1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>equal</title> 5<link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../../index.html" title="Chapter 1. Range 2.0"> 8<link rel="up" href="../non_mutating.html" title="Non-mutating algorithms"> 9<link rel="prev" href="count_if.html" title="count_if"> 10<link rel="next" href="equal_range.html" title="equal_range"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="count_if.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../non_mutating.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="equal_range.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="range.reference.algorithms.non_mutating.equal"></a><a class="link" href="equal.html" title="equal">equal</a> 28</h5></div></div></div> 29<h6> 30<a name="range.reference.algorithms.non_mutating.equal.h0"></a> 31 <span class="phrase"><a name="range.reference.algorithms.non_mutating.equal.prototype"></a></span><a class="link" href="equal.html#range.reference.algorithms.non_mutating.equal.prototype">Prototype</a> 32 </h6> 33<p> 34</p> 35<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> 36 <span class="keyword">class</span> <span class="identifier">SinglePassRange1</span><span class="special">,</span> 37 <span class="keyword">class</span> <span class="identifier">SinglePassRange2</span> 38<span class="special">></span> 39<span class="keyword">bool</span> <span class="identifier">equal</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">SinglePassRange1</span><span class="special">&</span> <span class="identifier">rng1</span><span class="special">,</span> 40 <span class="keyword">const</span> <span class="identifier">SinglePassRange2</span><span class="special">&</span> <span class="identifier">rng2</span><span class="special">);</span> 41 42<span class="keyword">template</span><span class="special"><</span> 43 <span class="keyword">class</span> <span class="identifier">SinglePassRange1</span><span class="special">,</span> 44 <span class="keyword">class</span> <span class="identifier">SinglePassRange2</span><span class="special">,</span> 45 <span class="keyword">class</span> <span class="identifier">BinaryPredicate</span> 46<span class="special">></span> 47<span class="keyword">bool</span> <span class="identifier">equal</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">SinglePassRange1</span><span class="special">&</span> <span class="identifier">rng1</span><span class="special">,</span> 48 <span class="keyword">const</span> <span class="identifier">SinglePassRange2</span><span class="special">&</span> <span class="identifier">rng2</span><span class="special">,</span> 49 <span class="identifier">BinaryPredicate</span> <span class="identifier">pred</span><span class="special">);</span> 50</pre> 51<p> 52 </p> 53<h6> 54<a name="range.reference.algorithms.non_mutating.equal.h1"></a> 55 <span class="phrase"><a name="range.reference.algorithms.non_mutating.equal.description"></a></span><a class="link" href="equal.html#range.reference.algorithms.non_mutating.equal.description">Description</a> 56 </h6> 57<p> 58 <code class="computeroutput"><span class="identifier">equal</span></code> returns <code class="computeroutput"><span class="keyword">true</span></code> if <code class="computeroutput"><span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">)</span></code> is equal to the <code class="computeroutput"><span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng2</span><span class="special">)</span></code> and for each element <code class="computeroutput"><span class="identifier">x</span></code> 59 in <code class="computeroutput"><span class="identifier">rng1</span></code>, the corresponding 60 element <code class="computeroutput"><span class="identifier">y</span></code> in <code class="computeroutput"><span class="identifier">rng2</span></code> is equal. Otherwise <code class="computeroutput"><span class="keyword">false</span></code> is returned. 61 </p> 62<p> 63 In this range version of <code class="computeroutput"><span class="identifier">equal</span></code> 64 it is perfectly acceptable to pass in two ranges of unequal lengths. 65 </p> 66<p> 67 Elements are considered equal in the non-predicate version if <code class="computeroutput"><span class="keyword">operator</span><span class="special">==</span></code> 68 returns <code class="computeroutput"><span class="keyword">true</span></code>. Elements are 69 considered equal in the predicate version if <code class="computeroutput"><span class="identifier">pred</span><span class="special">(</span><span class="identifier">x</span><span class="special">,</span><span class="identifier">y</span><span class="special">)</span></code> is <code class="computeroutput"><span class="keyword">true</span></code>. 