ceph/src/boost/libs/mpl/doc/refmanual/advance.html

   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: advance</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="./iterator-metafunctions.html" class="navigation-link">Prev</a>&nbsp;<a href="./distance.html" class="navigation-link">Next</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group">Back&nbsp;<a href="./distance.html" class="navigation-link">Along</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./iterator-metafunctions.html" class="navigation-link">Up</a>&nbsp;<a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</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="./iterators.html" class="navigation-link">Iterators</a> / <a href="./iterator-metafunctions.html" class="navigation-link">Iterator Metafunctions</a> / <a href="./advance.html" class="navigation-link">advance</a></td>
  13 </tr></table><div class="header-separator"></div>
  14 <div class="section" id="advance">
  15 <h1><a class="toc-backref" href="./iterator-metafunctions.html#id1454">advance</a></h1>
  16 <div class="section" id="id403">
  17 <h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3>
  18 <pre class="literal-block">
  19 template&lt;
  20       typename Iterator
  21     , typename N
  22     &gt;
  23 struct <a href="./advance.html" class="identifier">advance</a>
  24 {
  25     typedef <em>unspecified</em> type;
  26 };
  27 </pre>
  28 </div>
  29 <div class="section" id="id404">
  30 <h3><a class="subsection-title" href="#description" name="description">Description</a></h3>
  31 <p>Moves <tt class="literal"><span class="pre">Iterator</span></tt> by the distance <tt class="literal"><span class="pre">N</span></tt>. For <a class="reference internal" href="./bidirectional-iterator.html">bidirectional</a> and
  32 <a class="reference internal" href="./random-access-iterator.html">random access</a> iterators, the distance may be negative.</p>
  33 </div>
  34 <div class="section" id="id405">
  35 <h3><a class="subsection-title" href="#header" name="header">Header</a></h3>
  36 <pre class="literal-block">
  37 #include &lt;<a href="../../../../boost/mpl/advance.hpp" class="header">boost/mpl/advance.hpp</a>&gt;
  38 </pre>
  39 </div>
  40 <div class="section" id="id406">
  41 <h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3>
  42 <table border="1" class="docutils table">
  43 <colgroup>
  44 <col width="19%" />
  45 <col width="35%" />
  46 <col width="45%" />
  47 </colgroup>
  48 <thead valign="bottom">
  49 <tr><th class="head">Parameter</th>
  50 <th class="head">Requirement</th>
  51 <th class="head">Description</th>
  52 </tr>
  53 </thead>
  54 <tbody valign="top">
  55 <tr><td><tt class="literal"><span class="pre">Iterator</span></tt></td>
  56 <td><a class="reference internal" href="./forward-iterator.html">Forward Iterator</a></td>
  57 <td>An iterator to advance.</td>
  58 </tr>
  59 <tr><td><tt class="literal"><span class="pre">N</span></tt></td>
  60 <td><a class="reference internal" href="./integral-constant.html">Integral Constant</a></td>
  61 <td>A distance.</td>
  62 </tr>
  63 </tbody>
  64 </table>
  65 </div>
  66 <div class="section" id="id407">
  67 <h3><a class="subsection-title" href="#model-of" name="model-of">Model Of</a></h3>
  68 <p><a class="reference internal" href="./tag-dispatched-metafunction.html">Tag Dispatched Metafunction</a></p>
  69 </div>
  70 <div class="section" id="id408">
  71 <h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3>
  72 <p>For a <a class="reference internal" href="./forward-iterator.html">Forward Iterator</a> <tt class="literal"><span class="pre">iter</span></tt> and arbitrary <a class="reference internal" href="./integral-constant.html">Integral Constant</a> <tt class="literal"><span class="pre">n</span></tt>:</p>
  73 <pre class="literal-block">
  74 typedef <a href="./advance.html" class="identifier">advance</a>&lt;iter,n&gt;::type j;
  75 </pre>
  76 <table class="docutils field-list" frame="void" rules="none">
  77 <col class="field-name" />
  78 <col class="field-body" />
  79 <tbody valign="top">
  80 <tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="./forward-iterator.html">Forward Iterator</a>.</p>
  81 </td>
  82 </tr>
  83 <tr class="field"><th class="field-name">Precondition:</th><td class="field-body"><p class="first">If <tt class="literal"><span class="pre">Iterator</span></tt> is a <a class="reference internal" href="./forward-iterator.html">Forward Iterator</a>, <tt class="literal"><span class="pre">n::value</span></tt> must be nonnegative.</p>
