<?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 0.6: http://docutils.sourceforge.net/" /> <title>The MPL Reference Manual: map</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="./set.html" class="navigation-link">Prev</a> <a href="./range-c.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./set.html" class="navigation-link">Back</a> <a href="./range-c.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./classes.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="./sequences.html" class="navigation-link">Sequences</a> / <a href="./classes.html" class="navigation-link">Classes</a> / <a href="./map.html" class="navigation-link">map</a></td> </tr></table><div class="header-separator"></div> <div class="section" id="map"> <h1><a class="toc-backref" href="./classes.html#id1393">map</a></h1> <div class="section" id="id80"> <h3><a class="subsection-title" href="#description" name="description">Description</a></h3> <p><tt class="literal"><span class="pre"><a href="./map.html" class="identifier">map</a></span></tt> is a <a class="reference internal" href="./variadic-sequence.html#variadic">variadic</a>, <a class="reference internal" href="./associative-sequence.html">associative</a>, <a class="reference internal" href="./extensible-associative-sequence.html">extensible</a> sequence of type pairs that supports constant-time insertion and removal of elements, and testing for membership. A <tt class="literal"><span class="pre"><a href="./map.html" class="identifier">map</a></span></tt> may contain at most one element for each key.</p> </div> <div class="section" id="id83"> <h3><a class="subsection-title" href="#header" name="header">Header</a></h3> <table border="1" class="docutils table"> <colgroup> <col width="26%" /> <col width="74%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Sequence form</th> <th class="head">Header</th> </tr> </thead> <tbody valign="top"> <tr><td>Variadic</td> <td><tt class="literal"><span class="pre">#include <<a href="../../../../boost/mpl/map.hpp" class="header">boost/mpl/map.hpp</a>></span></tt></td> </tr> <tr><td>Numbered</td> <td><tt class="literal"><span class="pre">#include <boost/mpl/map/map</span></tt><em>n</em><tt class="literal"><span class="pre">.hpp></span></tt></td> </tr> </tbody> </table> </div> <div class="section" id="id84"> <h3><a class="subsection-title" href="#model-of" name="model-of">Model of</a></h3> <ul class="simple"> <li><a class="reference internal" href="./variadic-sequence.html">Variadic Sequence</a></li> <li><a class="reference internal" href="./associative-sequence.html">Associative Sequence</a></li> <li><a class="reference internal" href="./extensible-associative-sequence.html">Extensible Associative Sequence</a></li> </ul> </div> <div class="section" id="id85"> <h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3> <p>In the following table and subsequent specifications, <tt class="literal"><span class="pre">m</span></tt> is an instance of <tt class="literal"><span class="pre"><a href="./map.html" class="identifier">map</a></span></tt>, <tt class="literal"><span class="pre">pos</span></tt> is an iterator into <tt class="literal"><span class="pre">m</span></tt>, <tt class="literal"><span class="pre">x</span></tt> and <em>p</em><sub>1</sub>,<em>p</em><sub>2</sub>,... <em>p</em><sub>n</sub> are <tt class="literal"><span class="pre"><a href="./pair.html" class="identifier">pair</a></span></tt>s, and <tt class="literal"><span class="pre">k</span></tt> is an arbitrary type.</p> <table border="1" class="docutils table"> <colgroup> <col width="40%" /> <col width="60%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Expression</th> <th class="head">Semantics</th> </tr> </thead> <tbody valign="top"> <tr><td><pre class="first last literal-block"> <a href="./map.html" class="identifier">map</a><<em>p</em><sub>1</sub>,<em>p</em><sub>2</sub>,... <em>p</em><sub>n</sub>> <a href="./map.html" class="identifier">map</a><em>n</em><<em>p</em><sub>1</sub>,<em>p</em><sub>2</sub>,... <em>p</em><sub>n</sub>> </pre> </td> <td><tt class="literal"><span class="pre"><a href="./map.html" class="identifier">map</a></span></tt> of elements <em>p</em><sub>1</sub>,<em>p</em><sub>2</sub>,... <em>p</em><sub>n</sub>; see <a class="reference internal" href="./variadic-sequence.html">Variadic Sequence</a>.</td> </tr> <tr><td><pre class="first last literal-block"> <a href="./map.html" class="identifier">map</a><<em>p</em><sub>1</sub>,<em>p</em><sub>2</sub>,... <em>p</em><sub>n</sub>>::type <a href="./map.html" class="identifier">map</a><em>n</em><<em>p</em><sub>1</sub>,<em>p</em><sub>2</sub>,... <em>p</em><sub>n</sub>>::type </pre> </td> <td>Identical to <tt class="literal"><span class="pre"><a href="./map.html" class="identifier">map</a></span></tt><em>n</em><tt class="literal"><span class="pre"><</span></tt><em>p</em><sub>1</sub>,<em>p</em><sub>2</sub>,... <em>p</em><sub>n</sub><tt class="literal"><span class="pre">></span></tt>; see <a class="reference internal" href="./variadic-sequence.html">Variadic Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a><m>::type</span></tt></td> <td>An iterator pointing to the beginning of <tt class="literal"><span class="pre">m</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a><m>::type</span></tt></td> <td>An iterator pointing to the end of <tt class="literal"><span class="pre">m</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a><m>::type</span></tt></td> <td>The size of <tt class="literal"><span class="pre">m</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./empty.html" class="identifier">empty</a><m>::type</span></tt></td> <td>A boolean <a class="reference internal" href="./integral-constant.html">Integral Constant</a> <tt class="literal"><span class="pre">c</span></tt> such that <tt class="literal"><span class="pre">c::value</span> <span class="pre">==</span> <span class="pre">true</span></tt> if and only if <tt class="literal"><span class="pre">m</span></tt> is empty; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./front.html" class="identifier">front</a><m>::type</span></tt></td> <td>The first element in <tt class="literal"><span class="pre">m</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./has-key.html" class="identifier">has_key</a><m,k>::type</span></tt></td> <td>Queries