ceph/src/boost/libs/type_traits/doc/html/boost_typetraits/reference/extent.html

   1 <html>
   2 <head>
   3 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
   4 <title>extent</title>
   5 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
   6 <meta name="generator" content="DocBook XSL Stylesheets V1.77.1">
   7 <link rel="home" href="../../index.html" title="Chapter&#160;1.&#160;Boost.TypeTraits">
   8 <link rel="up" href="../reference.html" title="Alphabetical Reference">
   9 <link rel="prev" href="declval.html" title="declval">
  10 <link rel="next" href="floating_point_promotion.html" title="floating_point_promotion">
  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="declval.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="floating_point_promotion.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
  24 </div>
  25 <div class="section">
  26 <div class="titlepage"><div><div><h3 class="title">
  27 <a name="boost_typetraits.reference.extent"></a><a class="link" href="extent.html" title="extent">extent</a>
  28 </h3></div></div></div>
  29 <pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">N</span> <span class="special">=</span> <span class="number">0</span><span class="special">&gt;</span>
  30 <span class="keyword">struct</span> <span class="identifier">extent</span> <span class="special">:</span> <span class="keyword">public</span> <a class="link" href="integral_constant.html" title="integral_constant">integral_constant</a><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">,</span> <span class="identifier">EXTENT</span><span class="special">(</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">N</span><span class="special">)&gt;</span> <span class="special">{};</span>
  31 </pre>
  32 <p>
  33         <span class="bold"><strong>Inherits:</strong></span> Class template extent inherits
  34         from <code class="computeroutput"><a class="link" href="integral_constant.html" title="integral_constant">integral_constant</a><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">,</span> <span class="identifier">EXTENT</span><span class="special">(</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">N</span><span class="special">)&gt;</span></code>,
  35         where <code class="computeroutput"><span class="identifier">EXTENT</span><span class="special">(</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">N</span><span class="special">)</span></code> is the number of elements in the N'th array
  36         dimension of type <code class="computeroutput"><span class="identifier">T</span></code>.
  37       </p>
  38 <p>
  39         If <code class="computeroutput"><span class="identifier">T</span></code> is not a (built-in)
  40         array type, or if <code class="computeroutput"><span class="identifier">N</span> <span class="special">&gt;</span>
  41         <a class="link" href="rank.html" title="rank">rank</a><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="identifier">value</span></code>, or if the N'th array bound is incomplete,
  42         then <code class="computeroutput"><span class="identifier">EXTENT</span><span class="special">(</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">N</span><span class="special">)</span></code> is zero.
  43       </p>
  44 <p>
  45         <span class="bold"><strong>Header:</strong></span> <code class="computeroutput"> <span class="preprocessor">#include</span>
  46         <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">type_traits</span><span class="special">/</span><span class="identifier">extent</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
  47         or <code class="computeroutput"> <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">type_traits</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
  48       </p>
  49 <p>
  50         <span class="bold"><strong>Examples:</strong></span>
  51       </p>
  52 <div class="blockquote"><blockquote class="blockquote"><p>
  53           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">[</span><span class="number">1</span><span class="special">]&gt;</span></code> inherits from <code class="computeroutput"><a class="link" href="integral_constant.html" title="integral_constant">integral_constant</a><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">,</span> <span class="number">1</span><span class="special">&gt;</span></code>.
  54         </p></blockquote></div>
  55 <div class="blockquote"><blockquote class="blockquote"><p>
  56           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">[</span><span class="number">2</span><span class="special">][</span><span class="number">3</span><span class="special">][</span><span class="number">4</span><span class="special">],</span>
  57           <span class="number">0</span><span class="special">&gt;::</span><span class="identifier">type</span></code> is the type <code class="computeroutput"><a class="link" href="integral_constant.html" title="integral_constant">integral_constant</a><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">,</span> <span class="number">2</span><span class="special">&gt;</span></code>.
