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Diffstat (limited to 'src/boost/libs/container/example/doc_pmr.cpp')
-rw-r--r-- | src/boost/libs/container/example/doc_pmr.cpp | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/boost/libs/container/example/doc_pmr.cpp b/src/boost/libs/container/example/doc_pmr.cpp new file mode 100644 index 00000000..0d4f5a26 --- /dev/null +++ b/src/boost/libs/container/example/doc_pmr.cpp @@ -0,0 +1,98 @@ +////////////////////////////////////////////////////////////////////////////// +// +// (C) Copyright Ion Gaztanaga 2015-2015. 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) +// +// See http://www.boost.org/libs/container for documentation. +// +////////////////////////////////////////////////////////////////////////////// +//[doc_pmr_ShoppingList_hpp +//ShoppingList.hpp +#include <boost/container/pmr/vector.hpp> +#include <boost/container/pmr/string.hpp> + +class ShoppingList +{ + // A vector of strings using polymorphic allocators. Every element + // of the vector will use the same allocator as the vector itself. + boost::container::pmr::vector_of + <boost::container::pmr::string>::type m_strvec; + //Alternatively in compilers that support template aliases: + // boost::container::pmr::vector<boost::container::pmr::string> m_strvec; + public: + + // This makes uses_allocator<ShoppingList, memory_resource*>::value true + typedef boost::container::pmr::memory_resource* allocator_type; + + // If the allocator is not specified, "m_strvec" uses pmr::get_default_resource(). + explicit ShoppingList(allocator_type alloc = 0) + : m_strvec(alloc) {} + + // Copy constructor. As allocator is not specified, + // "m_strvec" uses pmr::get_default_resource(). + ShoppingList(const ShoppingList& other) + : m_strvec(other.m_strvec) {} + + // Copy construct using the given memory_resource. + ShoppingList(const ShoppingList& other, allocator_type a) + : m_strvec(other.m_strvec, a) {} + + allocator_type get_allocator() const + { return m_strvec.get_allocator().resource(); } + + void add_item(const char *item) + { m_strvec.emplace_back(item); } + + //... +}; + +//]] + +//[doc_pmr_main_cpp + +//=#include "ShoppingList.hpp" +#include <cassert> +#include <boost/container/pmr/list.hpp> +#include <boost/container/pmr/monotonic_buffer_resource.hpp> + +void processShoppingList(const ShoppingList&) +{ /**/ } + +int main() +{ + using namespace boost::container; + //All memory needed by folder and its contained objects will + //be allocated from the default memory resource (usually new/delete) + pmr::list_of<ShoppingList>::type folder; // Default allocator resource + //Alternatively in compilers that support template aliases: + // boost::container::pmr::list<ShoppingList> folder; + { + char buffer[1024]; + pmr::monotonic_buffer_resource buf_rsrc(&buffer, 1024); + + //All memory needed by temporaryShoppingList will be allocated + //from the local buffer (speeds up "processShoppingList") + ShoppingList temporaryShoppingList(&buf_rsrc); + assert(&buf_rsrc == temporaryShoppingList.get_allocator()); + + //list nodes, and strings "salt" and "pepper" will be allocated + //in the stack thanks to "monotonic_buffer_resource". + temporaryShoppingList.add_item("salt"); + temporaryShoppingList.add_item("pepper"); + //... + + //All modifications and additions to "temporaryShoppingList" + //will use memory from "buffer" until it's exhausted. + processShoppingList(temporaryShoppingList); + + //Processing done, now insert it in "folder", + //which uses the default memory resource + folder.push_back(temporaryShoppingList); + assert(pmr::get_default_resource() == folder.back().get_allocator()); + //temporaryShoppingList, buf_rsrc, and buffer go out of scope + } + return 0; +} + +//] |