Note that using meta-programming
+ to omit a call to a single trivial-constructor call is of no benefit whatsoever.
+ However, if loops and/or exception handling code can also be omitted, then
+ some benefit in terms of code size and speed can be obtained.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_destructor
+ will never report that a user-defined class or struct has a trivial destructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.4p3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_virtual_destructor">
+ <title><link linkend="boost_typetraits.reference.has_virtual_destructor"> has_virtual_destructor</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_virtual_destructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a virtual destructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> This trait is provided
+ for completeness, since it's part of the Technical Report on C++ Library
+ Extensions. However, there is currently no way to portably implement this
+ trait. The default version provided always inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>,
+ and has to be explicitly specialized for types with virtual destructors unless
+ the compiler used has compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ that enable the trait to do the right thing: currently (May 2005) only Visual
+ C++ 8 and GCC-4.3 have the necessary <link linkend="boost_typetraits.intrinsics">intrinsics</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.4.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_virtual_destructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.integral_constant">
+ <title><link linkend="boost_typetraits.reference.integral_constant"> integral_constant</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">val</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">integral_constant</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">static</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">val</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="keyword">true</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">true_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="keyword">false</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">false_type</phrase><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ Class template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_constant</phrase></computeroutput>
+ is the common base class for all the value-based type traits. The two typedef's
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">true_type</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">false_type</phrase></computeroutput> are provided for convenience:
+ most of the value traits are Boolean properties and so will inherit from
+ one of these.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.integral_promotion">
+ <title><link linkend="boost_typetraits.reference.integral_promotion"> integral_promotion</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">integral_promotion</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If integral promotion can be applied
+ to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>, then
+ applies integral promotion to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.5 except 4.5/3
+ (integral bit-field).
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">integral_promotion</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">enum</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">float_round_style</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.is_abstract">
+ <title><link linkend="boost_typetraits.reference.is_abstract"> is_abstract</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_abstract</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ abstract type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_abstract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> The compiler must
+ support DR337 (as of April 2005: GCC 3.4, VC++ 7.1 (and later), Intel C++
+ 7 (and later), and Comeau 4.3.2). Otherwise behaves the same as <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link>;
+ this is the "safe fallback position" for which polymorphic types
+ are always regarded as potentially abstract. The macro BOOST_NO_IS_ABSTRACT
+ is used to signify that the implementation is buggy, users should check for
+ this in their own code if the "safe fallback" is not suitable for
+ their particular use-case.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">abc</phrase><phrase role="special">{</phrase> <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">abc</phrase><phrase role="special">()</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_arithmetic">
+ <title><link linkend="boost_typetraits.reference.is_arithmetic"> is_arithmetic</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_arithmetic</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ arithmetic type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Arithmetic types include integral and floating point types (see also <link linkend="boost_typetraits.reference.is_integral">is_integral</link> and
+ <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link>).
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p8.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_arithmetic</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_array">
+ <title><link linkend="boost_typetraits.reference.is_array"> is_array</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_array</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ array type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_array</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can give the wrong result with function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_base_of">
+ <title><link linkend="boost_typetraits.reference.is_base_of"> is_base_of</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_base_of</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If Base is base class of type
+ Derived or if both types are the same then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ This template will detect non-public base classes, and ambiguous base classes.
+ </para>
+ <para>
+ Note that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">X</phrase><phrase role="special">,</phrase><phrase role="identifier">X</phrase><phrase role="special">&gt;</phrase></computeroutput> will always inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>.
+ <emphasis role="bold">This is the case even if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">X</phrase></computeroutput>
+ is not a class type</emphasis>. This is a change in behaviour from Boost-1.33
+ in order to track the Technical Report on C++ Library Extensions.
+ </para>
+ <para>
+ Types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput> must not be incomplete types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_base_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types. There are some older compilers which
+ will produce compiler errors if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput>
+ is a private base class of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput>,
+ or if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput> is an ambiguous
+ base of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput>. These compilers
+ include Borland C++, older versions of Sun Forte C++, Digital Mars C++, and
+ older versions of EDG based compilers.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">{};</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase> <phrase role="special">:</phrase>
+ <phrase role="keyword">public</phrase> <phrase role="identifier">Base</phrase><phrase role="special">{};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Base</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>: a class is regarded as it's
+ own base.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_class">
+ <title><link linkend="boost_typetraits.reference.is_class"> is_class</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_class</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ class type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 9.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_class</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Without (some as
+ yet unspecified) help from the compiler, we cannot distinguish between union
+ and class types, as a result this type will erroneously inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link> for
+ union types. See also <link linkend="boost_typetraits.reference.is_union">is_union</link>.
+ Currently (May 2005) only Visual C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to correctly identify union types, and therefore make is_class function correctly.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">MyClass</phrase><phrase role="special">;</phrase></computeroutput> then:
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_complex">
+ <title><link linkend="boost_typetraits.reference.is_complex"> is_complex</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_complex</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is a complex number type then true (of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">complex</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ for some type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>), otherwise
+ false.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 26.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_complex</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.is_compound">
+ <title><link linkend="boost_typetraits.reference.is_compound"> is_compound</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_compound</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ compound type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Any type that is not a fundamental type is a compound type (see also <link linkend="boost_typetraits.reference.is_fundamental">is_fundamental</link>).
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_compound</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyEnum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_const">
+ <title><link linkend="boost_typetraits.reference.is_const"> is_const</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_const</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (top level) const-qualified
+ type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the const-qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the const-qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_convertible">
+ <title><link linkend="boost_typetraits.reference.is_convertible"> is_convertible</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_convertible</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If an imaginary lvalue of type
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">From</phrase></computeroutput> is convertible to type
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput> then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ Type From must not be an incomplete type.
+ </para>
+ <para>
+ Type To must not be an incomplete, or function type.
+ </para>
+ <para>
+ No types are considered to be convertible to array types or abstract-class
+ types.
+ </para>
+ <para>
+ This template can not detect whether a converting-constructor is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput> or not: if type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput>
+ has a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput> converting constructor
+ from type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">From</phrase></computeroutput> then instantiating
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ will produce a compiler error. For this reason <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase></computeroutput>
+ can not be used to determine whether a type has a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
+ copy-constructor or not.
+ </para>
+ <para>
+ This template will also produce compiler errors if the conversion is ambiguous,
+ for example:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">B</phrase> <phrase role="special">:</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">C</phrase> <phrase role="special">:</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">D</phrase> <phrase role="special">:</phrase> <phrase role="identifier">B</phrase><phrase role="special">,</phrase> <phrase role="identifier">C</phrase> <phrase role="special">{};</phrase>
+<phrase role="comment">// This produces a compiler error, the conversion is ambiguous:
+</phrase><phrase role="keyword">bool</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">y</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">D</phrase><phrase role="special">*,</phrase><phrase role="identifier">A</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4 and 8.5.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> This template is
+ currently broken with Borland C++ Builder 5 (and earlier), for constructor-based
+ conversions, and for the Metrowerks 7 (and earlier) compiler in all cases.
+ If the compiler does not support <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_abstract">is_abstract</link></computeroutput>,
+ then the template parameter <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput>
+ must not be an abstract type.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_convertible</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*,</phrase> <phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the conversion would require a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const_cast</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;,</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_empty">
+ <title><link linkend="boost_typetraits.reference.is_empty"> is_empty</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_empty</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an empty class type then
+ inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10p5.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> In order to correctly
+ detect empty classes this trait relies on either:
+ </para>
+ <itemizedlist>
+ <listitem>
+ the compiler implementing zero sized empty base classes, or
+ </listitem>
+ <listitem>
+ the compiler providing <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect empty classes.
+ </listitem>
+ </itemizedlist>
+ <para>
+ Can not be used with incomplete types.
+ </para>
+ <para>
+ Can not be used with union types, until is_union can be made to work.
+ </para>
+ <para>
+ If the compiler does not support partial-specialization of class templates,
+ then this template can not be used with abstract types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">empty_class</phrase>
+ <phrase role="special">{};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_enum">
+ <title><link linkend="boost_typetraits.reference.is_enum"> is_enum</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_enum</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ enum type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_enum</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Requires a correctly
+ functioning <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link>
+ template; this means that is_enum is currently broken under Borland C++ Builder
+ 5, and for the Metrowerks compiler prior to version 8, other compilers should
+ handle this template just fine.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">enum</phrase> <phrase role="identifier">my_enum</phrase>
+ <phrase role="special">{</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">two</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_floating_point">
+ <title><link linkend="boost_typetraits.reference.is_floating_point"> is_floating_point</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_floating_point</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ floating point type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p8.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_floating_point</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_function">
+ <title><link linkend="boost_typetraits.reference.is_function"> is_function</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_function</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ function type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Note that this template does not detect <emphasis>pointers to functions</emphasis>,
+ or <emphasis>references to functions</emphasis>, these are detected by <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link> and <link linkend="boost_typetraits.reference.is_reference">is_reference</link> respectively:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">f1</phrase><phrase role="special">();</phrase> <phrase role="comment">// f1 is of function type.
+</phrase><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">f2</phrase><phrase role="special">*)();</phrase> <phrase role="comment">// f2 is a pointer to a function.
+</phrase><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">f3</phrase><phrase role="special">&amp;)();</phrase> <phrase role="comment">// f3 is a reference to a function.
+</phrase></programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2p1 and 8.3.5.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_function</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a pointer type, not a function type.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(&amp;)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a reference to a function, not a function type.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a pointer to a member function.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <tip>
+ <para>
+ Don't confuse function-types with pointers to functions:
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">);</phrase></computeroutput>
+ </para>
+ <para>
+ defines a function type,
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase> <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ declares a prototype for a function of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase></computeroutput>,
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase><phrase role="special">*</phrase>
+ <phrase role="identifier">pf</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase><phrase role="special">&amp;</phrase>
+ <phrase role="identifier">fr</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ declares a pointer and a reference to the function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">foo</phrase></computeroutput>.
+ </para>
+ <para>
+ If you want to detect whether some type is a pointer-to-function then use:
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_function">is_function</link><phrase role="special">&lt;</phrase><link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ </para>
+ <para>
+ or for pointers to member functions you can just use <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link>
+ directly.
+ </para>
+ </tip>
+ </section>
+ <section id="boost_typetraits.reference.is_fundamental">
+ <title><link linkend="boost_typetraits.reference.is_fundamental"> is_fundamental</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_fundamental</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ fundamental type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Fundamental types include integral, floating point and void types (see also
+ <link linkend="boost_typetraits.reference.is_integral">is_integral</link>,
+ <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link>
+ and <link linkend="boost_typetraits.reference.is_void">is_void</link>)
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_fundamental</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_integral">
+ <title><link linkend="boost_typetraits.reference.is_integral"> is_integral</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_integral</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ integral type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p7.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_integral</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_function_pointer">
+ <title><link linkend="boost_typetraits.reference.is_member_function_pointer">
+ is_member_function_pointer</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_function_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member function then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the argument in this case is a pointer to a data member and not a member
+ function, see <link linkend="boost_typetraits.reference.is_member_object_pointer">is_member_object_pointer</link>
+ and <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_object_pointer">
+ <title><link linkend="boost_typetraits.reference.is_member_object_pointer">
+ is_member_object_pointer</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_object_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member object (a data member) then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the argument in this case is a pointer to a member function and not a
+ member object, see <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link>
+ and <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_pointer">
+ <title><link linkend="boost_typetraits.reference.is_member_pointer"> is_member_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member (either a function or a data member) then inherits from
+ <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_object">
+ <title><link linkend="boost_typetraits.reference.is_object"> is_object</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_object</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ object type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ All types are object types except references, void, and function types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p9.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_object</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: reference types are not
+ objects
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: function types are not
+ objects
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ void is not an object type
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_pod">
+ <title><link linkend="boost_typetraits.reference.is_pod"> is_pod</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_pod</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ POD type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ POD stands for "Plain old data". Arithmetic types, and enumeration
+ types, a pointers and pointer to members are all PODs. Classes and unions
+ can also be POD's if they have no non-static data members that are of reference
+ or non-POD type, no user defined constructors, no user defined assignment
+ operators, no private or protected non-static data members, no virtual functions
+ and no base classes. Finally, a cv-qualified POD is still a POD, as is an
+ array of PODs.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10 and 9p4 (Note
+ that POD's are also aggregates, see 8.5.1).
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, is<emphasis role="underline">pod
+ will never report that a class or struct is a POD; this is always safe, if
+ possibly sub-optimal. Currently (May 2005) only MWCW 9 and Visual C++ 8 have
+ the necessary compiler-</emphasis>_intrinsics.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pod</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_pointer">
+ <title><link linkend="boost_typetraits.reference.is_pointer"> is_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer type (includes function pointers, but excludes pointers to members)
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2p2 and 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <important>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase></computeroutput> detects "real"
+ pointer types only, and <emphasis>not</emphasis> smart pointers. Users
+ should not specialise <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase></computeroutput>
+ for smart pointer types, as doing so may cause Boost (and other third party)
+ code to fail to function correctly. Users wanting a trait to detect smart
+ pointers should create their own. However, note that there is no way in
+ general to auto-magically detect smart pointer types, so such a trait would
+ have to be partially specialised for each supported smart pointer type.
+ </para>
+ </important>
+ </section>
+ <section id="boost_typetraits.reference.is_polymorphic">
+ <title><link linkend="boost_typetraits.reference.is_polymorphic"> is_polymorphic</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_polymorphic</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ polymorphic type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> The implementation
+ requires some knowledge of the compilers ABI, it does actually seem to work
+ with the majority of compilers though.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_polymorphic</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">poly</phrase><phrase role="special">{</phrase> <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">poly</phrase><phrase role="special">();</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_same">
+ <title><link linkend="boost_typetraits.reference.is_same"> is_same</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_same</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T and U are the same types
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_same</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with abstract, incomplete or function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_scalar">
+ <title><link linkend="boost_typetraits.reference.is_scalar"> is_scalar</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_scalar</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ scalar type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Scalar types include integral, floating point, enumeration, pointer, and
+ pointer-to-member types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_scalar</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_signed">
+ <title><link linkend="boost_typetraits.reference.is_signed"> is_signed</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_signed</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an signed integer type
+ or an enumerated type with an underlying signed integer type, then inherits
+ from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1, 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_signed</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myclass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ whose value depends upon the signedness of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_stateless">
+ <title><link linkend="boost_typetraits.reference.is_stateless"> is_stateless</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_stateless</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Ff T is a stateless type then
+ inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ Type T must be a complete type.
+ </para>
+ <para>
+ A stateless type is a type that has no storage and whose constructors and
+ destructors are trivial. That means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_stateless</phrase></computeroutput>
+ only inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the following expression is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput>:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_stateless</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, is_stateless will
+ never report that a class or struct is stateless; this is always safe, if
+ possibly sub-optimal. Currently (May 2005) only MWCW 9 and Visual C++ 8 have
+ the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to make this template work automatically.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.is_reference">
+ <title><link linkend="boost_typetraits.reference.is_reference"> is_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_reference</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a reference pointer type
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ may report the wrong result for function types, and for types that are both
+ const and volatile qualified.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(&amp;)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis> (the argument in this case
+ is a reference to a function).
