1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Algorithms</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. Boost.Iterator"> 8<link rel="up" href="../index.html" title="Chapter 1. Boost.Iterator"> 9<link rel="prev" href="utilities/traits.html" title="Type Traits"> 10<link rel="next" href="algorithms/distance.html" title="Function template distance()"> 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="utilities/traits.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.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="algorithms/distance.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 27<a name="iterator.algorithms"></a><a class="link" href="algorithms.html" title="Algorithms">Algorithms</a> 28</h2></div></div></div> 29<div class="toc"><dl class="toc"> 30<dt><span class="section"><a href="algorithms.html#iterator.algorithms.advance">Function template <code class="computeroutput"><span class="identifier">advance</span><span class="special">()</span></code></a></span></dt> 31<dt><span class="section"><a href="algorithms/distance.html">Function template <code class="computeroutput"><span class="identifier">distance</span><span class="special">()</span></code></a></span></dt> 32<dt><span class="section"><a href="algorithms/next_prior.html">Function templates <code class="computeroutput"><span class="identifier">next</span><span class="special">()</span></code> and 33 <code class="computeroutput"><span class="identifier">prior</span><span class="special">()</span></code></a></span></dt> 34</dl></div> 35<div class="section"> 36<div class="titlepage"><div><div><h3 class="title"> 37<a name="iterator.algorithms.advance"></a><a class="link" href="algorithms.html#iterator.algorithms.advance" title="Function template advance()">Function template <code class="computeroutput"><span class="identifier">advance</span><span class="special">()</span></code></a> 38</h3></div></div></div> 39<p> 40 The <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">iterators</span><span class="special">::</span><span class="identifier">advance</span></code> function template is an adapted 41 version of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">advance</span></code> for the Boost iterator <a class="link" href="concepts/traversal.html" title="Traversal">traversal 42 concepts</a>. 43 </p> 44<h5> 45<a name="iterator.algorithms.advance.h0"></a> 46 <span class="phrase"><a name="iterator.algorithms.advance.header"></a></span><a class="link" href="algorithms.html#iterator.algorithms.advance.header">Header</a> 47 </h5> 48<pre class="programlisting"><span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">iterator</span><span class="special">/</span><span class="identifier">advance</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 49</pre> 50<h5> 51<a name="iterator.algorithms.advance.h1"></a> 52 <span class="phrase"><a name="iterator.algorithms.advance.synopsis"></a></span><a class="link" href="algorithms.html#iterator.algorithms.advance.synopsis">Synopsis</a> 53 </h5> 54<pre class="programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Iterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Distance</span><span class="special">></span> 55<span class="keyword">constexpr</span> <span class="keyword">void</span> <span class="identifier">advance</span><span class="special">(</span><span class="identifier">Iterator</span><span class="special">&</span> <span class="identifier">it</span><span class="special">,</span> <span class="identifier">Distance</span> <span class="identifier">n</span><span class="special">);</span> 56</pre> 57<h5> 58<a name="iterator.algorithms.advance.h2"></a> 59 <span class="phrase"><a name="iterator.algorithms.advance.description"></a></span><a class="link" href="algorithms.html#iterator.algorithms.advance.description">Description</a> 60 </h5> 61<p> 62 Moves <code class="computeroutput"><span class="identifier">it</span></code> forward by <code class="computeroutput"><span class="identifier">n</span></code> increments (or backward by <code class="computeroutput"><span class="special">|</span><span class="identifier">n</span><span class="special">|</span></code> 63 decrements if <code class="computeroutput"><span class="identifier">n</span></code> is negative). 