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diff --git a/src/boost/libs/spirit/example/x3/complex_number.cpp b/src/boost/libs/spirit/example/x3/complex_number.cpp
new file mode 100644
index 00000000..3d63ab61
--- /dev/null
+++ b/src/boost/libs/spirit/example/x3/complex_number.cpp
@@ -0,0 +1,98 @@
+/*=============================================================================
+    Copyright (c) 2002-2015 Joel de Guzman
+
+    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)
+=============================================================================*/
+///////////////////////////////////////////////////////////////////////////////
+//
+//  A complex number micro parser.
+//
+//  [ JDG May 10, 2002 ]    spirit1
+//  [ JDG May 9, 2007 ]     spirit2
+//  [ JDG May 12, 2015 ]    spirit X3
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include <boost/config/warning_disable.hpp>
+#include <boost/spirit/home/x3.hpp>
+
+#include <iostream>
+#include <string>
+#include <complex>
+
+///////////////////////////////////////////////////////////////////////////////
+//  Our complex number parser/compiler
+///////////////////////////////////////////////////////////////////////////////
+namespace client
+{
+    template <typename Iterator>
+    bool parse_complex(Iterator first, Iterator last, std::complex<double>& c)
+    {
+        using boost::spirit::x3::double_;
+        using boost::spirit::x3::_attr;
+        using boost::spirit::x3::phrase_parse;
+        using boost::spirit::x3::ascii::space;
+
+        double rN = 0.0;
+        double iN = 0.0;
+        auto fr = [&](auto& ctx){ rN = _attr(ctx); };
+        auto fi = [&](auto& ctx){ iN = _attr(ctx); };
+
+        bool r = phrase_parse(first, last,
+
+            //  Begin grammar
+            (
+                    '(' >> double_[fr]
+                        >> -(',' >> double_[fi]) >> ')'
+                |   double_[fr]
+            ),
+            //  End grammar
+
+            space);
+
+        if (!r || first != last) // fail if we did not get a full match
+            return false;
+        c = std::complex<double>(rN, iN);
+        return r;
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////
+//  Main program
+////////////////////////////////////////////////////////////////////////////
+int
+main()
+{
+    std::cout << "/////////////////////////////////////////////////////////\n\n";
+    std::cout << "\t\tA complex number micro parser for Spirit...\n\n";
+    std::cout << "/////////////////////////////////////////////////////////\n\n";
+
+    std::cout << "Give me a complex number of the form r or (r) or (r,i) \n";
+    std::cout << "Type [q or Q] to quit\n\n";
+
+    std::string str;
+    while (getline(std::cin, str))
+    {
+        if (str.empty() || str[0] == 'q' || str[0] == 'Q')
+            break;
+
+        std::complex<double> c;
+        if (client::parse_complex(str.begin(), str.end(), c))
+        {
+            std::cout << "-------------------------\n";
+            std::cout << "Parsing succeeded\n";
+            std::cout << "got: " << c << std::endl;
+            std::cout << "\n-------------------------\n";
+        }
+        else
+        {
+            std::cout << "-------------------------\n";
+            std::cout << "Parsing failed\n";
+            std::cout << "-------------------------\n";
+        }
+    }
+
+    std::cout << "Bye... :-) \n\n";
+    return 0;
+}