the presence of elements with the key <tt class="literal"><span class="pre">k</span></tt> in <tt class="literal"><span class="pre">m</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./count.html" class="identifier">count</a><m,k>::type</span></tt></td> <td>The number of elements with the key <tt class="literal"><span class="pre">k</span></tt> in <tt class="literal"><span class="pre">m</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./order.html" class="identifier">order</a><m,k>::type</span></tt></td> <td>A unique unsigned <a class="reference internal" href="./integral-constant.html">Integral Constant</a> associated with the key <tt class="literal"><span class="pre">k</span></tt> in <tt class="literal"><span class="pre">m</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><pre class="first last literal-block"> <a href="./at.html" class="identifier">at</a><m,k>::type <a href="./at.html" class="identifier">at</a><m,k,default>::type </pre> </td> <td>The element associated with the key <tt class="literal"><span class="pre">k</span></tt> in <tt class="literal"><span class="pre">m</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./key-type.html" class="identifier">key_type</a><m,x>::type</span></tt></td> <td>Identical to <tt class="literal"><span class="pre">x::first</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./value-type.html" class="identifier">value_type</a><m,x>::type</span></tt></td> <td>Identical to <tt class="literal"><span class="pre">x::second</span></tt>; see <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./insert.html" class="identifier">insert</a><m,x>::type</span></tt></td> <td><p class="first">A new <tt class="literal"><span class="pre"><a href="./map.html" class="identifier">map</a></span></tt>, <tt class="literal"><span class="pre">t</span></tt>, equivalent to <tt class="literal"><span class="pre">m</span></tt> except that</p> <pre class="literal-block"> <a href="./at.html" class="identifier">at</a>< t, <a href="./key-type.html" class="identifier">key_type</a><m,x>::type >::type </pre> <p class="last">is identical to <tt class="literal"><span class="pre"><a href="./value-type.html" class="identifier">value_type</a><m,x>::type</span></tt>.</p> </td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./insert.html" class="identifier">insert</a><m,pos,x>::type</span></tt></td> <td>Equivalent to <tt class="literal"><span class="pre"><a href="./insert.html" class="identifier">insert</a><m,x>::type</span></tt>; <tt class="literal"><span class="pre">pos</span></tt> is ignored.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./erase-key.html" class="identifier">erase_key</a><m,k>::type</span></tt></td> <td>A new <tt class="literal"><span class="pre"><a href="./map.html" class="identifier">map</a></span></tt>, <tt class="literal"><span class="pre">t</span></tt>, equivalent to <tt class="literal"><span class="pre">m</span></tt> except that <tt class="literal"><span class="pre"><a href="./has-key.html" class="identifier">has_key</a><t,</span> <span class="pre">k>::value</span> <span class="pre">==</span> <span class="pre">false</span></tt>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./erase.html" class="identifier">erase</a><m,pos>::type</span></tt></td> <td>Equivalent to <tt class="literal"><span class="pre"><a href="./erase.html" class="identifier">erase</a><m,</span> <span class="pre"><a href="./deref.html" class="identifier">deref</a><pos>::type</span> <span class="pre">>::type</span></tt>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./clear.html" class="identifier">clear</a><m>::type</span></tt></td> <td>An empty <tt class="literal"><span class="pre"><a href="./map.html" class="identifier">map</a></span></tt>; see <a class="reference internal" href="./clear.html">clear</a>.</td> </tr> </tbody> </table> </div> <div class="section" id="id86"> <h3><a class="subsection-title" href="#example" name="example">Example</a></h3> <pre class="literal-block"> typedef <a href="./map.html" class="identifier">map</a>< <a href="./pair.html" class="identifier">pair</a><int,unsigned> , <a href="./pair.html" class="identifier">pair</a><char,unsigned char> , <a href="./pair.html" class="identifier">pair</a><<a href="./long.html" class="identifier">long_</a><5>,char[17]> , <a href="./pair.html" class="identifier">pair</a><int[42],bool> > m; <a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( <a href="./size.html" class="identifier">size</a><m>::value, ==, 4 ); <a href="./assert-not.html" class="identifier">BOOST_MPL_ASSERT_NOT</a>(( <a href="./empty.html" class="identifier">empty</a><m> )); <a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( is_same< <a href="./at.html" class="identifier">at</a><m,int>::type, unsigned > )); <a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( is_same< <a href="./at.html" class="identifier">at</a><m,<a href="./long.html" class="identifier">long_</a><5> >::type, char[17] > )); <a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( is_same< <a href="./at.html" class="identifier">at</a><m,int[42]>::type, bool > )); <a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( is_same< <a href="./at.html" class="identifier">at</a><m,long>::type, <a href="./void.html" class="identifier">void_</a> > )); </pre> </div> <div class="section" id="id87"> <h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> <p><a class="reference internal" href="./sequences.html">Sequences</a>, <a class="reference internal" href="./variadic-sequence.html">Variadic Sequence</a>, <a class="reference internal" href="./associative-sequence.html">Associative Sequence</a>, <a class="reference internal" href="./extensible-associative-sequence.html">Extensible Associative Sequence</a>, <a class="reference internal" href="./set.html">set</a>, <a class="reference internal" href="./vector.html">vector</a></p> <!-- Sequences/Classes//range_c |60 --> </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="./set.html" class="navigation-link">Prev</a> <a href="./range-c.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./set.html" class="navigation-link">Back</a> <a href="./range-c.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./classes.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>