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_union">
+ <title><link linkend="boost_typetraits.reference.is_union"> is_union</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_union</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ union type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Currently requires some kind of compiler support, otherwise unions are identified
+ as classes.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 9.5.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Without (some as
+ yet unspecified) help from the compiler, we cannot distinguish between union
+ and class types using only standard C++, as a result this type will never
+ inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ unless the user explicitly specializes the template for their user-defined
+ union types, or unless the compiler supplies some unspecified intrinsic that
+ implements this functionality. Currently (May 2005) only Visual C++ 8 has
+ the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to make this trait "just work" without user intervention.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_union</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_unsigned">
+ <title><link linkend="boost_typetraits.reference.is_unsigned"> is_unsigned</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_unsigned</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an unsigned integer type
+ or an enumerated type with an underlying unsigned integer type, then inherits
+ from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1, 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_unsigned</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myclass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ whose value depends upon the signedness of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">long</phrase>
+ <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_void">
+ <title><link linkend="boost_typetraits.reference.is_void"> is_void</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_void</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ void type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p9.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_void</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_volatile">
+ <title><link linkend="boost_typetraits.reference.is_volatile"> is_volatile</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_volatile</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (top level) volatile-qualified
+ type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">volatile</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase>
+ <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the volatile qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.make_signed">
+ <title><link linkend="boost_typetraits.reference.make_signed"> make_signed</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">make_signed</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If T is a signed integer type then
+ the same type as T, if T is an unsigned integer type then the corresponding
+ signed type. Otherwise if T is an enumerated or character type (char or wchar_t)
+ then a signed integer type with the same width as T.
+ </para>
+ <para>
+ If T has any cv-qualifiers then these are also present on the result type.
+ </para>
+ <para>
+ <emphasis role="bold">Requires:</emphasis> T must be an integer or enumerated
+ type, and must not be the type bool.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">make_signed</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">long</phrase>
+ <phrase role="keyword">long</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A signed integer type with the same width as the enum.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">wchar_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A signed integer type with the same width as wchar_t.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.make_unsigned">
+ <title><link linkend="boost_typetraits.reference.make_unsigned"> make_unsigned</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">make_unsigned</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If T is a unsigned integer type then
+ the same type as T, if T is an signed integer type then the corresponding
+ unsigned type. Otherwise if T is an enumerated or character type (char or
+ wchar_t) then an unsigned integer type with the same width as T.
+ </para>
+ <para>
+ If T has any cv-qualifiers then these are also present on the result type.
+ </para>
+ <para>
+ <emphasis role="bold">Requires:</emphasis> T must be an integer or enumerated
+ type, and must not be the type bool.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">make_unsigned</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An unsigned integer type with the same width as the enum.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">wchar_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An unsigned integer type with the same width as wchar_t.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.promote">
+ <title><link linkend="boost_typetraits.reference.promote"> promote</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">promote</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If integral or floating point promotion
+ can be applied to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ then applies integral and floating point promotions to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ See also <link linkend="boost_typetraits.reference.integral_promotion">integral_promotion</link>
+ and <link linkend="boost_typetraits.reference.floating_point_promotion">floating_point_promotion</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.5 except 4.5/3
+ (integral bit-field) and 4.6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">promote</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.rank">
+ <title><link linkend="boost_typetraits.reference.rank"> rank</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">rank</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template rank inherits from
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> is the
+ number of array dimensions in type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not an array type,
+ then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> is zero.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">rank</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[]&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">3</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>1</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>2</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.remove_all_extents">
+ <title><link linkend="boost_typetraits.reference.remove_all_extents"> remove_all_extents</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_all_extents</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is an array type, then removes all of the array bounds on <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_all_extents</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_const">
+ <title><link linkend="boost_typetraits.reference.remove_const"> remove_const</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> const-qualifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_cv">
+ <title><link linkend="boost_typetraits.reference.remove_cv"> remove_cv</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_cv</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> cv-qualifiers removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_cv</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_extent">
+ <title><link linkend="boost_typetraits.reference.remove_extent"> remove_extent</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_extent</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is an array type, then removes the topmost array bound, otherwise leaves
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_extent</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">]</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_pointer">
+ <title><link linkend="boost_typetraits.reference.remove_pointer"> remove_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_pointer</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any pointer modifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">**&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_reference">
+ <title><link linkend="boost_typetraits.reference.remove_reference"> remove_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_reference</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any reference modifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_volatile">
+ <title><link linkend="boost_typetraits.reference.remove_volatile"> remove_volatile</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> volatile-qualifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.type_with_alignment">
+ <title><link linkend="boost_typetraits.reference.type_with_alignment"> type_with_alignment</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">type_with_alignment</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> a built-in or POD type with an alignment
+ that is a multiple of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Align</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">type_with_alignment</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ </section>
+ <section id="boost_typetraits.credits">
+ <title><link linkend="boost_typetraits.credits"> Credits</link></title>
+ <para>
+ This documentation was pulled together by John Maddock, using <ulink url="../../../../doc/html/quickbook.html">Boost.Quickbook</ulink>
+ and <ulink url="../../../../doc/html/boostbook.html">Boost.DocBook</ulink>.
+ </para>
+ <para>
+ The original version of this library was created by Steve Cleary, Beman Dawes,
+ Howard Hinnant, and John Maddock. John Maddock is the current maintainer of
+ the library.
+ </para>
+ <para>
+ This version of type traits library is based on contributions by Adobe Systems
+ Inc, David Abrahams, Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant,
+ Jesse Jones, Mat Marcus, Itay Maman, John Maddock, Thorsten Ottosen, Robert
+ Ramey and Jeremy Siek.
+ </para>
+ <para>
+ Mat Marcus and Jesse Jones invented, and <ulink url="http://opensource.adobe.com/project4/project.shtml">published
+ a paper describing</ulink>, the partial specialization workarounds used in
+ this library.
+ </para>
+ <para>
+ Aleksey Gurtovoy added MPL integration to the library.
+ </para>
+ <para>
+ The <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link>
+ template is based on code originally devised by Andrei Alexandrescu, see "<ulink url="http://www.cuj.com/experts/1810/alexandr.htm?topic=experts">Generic&lt;Programming&gt;:
+ Mappings between Types and Values</ulink>".
+ </para>
+ <para>
+ The latest version of this library and documentation can be found at <ulink url="http://www.boost.org">www.boost.org</ulink>. Bugs, suggestions and discussion
+ should be directed to boost@lists.boost.org (see <ulink url="http://www.boost.org/more/mailing_lists.htm#main">www.boost.org/more/mailing_lists.htm#main</ulink>
+ for subscription details).
+ </para>
+ </section>
+
+ <section id="boost_typetraits.ignored_section">
+ <title>This section must not be indexed.</title>
+ <?BoostAutoIndex IgnoreSection?>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ </section>
+
+ <section id="boost_typetraits.ignored_block">
+ <title>This section contains one block that must not be indexed and one that should be.</title>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">
+ <?BoostAutoIndex IgnoreBlock?>
+ template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">
+ template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ </section>
+
+
+ <index>
+ <title>Class Index</title>
+ <para><link linkend="idx_id_0">A</link> <link linkend="idx_id_2">C</link> <link linkend="idx_id_3">D</link> <link linkend="idx_id_4">E</link> <link linkend="idx_id_5">F</link> <link linkend="idx_id_6">H</link> <link linkend="idx_id_7">I</link> <link linkend="idx_id_8">M</link> <link linkend="idx_id_9">O</link> <link linkend="idx_id_10">P</link> <link linkend="idx_id_11">R</link> <link linkend="idx_id_13">T</link></para><variablelist><varlistentry id="idx_id_0"><term>A</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-0">add_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_cv"><phrase role="index-entry-level-0">add_cv</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_pointer"><phrase role="index-entry-level-0">add_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_reference"><phrase role="index-entry-level-0">add_reference</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">add_volatile</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.add_volatile"><phrase role="index-entry-level-1">add_volatile</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.ignored_block"><phrase role="index-entry-level-1">This section contains one block that must not be indexed and one that should be.</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.aligned_storage"><phrase role="index-entry-level-0">aligned_storage</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-0">alignment_of</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_2"><term>C</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">Constrained Index Term</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-1">add_const</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_3"><term>D</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.decay"><phrase role="index-entry-level-0">decay</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_4"><term>E</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-0">extent</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_5"><term>F</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.floating_point_promotion"><phrase role="index-entry-level-0">floating_point_promotion</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-0">function_traits</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_6"><term>H</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_assign"><phrase role="index-entry-level-0">has_nothrow_assign</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-0">has_nothrow_constructor</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-0">has_nothrow_copy</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_copy_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-1">has_nothrow_copy</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_default_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-1">has_nothrow_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_assign"><phrase role="index-entry-level-0">has_trivial_assign</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-0">has_trivial_copy</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_copy_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-1">has_trivial_copy</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_default_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_constructor"><phrase role="index-entry-level-1">has_trivial_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_destructor"><phrase role="index-entry-level-0">has_trivial_destructor</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_virtual_destructor"><phrase role="index-entry-level-0">has_virtual_destructor</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_7"><term>I</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">integral_constant</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-1">alignment_of</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-1">extent</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.rank"><phrase role="index-entry-level-1">rank</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_promotion"><phrase role="index-entry-level-0">integral_promotion</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_abstract"><phrase role="index-entry-level-0">is_abstract</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_arithmetic"><phrase role="index-entry-level-0">is_arithmetic</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_array"><phrase role="index-entry-level-0">is_array</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_base_of"><phrase role="index-entry-level-0">is_base_of</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_class</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_class"><phrase role="index-entry-level-1">is_class</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">User Defined Specializations</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_complex"><phrase role="index-entry-level-0">is_complex</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_compound"><phrase role="index-entry-level-0">is_compound</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_const"><phrase role="index-entry-level-0">is_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_convertible"><phrase role="index-entry-level-0">is_convertible</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_empty"><phrase role="index-entry-level-0">is_empty</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_enum"><phrase role="index-entry-level-0">is_enum</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_floating_point"><phrase role="index-entry-level-0">is_floating_point</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_function"><phrase role="index-entry-level-0">is_function</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_fundamental"><phrase role="index-entry-level-0">is_fundamental</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_integral"><phrase role="index-entry-level-0">is_integral</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_function_pointer"><phrase role="index-entry-level-0">is_member_function_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_object_pointer"><phrase role="index-entry-level-0">is_member_object_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_pointer"><phrase role="index-entry-level-0">is_member_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_object"><phrase role="index-entry-level-0">is_object</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_pointer</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_pointer"><phrase role="index-entry-level-1">is_pointer</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_polymorphic"><phrase role="index-entry-level-0">is_polymorphic</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_reference"><phrase role="index-entry-level-0">is_reference</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_same"><phrase role="index-entry-level-0">is_same</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_scalar"><phrase role="index-entry-level-0">is_scalar</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_signed"><phrase role="index-entry-level-0">is_signed</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_union</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_union"><phrase role="index-entry-level-1">is_union</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">User Defined Specializations</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_unsigned"><phrase role="index-entry-level-0">is_unsigned</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_void</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_void"><phrase role="index-entry-level-1">is_void</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_volatile"><phrase role="index-entry-level-0">is_volatile</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_8"><term>M</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.make_signed"><phrase role="index-entry-level-0">make_signed</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.make_unsigned"><phrase role="index-entry-level-0">make_unsigned</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_9"><term>O</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">one</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_volatile"><phrase role="index-entry-level-1">add_volatile</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-1">two</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-2">add_const</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-2">three</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_cv"><phrase role="index-entry-level-3">add_cv</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_10"><term>P</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.promote"><phrase role="index-entry-level-0">promote</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_11"><term>R</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.remove_all_extents"><phrase role="index-entry-level-0">remove_all_extents</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_const"><phrase role="index-entry-level-0">remove_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_cv"><phrase role="index-entry-level-0">remove_cv</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">remove_extent</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.remove_extent"><phrase role="index-entry-level-1">remove_extent</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_pointer"><phrase role="index-entry-level-0">remove_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_reference"><phrase role="index-entry-level-0">remove_reference</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_volatile"><phrase role="index-entry-level-0">remove_volatile</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_13"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.type_with_alignment"><phrase role="index-entry-level-0">type_with_alignment</phrase></link></para></listitem></itemizedlist></listitem></varlistentry></variablelist></index>
+ <index>
+ <title>Typedef Index</title>
+ <para><link linkend="idx_id_21">F</link> <link linkend="idx_id_27">R</link> <link linkend="idx_id_29">T</link> <link linkend="idx_id_31">V</link></para><variablelist><varlistentry id="idx_id_21"><term>F</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">false_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_27"><term>R</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">result_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-1">function_traits</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_29"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">true_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_31"><term>V</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">value_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.examples.copy"><phrase role="index-entry-level-1">An Optimized Version of std::copy</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></index>
+ <index>
+ <title>Macro Index</title>
+ <para><link linkend="idx_id_33">B</link></para><variablelist><varlistentry id="idx_id_33"><term>B</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">BOOST_ALIGNMENT_OF</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.category.transform"><phrase role="index-entry-level-1">Type Traits that Transform One Type to Another</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_ASSIGN</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_CONSTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_COPY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_ASSIGN</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_CONSTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_COPY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_DESTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_VIRTUAL_DESTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_ABSTRACT</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_BASE_OF</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_CLASS</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_CONVERTIBLE</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_EMPTY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_ENUM</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_POD</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_POLYMORPHIC</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_UNION</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></index>
+ <index>
+ <title>Index Test 1</title>
+ <para><link linkend="idx_id_61">T</link></para><variablelist><varlistentry id="idx_id_61"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">type-traits</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intro"><phrase role="index-entry-level-1">Introduction</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></index>
+ <index>
+ <title>Index Test 2</title>
+ <para><link linkend="idx_id_77">T</link></para><variablelist><varlistentry id="idx_id_77"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">type-traits</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></index>
