<?xml version="1.0" encoding="utf-8" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="generator" content="Docutils 0.7: http://docutils.sourceforge.net/" /> <title>The MPL Reference Manual: pair</title> <link rel="stylesheet" href="../style.css" type="text/css" /> </head> <body class="docframe refmanual"> <table class="header"><tr class="header"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./data-types-miscellaneous.html" class="navigation-link">Prev</a> <a href="./empty-base.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group">Back <a href="./empty-base.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./data-types-miscellaneous.html" class="navigation-link">Up</a> <a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td> <td class="header-group page-location"><a href="../refmanual.html" class="navigation-link">Front Page</a> / <a href="./data-types.html" class="navigation-link">Data Types</a> / <a href="./data-types-miscellaneous.html" class="navigation-link">Miscellaneous</a> / <a href="./pair.html" class="navigation-link">pair</a></td> </tr></table><div class="header-separator"></div> <div class="section" id="pair"> <h1><a class="toc-backref" href="./data-types-miscellaneous.html#id1583">pair</a></h1> <div class="section" id="id1271"> <h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3> <pre class="literal-block"> template< typename T1 , typename T2 > struct <a href="./pair.html" class="identifier">pair</a> { typedef <a href="./pair.html" class="identifier">pair</a> type; typedef T1 first; typedef T2 second; }; </pre> </div> <div class="section" id="id1272"> <h3><a class="subsection-title" href="#description" name="description">Description</a></h3> <p>A transparent holder for two arbitrary types.</p> </div> <div class="section" id="id1273"> <h3><a class="subsection-title" href="#header" name="header">Header</a></h3> <pre class="literal-block"> #include <<a href="../../../../boost/mpl/pair.hpp" class="header">boost/mpl/pair.hpp</a>> </pre> </div> <div class="section" id="id1274"> <h3><a class="subsection-title" href="#example" name="example">Example</a></h3> <p>Count a number of elements in the sequence together with a number of negative elements among these.</p> <pre class="literal-block"> typedef <a href="./fold.html" class="identifier">fold</a>< <a href="./vector-c.html" class="identifier">vector_c</a><int,-1,0,5,-7,-2,4,5,7> , <a href="./pair.html" class="identifier">pair</a>< <a href="./int.html" class="identifier">int_</a><0>, <a href="./int.html" class="identifier">int_</a><0> > , <a href="./pair.html" class="identifier">pair</a>< <a href="./next.html" class="identifier">next</a>< first<<a href="./placeholders.html" class="identifier">_1</a>> > , <a href="./if.html" class="identifier">if_</a>< <a href="./less.html" class="identifier">less</a>< <a href="./placeholders.html" class="identifier">_2</a>, <a href="./int.html" class="identifier">int_</a><0> > , <a href="./next.html" class="identifier">next</a>< second<<a href="./placeholders.html" class="identifier">_1</a>> > , second<<a href="./placeholders.html" class="identifier">_1</a>> > > >::type p; <a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( p::first::value, ==, 8 ); <a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( p::second::value, ==, 3 ); </pre> </div> <div class="section" id="id1275"> <h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> <p><a class="reference internal" href="./data-types.html">Data Types</a>, <a class="reference internal" href="./sequences.html">Sequences</a>, <a class="reference internal" href="./trivial-metafunctions-summary.html#first">first</a>, <a class="reference internal" href="./trivial-metafunctions-summary.html#second">second</a></p> <!-- Data Types/Miscellaneous//empty_base |20 --> </div> </div> <div class="footer-separator"></div> <table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./data-types-miscellaneous.html" class="navigation-link">Prev</a> <a href="./empty-base.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group">Back <a href="./empty-base.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./data-types-miscellaneous.html" class="navigation-link">Up</a> <a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td> <td><div class="copyright-footer"><div class="copyright">Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams</div> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a class="reference external" href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)</div></td></tr></table></body> </html>