70 </p> 71<h6> 72<a name="range.reference.algorithms.non_mutating.equal.h2"></a> 73 <span class="phrase"><a name="range.reference.algorithms.non_mutating.equal.definition"></a></span><a class="link" href="equal.html#range.reference.algorithms.non_mutating.equal.definition">Definition</a> 74 </h6> 75<p> 76 Defined in the header file <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">range</span><span class="special">/</span><span class="identifier">algorithm</span><span class="special">/</span><span class="identifier">equal</span><span class="special">.</span><span class="identifier">hpp</span></code> 77 </p> 78<h6> 79<a name="range.reference.algorithms.non_mutating.equal.h3"></a> 80 <span class="phrase"><a name="range.reference.algorithms.non_mutating.equal.requirements"></a></span><a class="link" href="equal.html#range.reference.algorithms.non_mutating.equal.requirements">Requirements</a> 81 </h6> 82<p> 83 <span class="bold"><strong>For the non-predicate versions:</strong></span> 84 </p> 85<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 86<li class="listitem"> 87 <code class="computeroutput"><span class="identifier">SinglePassRange1</span></code> 88 is a model of the <a class="link" href="../../../concepts/single_pass_range.html" title="Single Pass Range">Single 89 Pass Range</a> Concept. 90 </li> 91<li class="listitem"> 92 <code class="computeroutput"><span class="identifier">SinglePassRange2</span></code> 93 is a model of the <a class="link" href="../../../concepts/single_pass_range.html" title="Single Pass Range">Single 94 Pass Range</a> Concept. 95 </li> 96<li class="listitem"> 97 <code class="computeroutput"><span class="identifier">SinglePassRange1</span></code>'s 98 value type is a model of the <code class="computeroutput"><span class="identifier">EqualityComparableConcept</span></code>. 99 </li> 100<li class="listitem"> 101 <code class="computeroutput"><span class="identifier">SinglePassRange2</span></code>'s 102 value type is a model of the <code class="computeroutput"><span class="identifier">EqualityComparableConcept</span></code>. 103 </li> 104<li class="listitem"> 105 <code class="computeroutput"><span class="identifier">SinglePassRange1</span></code>'s 106 value type can be compared for equality with <code class="computeroutput"><span class="identifier">SinglePassRange2</span></code>'s 107 value type. 108 </li> 109</ul></div> 110<p> 111 <span class="bold"><strong>For the predicate versions:</strong></span> 112 </p> 113<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 114<li class="listitem"> 115 <code class="computeroutput"><span class="identifier">SinglePassRange1</span></code> 116 is a model of the <a class="link" href="../../../concepts/single_pass_range.html" title="Single Pass Range">Single 117 Pass Range</a> Concept. 118 </li> 119<li class="listitem"> 120 <code class="computeroutput"><span class="identifier">SinglePassRange2</span></code> 121 is a model of the <a class="link" href="../../../concepts/single_pass_range.html" title="Single Pass Range">Single 122 Pass Range</a> Concept. 123 </li> 124<li class="listitem"> 125 <code class="computeroutput"><span class="identifier">BinaryPredicate</span></code> is 126 a model of the <code class="computeroutput"><span class="identifier">BinaryPredicateConcept</span></code>. 127 </li> 128<li class="listitem"> 129 <code class="computeroutput"><span class="identifier">SinglePassRange1</span></code>'s 130 value type is convertible to <code class="computeroutput"><span class="identifier">BinaryPredicate</span></code>'s 131 first argument type. 132 </li> 133<li class="listitem"> 134 <code class="computeroutput"><span class="identifier">SinglePassRange2</span></code>'s 135 value type is convertible to <code class="computeroutput"><span class="identifier">BinaryPredicate</span></code>'s 136 second argument type. 137 </li> 138</ul></div> 139<h6> 140<a name="range.reference.algorithms.non_mutating.equal.h4"></a> 141 <span class="phrase"><a name="range.reference.algorithms.non_mutating.equal.complexity"></a></span><a class="link" href="equal.html#range.reference.algorithms.non_mutating.equal.complexity">Complexity</a> 142 </h6> 143<p> 144 Linear. At most <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">),</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng2</span><span class="special">))</span></code> 145 comparisons. 146 </p> 147</div> 148<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 149<td align="left"></td> 150<td align="right"><div class="copyright-footer">Copyright © 2003-2010 Thorsten Ottosen, 151 Neil Groves<p> 152 Distributed under the Boost Software License, Version 1.0. (See accompanying 153 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 154 </p> 155</div></td> 156</tr></table> 157<hr> 158<div class="spirit-nav"> 159<a accesskey="p" href="count_if.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../non_mutating.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="equal_range.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 160</div> 161</body> 162</html> 163