+ <index><title>Index</title><para><link linkend="idx_id_80">A</link> <link linkend="idx_id_81">B</link> <link linkend="idx_id_82">C</link> <link linkend="idx_id_83">D</link> <link linkend="idx_id_84">E</link> <link linkend="idx_id_85">F</link> <link linkend="idx_id_86">H</link> <link linkend="idx_id_87">I</link> <link linkend="idx_id_88">M</link> <link linkend="idx_id_89">O</link> <link linkend="idx_id_90">P</link> <link linkend="idx_id_91">R</link> <link linkend="idx_id_92">S</link> <link linkend="idx_id_93">T</link> <link linkend="idx_id_94">U</link> <link linkend="idx_id_95">V</link></para><variablelist><varlistentry id="idx_id_80"><term>A</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">add_const</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-1">add_const</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-1">Constrained Index Term</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.add_cv"><phrase role="index-entry-level-0">add_cv</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_pointer"><phrase role="index-entry-level-0">add_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.add_reference"><phrase role="index-entry-level-0">add_reference</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">add_volatile</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.add_volatile"><phrase role="index-entry-level-1">add_volatile</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.ignored_block"><phrase role="index-entry-level-1">This section contains one block that must not be indexed and one that should be.</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.aligned_storage"><phrase role="index-entry-level-0">aligned_storage</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">alignment_of</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-1">alignment_of</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_81"><term>B</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">Background and Tutorial</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">is_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">is_void</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">remove_extent</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">type-traits</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_ALIGNMENT_OF</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.category.transform"><phrase role="index-entry-level-1">Type Traits that Transform One Type to Another</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_ASSIGN</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_CONSTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_NOTHROW_COPY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_ASSIGN</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_CONSTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_COPY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_TRIVIAL_DESTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_HAS_VIRTUAL_DESTRUCTOR</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_ABSTRACT</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_BASE_OF</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_CLASS</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_CONVERTIBLE</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_EMPTY</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_ENUM</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_POD</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_POLYMORPHIC</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">BOOST_IS_UNION</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">Support for Compiler Intrinsics</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_82"><term>C</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">Constrained Index Term</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-1">add_const</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_83"><term>D</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.decay"><phrase role="index-entry-level-0">decay</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_84"><term>E</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">extent</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-1">extent</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_85"><term>F</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">false_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.floating_point_promotion"><phrase role="index-entry-level-0">floating_point_promotion</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">Foo1</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">Foo2</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-1">Bar2</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.category.value_traits"><phrase role="index-entry-level-2">Type Traits that Describe the Properties of a Type</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">function_traits</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-1">function_traits</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-1">result_type</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_86"><term>H</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_assign"><phrase role="index-entry-level-0">has_nothrow_assign</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-1">has_nothrow_constructor</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-1">has_nothrow_default_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_copy</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-1">has_nothrow_copy</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-1">has_nothrow_copy_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_copy_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_copy"><phrase role="index-entry-level-1">has_nothrow_copy</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_nothrow_default_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_nothrow_constructor"><phrase role="index-entry-level-1">has_nothrow_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_assign"><phrase role="index-entry-level-0">has_trivial_assign</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_constructor"><phrase role="index-entry-level-1">has_trivial_default_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_copy</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-1">has_trivial_copy</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-1">has_trivial_copy_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_copy_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_copy"><phrase role="index-entry-level-1">has_trivial_copy</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">has_trivial_default_constructor</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.has_trivial_constructor"><phrase role="index-entry-level-1">has_trivial_constructor</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.has_trivial_destructor"><phrase role="index-entry-level-0">has_trivial_destructor</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.has_virtual_destructor"><phrase role="index-entry-level-0">has_virtual_destructor</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_87"><term>I</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">integral_constant</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.alignment_of"><phrase role="index-entry-level-1">alignment_of</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.extent"><phrase role="index-entry-level-1">extent</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">false_type</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.reference.rank"><phrase role="index-entry-level-1">rank</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">true_type</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">value_type</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_promotion"><phrase role="index-entry-level-0">integral_promotion</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">Introduction</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intro"><phrase role="index-entry-level-1">type-traits</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_abstract"><phrase role="index-entry-level-0">is_abstract</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_arithmetic"><phrase role="index-entry-level-0">is_arithmetic</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_array"><phrase role="index-entry-level-0">is_array</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_base_of"><phrase role="index-entry-level-0">is_base_of</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_class</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_class"><phrase role="index-entry-level-1">is_class</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">User Defined Specializations</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_complex"><phrase role="index-entry-level-0">is_complex</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_compound"><phrase role="index-entry-level-0">is_compound</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_const"><phrase role="index-entry-level-0">is_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_convertible"><phrase role="index-entry-level-0">is_convertible</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_empty"><phrase role="index-entry-level-0">is_empty</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_enum"><phrase role="index-entry-level-0">is_enum</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_floating_point"><phrase role="index-entry-level-0">is_floating_point</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_function"><phrase role="index-entry-level-0">is_function</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_fundamental"><phrase role="index-entry-level-0">is_fundamental</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_integral"><phrase role="index-entry-level-0">is_integral</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_function_pointer"><phrase role="index-entry-level-0">is_member_function_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_object_pointer"><phrase role="index-entry-level-0">is_member_object_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_member_pointer"><phrase role="index-entry-level-0">is_member_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_object"><phrase role="index-entry-level-0">is_object</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_pointer</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_pointer"><phrase role="index-entry-level-1">is_pointer</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_polymorphic"><phrase role="index-entry-level-0">is_polymorphic</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_reference"><phrase role="index-entry-level-0">is_reference</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_same"><phrase role="index-entry-level-0">is_same</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_scalar"><phrase role="index-entry-level-0">is_scalar</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.is_signed"><phrase role="index-entry-level-0">is_signed</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_union</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_union"><phrase role="index-entry-level-1">is_union</phrase></link></emphasis></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">User Defined Specializations</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_unsigned"><phrase role="index-entry-level-0">is_unsigned</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">is_void</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.is_void"><phrase role="index-entry-level-1">is_void</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.is_volatile"><phrase role="index-entry-level-0">is_volatile</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_88"><term>M</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.make_signed"><phrase role="index-entry-level-0">make_signed</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.make_unsigned"><phrase role="index-entry-level-0">make_unsigned</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_89"><term>O</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">one</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_volatile"><phrase role="index-entry-level-1">add_volatile</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-1">two</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_const"><phrase role="index-entry-level-2">add_const</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-2">three</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.add_cv"><phrase role="index-entry-level-3">add_cv</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">Optimized Version of std::copy</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.examples.copy"><phrase role="index-entry-level-1">value_type</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_90"><term>P</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.promote"><phrase role="index-entry-level-0">promote</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_91"><term>R</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">rank</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.rank"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_all_extents"><phrase role="index-entry-level-0">remove_all_extents</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_const"><phrase role="index-entry-level-0">remove_const</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_cv"><phrase role="index-entry-level-0">remove_cv</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">remove_extent</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><emphasis role="bold"><link linkend="boost_typetraits.reference.remove_extent"><phrase role="index-entry-level-1">remove_extent</phrase></link></emphasis></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_pointer"><phrase role="index-entry-level-0">remove_pointer</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_reference"><phrase role="index-entry-level-0">remove_reference</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.remove_volatile"><phrase role="index-entry-level-0">remove_volatile</phrase></link></para></listitem><listitem><para><phrase role="index-entry-level-0">result_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.function_traits"><phrase role="index-entry-level-1">function_traits</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_92"><term>S</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">Support for Compiler Intrinsics</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_ALIGNMENT_OF</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_NOTHROW_ASSIGN</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_NOTHROW_CONSTRUCTOR</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_NOTHROW_COPY</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_TRIVIAL_ASSIGN</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_TRIVIAL_CONSTRUCTOR</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_TRIVIAL_COPY</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_TRIVIAL_DESTRUCTOR</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_HAS_VIRTUAL_DESTRUCTOR</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_ABSTRACT</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_BASE_OF</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_CLASS</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_CONVERTIBLE</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_EMPTY</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_ENUM</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_POD</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_POLYMORPHIC</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intrinsics"><phrase role="index-entry-level-1">BOOST_IS_UNION</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_93"><term>T</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">This section contains one block that must not be indexed and one that should be.</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.ignored_block"><phrase role="index-entry-level-1">add_volatile</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">true_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">Type Traits that Transform One Type to Another</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.category.transform"><phrase role="index-entry-level-1">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><phrase role="index-entry-level-0">type-traits</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.background"><phrase role="index-entry-level-1">Background and Tutorial</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.intro"><phrase role="index-entry-level-1">Introduction</phrase></link></para></listitem></itemizedlist></listitem><listitem><para><link linkend="boost_typetraits.reference.type_with_alignment"><phrase role="index-entry-level-0">type_with_alignment</phrase></link></para></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_94"><term>U</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">User Defined Specializations</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">is_class</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.user_defined"><phrase role="index-entry-level-1">is_union</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry><varlistentry id="idx_id_95"><term>V</term><listitem><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><phrase role="index-entry-level-0">value_type</phrase></para><itemizedlist mark="none" spacing="compact" role="index"><listitem><para><link linkend="boost_typetraits.examples.copy"><phrase role="index-entry-level-1">An Optimized Version of std::copy</phrase></link></para></listitem><listitem><para><link linkend="boost_typetraits.reference.integral_constant"><phrase role="index-entry-level-1">integral_constant</phrase></link></para></listitem></itemizedlist></listitem></itemizedlist></listitem></varlistentry></variablelist></index>
+
+</chapter> \ No newline at end of file
diff --git a/src/boost/tools/auto_index/test/type_traits.docbook b/src/boost/tools/auto_index/test/type_traits.docbook
new file mode 100644
index 00000000..64837d71
--- /dev/null
+++ b/src/boost/tools/auto_index/test/type_traits.docbook
@@ -0,0 +1,6673 @@
+<?xml version="1.0"?>
+<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+
+This file is based upon the type traits docs, but has had additional XML elements added to it
+to ensure complete testing.
+
+-->
+
+<chapter xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" id="boost_typetraits" rev:last-revision="$Date: 2008-11-28 12:41:45 +0000 (Fri, 28 Nov 2008) $">
+ <chapterinfo><author>
+ <firstname>various</firstname> <surname>authors</surname>
+ </author><copyright>
+ <year>2000</year> <year>2006</year> <holder>Adobe Systems Inc, David Abrahams,
+ Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant, Jesse Jones, Mat
+ Marcus, Itay Maman, John Maddock, Alexander Nasonov, Thorsten Ottosen, Robert
+ Ramey and Jeremy Siek</holder>
+ </copyright><legalnotice>
+ <para>
+ Distributed under the Boost Software License, Version 1.0. (See accompanying
+ file LICENSE_1_0.txt or copy at <ulink url="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</ulink>)
+ </para>
+ </legalnotice></chapterinfo>
+ <title>Boost.TypeTraits</title>
+ <para>
+ A printer-friendly <ulink url="http://svn.boost.org/svn/boost/sandbox/pdf/type_traits/release/type_traits.pdf">PDF
+ version of this manual is also available</ulink>.
+ </para>
+ <section id="boost_typetraits.intro">
+ <title><link linkend="boost_typetraits.intro"> Introduction</link></title>
+ <para>
+ The Boost type-traits library contains a set of very specific traits classes,
+ each of which encapsulate a single trait from the C++ type system; for example,
+ is a type a pointer or a reference type? Or does a type have a trivial constructor,
+ or a const-qualifier?
+ </para>
+ <para>
+ The type-traits classes share a unified design: each class inherits from a
+ the type <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the type has the specified property and inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ otherwise.
+ </para>
+ <para>
+ The type-traits library also contains a set of classes that perform a specific
+ transformation on a type; for example, they can remove a top-level const or
+ volatile qualifier from a type. Each class that performs a transformation defines
+ a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of the transformation.
+ </para>
+ </section>
+ <section id="boost_typetraits.background">
+ <title><link linkend="boost_typetraits.background"> Background and Tutorial</link></title>
+ <para>
+ The following is an updated version of the article "C++ Type traits"
+ by John Maddock and Steve Cleary that appeared in the October 2000 issue of
+ <ulink url="http://www.ddj.com">Dr Dobb's Journal</ulink>.
+ </para>
+ <para>
+ Generic programming (writing code which works with any data type meeting a
+ set of requirements) has become the method of choice for providing reusable
+ code. However, there are times in generic programming when "generic"
+ just isn't good enough - sometimes the differences between types are too large
+ for an efficient generic implementation. This is when the traits technique
+ becomes important - by encapsulating those properties that need to be considered
+ on a type by type basis inside a traits class, we can minimize the amount of
+ code that has to differ from one type to another, and maximize the amount of
+ generic code.
+ </para>
+ <?dbfo keep-together="auto" ?>
+ <para>
+ <indexterm>
+ <primary>Foo1</primary>
+ </indexterm>
+ Consider an example: when working with character strings, one common operation
+ is to determine the length of a null terminated string. Clearly it's possible
+ to write generic code that can do this, but it turns out that there are much
+ more efficient methods available: for example, the C library functions <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">strlen</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">wcslen</phrase></computeroutput>
+ are usually written in assembler, and with suitable hardware support can be
+ considerably faster than a generic version written in C++. The authors of the
+ C++ standard library realized this, and abstracted the properties of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">wchar_t</phrase></computeroutput>
+ into the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput>.
+ Generic code that works with character strings can simply use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase><phrase role="special">&lt;&gt;::</phrase><phrase role="identifier">length</phrase></computeroutput> to determine the length of a null
+ terminated string, safe in the knowledge that specializations of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput> will use the most appropriate
+ method available to them.
+ </para>
+ <anchor id="boost_typetraits.background.type_traits"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.type_traits">Type Traits</link>
+ </bridgehead>
+ <para>
+ Class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">char_traits</phrase></computeroutput> is a classic
+ example of a collection of type specific properties wrapped up in a single
+ class - what Nathan Myers termed a <emphasis>baggage class</emphasis><link linkend="background.references">[1]</link>. In the Boost type-traits library,
+ we<link linkend="background.references">[2]</link> have written a set of very
+ specific traits classes, each of which encapsulate a single trait from the
+ C++ type system; for example, is a type a pointer or a reference type? Or does
+ a type have a trivial constructor, or a const-qualifier? The type-traits classes
+ share a unified design: each class inherits from a the type <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the type has the specified property and inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ otherwise. As we will show, these classes can be used in generic programming
+ to determine the properties of a given type and introduce optimizations that
+ are appropriate for that case.
+ </para>
+ <para>
+ The type-traits library also contains a set of classes that perform a specific
+ transformation on a type; for example, they can remove a top-level const or
+ volatile qualifier from a type. Each class that performs a transformation defines
+ a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of the transformation. All of the type-traits classes are
+ defined inside namespace <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase></computeroutput>;
+ for brevity, namespace-qualification is omitted in most of the code samples
+ given.
+ </para>
+ <anchor id="boost_typetraits.background.implementation"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.implementation">Implementation</link>
+ </bridgehead>
+ <para>
+ There are far too many separate classes contained in the type-traits library
+ to give a full implementation here - see the source code in the Boost library
+ for the full details - however, most of the implementation is fairly repetitive
+ anyway, so here we will just give you a flavor for how some of the classes
+ are implemented. Beginning with possibly the simplest class in the library,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits
+ from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ only if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>.
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ Here we define a primary version of the template class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_void">is_void</link></computeroutput>,
+ and provide a full-specialization when <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>. While full specialization
+ of a template class is an important technique, sometimes we need a solution
+ that is halfway between a fully generic solution, and a full specialization.
+ This is exactly the situation for which the standards committee defined partial
+ template-class specialization. As an example, consider the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput>:
+ here we needed a primary version that handles all the cases where T is not
+ a pointer, and a partial specialization to handle all the cases where T is
+ a pointer:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">*&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ The syntax for partial specialization is somewhat arcane and could easily occupy
+ an article in its own right; like full specialization, in order to write a
+ partial specialization for a class, you must first declare the primary template.
+ The partial specialization contains an extra &lt;...&gt; after the class name
+ that contains the partial specialization parameters; these define the types
+ that will bind to that partial specialization rather than the default template.
