1<?xml version="1.0" encoding="utf-8" ?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 4<head> 5<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 6<meta name="generator" content="Docutils 0.7: http://docutils.sourceforge.net/" /> 7<title>The MPL Reference Manual: equal</title> 8<link rel="stylesheet" href="../style.css" type="text/css" /> 9</head> 10<body class="docframe refmanual"> 11<table class="header"><tr class="header"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./max-element.html" class="navigation-link">Prev</a> <a href="./transformation-algorithms.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./max-element.html" class="navigation-link">Back</a> Along</span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./querying-algorithms.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> 12<td class="header-group page-location"><a href="../refmanual.html" class="navigation-link">Front Page</a> / <a href="./algorithms.html" class="navigation-link">Algorithms</a> / <a href="./querying-algorithms.html" class="navigation-link">Querying Algorithms</a> / <a href="./equal.html" class="navigation-link">equal</a></td> 13</tr></table><div class="header-separator"></div> 14<div class="section" id="equal"> 15<h1><a class="toc-backref" href="./querying-algorithms.html#id1484">equal</a></h1> 16<div class="section" id="id607"> 17<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3> 18<pre class="literal-block"> 19template< 20 typename Seq1 21 , typename Seq2 22 , typename Pred = is_same<<a href="./placeholders.html" class="identifier">_1</a>,<a href="./placeholders.html" class="identifier">_2</a>> 23 > 24struct <a href="./equal.html" class="identifier">equal</a> 25{ 26 typedef <em>unspecified</em> type; 27}; 28</pre> 29</div> 30<div class="section" id="id608"> 31<h3><a class="subsection-title" href="#description" name="description">Description</a></h3> 32<p>Returns a true-valued <a class="reference internal" href="./integral-constant.html">Integral Constant</a> if the two sequences <tt class="literal"><span class="pre">Seq1</span></tt> 33and <tt class="literal"><span class="pre">Seq2</span></tt> are identical when compared element-by-element.</p> 34</div> 35<div class="section" id="id609"> 36<h3><a class="subsection-title" href="#header" name="header">Header</a></h3> 37<pre class="literal-block"> 38#include <<a href="../../../../boost/mpl/equal.hpp" class="header">boost/mpl/equal.hpp</a>> 39</pre> 40</div> 41<div class="section" id="id610"> 42<h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3> 43<table border="1" class="docutils table"> 44<colgroup> 45<col width="22%" /> 46<col width="36%" /> 47<col width="41%" /> 48</colgroup> 49<thead valign="bottom"> 50<tr><th class="head">Parameter</th> 51<th class="head">Requirement</th> 52<th class="head">Description</th> 53</tr> 54</thead> 55<tbody valign="top"> 56<tr><td><tt class="literal"><span class="pre">Seq1</span></tt>, <tt class="literal"><span class="pre">Seq2</span></tt></td> 57<td><a class="reference internal" href="./forward-sequence.html">Forward Sequence</a></td> 58<td>Sequences to compare.</td> 59</tr> 60<tr><td><tt class="literal"><span class="pre">Pred</span></tt></td> 61<td>Binary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a></td> 62<td>A comparison criterion.</td> 63</tr> 64</tbody> 65</table> 66</div> 67<div class="section" id="id611"> 68<h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3> 69<p>For any <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a>s <tt class="literal"><span class="pre">s1</span></tt> and <tt class="literal"><span class="pre">s2</span></tt> and a binary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a> <tt class="literal"><span class="pre">pred</span></tt>:</p> 70<pre class="literal-block"> 71typedef <a href="./equal.html" class="identifier">equal</a><s1,s2,pred>::type c; 72</pre> 73<table class="docutils field-list" frame="void" rules="none"> 74<col class="field-name" /> 75<col class="field-body" /> 76<tbody valign="top"> 77<tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="./integral-constant.html">Integral Constant</a></p> 78</td> 79</tr> 80<tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><p class="first"><tt class="literal"><span class="pre">c::value</span> <span class="pre">==</span> <span class="pre">true</span></tt> is and only if <tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a><s1>::value</span> <span class="pre">==</span> <span class="pre"><a href="./size.html" class="identifier">size</a><s2>::value</span></tt> 81and for every iterator <tt class="literal"><span class="pre">i</span></tt> in [<tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a><s1>::type</span></tt>, <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a><s1>::type</span></tt>) <tt class="literal"><span class="pre"><a href="./deref.html" class="identifier">deref</a><i>::type</span></tt> is identical to</p> 82<pre class="last literal-block"> 83<a href="./advance.html" class="identifier">advance</a>< <a href="./begin.html" class="identifier">begin</a><s2>::type, <a href="./distance.html" class="identifier">distance</a>< <a href="./begin.html" class="identifier">begin</a><s1>::type,i >::type >::type 84</pre> 85</td> 86</tr> 87</tbody> 88</table> 89</div> 90<div class="section" id="id612"> 91<h3><a class="subsection-title" href="#complexity" name="complexity">Complexity</a></h3> 92<p>Linear. At most <tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a><s1>::value</span></tt> comparisons.</p> 93</div> 94<div class="section" id="id613"> 95<h3><a class="subsection-title" href="#example" name="example">Example</a></h3> 96<pre class="literal-block"> 97typedef <a href="./vector.html" class="identifier">vector</a><char,int,unsigned,long,unsigned long> s1; 98typedef <a href="./list.html" class="identifier">list</a><char,int,unsigned,long,unsigned long> s2; 99 100<a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( <a href="./equal.html" class="identifier">equal</a><s1,s2> )); 101</pre> 102</div> 103<div class="section" id="id614"> 104<h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> 105<p><a class="reference internal" href="./querying-algorithms.html">Querying Algorithms</a>, <a class="reference internal" href="./find.html">find</a>, <a class="reference internal" href="./find-if.html">find_if</a></p> 106</div> 107</div> 108 109<div class="footer-separator"></div> 110<table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./max-element.html" class="navigation-link">Prev</a> <a href="./transformation-algorithms.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./max-element.html" class="navigation-link">Back</a> Along</span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./querying-algorithms.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> 111<td><div class="copyright-footer"><div class="copyright">Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams</div> 112Distributed under the Boost Software License, Version 1.0. (See accompanying 113file 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> 114</html> 115