1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>copy_backward</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="../mutating.html" title="Mutating algorithms"> 9<link rel="prev" href="copy.html" title="copy"> 10<link rel="next" href="fill.html" title="fill"> 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="copy.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../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="fill.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.mutating.copy_backward"></a><a class="link" href="copy_backward.html" title="copy_backward">copy_backward</a> 28</h5></div></div></div> 29<h6> 30<a name="range.reference.algorithms.mutating.copy_backward.h0"></a> 31 <span class="phrase"><a name="range.reference.algorithms.mutating.copy_backward.prototype"></a></span><a class="link" href="copy_backward.html#range.reference.algorithms.mutating.copy_backward.prototype">Prototype</a> 32 </h6> 33<p> 34</p> 35<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">BidirectionalRange</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">BidirectionalOutputIterator</span><span class="special">></span> 36 <span class="identifier">BidirectionalOutputIterator</span> 37 <span class="identifier">copy_backward</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">BidirectionalRange</span><span class="special">&</span> <span class="identifier">source_rng</span><span class="special">,</span> 38 <span class="identifier">BidirectionalOutputIterator</span> <span class="identifier">out_it</span><span class="special">);</span> 39</pre> 40<p> 41 </p> 42<h6> 43<a name="range.reference.algorithms.mutating.copy_backward.h1"></a> 44 <span class="phrase"><a name="range.reference.algorithms.mutating.copy_backward.description"></a></span><a class="link" href="copy_backward.html#range.reference.algorithms.mutating.copy_backward.description">Description</a> 45 </h6> 46<p> 47 <code class="computeroutput"><span class="identifier">copy_backward</span></code> copies 48 all elements from <code class="computeroutput"><span class="identifier">source_rng</span></code> 49 to the range <code class="computeroutput"><span class="special">[</span><span class="identifier">out_it</span> 50 <span class="special">-</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">source_rng</span><span class="special">),</span> <span class="identifier">out_it</span><span class="special">)</span></code>. 51 </p> 52<p> 53 The values are copied in reverse order. The return value is <code class="computeroutput"><span class="identifier">out_it</span> <span class="special">-</span> 54 <span class="identifier">distance</span><span class="special">(</span><span class="identifier">source_rng</span><span class="special">)</span></code>. 55 </p> 56<p> 57 Note well that unlike all other standard algorithms <code class="computeroutput"><span class="identifier">out_it</span></code> 58 denotes the <span class="bold"><strong>end</strong></span> of the output sequence. 59 </p> 60<h6> 61<a name="range.reference.algorithms.mutating.copy_backward.h2"></a> 62 <span class="phrase"><a name="range.reference.algorithms.mutating.copy_backward.definition"></a></span><a class="link" href="copy_backward.html#range.reference.algorithms.mutating.copy_backward.definition">Definition</a> 63 </h6> 64<p> 65 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">copy_backward</span><span class="special">.</span><span class="identifier">hpp</span></code> 66 </p> 67<h6> 68<a name="range.reference.algorithms.mutating.copy_backward.h3"></a> 69 <span class="phrase"><a name="range.reference.algorithms.mutating.copy_backward.requirements"></a></span><a class="link" href="copy_backward.html#range.reference.algorithms.mutating.copy_backward.requirements">Requirements</a> 70 </h6> 71<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 72<li class="listitem"> 73 <code class="computeroutput"><span class="identifier">BidirectionalRange</span></code> 74 is a model of <a class="link" href="../../../concepts/bidirectional_range.html" title="Bidirectional Range">Bidirectional 75 Range</a> Concept. 76 </li> 77<li class="listitem"> 78 <code class="computeroutput"><span class="identifier">OutputIterator</span></code> is 79 a model of the <code class="computeroutput"><span class="identifier">OutputIteratorConcept</span></code>. 80 </li> 81<li class="listitem"> 82 The <code class="computeroutput"><span class="identifier">value_type</span></code> of 83 <a class="link" href="../../../concepts/bidirectional_range.html" title="Bidirectional Range">Bidirectional 84 Range</a> Concept is convertible to a type in <code class="computeroutput"><span class="identifier">OutputIterator</span></code>'s 85 set of value types. 86 </li> 87</ul></div> 88<h6> 89<a name="range.reference.algorithms.mutating.copy_backward.h4"></a> 90 <span class="phrase"><a name="range.reference.algorithms.mutating.copy_backward.precondition_"></a></span><a class="link" href="copy_backward.html#range.reference.algorithms.mutating.copy_backward.precondition_">Precondition:</a> 91 </h6> 92<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 93<li class="listitem"> 94 <code class="computeroutput"><span class="identifier">out_it</span></code> is not an 95 iterator within the <code class="computeroutput"><span class="identifier">source_rng</span></code>. 96 </li> 97<li class="listitem"> 98 <code class="computeroutput"><span class="special">[</span><span class="identifier">out_it</span><span class="special">,</span> <span class="identifier">out_it</span> 99 <span class="special">+</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">source_rng</span><span class="special">))</span></code> is a valid range. 100 </li> 101</ul></div> 102<h6> 103<a name="range.reference.algorithms.mutating.copy_backward.h5"></a> 104 <span class="phrase"><a name="range.reference.algorithms.mutating.copy_backward.complexity"></a></span><a class="link" href="copy_backward.html#range.reference.algorithms.mutating.copy_backward.complexity">Complexity</a> 105 </h6> 106<p> 107 Linear. Exactly <code class="computeroutput"><span class="identifier">distance</span><span class="special">(</span><span class="identifier">source_rng</span><span class="special">)</span></code> assignments are performed. 108 </p> 109</div> 110<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 111<td align="left"></td> 112<td align="right"><div class="copyright-footer">Copyright © 2003-2010 Thorsten Ottosen, 113 Neil Groves<p> 114 Distributed under the Boost Software License, Version 1.0. (See accompanying 115 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>) 116 </p> 117</div></td> 118</tr></table> 119<hr> 120<div class="spirit-nav"> 121<a accesskey="p" href="copy.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../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="fill.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 122</div> 123</body> 124</html> 125