+ The rules for what can appear in a partial specialization are somewhat convoluted,
+ but as a rule of thumb if you can legally write two function overloads of the
+ form:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase> <phrase role="identifier">foo</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">);</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">foo</phrase><phrase role="special">(</phrase><phrase role="identifier">U</phrase><phrase role="special">);</phrase>
+</programlisting>
+ <para>
+ Then you can also write a partial specialization of the form:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">class</phrase> <phrase role="identifier">c</phrase><phrase role="special">{</phrase> <phrase role="comment">/*details*/</phrase> <phrase role="special">};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">class</phrase> <phrase role="identifier">c</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;{</phrase> <phrase role="comment">/*details*/</phrase> <phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ This rule is by no means foolproof, but it is reasonably simple to remember
+ and close enough to the actual rule to be useful for everyday use.
+ </para>
+ <para>
+ As a more complex example of partial specialization consider the class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase></computeroutput>. This
+ class defines a single typedef-member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the same type as T but with any top-level array bounds removed; this
+ is an example of a traits class that performs a transformation on a type:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link>
+<phrase role="special">{</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">[</phrase><phrase role="identifier">N</phrase><phrase role="special">]&gt;</phrase>
+<phrase role="special">{</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ The aim of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.remove_extent">remove_extent</link></computeroutput>
+ is this: imagine a generic algorithm that is passed an array type as a template
+ parameter, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.remove_extent">remove_extent</link></computeroutput>
+ provides a means of determining the underlying type of the array. For example
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">][</phrase><phrase role="number">5</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> would evaluate to the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">5</phrase><phrase role="special">]</phrase></computeroutput>. This example also shows that the number of
+ template parameters in a partial specialization does not have to match the
+ number in the default template. However, the number of parameters that appear
+ after the class name do have to match the number and type of the parameters
+ in the default template.
+ </para>
+ <anchor id="boost_typetraits.background.optimized_copy"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.optimized_copy">Optimized copy</link>
+ </bridgehead>
+ <para>
+ As an example of how the type traits classes can be used, consider the standard
+ library algorithm copy:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">Iter1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">Iter2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">Iter2</phrase> <phrase role="identifier">copy</phrase><phrase role="special">(</phrase><phrase role="identifier">Iter1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">Iter2</phrase> <phrase role="identifier">out</phrase><phrase role="special">);</phrase>
+</programlisting>
+ <para>
+ Obviously, there's no problem writing a generic version of copy that works
+ for all iterator types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput>; however, there are
+ some circumstances when the copy operation can best be performed by a call
+ to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>. In order to implement
+ copy in terms of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput> all
+ of the following conditions need to be met:
+ </para>
+ <itemizedlist>
+ <listitem>
+ Both of the iterator types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput> must be pointers.
+ </listitem>
+ <listitem>
+ Both <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter2</phrase></computeroutput> must point to the same type - excluding
+ const and volatile-qualifiers.
+ </listitem>
+ <listitem>
+ The type pointed to by <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Iter1</phrase></computeroutput>
+ must have a trivial assignment operator.
+ </listitem>
+ </itemizedlist>
+ <para>
+ By trivial assignment operator we mean that the type is either a scalar type<link linkend="background.references">[3]</link> or:
+ </para>
+ <itemizedlist>
+ <listitem>
+ The type has no user defined assignment operator.
+ </listitem>
+ <listitem>
+ The type does not have any data members that are references.
+ </listitem>
+ <listitem>
+ All base classes, and all data member objects must have trivial assignment
+ operators.
+ </listitem>
+ </itemizedlist>
+ <para>
+ If all these conditions are met then a type can be copied using <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput> rather than using a compiler generated
+ assignment operator. The type-traits library provides a class <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>,
+ such that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is true only if T has a trivial assignment
+ operator. This class "just works" for scalar types, but has to be
+ explicitly specialised for class/struct types that also happen to have a trivial
+ assignment operator. In other words if <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link>
+ gives the wrong answer, it will give the "safe" wrong answer - that
+ trivial assignment is not allowable.
+ </para>
+ <para>
+ The code for an optimized version of copy that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>
+ where appropriate is given in <link linkend="boost_typetraits.examples.copy">the
+ examples</link>. The code begins by defining a template function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">do_copy</phrase></computeroutput> that performs a "slow but safe"
+ copy. The last parameter passed to this function may be either a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ or a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">false_type</link></computeroutput>.
+ Following that there is an overload of do<emphasis role="underline">copy that
+ uses `memcpy`: this time the iterators are required to actually be pointers
+ to the same type, and the final parameter must be a `</emphasis>_true_type<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">.</phrase> <phrase role="identifier">Finally</phrase><phrase role="special">,</phrase> <phrase role="identifier">the</phrase> <phrase role="identifier">version</phrase>
+ <phrase role="identifier">of</phrase> </computeroutput>copy<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="identifier">calls</phrase>
+ </computeroutput>do<emphasis role="underline">copy`, passing `</emphasis>_has_trivial_assign&lt;value_type&gt;()`
+ as the final parameter: this will dispatch to the optimized version where appropriate,
+ otherwise it will call the "slow but safe version".
+ </para>
+ <anchor id="boost_typetraits.background.was_it_worth_it_"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.was_it_worth_it_">Was it worth it?</link>
+ </bridgehead>
+ <para>
+ It has often been repeated in these columns that "premature optimization
+ is the root of all evil" <link linkend="background.references">[4]</link>.
+ So the question must be asked: was our optimization premature? To put this
+ in perspective the timings for our version of copy compared a conventional
+ generic copy<link linkend="background.references">[5]</link> are shown in table
+ 1.
+ </para>
+ <para>
+ Clearly the optimization makes a difference in this case; but, to be fair,
+ the timings are loaded to exclude cache miss effects - without this accurate
+ comparison between algorithms becomes difficult. However, perhaps we can add
+ a couple of caveats to the premature optimization rule:
+ </para>
+ <itemizedlist>
+ <listitem>
+ If you use the right algorithm for the job in the first place then optimization
+ will not be required; in some cases, memcpy is the right algorithm.
+ </listitem>
+ <listitem>
+ If a component is going to be reused in many places by many people then optimizations
+ may well be worthwhile where they would not be so for a single case - in
+ other words, the likelihood that the optimization will be absolutely necessary
+ somewhere, sometime is that much higher. Just as importantly the perceived
+ value of the stock implementation will be higher: there is no point standardizing
+ an algorithm if users reject it on the grounds that there are better, more
+ heavily optimized versions available.
+ </listitem>
+ </itemizedlist>
+ <table frame="all"> <title>Time taken to copy 1000 elements using `copy&lt;const
+ T*, T*&gt;` (times in micro-seconds)</title>
+ <tgroup cols="3">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Version
+ </para>
+ </entry><entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ Time
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ "Optimized" copy
+ </para>
+ </entry><entry>
+ <para>
+ char
+ </para>
+ </entry><entry>
+ <para>
+ 0.99
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ Conventional copy
+ </para>
+ </entry><entry>
+ <para>
+ char
+ </para>
+ </entry><entry>
+ <para>
+ 8.07
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ "Optimized" copy
+ </para>
+ </entry><entry>
+ <para>
+ int
+ </para>
+ </entry><entry>
+ <para>
+ 2.52
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ Conventional copy
+ </para>
+ </entry><entry>
+ <para>
+ int
+ </para>
+ </entry><entry>
+ <para>
+ 8.02
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table> <anchor id="boost_typetraits.background.pair_of_references"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.pair_of_references">Pair of References</link>
+ </bridgehead>
+ <para>
+ The optimized copy example shows how type traits may be used to perform optimization
+ decisions at compile-time. Another important usage of type traits is to allow
+ code to compile that otherwise would not do so unless excessive partial specialization
+ is used. This is possible by delegating partial specialization to the type
+ traits classes. Our example for this form of usage is a pair that can hold
+ references <link linkend="background.references">[6]</link>.
+ </para>
+ <para>
+ First, let us examine the definition of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">pair</phrase></computeroutput>, omitting
+ the comparison operators, default constructor, and template copy constructor
+ for simplicity:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">pair</phrase>
+<phrase role="special">{</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T1</phrase> <phrase role="identifier">first_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T2</phrase> <phrase role="identifier">second_type</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">T1</phrase> <phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+<phrase role="identifier">T2</phrase> <phrase role="identifier">second</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">pair</phrase><phrase role="special">(</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">nfirst</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T2</phrase> <phrase role="special">&amp;</phrase> <phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase>
+<phrase role="special">:</phrase><phrase role="identifier">first</phrase><phrase role="special">(</phrase><phrase role="identifier">nfirst</phrase><phrase role="special">),</phrase> <phrase role="identifier">second</phrase><phrase role="special">(</phrase><phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">}</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ Now, this "pair" cannot hold references as it currently stands, because
+ the constructor would require taking a reference to a reference, which is currently
+ illegal <link linkend="background.references">[7]</link>. Let us consider what
+ the constructor's parameters would have to be in order to allow "pair"
+ to hold non-reference types, references, and constant references:
+ </para>
+ <table frame="all"> <title>Required Constructor Argument Types</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of parameter to initializing constructor
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ A little familiarity with the type traits classes allows us to construct a
+ single mapping that allows us to determine the type of parameter from the type
+ of the contained class. The type traits classes provide a transformation <link linkend="boost_typetraits.reference.add_reference">add_reference</link>, which
+ adds a reference to its type, unless it is already a reference.
+ </para>
+ <table frame="all"> <title>Using add_reference to synthesize the correct constructor
+ type</title>
+ <tgroup cols="3">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ Type of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ T
+ </para>
+ </entry><entry>
+ <para>
+ const T
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ T &amp; [8]
+ </para>
+ </entry><entry>
+ <para>
+ T &amp;
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry><entry>
+ <para>
+ const T &amp;
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ This allows us to build a primary template definition for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput>
+ that can contain non-reference types, reference types, and constant reference
+ types:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">pair</phrase>
+<phrase role="special">{</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T1</phrase> <phrase role="identifier">first_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">T2</phrase> <phrase role="identifier">second_type</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">T1</phrase> <phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+<phrase role="identifier">T2</phrase> <phrase role="identifier">second</phrase><phrase role="special">;</phrase>
+
+<phrase role="identifier">pair</phrase><phrase role="special">(</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">nfirst</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T2</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase>
+<phrase role="special">:</phrase><phrase role="identifier">first</phrase><phrase role="special">(</phrase><phrase role="identifier">nfirst</phrase><phrase role="special">),</phrase> <phrase role="identifier">second</phrase><phrase role="special">(</phrase><phrase role="identifier">nsecond</phrase><phrase role="special">)</phrase> <phrase role="special">{</phrase> <phrase role="special">}</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ Add back in the standard comparison operators, default constructor, and template
+ copy constructor (which are all the same), and you have a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">pair</phrase></computeroutput> that
+ can hold reference types!
+ </para>
+ <para>
+ This same extension could have been done using partial template specialization
+ of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput>, but to specialize
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">pair</phrase></computeroutput> in this way would require
+ three partial specializations, plus the primary template. Type traits allows
+ us to define a single primary template that adjusts itself auto-magically to
+ any of these partial specializations, instead of a brute-force partial specialization
+ approach. Using type traits in this fashion allows programmers to delegate
+ partial specialization to the type traits classes, resulting in code that is
+ easier to maintain and easier to understand.
+ </para>
+ <anchor id="boost_typetraits.background.conclusion"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.conclusion">Conclusion</link>
+ </bridgehead>
+ <para>
+ We hope that in this article we have been able to give you some idea of what
+ type-traits are all about. A more complete listing of the available classes
+ are in the boost documentation, along with further examples using type traits.
+ Templates have enabled C++ uses to take the advantage of the code reuse that
+ generic programming brings; hopefully this article has shown that generic programming
+ does not have to sink to the lowest common denominator, and that templates
+ can be optimal as well as generic.
+ </para>
+ <anchor id="boost_typetraits.background.acknowledgements"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.acknowledgements">Acknowledgements</link>
+ </bridgehead>
+ <para>
+ The authors would like to thank Beman Dawes and Howard Hinnant for their helpful
+ comments when preparing this article.
+ </para>
+ <anchor id="background.references"/> <anchor id="boost_typetraits.background.references"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.background.references">References</link>
+ </bridgehead>
+ <orderedlist inheritnum="ignore" continuation="restarts">
+ <listitem>
+ Nathan C. Myers, C++ Report, June 1995.
+ </listitem>
+ <listitem>
+ The type traits library is based upon contributions by Steve Cleary, Beman
+ Dawes, Howard Hinnant and John Maddock: it can be found at www.boost.org.
+ </listitem>
+ <listitem>
+ A scalar type is an arithmetic type (i.e. a built-in integer or floating
+ point type), an enumeration type, a pointer, a pointer to member, or a const-
+ or volatile-qualified version of one of these types.
+ </listitem>
+ <listitem>
+ This quote is from Donald Knuth, ACM Computing Surveys, December 1974, pg
+ 268.
+ </listitem>
+ <listitem>
+ The test code is available as part of the boost utility library (see algo_opt_examples.cpp),
+ the code was compiled with gcc 2.95 with all optimisations turned on, tests
+ were conducted on a 400MHz Pentium II machine running Microsoft Windows 98.
+ </listitem>
+ <listitem>
+ John Maddock and Howard Hinnant have submitted a "compressed_pair"
+ library to Boost, which uses a technique similar to the one described here
+ to hold references. Their pair also uses type traits to determine if any
+ of the types are empty, and will derive instead of contain to conserve space
+ -- hence the name "compressed".
+ </listitem>
+ <listitem>
+ This is actually an issue with the C++ Core Language Working Group (issue
+ #106), submitted by Bjarne Stroustrup. The tentative resolution is to allow
+ a "reference to a reference to T" to mean the same thing as a "reference
+ to T", but only in template instantiation, in a method similar to multiple
+ cv-qualifiers.
+ </listitem>
+ <listitem>
+ For those of you who are wondering why this shouldn't be const-qualified,
+ remember that references are always implicitly constant (for example, you
+ can't re-assign a reference). Remember also that "const T &amp;"
+ is something completely different. For this reason, cv-qualifiers on template
+ type arguments that are references are ignored.
+ </listitem>
+ </orderedlist>
+ </section>
+ <section id="boost_typetraits.category">
+ <title><link linkend="boost_typetraits.category"> Type Traits by Category</link></title>
+ <section id="boost_typetraits.category.value_traits">
+ <title><link linkend="boost_typetraits.category.value_traits"> Type Traits
+ that Describe the Properties of a Type</link></title>
+ <para>
+ <indexterm>
+ <primary>Foo2</primary>
+ <secondary>Bar2</secondary>
+ </indexterm>
+ These traits are all <emphasis>value traits</emphasis>, which is to say the
+ traits classes all inherit from <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link>,
+ and are used to access some numerical property of a type. Often this is a
+ simple true or false Boolean value, but in a few cases may be some other
+ integer value (for example when dealing with type alignments, or array bounds:
+ see <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.alignment_of">alignment_of</link></computeroutput>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.rank">rank</link></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.extent">extent</link></computeroutput>).
+ </para>
+ <section id="boost_typetraits.category.value_traits.primary">
+ <title><link linkend="boost_typetraits.category.value_traits.primary"> Categorizing
+ a Type</link></title>
+ <para>
+ These traits identify what "kind" of type some type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is. These are split into two groups:
+ primary traits which are all mutually exclusive, and composite traits that
+ are compositions of one or more primary traits.
+ </para>
+ <para>
+ For any given type, exactly one primary type trait will inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ and all the others will inherit from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>,
+ in other words these traits are mutually exclusive.