  58         </p></blockquote></div>
  59 <div class="blockquote"><blockquote class="blockquote"><p>
  60           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">[</span><span class="number">2</span><span class="special">][</span><span class="number">3</span><span class="special">][</span><span class="number">4</span><span class="special">],</span>
  61           <span class="number">1</span><span class="special">&gt;::</span><span class="identifier">type</span></code> is the type <code class="computeroutput"><a class="link" href="integral_constant.html" title="integral_constant">integral_constant</a><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">,</span> <span class="number">3</span><span class="special">&gt;</span></code>.
  62         </p></blockquote></div>
  63 <div class="blockquote"><blockquote class="blockquote"><p>
  64           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">[</span><span class="number">2</span><span class="special">][</span><span class="number">3</span><span class="special">][</span><span class="number">4</span><span class="special">],</span>
  65           <span class="number">2</span><span class="special">&gt;::</span><span class="identifier">type</span></code> is the type <code class="computeroutput"><a class="link" href="integral_constant.html" title="integral_constant">integral_constant</a><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">,</span> <span class="number">4</span><span class="special">&gt;</span></code>.
  66         </p></blockquote></div>
  67 <div class="blockquote"><blockquote class="blockquote"><p>
  68           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">[</span><span class="number">4</span><span class="special">]&gt;::</span><span class="identifier">value</span></code>
  69           is an integral constant expression that evaluates to <span class="emphasis"><em>4</em></span>.
  70         </p></blockquote></div>
  71 <div class="blockquote"><blockquote class="blockquote"><p>
  72           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">[][</span><span class="number">2</span><span class="special">]&gt;::</span><span class="identifier">value</span></code>
  73           is an integral constant expression that evaluates to <span class="emphasis"><em>0</em></span>.
  74         </p></blockquote></div>
  75 <div class="blockquote"><blockquote class="blockquote"><p>
  76           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">[][</span><span class="number">2</span><span class="special">],</span> <span class="number">1</span><span class="special">&gt;::</span><span class="identifier">value</span></code> is an integral constant expression
  77           that evaluates to <span class="emphasis"><em>2</em></span>.
  78         </p></blockquote></div>
  79 <div class="blockquote"><blockquote class="blockquote"><p>
  80           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">*&gt;::</span><span class="identifier">value</span></code> is an integral constant expression
  81           that evaluates to <span class="emphasis"><em>0</em></span>.
  82         </p></blockquote></div>
  83 <div class="blockquote"><blockquote class="blockquote"><p>
  84           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span> <span class="number">3</span><span class="special">&gt;</span> <span class="special">&gt;::</span><span class="identifier">value</span></code> is an integral constant expression
  85           that evaluates to <span class="emphasis"><em>0</em></span>: <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span></code>
  86           is a class type and <span class="bold"><strong>not an array type</strong></span>!
  87         </p></blockquote></div>
  88 <div class="blockquote"><blockquote class="blockquote"><p>
  89           <code class="computeroutput"><span class="identifier">extent</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="identifier">value_type</span></code> is the type <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span></code>.
  90         </p></blockquote></div>
  91 <p>
  92         <span class="bold"><strong>Compiler Compatibility:</strong></span> All current compilers
  93         are supported by this trait.
  94       </p>
  95 </div>
  96 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
  97 <td align="left"></td>
  98 <td align="right"><div class="copyright-footer">Copyright &#169; 2000, 2011 Adobe Systems Inc, David Abrahams,
  99       Frederic Bron, Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant,
 100       Jesse Jones, Mat Marcus, Itay Maman, John Maddock, Alexander Nasonov, Thorsten
 101       Ottosen, Roman Perepelitsa, Robert Ramey, Jeremy Siek, Robert Stewart and Steven
 102       Watanabe<p>
 103         Distributed under the Boost Software License, Version 1.0. (See accompanying
 104         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>)
 105       </p>
 106 </div></td>
 107 </tr></table>
 108 <hr>
 109 <div class="spirit-nav">
 110 <a accesskey="p" href="declval.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="floating_point_promotion.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
 111 </div>
 112 </body>
 113 </html>