64 </p> 65<h5> 66<a name="iterator.algorithms.advance.h3"></a> 67 <span class="phrase"><a name="iterator.algorithms.advance.requirements"></a></span><a class="link" href="algorithms.html#iterator.algorithms.advance.requirements">Requirements</a> 68 </h5> 69<p> 70 <code class="computeroutput"><span class="identifier">Iterator</span></code> should model Incrementable 71 Iterator. 72 </p> 73<h5> 74<a name="iterator.algorithms.advance.h4"></a> 75 <span class="phrase"><a name="iterator.algorithms.advance.preconditions"></a></span><a class="link" href="algorithms.html#iterator.algorithms.advance.preconditions">Preconditions</a> 76 </h5> 77<p> 78 Let <code class="computeroutput"><span class="identifier">it</span></code><sub><code class="computeroutput"><span class="identifier">i</span></code></sub> be 79 the iterator obtained by incrementing (or decrementing if <code class="computeroutput"><span class="identifier">n</span></code> 80 is negative) <code class="computeroutput"><span class="identifier">it</span></code> by <code class="computeroutput"><span class="identifier">i</span></code>. All the iterators <code class="computeroutput"><span class="identifier">it</span></code><sub><code class="computeroutput"><span class="identifier">i</span></code></sub> for <code class="computeroutput"><span class="identifier">i</span></code> 81 = 0, 1, 2, ..., <code class="computeroutput"><span class="special">|</span><span class="identifier">n</span><span class="special">|</span></code> should be valid. 82 </p> 83<p> 84 If <code class="computeroutput"><span class="identifier">Iterator</span></code> does not model 85 <a class="link" href="concepts/traversal.html#iterator.concepts.traversal.bidirectional" title="Bidirectional Traversal Concept">Bidirectional Traversal 86 Iterator</a>, <code class="computeroutput"><span class="identifier">n</span></code> should 87 be non-negative. 88 </p> 89<h5> 90<a name="iterator.algorithms.advance.h5"></a> 91 <span class="phrase"><a name="iterator.algorithms.advance.complexity"></a></span><a class="link" href="algorithms.html#iterator.algorithms.advance.complexity">Complexity</a> 92 </h5> 93<p> 94 If <code class="computeroutput"><span class="identifier">Iterator</span></code> models <a class="link" href="concepts/traversal.html#iterator.concepts.traversal.random_access" title="Random Access Traversal Concept">Random Access Traversal 95 Iterator</a>, it takes constant time; otherwise it takes linear time. 96 </p> 97<h5> 98<a name="iterator.algorithms.advance.h6"></a> 99 <span class="phrase"><a name="iterator.algorithms.advance.notes"></a></span><a class="link" href="algorithms.html#iterator.algorithms.advance.notes">Notes</a> 100 </h5> 101<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 102<li class="listitem"> 103 This function is not a customization point and is protected against being 104 found by argument-dependent lookup (ADL). 105 </li> 106<li class="listitem"> 107 This function is <code class="computeroutput"><span class="keyword">constexpr</span></code> 108 only in C++14 or later. 109 </li> 110</ul></div> 111<h5> 112<a name="iterator.algorithms.advance.h7"></a> 113 <span class="phrase"><a name="iterator.algorithms.advance.acknowledgements"></a></span><a class="link" href="algorithms.html#iterator.algorithms.advance.acknowledgements">Acknowledgements</a> 114 </h5> 115<p> 116 Contributed by Michel Morin. 117 </p> 118</div> 119</div> 120<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 121<td align="left"></td> 122<td align="right"><div class="copyright-footer">Copyright © 2003, 2005 David Abrahams Jeremy Siek Thomas 123 Witt<p> 124 Distributed under the Boost Software License, Version 1.0. (See accompanying 125 file LICENSE_1_0.txt or copy at <ulink url="http://www.boost.org/LICENSE_1_0.txt"> 126 http://www.boost.org/LICENSE_1_0.txt </ulink>) 127 </p> 128</div></td> 129</tr></table> 130<hr> 131<div class="spirit-nav"> 132<a accesskey="p" href="utilities/traits.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.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="algorithms/distance.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 133</div> 134</body> 135</html> 136