+ </para>
+ <para>
+ This means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_integral">is_integral</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ will only ever be true for built-in types; if you want to check for a user-defined
+ class type that behaves "as if" it is an integral or floating
+ point type, then use the <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric_limits</phrase>
+ <phrase role="keyword">template</phrase></computeroutput> instead.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_array">is_array</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_class">is_class</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_complex">is_complex</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_enum">is_enum</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_function">is_function</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_integral">is_integral</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_object_pointer">is_member_object_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_union">is_union</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_void">is_void</link><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ The following traits are made up of the union of one or more type categorizations.
+ A type may belong to more than one of these categories, in addition to
+ one of the primary categories.
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_arithmetic">is_arithmetic</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_compound">is_compound</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_fundamental">is_fundamental</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_object">is_object</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_scalar">is_scalar</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.value_traits.properties">
+ <title><link linkend="boost_typetraits.category.value_traits.properties">
+ General Type Properties</link></title>
+ <para>
+ The following templates describe the general properties of a type.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.alignment_of">alignment_of</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_assign">has_nothrow_assign</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_default_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_default_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy_constructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.has_virtual_destructor">has_virtual_destructor</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_abstract">is_abstract</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_const">is_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_empty">is_empty</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_stateless">is_stateless</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_signed">is_signed</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_unsigned">is_unsigned</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_volatile">is_volatile</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.extent">extent</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.rank">rank</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.value_traits.relate">
+ <title><link linkend="boost_typetraits.category.value_traits.relate"> Relationships
+ Between Two Types</link></title>
+ <para>
+ These templates determine the whether there is a relationship between two
+ types:
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_base_of">is_base_of</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_same">is_same</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.category.transform">
+ <title><link linkend="boost_typetraits.category.transform"> Type Traits that
+ Transform One Type to Another</link></title>
+ <para>
+ The following templates transform one type to another, based upon some well-defined
+ rule. Each template has a single member called <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ that is the result of applying the transformation to the template argument
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis:</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_const">add_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_cv">add_cv</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_pointer">add_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_reference">add_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.add_volatile">add_volatile</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.decay">decay</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.floating_point_promotion">floating_point_promotion</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.integral_promotion">integral_promotion</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.make_signed">make_signed</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.make_unsigned">make_unsigned</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.promote">promote</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_all_extents">remove_all_extents</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_const">remove_const</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_cv">remove_cv</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_extent">remove_extent</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_reference">remove_reference</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.remove_volatile">remove_volatile</link><phrase role="special">;</phrase>
+</programlisting>
+ <anchor id="boost_typetraits.category.transform.broken_compiler_workarounds_"/>
+ <bridgehead renderas="sect4">
+ <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">Broken
+ Compiler Workarounds:</link>
+ </bridgehead>
+ <para>
+ For all of these templates support for partial specialization of class templates
+ is required to correctly implement the transformation. On the other hand,
+ practice shows that many of the templates from this category are very useful,
+ and often essential for implementing some generic libraries. Lack of these
+ templates is often one of the major limiting factors in porting those libraries
+ to compilers that do not yet support this language feature. As some of these
+ compilers are going to be around for a while, and at least one of them is
+ very wide-spread, it was decided that the library should provide workarounds
+ where possible.
+ </para>
+ <para>
+ The basic idea behind the workaround is to manually define full specializations
+ of all type transformation templates for all fundamental types, and all their
+ 1st and 2nd rank cv-[un]qualified derivative pointer types, and to provide
+ a user-level macro that will define all the explicit specializations needed
+ for any user-defined type T.
+ </para>
+ <para>
+ The first part guarantees the successful compilation of something like this:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="special">...</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+</programlisting>
+ <para>
+ and the second part provides the library's users with a mechanism to make
+ the above code work not only for <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput> or other built-in type,
+ but for their own types as well:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">namespace</phrase> <phrase role="identifier">myspace</phrase><phrase role="special">{</phrase>
+ <phrase role="keyword">struct</phrase> <phrase role="identifier">MyClass</phrase> <phrase role="special">{};</phrase>
+<phrase role="special">}</phrase>
+<phrase role="comment">// declare this at global scope:
+</phrase><phrase role="identifier">BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION</phrase><phrase role="special">(</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">)</phrase>
+<phrase role="comment">// transformations on myspace::MyClass now work:
+</phrase><phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="identifier">BOOST_STATIC_ASSERT</phrase><phrase role="special">((</phrase><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">,</phrase> <phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myspace</phrase><phrase role="special">::</phrase><phrase role="identifier">MyClass</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">));</phrase>
+<phrase role="comment">// etc.
+</phrase></programlisting>
+ <para>
+ Note that the macro BOOST_BROKEN_COMPILER_TYPE_TRAITS_SPECIALIZATION evaluates
+ to nothing on those compilers that <emphasis role="bold">do</emphasis> support
+ partial specialization.
+ </para>
+ </section>
+ <section id="boost_typetraits.category.alignment">
+ <title><link linkend="boost_typetraits.category.alignment"> Synthesizing Types
+ with Specific Alignments</link></title>
+ <para>
+ Some low level memory management routines need to synthesize a POD type with
+ specific alignment properties. The template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.type_with_alignment">type_with_alignment</link></computeroutput>
+ finds the smallest type with a specified alignment, while template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.aligned_storage">aligned_storage</link></computeroutput>
+ creates a type with a specific size and alignment.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.type_with_alignment">type_with_alignment</link><phrase role="special">;</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Size</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.aligned_storage">aligned_storage</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.category.function">
+ <title><link linkend="boost_typetraits.category.function"> Decomposing Function
+ Types</link></title>
+ <para>
+ The class template <link linkend="boost_typetraits.reference.function_traits">function_traits</link>
+ extracts information from function types (see also <link linkend="boost_typetraits.reference.is_function">is_function</link>).
+ This traits class allows you to tell how many arguments a function takes,
+ what those argument types are, and what the return type is.
+ </para>
+ <para>
+ <emphasis role="bold">Synopsis</emphasis>
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.function_traits">function_traits</link><phrase role="special">;</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.user_defined">
+ <title><link linkend="boost_typetraits.user_defined"> User Defined Specializations</link></title>
+ <para>
+ Occationally the end user may need to provide their own specialization for
+ one of the type traits - typically where intrinsic compiler support is required
+ to implement a specific trait fully. These specializations should derive from
+ boost::<link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ or boost::<link linkend="boost_typetraits.reference.integral_constant">false_type</link>
+ as appropriate:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pod</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+<phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_class</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+<phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_union</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase>
+
+<phrase role="keyword">struct</phrase> <phrase role="identifier">my_pod</phrase><phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">my_union</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">char</phrase> <phrase role="identifier">c</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">int</phrase> <phrase role="identifier">i</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">boost</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_pod</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_pod">is_pod</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_union">is_union</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">{};</phrase>
+
+ <phrase role="keyword">template</phrase><phrase role="special">&lt;&gt;</phrase>
+ <phrase role="keyword">struct</phrase> <link linkend="boost_typetraits.reference.is_class">is_class</link><phrase role="special">&lt;</phrase><phrase role="identifier">my_union</phrase><phrase role="special">&gt;</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">{};</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.intrinsics">
+ <title><link linkend="boost_typetraits.intrinsics"> Support for Compiler Intrinsics</link></title>
+ <para>
+ There are some traits that can not be implemented within the current C++ language:
+ to make these traits "just work" with user defined types, some kind
+ of additional help from the compiler is required. Currently (April 2008) Visual
+ C++ 8 and 9, GNU GCC 4.3 and MWCW 9 provide the necessary intrinsics, and other
+ compilers will no doubt follow in due course.
+ </para>
+ <para>
+ The Following traits classes always need compiler support to do the right thing
+ for all types (but all have safe fallback positions if this support is unavailable):
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_union">is_union</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_pod">is_pod</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_nothrow_assign">has_nothrow_assign</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.has_virtual_destructor">has_virtual_destructor</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The following traits classes can't be portably implemented in the C++ language,
+ although in practice, the implementations do in fact do the right thing on
+ all the compilers we know about:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_empty">is_empty</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The following traits classes are dependent on one or more of the above:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_class">is_class</link>
+ </listitem>
+ <listitem>
+ <link linkend="boost_typetraits.reference.is_stateless">is_stateless</link>
+ </listitem>
+ </itemizedlist>
+ <para>
+ The hooks for compiler-intrinsic support are defined in <ulink url="../../../../boost/type_traits/intrinsics.hpp">boost/type_traits/intrinsics.hpp</ulink>,
+ adding support for new compilers is simply a matter of defining one of more
+ of the following macros:
+ </para>
+ <table frame="all"> <title>Macros for Compiler Intrinsics</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_UNION(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a union type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_POD(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a POD type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_EMPTY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is an empty struct or union
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_CONSTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if the default constructor for T is trivial (i.e.
+ has no effect)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_COPY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial copy constructor (and can
+ therefore be replaced by a call to memcpy)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_ASSIGN(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial assignment operator (and can
+ therefore be replaced by a call to memcpy)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_TRIVIAL_DESTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T has a trivial destructor (i.e. ~T() has
+ no effect)
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_CONSTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="identifier">x</phrase><phrase role="special">;</phrase></computeroutput>
+ can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_COPY(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase><phrase role="special">(</phrase><phrase role="identifier">t</phrase><phrase role="special">)</phrase></computeroutput> can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_NOTHROW_ASSIGN(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="identifier">t</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">u</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">t</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">u</phrase></computeroutput> can not throw
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_HAS_VIRTUAL_DESTRUCTOR(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true T has a virtual destructor
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_ABSTRACT(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is an abstract type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_BASE_OF(T,U)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a base class of U
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_CLASS(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a class type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_CONVERTIBLE(T,U)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is convertible to U
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_ENUM(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true is T is an enum
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_IS_POLYMORPHIC(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to true if T is a polymorphic type
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ BOOST_ALIGNMENT_OF(T)
+ </para>
+ </entry><entry>
+ <para>
+ Should evaluate to the alignment requirements of type T.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.mpl">
+ <title><link linkend="boost_typetraits.mpl"> MPL Interoperability</link></title>
+ <para>
+ All the value based traits in this library conform to MPL's requirements for
+ an <ulink url="../../../../libs/mpl/doc/refmanual/integral-constant.html">Integral
+ Constant type</ulink>: that includes a number of rather intrusive workarounds
+ for broken compilers.
+ </para>
+ <para>
+ Purely as an implementation detail, this means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/bool.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">true_</phrase></computeroutput></ulink>,
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">false_type</link></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/bool.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">false_</phrase></computeroutput></ulink>,
+ and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase>
+ <phrase role="identifier">v</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <ulink url="../../../../libs/mpl/doc/refmanual/integral-c.html"><computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">mpl</phrase><phrase role="special">::</phrase><phrase role="identifier">integral_c</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">v</phrase><phrase role="special">&gt;</phrase></computeroutput></ulink>
+ (provided <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>)
+ </para>
+ </section>
+ <section id="boost_typetraits.examples">
+ <title><link linkend="boost_typetraits.examples"> Examples</link></title>
+ <section id="boost_typetraits.examples.copy">
+ <title><link linkend="boost_typetraits.examples.copy"> An Optimized Version
+ of std::copy</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">copy</phrase></computeroutput>
+ that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>
+ to determine whether to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>
+ to optimise the copy operation (see <ulink url="../../examples/copy_example.cpp">copy_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// opt::copy
+</phrase><phrase role="comment">// same semantics as std::copy
+</phrase><phrase role="comment">// calls memcpy where appropriate.
+</phrase><phrase role="comment">//
+</phrase>
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">I2</phrase> <phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">out</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">out</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">out</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">memcpy</phrase><phrase role="special">(</phrase><phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="special">(</phrase><phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">)*</phrase><phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">));</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">out</phrase><phrase role="special">+(</phrase><phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">copy</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I1</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">out</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// We can copy with memcpy if T has a trivial assignment operator,
+</phrase> <phrase role="comment">// and if the iterator arguments are actually pointers (this last
+</phrase> <phrase role="comment">// requirement we detect with overload resolution):
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">copy_imp</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">out</phrase><phrase role="special">,</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">&lt;</phrase><phrase role="identifier">value_type</phrase><phrase role="special">&gt;());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.fill">
+ <title><link linkend="boost_typetraits.examples.fill"> An Optimised Version
+ of std::fill</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">fill</phrase></computeroutput>
+ that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link></computeroutput>
+ to determine whether to use <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memset</phrase></computeroutput>
+ to optimise the fill operation (see <ulink url="../../examples/fill_example.cpp">fill_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// fill
+</phrase><phrase role="comment">// same as std::fill, but uses memset where appropriate
+</phrase><phrase role="comment">//
+</phrase><phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">bool</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="identifier">b</phrase><phrase role="special">&gt;&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">first</phrase> <phrase role="special">=</phrase> <phrase role="identifier">val</phrase><phrase role="special">;</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">memset</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">-</phrase><phrase role="identifier">first</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">I</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">fill</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">val</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// We can do an optimised fill if T has a trivial assignment
+</phrase> <phrase role="comment">// operator and if it's size is one:
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase>
+ <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_assign">has_trivial_assign</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase> <phrase role="special">&amp;&amp;</phrase> <phrase role="special">(</phrase><phrase role="keyword">sizeof</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase> <phrase role="special">==</phrase> <phrase role="number">1</phrase><phrase role="special">)&gt;</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_fill</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">,</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.destruct">
+ <title><link linkend="boost_typetraits.examples.destruct"> An Example that
+ Omits Destructor Calls For Types with Trivial Destructors</link></title>
+ <para>
+ Demonstrates a simple algorithm that uses <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">__has_trivial_destruct</phrase></computeroutput>
+ to determine whether to destructors need to be called (see <ulink url="../../examples/trivial_destructor_example.cpp">trivial_destructor_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// algorithm destroy_array:
+</phrase><phrase role="comment">// The reverse of std::unitialized_copy, takes a block of
+</phrase><phrase role="comment">// initialized memory and calls destructors on all objects therein.