  84 </td>
  85 </tr>
  86 <tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><p class="first">Equivalent to:</p>
  87 <pre class="literal-block">
  88 typedef iter i0;
  89 typedef <a href="./next.html" class="identifier">next</a>&lt;i0&gt;::type i1;
  90 <em>...</em>
  91 typedef <a href="./next.html" class="identifier">next</a>&lt;i<em>n-1</em>&gt;::type j;
  92 </pre>
  93 <p>if <tt class="literal"><span class="pre">n::value</span> <span class="pre">&gt;</span> <span class="pre">0</span></tt>, and</p>
  94 <pre class="literal-block">
  95 typedef iter i0;
  96 typedef <a href="./prior.html" class="identifier">prior</a>&lt;i0&gt;::type i1;
  97 <em>...</em>
  98 typedef <a href="./prior.html" class="identifier">prior</a>&lt;i<em>n-1</em>&gt;::type j;
  99 </pre>
 100 <p>otherwise.</p>
 101 </td>
 102 </tr>
 103 <tr class="field"><th class="field-name">Postcondition:</th><td class="field-body"><p class="first last"><tt class="literal"><span class="pre">j</span></tt> is dereferenceable or past-the-end;
 104 <tt class="literal"><span class="pre"><a href="./distance.html" class="identifier">distance</a>&lt;iter,j&gt;::value</span> <span class="pre">==</span> <span class="pre">n::value</span></tt> if <tt class="literal"><span class="pre">n::value</span> <span class="pre">&gt;</span> <span class="pre">0</span></tt>, and
 105 <tt class="literal"><span class="pre"><a href="./distance.html" class="identifier">distance</a>&lt;j,iter&gt;::value</span> <span class="pre">==</span> <span class="pre">n::value</span></tt> otherwise.</p>
 106 </td>
 107 </tr>
 108 </tbody>
 109 </table>
 110 </div>
 111 <div class="section" id="id409">
 112 <h3><a class="subsection-title" href="#complexity" name="complexity">Complexity</a></h3>
 113 <p>Amortized constant time if <tt class="literal"><span class="pre">iter</span></tt> is a model of
 114 <a class="reference internal" href="./random-access-iterator.html">Random Access Iterator</a>, otherwise linear time.</p>
 115 </div>
 116 <div class="section" id="id410">
 117 <h3><a class="subsection-title" href="#example" name="example">Example</a></h3>
 118 <pre class="literal-block">
 119 typedef <a href="./range-c.html" class="identifier">range_c</a>&lt;int,0,10&gt; numbers;
 120 typedef <a href="./begin.html" class="identifier">begin</a>&lt;numbers&gt;::type first;
 121 typedef <a href="./end.html" class="identifier">end</a>&lt;numbers&gt;::type last;
 122
 123 typedef <a href="./advance.html" class="identifier">advance</a>&lt;first,<a href="./int.html" class="identifier">int_</a>&lt;10&gt; &gt;::type i1;
 124 typedef <a href="./advance.html" class="identifier">advance</a>&lt;last,<a href="./int.html" class="identifier">int_</a>&lt;-10&gt; &gt;::type i2;
 125
 126 <a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( boost::is_same&lt;i1,last&gt; ));
 127 <a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( boost::is_same&lt;i2,first&gt; ));
 128 </pre>
 129 </div>
 130 <div class="section" id="id411">
 131 <h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3>
 132 <p><a class="reference internal" href="./iterators.html">Iterators</a>, <a class="reference internal" href="./tag-dispatched-metafunction.html">Tag Dispatched Metafunction</a>, <a class="reference internal" href="./distance.html">distance</a>, <a class="reference internal" href="./next.html">next</a></p>
 133 <!-- Iterators/Iterator Metafunctions//distance |20 -->
 134 </div>
 135 </div>
 136
 137 <div class="footer-separator"></div>
 138 <table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./iterator-metafunctions.html" class="navigation-link">Prev</a>&nbsp;<a href="./distance.html" class="navigation-link">Next</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group">Back&nbsp;<a href="./distance.html" class="navigation-link">Along</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./iterator-metafunctions.html" class="navigation-link">Up</a>&nbsp;<a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td>
 139 <td><div class="copyright-footer"><div class="copyright">Copyright ©  2001-2009 Aleksey Gurtovoy and David Abrahams</div>
 140 Distributed under the Boost Software License, Version 1.0. (See accompanying
 141 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>
 142 </html>