+</phrase><phrase role="comment">//
+</phrase>
+<phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">void</phrase> <phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">while</phrase><phrase role="special">(</phrase><phrase role="identifier">first</phrase> <phrase role="special">!=</phrase> <phrase role="identifier">last</phrase><phrase role="special">)</phrase>
+ <phrase role="special">{</phrase>
+ <phrase role="identifier">first</phrase><phrase role="special">-&gt;~</phrase><phrase role="identifier">T</phrase><phrase role="special">();</phrase>
+ <phrase role="special">++</phrase><phrase role="identifier">first</phrase><phrase role="special">;</phrase>
+ <phrase role="special">}</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">first</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">last</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase> <phrase role="comment">// namespace detail
+</phrase>
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">p1</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase><phrase role="special">*</phrase> <phrase role="identifier">p2</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_destroy_array</phrase><phrase role="special">(</phrase><phrase role="identifier">p1</phrase><phrase role="special">,</phrase> <phrase role="identifier">p2</phrase><phrase role="special">,</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.has_trivial_destructor">has_trivial_destructor</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.iter">
+ <title><link linkend="boost_typetraits.examples.iter"> An improved Version
+ of std::iter_swap</link></title>
+ <para>
+ Demonstrates a version of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iter_swap</phrase></computeroutput>
+ that use type traits to determine whether an it's arguments are proxying
+ iterators or not, if they're not then it just does a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">swap</phrase></computeroutput>
+ of it's dereferenced arguments (the same as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iter_swap</phrase></computeroutput>
+ does), however if they are proxying iterators then takes special care over
+ the swap to ensure that the algorithm works correctly for both proxying iterators,
+ and even iterators of different types (see <ulink url="../../examples/iter_swap_example.cpp">iter_swap_example.cpp</ulink>):
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="comment">//
+</phrase><phrase role="comment">// iter_swap:
+</phrase><phrase role="comment">// tests whether iterator is a proxying iterator or not, and
+</phrase><phrase role="comment">// uses optimal form accordingly:
+</phrase><phrase role="comment">//
+</phrase><phrase role="keyword">namespace</phrase> <phrase role="identifier">detail</phrase><phrase role="special">{</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">false_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase> <phrase role="identifier">v_t</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">v_t</phrase> <phrase role="identifier">v</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">one</phrase><phrase role="special">;</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">one</phrase> <phrase role="special">=</phrase> <phrase role="special">*</phrase><phrase role="identifier">two</phrase><phrase role="special">;</phrase>
+ <phrase role="special">*</phrase><phrase role="identifier">two</phrase> <phrase role="special">=</phrase> <phrase role="identifier">v</phrase><phrase role="special">;</phrase>
+<phrase role="special">}</phrase>
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">static</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">true_type</link><phrase role="special">&amp;)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">using</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">swap</phrase><phrase role="special">;</phrase>
+ <phrase role="identifier">swap</phrase><phrase role="special">(*</phrase><phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="special">*</phrase><phrase role="identifier">two</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+
+<phrase role="special">}</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">typename</phrase> <phrase role="identifier">I1</phrase><phrase role="special">,</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">I2</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">void</phrase> <phrase role="identifier">iter_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">I1</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">I2</phrase> <phrase role="identifier">two</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="comment">//
+</phrase> <phrase role="comment">// See is both arguments are non-proxying iterators,
+</phrase> <phrase role="comment">// and if both iterator the same type:
+</phrase> <phrase role="comment">//
+</phrase> <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">r1_t</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">iterator_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">I2</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">reference</phrase> <phrase role="identifier">r2_t</phrase><phrase role="special">;</phrase>
+
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase>
+ <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">&lt;</phrase><phrase role="identifier">r1_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_reference">is_reference</link><phrase role="special">&lt;</phrase><phrase role="identifier">r2_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><link linkend="boost_typetraits.reference.is_same">is_same</link><phrase role="special">&lt;</phrase><phrase role="identifier">r1_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">r2_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">;</phrase>
+
+ <phrase role="identifier">detail</phrase><phrase role="special">::</phrase><phrase role="identifier">do_swap</phrase><phrase role="special">(</phrase><phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">two</phrase><phrase role="special">,</phrase> <phrase role="identifier">truth_type</phrase><phrase role="special">());</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ <section id="boost_typetraits.examples.to_double">
+ <title><link linkend="boost_typetraits.examples.to_double"> Convert Numeric
+ Types and Enums to double</link></title>
+ <para>
+ Demonstrates a conversion of <ulink url="../../../../libs/numeric/conversion/doc/html/boost_numericconversion/definitions.html#boost_numericconversion.definitions.numeric_types">Numeric
+ Types</ulink> and enum types to double:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">inline</phrase> <phrase role="keyword">double</phrase> <phrase role="identifier">to_double</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase> <phrase role="identifier">value</phrase><phrase role="special">)</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="keyword">typename</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase> <phrase role="identifier">promoted</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">return</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">numeric</phrase><phrase role="special">::</phrase><phrase role="identifier">converter</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase><phrase role="identifier">promoted</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">convert</phrase><phrase role="special">(</phrase><phrase role="identifier">value</phrase><phrase role="special">);</phrase>
+<phrase role="special">}</phrase>
+</programlisting>
+ </section>
+ </section>
+ <section id="boost_typetraits.reference">
+ <title><link linkend="boost_typetraits.reference"> Alphabetical Reference</link></title>
+ <section id="boost_typetraits.reference.add_const">
+ <title><link linkend="boost_typetraits.reference.add_const"> add_const</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ <secondary>two</secondary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">const</phrase></computeroutput> for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_cv">
+ <title><link linkend="boost_typetraits.reference.add_cv"> add_cv</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ <secondary>two</secondary>
+ <tertiary>three</tertiary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_cv</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_cv</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_pointer">
+ <title><link linkend="boost_typetraits.reference.add_pointer"> add_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_pointer</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">*</phrase></computeroutput>.
+ </para>
+ <para>
+ The rationale for this template is that it produces the same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">TYPEOF</phrase><phrase role="special">(&amp;</phrase><phrase role="identifier">t</phrase><phrase role="special">)</phrase></computeroutput>, where
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">t</phrase></computeroutput> is an object of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">**</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">**</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_reference">
+ <title><link linkend="boost_typetraits.reference.add_reference"> add_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_reference</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is not a reference type then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase><phrase role="special">&amp;</phrase></computeroutput>, otherwise <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.add_volatile">
+ <title><link linkend="boost_typetraits.reference.add_volatile"> add_volatile</link></title>
+ <indexterm type="class_name">
+ <primary>one</primary>
+ </indexterm>
+
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput> for all <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">add_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">add_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.aligned_storage">
+ <title><link linkend="boost_typetraits.reference.aligned_storage"> aligned_storage</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Size</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">aligned_storage</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> a built-in or POD type with size
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Size</phrase></computeroutput> and an alignment that
+ is a multiple of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Align</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">aligned_storage</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.alignment_of">
+ <title><link linkend="boost_typetraits.reference.alignment_of"> alignment_of</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">alignment_of</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template alignment<emphasis role="underline">of inherits from `</emphasis>_integral_constant&lt;std::size_t,
+ ALIGNOF(T)&gt;<computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">,</phrase> <phrase role="identifier">where</phrase>
+ </computeroutput>ALIGNOF(T)` is the alignment of type T.
+ </para>
+ <para>
+ <emphasis>Note: strictly speaking you should only rely on the value of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> being
+ a multiple of the true alignment of T, although in practice it does compute
+ the correct value in all the cases we know about.</emphasis>
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">alignment_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ with value <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">ALIGNOF</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">alignment_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.decay">
+ <title><link linkend="boost_typetraits.reference.decay"> decay</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">decay</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> Let <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>
+ be the result of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>, then if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>
+ is an array type, the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;*</phrase></computeroutput>,
+ otherwise if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput> is a function
+ type then the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase><phrase role="special">*</phrase></computeroutput>, otherwise the result is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">decay</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">(&amp;)[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">decay</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">(&amp;)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">)</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.extent">
+ <title><link linkend="boost_typetraits.reference.extent"> extent</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">N</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">extent</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template extent inherits
+ from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)&gt;</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)</phrase></computeroutput> is the number of elements in the N'th array
+ dimention of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not an array type,
+ or if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">N</phrase> <phrase role="special">&gt;</phrase>
+ <link linkend="boost_typetraits.reference.rank">rank</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>, or if the N'th array bound is incomplete,
+ then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">EXTENT</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase><phrase role="identifier">N</phrase><phrase role="special">)</phrase></computeroutput> is zero.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">extent</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">],</phrase>
+ <phrase role="number">1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">3</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>4</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">],</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>2</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">extent</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.floating_point_promotion">
+ <title><link linkend="boost_typetraits.reference.floating_point_promotion">
+ floating_point_promotion</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">floating_point_promotion</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If floating point promotion can be
+ applied to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ then applies floating point promotion to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">float</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">floating_point_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.function_traits">
+ <title><link linkend="boost_typetraits.reference.function_traits"> function_traits</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">F</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">function_traits</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">static</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">arity</phrase> <phrase role="special">=</phrase> <replaceable>see-below</replaceable><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">result_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> arg<replaceable>N</replaceable>_type<phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ The class template function_traits will only compile if:
+ </para>
+ <itemizedlist>
+ <listitem>
+ The compiler supports partial specialization of class templates.
+ </listitem>
+ <listitem>
+ The template argument <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>
+ is a <emphasis>function type</emphasis>, note that this <emphasis><emphasis role="bold">is not</emphasis></emphasis> the same thing as a <emphasis>pointer
+ to a function</emphasis>.
+ </listitem>
+ </itemizedlist>
+ <tip>
+ <para>
+ function_traits is intended to introspect only C++ functions of the form
+ R (), R( A1 ), R ( A1, ... etc. ) and not function pointers or class member
+ functions. To convert a function pointer type to a suitable type use <link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link>.
+ </para>
+ </tip>
+ <table frame="all"> <title>Function Traits Members</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Member
+ </para>
+ </entry><entry>
+ <para>
+ Description
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that gives the number of arguments
+ accepted by the function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type returned by function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">F</phrase><phrase role="special">&gt;::</phrase>arg<replaceable>N</replaceable>_type</computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The <replaceable>N</replaceable>th argument type of function type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="number">1</phrase> <phrase role="special">&lt;=</phrase>
+ <phrase role="identifier">N</phrase> <phrase role="special">&lt;=</phrase>
+ <phrase role="identifier">arity</phrase></computeroutput> of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">F</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table> <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 0.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 1.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An integral constant expression that has the value 4.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">result_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">long</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arg1_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arg4_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ The type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">void</phrase><phrase role="special">*</phrase></computeroutput>.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">long</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">void</phrase><phrase role="special">*)&gt;::</phrase><phrase role="identifier">arg5_type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A compiler error: there is no <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">arg5_type</phrase></computeroutput>
+ since there are only four arguments.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">function_traits</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">arity</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A compiler error: argument type is a <emphasis>function pointer</emphasis>,
+ and not a <emphasis>function type</emphasis>.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_assign">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_assign"> has_nothrow_assign</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_assign</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing assignment-operator then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_assign</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing assignment-operator;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler support to ensure that this trait "just
+ works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_assign</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_constructor">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_constructor">
+ has_nothrow_constructor</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_default_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing default-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_constructor</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing default-constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to ensure that this trait "just works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_constructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_copy">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_copy"> has_nothrow_copy</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_copy</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_nothrow_copy_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a non-throwing copy-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_nothrow_copy</phrase></computeroutput>
+ will never report that a class or struct has a non-throwing copy-constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only Visual
+ C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to ensure that this trait "just works".
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_nothrow_copy</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_nothrow_cp_cons">
+ <title><link linkend="boost_typetraits.reference.has_nothrow_cp_cons"> has_nothrow_copy_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_nothrow_copy">has_nothrow_copy</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_no_throw_def_cons">
+ <title><link linkend="boost_typetraits.reference.has_no_throw_def_cons"> has_nothrow_default_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_nothrow_constructor">has_nothrow_constructor</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_assign">
+ <title><link linkend="boost_typetraits.reference.has_trivial_assign"> has_trivial_assign</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_assign</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial assignment-operator then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ If a type has a trivial assignment-operator then the operator has the same
+ effect as copying the bits of one object to the other: calls to the operator
+ can be safely replaced with a call to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_assign
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.8p11.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_assign</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_constructor">
+ <title><link linkend="boost_typetraits.reference.has_trivial_constructor">
+ has_trivial_constructor</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_default_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial default-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ If a type has a trivial default-constructor then the constructor have no
+ effect: calls to the constructor can be safely omitted. Note that using meta-programming
+ to omit a call to a single trivial-constructor call is of no benefit whatsoever.
+ However, if loops and/or exception handling code can also be omitted, then
+ some benefit in terms of code size and speed can be obtained.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_constructor
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.1p6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_copy">
+ <title><link linkend="boost_typetraits.reference.has_trivial_copy"> has_trivial_copy</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_copy</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+
+<phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_copy_constructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial copy-constructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ These two traits are synonyms for each other.
+ </para>
+ <para>
+ If a type has a trivial copy-constructor then the constructor has the same
+ effect as copying the bits of one object to the other: calls to the constructor
+ can be safely replaced with a call to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">memcpy</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_copy
+ will never report that a user-defined class or struct has a trivial constructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.8p6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_cp_cons">
+ <title><link linkend="boost_typetraits.reference.has_trivial_cp_cons"> has_trivial_copy_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_trivial_copy">has_trivial_copy</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_def_cons">
+ <title><link linkend="boost_typetraits.reference.has_trivial_def_cons"> has_trivial_default_constructor</link></title>
+ <para>
+ See <link linkend="boost_typetraits.reference.has_trivial_constructor">has_trivial_constructor</link>.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.has_trivial_destructor">
+ <title><link linkend="boost_typetraits.reference.has_trivial_destructor"> has_trivial_destructor</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_trivial_destructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a trivial destructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ If a type has a trivial destructor then the destructor has no effect: calls
+ to the destructor can be safely omitted. Note that using meta-programming
+ to omit a call to a single trivial-constructor call is of no benefit whatsoever.
+ However, if loops and/or exception handling code can also be omitted, then
+ some benefit in terms of code size and speed can be obtained.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, has_trivial_destructor
+ will never report that a user-defined class or struct has a trivial destructor;
+ this is always safe, if possibly sub-optimal. Currently (May 2005) only MWCW
+ 9 and Visual C++ 8 have the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect user-defined classes with trivial constructors.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.4p3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.has_virtual_destructor">
+ <title><link linkend="boost_typetraits.reference.has_virtual_destructor"> has_virtual_destructor</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">has_virtual_destructor</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ type with a virtual destructor then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> This trait is provided
+ for completeness, since it's part of the Technical Report on C++ Library
+ Extensions. However, there is currently no way to portably implement this
+ trait. The default version provided always inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>,
+ and has to be explicitly specialized for types with virtual destructors unless
+ the compiler used has compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ that enable the trait to do the right thing: currently (May 2005) only Visual
+ C++ 8 and GCC-4.3 have the necessary <link linkend="boost_typetraits.intrinsics">intrinsics</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 12.4.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">has_virtual_destructor</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.integral_constant">
+ <title><link linkend="boost_typetraits.reference.integral_constant"> integral_constant</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">val</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">integral_constant</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="identifier">val</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">typedef</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">value_type</phrase><phrase role="special">;</phrase>
+ <phrase role="keyword">static</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">T</phrase> <phrase role="identifier">value</phrase> <phrase role="special">=</phrase> <phrase role="identifier">val</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="keyword">true</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">true_type</phrase><phrase role="special">;</phrase>
+<phrase role="keyword">typedef</phrase> <phrase role="identifier">integral_constant</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">bool</phrase><phrase role="special">,</phrase> <phrase role="keyword">false</phrase><phrase role="special">&gt;</phrase> <phrase role="identifier">false_type</phrase><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ Class template <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_constant</phrase></computeroutput>
+ is the common base class for all the value-based type traits. The two typedef's
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">true_type</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">false_type</phrase></computeroutput> are provided for convenience:
+ most of the value traits are Boolean properties and so will inherit from
+ one of these.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.integral_promotion">
+ <title><link linkend="boost_typetraits.reference.integral_promotion"> integral_promotion</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">integral_promotion</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If integral promotion can be applied
+ to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>, then
+ applies integral promotion to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.5 except 4.5/3
+ (integral bit-field).
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">integral_promotion</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">integral_promotion</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">enum</phrase> <phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">float_round_style</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.is_abstract">
+ <title><link linkend="boost_typetraits.reference.is_abstract"> is_abstract</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_abstract</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ abstract type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_abstract</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> The compiler must
+ support DR337 (as of April 2005: GCC 3.4, VC++ 7.1 (and later), Intel C++
+ 7 (and later), and Comeau 4.3.2). Otherwise behaves the same as <link linkend="boost_typetraits.reference.is_polymorphic">is_polymorphic</link>;
+ this is the "safe fallback position" for which polymorphic types
+ are always regarded as potentially abstract. The macro BOOST_NO_IS_ABSTRACT
+ is used to signify that the implementation is buggy, users should check for
+ this in their own code if the "safe fallback" is not suitable for
+ their particular use-case.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">abc</phrase><phrase role="special">{</phrase> <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">abc</phrase><phrase role="special">()</phrase> <phrase role="special">=</phrase> <phrase role="number">0</phrase><phrase role="special">;</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">abc</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_abstract</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_arithmetic">
+ <title><link linkend="boost_typetraits.reference.is_arithmetic"> is_arithmetic</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_arithmetic</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ arithmetic type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Arithmetic types include integral and floating point types (see also <link linkend="boost_typetraits.reference.is_integral">is_integral</link> and
+ <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link>).
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p8.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_arithmetic</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_arithmetic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_array">
+ <title><link linkend="boost_typetraits.reference.is_array"> is_array</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_array</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ array type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_array</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can give the wrong result with function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_array</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_base_of">
+ <title><link linkend="boost_typetraits.reference.is_base_of"> is_base_of</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_base_of</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If Base is base class of type
+ Derived or if both types are the same then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ This template will detect non-public base classes, and ambiguous base classes.
+ </para>
+ <para>
+ Note that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">X</phrase><phrase role="special">,</phrase><phrase role="identifier">X</phrase><phrase role="special">&gt;</phrase></computeroutput> will always inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>.
+ <emphasis role="bold">This is the case even if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">X</phrase></computeroutput>
+ is not a class type</emphasis>. This is a change in behaviour from Boost-1.33
+ in order to track the Technical Report on C++ Library Extensions.
+ </para>
+ <para>
+ Types <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput> and <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput> must not be incomplete types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_base_of</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types. There are some older compilers which
+ will produce compiler errors if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput>
+ is a private base class of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput>,
+ or if <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Base</phrase></computeroutput> is an ambiguous
+ base of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Derived</phrase></computeroutput>. These compilers
+ include Borland C++, older versions of Sun Forte C++, Digital Mars C++, and
+ older versions of EDG based compilers.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="keyword">class</phrase> <phrase role="identifier">Base</phrase><phrase role="special">{};</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">Derived</phrase> <phrase role="special">:</phrase>
+ <phrase role="keyword">public</phrase> <phrase role="identifier">Base</phrase><phrase role="special">{};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Derived</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">Base</phrase><phrase role="special">,</phrase> <phrase role="identifier">Base</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>: a class is regarded as it's
+ own base.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_base_of</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_class">
+ <title><link linkend="boost_typetraits.reference.is_class"> is_class</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_class</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ class type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 9.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_class</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Without (some as
+ yet unspecified) help from the compiler, we cannot distinguish between union
+ and class types, as a result this type will erroneously inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link> for
+ union types. See also <link linkend="boost_typetraits.reference.is_union">is_union</link>.
+ Currently (May 2005) only Visual C++ 8 has the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to correctly identify union types, and therefore make is_class function correctly.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">MyClass</phrase><phrase role="special">;</phrase></computeroutput> then:
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_complex">
+ <title><link linkend="boost_typetraits.reference.is_complex"> is_complex</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_complex</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is a complex number type then true (of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">complex</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ for some type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">U</phrase></computeroutput>), otherwise
+ false.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 26.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_complex</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.is_compound">
+ <title><link linkend="boost_typetraits.reference.is_compound"> is_compound</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_compound</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ compound type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Any type that is not a fundamental type is a compound type (see also <link linkend="boost_typetraits.reference.is_fundamental">is_fundamental</link>).
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_compound</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyEnum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_compound</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_const">
+ <title><link linkend="boost_typetraits.reference.is_const"> is_const</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_const</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (top level) const-qualified
+ type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the const-qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the const-qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_const</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_convertible">
+ <title><link linkend="boost_typetraits.reference.is_convertible"> is_convertible</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_convertible</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If an imaginary lvalue of type
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">From</phrase></computeroutput> is convertible to type
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput> then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ Type From must not be an incomplete type.
+ </para>
+ <para>
+ Type To must not be an incomplete, or function type.
+ </para>
+ <para>
+ No types are considered to be convertible to array types or abstract-class
+ types.
+ </para>
+ <para>
+ This template can not detect whether a converting-constructor is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput> or not: if type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput>
+ has a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">private</phrase></computeroutput> converting constructor
+ from type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">From</phrase></computeroutput> then instantiating
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">From</phrase><phrase role="special">,</phrase> <phrase role="identifier">To</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ will produce a compiler error. For this reason <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase></computeroutput>
+ can not be used to determine whether a type has a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">public</phrase></computeroutput>
+ copy-constructor or not.
+ </para>
+ <para>
+ This template will also produce compiler errors if the conversion is ambiguous,
+ for example:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">B</phrase> <phrase role="special">:</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">C</phrase> <phrase role="special">:</phrase> <phrase role="identifier">A</phrase> <phrase role="special">{};</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">D</phrase> <phrase role="special">:</phrase> <phrase role="identifier">B</phrase><phrase role="special">,</phrase> <phrase role="identifier">C</phrase> <phrase role="special">{};</phrase>
+<phrase role="comment">// This produces a compiler error, the conversion is ambiguous:
+</phrase><phrase role="keyword">bool</phrase> <phrase role="keyword">const</phrase> <phrase role="identifier">y</phrase> <phrase role="special">=</phrase> <phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">D</phrase><phrase role="special">*,</phrase><phrase role="identifier">A</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase><phrase role="special">;</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4 and 8.5.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> This template is
+ currently broken with Borland C++ Builder 5 (and earlier), for constructor-based
+ conversions, and for the Metrowerks 7 (and earlier) compiler in all cases.
+ If the compiler does not support <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_abstract">is_abstract</link></computeroutput>,
+ then the template parameter <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">To</phrase></computeroutput>
+ must not be an abstract type.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_convertible</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*,</phrase> <phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the conversion would require a <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const_cast</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;,</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_convertible</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_empty">
+ <title><link linkend="boost_typetraits.reference.is_empty"> is_empty</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_empty</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an empty class type then
+ inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10p5.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> In order to correctly
+ detect empty classes this trait relies on either:
+ </para>
+ <itemizedlist>
+ <listitem>
+ the compiler implementing zero sized empty base classes, or
+ </listitem>
+ <listitem>
+ the compiler providing <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to detect empty classes.
+ </listitem>
+ </itemizedlist>
+ <para>
+ Can not be used with incomplete types.
+ </para>
+ <para>
+ Can not be used with union types, until is_union can be made to work.
+ </para>
+ <para>
+ If the compiler does not support partial-specialization of class templates,
+ then this template can not be used with abstract types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">struct</phrase> <phrase role="identifier">empty_class</phrase>
+ <phrase role="special">{};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">empty_class</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_enum">
+ <title><link linkend="boost_typetraits.reference.is_enum"> is_enum</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_enum</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ enum type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_enum</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Requires a correctly
+ functioning <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link>
+ template; this means that is_enum is currently broken under Borland C++ Builder
+ 5, and for the Metrowerks compiler prior to version 8, other compilers should
+ handle this template just fine.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">enum</phrase> <phrase role="identifier">my_enum</phrase>
+ <phrase role="special">{</phrase> <phrase role="identifier">one</phrase><phrase role="special">,</phrase> <phrase role="identifier">two</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_enum</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_floating_point">
+ <title><link linkend="boost_typetraits.reference.is_floating_point"> is_floating_point</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_floating_point</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ floating point type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p8.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_floating_point</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_floating_point</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_function">
+ <title><link linkend="boost_typetraits.reference.is_function"> is_function</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_function</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ function type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Note that this template does not detect <emphasis>pointers to functions</emphasis>,
+ or <emphasis>references to functions</emphasis>, these are detected by <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link> and <link linkend="boost_typetraits.reference.is_reference">is_reference</link> respectively:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="identifier">f1</phrase><phrase role="special">();</phrase> <phrase role="comment">// f1 is of function type.
+</phrase><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">f2</phrase><phrase role="special">*)();</phrase> <phrase role="comment">// f2 is a pointer to a function.
+</phrase><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">f3</phrase><phrase role="special">&amp;)();</phrase> <phrase role="comment">// f3 is a reference to a function.
+</phrase></programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2p1 and 8.3.5.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_function</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a pointer type, not a function type.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(&amp;)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a reference to a function, not a function type.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">double</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: the argument in this case
+ is a pointer to a member function.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_function</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <tip>
+ <para>
+ Don't confuse function-types with pointers to functions:
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">typedef</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="identifier">f</phrase><phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">);</phrase></computeroutput>
+ </para>
+ <para>
+ defines a function type,
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase> <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ declares a prototype for a function of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase></computeroutput>,
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase><phrase role="special">*</phrase>
+ <phrase role="identifier">pf</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">f</phrase><phrase role="special">&amp;</phrase>
+ <phrase role="identifier">fr</phrase> <phrase role="special">=</phrase>
+ <phrase role="identifier">foo</phrase><phrase role="special">;</phrase></computeroutput>
+ </para>
+ <para>
+ declares a pointer and a reference to the function <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">foo</phrase></computeroutput>.
+ </para>
+ <para>
+ If you want to detect whether some type is a pointer-to-function then use:
+ </para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.is_function">is_function</link><phrase role="special">&lt;</phrase><link linkend="boost_typetraits.reference.remove_pointer">remove_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+ <phrase role="special">&amp;&amp;</phrase> <link linkend="boost_typetraits.reference.is_pointer">is_pointer</link><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ </para>
+ <para>
+ or for pointers to member functions you can just use <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link>
+ directly.
+ </para>
+ </tip>
+ </section>
+ <section id="boost_typetraits.reference.is_fundamental">
+ <title><link linkend="boost_typetraits.reference.is_fundamental"> is_fundamental</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_fundamental</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ fundamental type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Fundamental types include integral, floating point and void types (see also
+ <link linkend="boost_typetraits.reference.is_integral">is_integral</link>,
+ <link linkend="boost_typetraits.reference.is_floating_point">is_floating_point</link>
+ and <link linkend="boost_typetraits.reference.is_void">is_void</link>)
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_fundamental</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_fundamental</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_integral">
+ <title><link linkend="boost_typetraits.reference.is_integral"> is_integral</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_integral</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ integral type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p7.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_integral</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_integral</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_function_pointer">
+ <title><link linkend="boost_typetraits.reference.is_member_function_pointer">
+ is_member_function_pointer</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_function_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member function then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the argument in this case is a pointer to a data member and not a member
+ function, see <link linkend="boost_typetraits.reference.is_member_object_pointer">is_member_object_pointer</link>
+ and <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_function_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_object_pointer">
+ <title><link linkend="boost_typetraits.reference.is_member_object_pointer">
+ is_member_object_pointer</link></title>
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_object_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member object (a data member) then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the argument in this case is a pointer to a member function and not a
+ member object, see <link linkend="boost_typetraits.reference.is_member_function_pointer">is_member_function_pointer</link>
+ and <link linkend="boost_typetraits.reference.is_member_pointer">is_member_pointer</link>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_object_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_member_pointer">
+ <title><link linkend="boost_typetraits.reference.is_member_pointer"> is_member_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_member_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer to a member (either a function or a data member) then inherits from
+ <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_member_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">char</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_member_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_object">
+ <title><link linkend="boost_typetraits.reference.is_object"> is_object</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_object</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ object type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ All types are object types except references, void, and function types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p9.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_object</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">void</phrase><phrase role="special">)</phrase><phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: reference types are not
+ objects
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="keyword">double</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>: function types are not
+ objects
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ void is not an object type
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_object</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_pod">
+ <title><link linkend="boost_typetraits.reference.is_pod"> is_pod</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_pod</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ POD type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ POD stands for "Plain old data". Arithmetic types, and enumeration
+ types, a pointers and pointer to members are all PODs. Classes and unions
+ can also be POD's if they have no non-static data members that are of reference
+ or non-POD type, no user defined constructors, no user defined assignment
+ operators, no private or protected non-static data members, no virtual functions
+ and no base classes. Finally, a cv-qualified POD is still a POD, as is an
+ array of PODs.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10 and 9p4 (Note
+ that POD's are also aggregates, see 8.5.1).
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, is<emphasis role="underline">pod
+ will never report that a class or struct is a POD; this is always safe, if
+ possibly sub-optimal. Currently (May 2005) only MWCW 9 and Visual C++ 8 have
+ the necessary compiler-</emphasis>_intrinsics.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pod</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pod</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_pointer">
+ <title><link linkend="boost_typetraits.reference.is_pointer"> is_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_pointer</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ pointer type (includes function pointers, but excludes pointers to members)
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2p2 and 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">*</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <important>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase></computeroutput> detects "real"
+ pointer types only, and <emphasis>not</emphasis> smart pointers. Users
+ should not specialise <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_pointer</phrase></computeroutput>
+ for smart pointer types, as doing so may cause Boost (and other third party)
+ code to fail to function correctly. Users wanting a trait to detect smart
+ pointers should create their own. However, note that there is no way in
+ general to auto-magically detect smart pointer types, so such a trait would
+ have to be partially specialised for each supported smart pointer type.
+ </para>
+ </important>
+ </section>
+ <section id="boost_typetraits.reference.is_polymorphic">
+ <title><link linkend="boost_typetraits.reference.is_polymorphic"> is_polymorphic</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_polymorphic</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ polymorphic type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> must be a complete
+ type.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 10.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> The implementation
+ requires some knowledge of the compilers ABI, it does actually seem to work
+ with the majority of compilers though.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_polymorphic</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ Given: <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">class</phrase> <phrase role="identifier">poly</phrase><phrase role="special">{</phrase> <phrase role="keyword">virtual</phrase> <phrase role="special">~</phrase><phrase role="identifier">poly</phrase><phrase role="special">();</phrase> <phrase role="special">};</phrase></computeroutput>
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">poly</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_polymorphic</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_same">
+ <title><link linkend="boost_typetraits.reference.is_same"> is_same</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">,</phrase> <phrase role="keyword">class</phrase> <phrase role="identifier">U</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_same</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T and U are the same types
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_same</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with abstract, incomplete or function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;,</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_same</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_scalar">
+ <title><link linkend="boost_typetraits.reference.is_scalar"> is_scalar</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_scalar</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ scalar type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Scalar types include integral, floating point, enumeration, pointer, and
+ pointer-to-member types.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_scalar</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(</phrase><phrase role="identifier">MyClass</phrase><phrase role="special">::*)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_scalar</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_signed">
+ <title><link linkend="boost_typetraits.reference.is_signed"> is_signed</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_signed</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an signed integer type
+ or an enumerated type with an underlying signed integer type, then inherits
+ from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1, 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_signed</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myclass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ whose value depends upon the signedness of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_stateless">
+ <title><link linkend="boost_typetraits.reference.is_stateless"> is_stateless</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_stateless</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Ff T is a stateless type then
+ inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ Type T must be a complete type.
+ </para>
+ <para>
+ A stateless type is a type that has no storage and whose constructors and
+ destructors are trivial. That means that <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_stateless</phrase></computeroutput>
+ only inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>
+ if the following expression is <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">true</phrase></computeroutput>:
+ </para>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_constructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_copy</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">has_trivial_destructor</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_class</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+<phrase role="special">&amp;&amp;</phrase> <phrase role="special">::</phrase><phrase role="identifier">boost</phrase><phrase role="special">::</phrase><phrase role="identifier">is_empty</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9p10.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_stateless</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ can not be used with function types.
+ </para>
+ <para>
+ Without some (as yet unspecified) help from the compiler, is_stateless will
+ never report that a class or struct is stateless; this is always safe, if
+ possibly sub-optimal. Currently (May 2005) only MWCW 9 and Visual C++ 8 have
+ the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to make this template work automatically.
+ </para>
+ </section>
+ <section id="boost_typetraits.reference.is_reference">
+ <title><link linkend="boost_typetraits.reference.is_reference"> is_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_reference</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a reference pointer type
+ then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial-specialization of class templates, then this template
+ may report the wrong result for function types, and for types that are both
+ const and volatile qualified.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="special">(&amp;)(</phrase><phrase role="keyword">long</phrase><phrase role="special">)&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis> (the argument in this case
+ is a reference to a function).
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_reference</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_union">
+ <title><link linkend="boost_typetraits.reference.is_union"> is_union</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_union</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ union type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ Currently requires some kind of compiler support, otherwise unions are identified
+ as classes.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.2 and 9.5.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> Without (some as
+ yet unspecified) help from the compiler, we cannot distinguish between union
+ and class types using only standard C++, as a result this type will never
+ inherit from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ unless the user explicitly specializes the template for their user-defined
+ union types, or unless the compiler supplies some unspecified intrinsic that
+ implements this functionality. Currently (May 2005) only Visual C++ 8 has
+ the necessary compiler <link linkend="boost_typetraits.intrinsics">intrinsics</link>
+ to make this trait "just work" without user intervention.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_union</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_union</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_unsigned">
+ <title><link linkend="boost_typetraits.reference.is_unsigned"> is_unsigned</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_unsigned</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is an unsigned integer type
+ or an enumerated type with an underlying unsigned integer type, then inherits
+ from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1, 7.2.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_unsigned</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">myclass</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">char</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ whose value depends upon the signedness of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">char</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">long</phrase>
+ <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_unsigned</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_void">
+ <title><link linkend="boost_typetraits.reference.is_void"> is_void</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_void</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (possibly cv-qualified)
+ void type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1p9.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_void</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">void</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>false</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_void</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.is_volatile">
+ <title><link linkend="boost_typetraits.reference.is_volatile"> is_volatile</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">is_volatile</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <replaceable><link linkend="boost_typetraits.reference.integral_constant">true_type</link>-or-<link linkend="boost_typetraits.reference.integral_constant">false_type</link></replaceable> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> If T is a (top level) volatile-qualified
+ type then inherits from <link linkend="boost_typetraits.reference.integral_constant">true_type</link>,
+ otherwise inherits from <link linkend="boost_typetraits.reference.integral_constant">false_type</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">is_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">volatile</phrase> <phrase role="keyword">int</phrase><phrase role="special">&gt;</phrase></computeroutput> inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">volatile</phrase>
+ <phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">true_type</link></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>true</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>false</emphasis>:
+ the volatile qualifier is not at the top level in this case.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">is_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">bool</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.make_signed">
+ <title><link linkend="boost_typetraits.reference.make_signed"> make_signed</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">make_signed</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If T is a signed integer type then
+ the same type as T, if T is an unsigned integer type then the corresponding
+ signed type. Otherwise if T is an enumerated or character type (char or wchar_t)
+ then a signed integer type with the same width as T.
+ </para>
+ <para>
+ If T has any cv-qualifiers then these are also present on the result type.
+ </para>
+ <para>
+ <emphasis role="bold">Requires:</emphasis> T must be an integer or enumerated
+ type, and must not be the type bool.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">make_signed</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">long</phrase>
+ <phrase role="keyword">long</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A signed integer type with the same width as the enum.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">wchar_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ A signed integer type with the same width as wchar_t.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.make_unsigned">
+ <title><link linkend="boost_typetraits.reference.make_unsigned"> make_unsigned</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">make_unsigned</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If T is a unsigned integer type then
+ the same type as T, if T is an signed integer type then the corresponding
+ unsigned type. Otherwise if T is an enumerated or character type (char or
+ wchar_t) then an unsigned integer type with the same width as T.
+ </para>
+ <para>
+ If T has any cv-qualifiers then these are also present on the result type.
+ </para>
+ <para>
+ <emphasis role="bold">Requires:</emphasis> T must be an integer or enumerated
+ type, and must not be the type bool.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.1.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">make_unsigned</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">unsigned</phrase> <phrase role="keyword">int</phrase>
+ <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">const</phrase> <phrase role="keyword">unsigned</phrase>
+ <phrase role="keyword">long</phrase> <phrase role="keyword">long</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">my_enum</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An unsigned integer type with the same width as the enum.
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">make_signed</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">wchar_t</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ An unsigned integer type with the same width as wchar_t.
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.promote">
+ <title><link linkend="boost_typetraits.reference.promote"> promote</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">promote</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If integral or floating point promotion
+ can be applied to an rvalue of type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ then applies integral and floating point promotions to <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ and keeps cv-qualifiers of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ See also <link linkend="boost_typetraits.reference.integral_promotion">integral_promotion</link>
+ and <link linkend="boost_typetraits.reference.floating_point_promotion">floating_point_promotion</link>.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 4.5 except 4.5/3
+ (integral bit-field) and 4.6.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">promote</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">float</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">double</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">promote</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">short</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">short</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.rank">
+ <title><link linkend="boost_typetraits.reference.rank"> rank</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">rank</phrase> <phrase role="special">:</phrase> <phrase role="keyword">public</phrase> <link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase> <phrase role="special">{};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">Inherits:</emphasis> Class template rank inherits from
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)&gt;</phrase></computeroutput>,
+ where <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> is the
+ number of array dimensions in type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>.
+ </para>
+ <para>
+ If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> is not an array type,
+ then <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">RANK</phrase><phrase role="special">(</phrase><phrase role="identifier">T</phrase><phrase role="special">)</phrase></computeroutput> is zero.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">rank</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <para>
+ <emphasis role="bold">Examples:</emphasis>
+ </para>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[]&gt;</phrase></computeroutput>
+ inherits from <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">1</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">double</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><link linkend="boost_typetraits.reference.integral_constant">integral_constant</link><phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase><phrase role="special">,</phrase> <phrase role="number">3</phrase><phrase role="special">&gt;</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">1</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput>
+ is an integral constant expression that evaluates to <emphasis>1</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>2</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">value</phrase></computeroutput> is an integral constant expression
+ that evaluates to <emphasis>0</emphasis>.
+ </para>
+ </para>
+ </blockquote>
+ <blockquote>
+ <para>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">rank</phrase><phrase role="special">&lt;</phrase><phrase role="identifier">T</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">value_type</phrase></computeroutput> is the type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase></computeroutput>.
+ </para>
+ </para>
+ </blockquote>
+ </section>
+ <section id="boost_typetraits.reference.remove_all_extents">
+ <title><link linkend="boost_typetraits.reference.remove_all_extents"> remove_all_extents</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_all_extents</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is an array type, then removes all of the array bounds on <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ otherwise leaves <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_all_extents</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">3</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_all_extents</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_const">
+ <title><link linkend="boost_typetraits.reference.remove_const"> remove_const</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> const-qualifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_const</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_const</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_cv">
+ <title><link linkend="boost_typetraits.reference.remove_cv"> remove_cv</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_cv</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> cv-qualifiers removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_cv</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_cv</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_extent">
+ <title><link linkend="boost_typetraits.reference.remove_extent"> remove_extent</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_extent</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> If <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ is an array type, then removes the topmost array bound, otherwise leaves
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput> unchanged.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.4.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_extent</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">][</phrase><phrase role="number">4</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">4</phrase><phrase role="special">]</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">[][</phrase><phrase role="number">2</phrase><phrase role="special">]&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">[</phrase><phrase role="number">2</phrase><phrase role="special">]</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_extent</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_pointer">
+ <title><link linkend="boost_typetraits.reference.remove_pointer"> remove_pointer</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_pointer</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any pointer modifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.1.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_pointer</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">**&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_pointer</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_reference">
+ <title><link linkend="boost_typetraits.reference.remove_reference"> remove_reference</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_reference</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any reference modifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 8.3.2.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_reference</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_reference</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">*&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.remove_volatile">
+ <title><link linkend="boost_typetraits.reference.remove_volatile"> remove_volatile</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">remove_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> The same type as <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>,
+ but with any <emphasis>top level</emphasis> volatile-qualifier removed.
+ </para>
+ <para>
+ <emphasis role="bold">C++ Standard Reference:</emphasis> 3.9.3.
+ </para>
+ <para>
+ <emphasis role="bold">Compiler Compatibility:</emphasis> If the compiler
+ does not support partial specialization of class-templates then this template
+ will compile, but the member <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">type</phrase></computeroutput>
+ will always be the same as type <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">T</phrase></computeroutput>
+ except where <link linkend="boost_typetraits.category.transform.broken_compiler_workarounds_">compiler
+ workarounds</link> have been applied.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">remove_volatile</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ <table frame="all"> <title>Examples</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>
+ <para>
+ Expression
+ </para>
+ </entry><entry>
+ <para>
+ Result Type
+ </para>
+ </entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase>
+ <phrase role="keyword">volatile</phrase><phrase role="special">&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">&amp;&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">&amp;</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ <row>
+ <entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">remove_volatile</phrase><phrase role="special">&lt;</phrase><phrase role="keyword">int</phrase> <phrase role="keyword">volatile</phrase><phrase role="special">*&gt;::</phrase><phrase role="identifier">type</phrase></computeroutput>
+ </para>
+ </entry><entry>
+ <para>
+ <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">int</phrase> <phrase role="keyword">const</phrase><phrase role="special">*</phrase></computeroutput>
+ </para>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section id="boost_typetraits.reference.type_with_alignment">
+ <title><link linkend="boost_typetraits.reference.type_with_alignment"> type_with_alignment</link></title>
+
+<programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">std</phrase><phrase role="special">::</phrase><phrase role="identifier">size_t</phrase> <phrase role="identifier">Align</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">type_with_alignment</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <para>
+ <emphasis role="bold">type:</emphasis> a built-in or POD type with an alignment
+ that is a multiple of <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="identifier">Align</phrase></computeroutput>.
+ </para>
+ <para>
+ <emphasis role="bold">Header:</emphasis> <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase>
+ <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">/</phrase><phrase role="identifier">type_with_alignment</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ or <computeroutput xmlns:xi="http://www.w3.org/2001/XInclude"> <phrase role="preprocessor">#include</phrase> <phrase role="special">&lt;</phrase><phrase role="identifier">boost</phrase><phrase role="special">/</phrase><phrase role="identifier">type_traits</phrase><phrase role="special">.</phrase><phrase role="identifier">hpp</phrase><phrase role="special">&gt;</phrase></computeroutput>
+ </para>
+ </section>
+ </section>
+ <section id="boost_typetraits.credits">
+ <title><link linkend="boost_typetraits.credits"> Credits</link></title>
+ <para>
+ This documentation was pulled together by John Maddock, using <ulink url="../../../../doc/html/quickbook.html">Boost.Quickbook</ulink>
+ and <ulink url="../../../../doc/html/boostbook.html">Boost.DocBook</ulink>.
+ </para>
+ <para>
+ The original version of this library was created by Steve Cleary, Beman Dawes,
+ Howard Hinnant, and John Maddock. John Maddock is the current maintainer of
+ the library.
+ </para>
+ <para>
+ This version of type traits library is based on contributions by Adobe Systems
+ Inc, David Abrahams, Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant,
+ Jesse Jones, Mat Marcus, Itay Maman, John Maddock, Thorsten Ottosen, Robert
+ Ramey and Jeremy Siek.
+ </para>
+ <para>
+ Mat Marcus and Jesse Jones invented, and <ulink url="http://opensource.adobe.com/project4/project.shtml">published
+ a paper describing</ulink>, the partial specialization workarounds used in
+ this library.
+ </para>
+ <para>
+ Aleksey Gurtovoy added MPL integration to the library.
+ </para>
+ <para>
+ The <link linkend="boost_typetraits.reference.is_convertible">is_convertible</link>
+ template is based on code originally devised by Andrei Alexandrescu, see "<ulink url="http://www.cuj.com/experts/1810/alexandr.htm?topic=experts">Generic&lt;Programming&gt;:
+ Mappings between Types and Values</ulink>".
+ </para>
+ <para>
+ The latest version of this library and documentation can be found at <ulink url="http://www.boost.org">www.boost.org</ulink>. Bugs, suggestions and discussion
+ should be directed to boost@lists.boost.org (see <ulink url="http://www.boost.org/more/mailing_lists.htm#main">www.boost.org/more/mailing_lists.htm#main</ulink>
+ for subscription details).
+ </para>
+ </section>
+
+ <section id="boost_typetraits.ignored_section">
+ <title>This section must not be indexed.</title>
+ <?BoostAutoIndex IgnoreSection?>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ </section>
+
+ <section id="boost_typetraits.ignored_block">
+ <title>This section contains one block that must not be indexed and one that should be.</title>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">
+ <?BoostAutoIndex IgnoreBlock?>
+ template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_const</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ <programlisting xmlns:xi="http://www.w3.org/2001/XInclude"><phrase role="keyword">
+ template</phrase> <phrase role="special">&lt;</phrase><phrase role="keyword">class</phrase> <phrase role="identifier">T</phrase><phrase role="special">&gt;</phrase>
+<phrase role="keyword">struct</phrase> <phrase role="identifier">add_volatile</phrase>
+<phrase role="special">{</phrase>
+ <phrase role="keyword">typedef</phrase> <replaceable>see-below</replaceable> <phrase role="identifier">type</phrase><phrase role="special">;</phrase>
+<phrase role="special">};</phrase>
+</programlisting>
+ </section>
+
+ <para>
+ <index type="class_name">
+ <title>Class Index</title>
+ </index>
+ <index type="typedef_name">
+ <title>Typedef Index</title>
+ </index>
+ <index type="macro_name">
+ <title>Macro Index</title>
+ </index>
+ <index type="test_index_1">
+ <title>Index Test 1</title>
+ </index>
+ <index type="test_index_2">
+ <title>Index Test 2</title>
+ </index>
+ <index/>
+ </para>
+</chapter>
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 11:40:52 +0000