ceph/src/boost/libs/mpl/doc/refmanual/filter-view.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: filter_view</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="./empty-sequence.html" class="navigation-link">Prev</a>&nbsp;<a href="./iterator-range.html" class="navigation-link">Next</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./empty-sequence.html" class="navigation-link">Back</a>&nbsp;<a href="./iterator-range.html" class="navigation-link">Along</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./views.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="./sequences.html" class="navigation-link">Sequences</a> / <a href="./views.html" class="navigation-link">Views</a> / <a href="./filter-view.html" class="navigation-link">filter_view</a></td>
  13 </tr></table><div class="header-separator"></div>
  14 <div class="section" id="filter-view">
  15 <h1><a class="toc-backref" href="./views.html#id1418">filter_view</a></h1>
  16 <div class="section" id="id126">
  17 <h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3>
  18 <pre class="literal-block">
  19 template&lt;
  20       typename Sequence
  21     , typename Pred
  22     &gt;
  23 struct <a href="./filter-view.html" class="identifier">filter_view</a>
  24 {
  25     // <em>unspecified</em>
  26     // <em>...</em>
  27 };
  28 </pre>
  29 </div>
  30 <div class="section" id="id127">
  31 <h3><a class="subsection-title" href="#description" name="description">Description</a></h3>
  32 <p>A view into a subset of <tt class="literal"><span class="pre">Sequence</span></tt>'s elements satisfying the predicate <tt class="literal"><span class="pre">Pred</span></tt>.</p>
  33 </div>
  34 <div class="section" id="id128">
  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/filter_view.hpp" class="header">boost/mpl/filter_view.hpp</a>&gt;
  38 </pre>
  39 </div>
  40 <div class="section" id="id129">
  41 <h3><a class="subsection-title" href="#model-of" name="model-of">Model of</a></h3>
  42 <ul class="simple">
  43 <li><a class="reference internal" href="./forward-sequence.html">Forward Sequence</a></li>
  44 </ul>
  45 </div>
  46 <div class="section" id="parameters">
  47 <h3>Parameters</h3>
  48 <table border="1" class="docutils table">
  49 <colgroup>
  50 <col width="15%" />
  51 <col width="36%" />
  52 <col width="48%" />
  53 </colgroup>
  54 <thead valign="bottom">
  55 <tr><th class="head">Parameter</th>
  56 <th class="head">Requirement</th>
  57 <th class="head">Description</th>
  58 </tr>
  59 </thead>
  60 <tbody valign="top">
  61 <tr><td><tt class="literal"><span class="pre">Sequence</span></tt></td>
  62 <td><a class="reference internal" href="./forward-sequence.html">Forward Sequence</a></td>
  63 <td>A sequence to wrap.</td>
  64 </tr>
  65 <tr><td><tt class="literal"><span class="pre">Pred</span></tt></td>
  66 <td>Unary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a></td>
  67 <td>A filtering predicate.</td>
  68 </tr>
  69 </tbody>
  70 </table>
  71 </div>
  72 <div class="section" id="id130">
  73 <h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3>
  74 <p>Semantics of an expression is defined only where it differs from, or is not
  75 defined in <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a>.</p>
  76 <p>In the following table, <tt class="literal"><span class="pre">v</span></tt> is an instance of <tt class="literal"><span class="pre"><a href="./filter-view.html" class="identifier">filter_view</a></span></tt>, <tt class="literal"><span class="pre">s</span></tt> is an arbitrary
  77 <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a>, <tt class="literal"><span class="pre">pred</span></tt> is an unary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a>.</p>
  78 <table border="1" class="docutils table">
  79 <colgroup>
  80 <col width="40%" />
  81 <col width="60%" />
  82 </colgroup>
  83 <thead valign="bottom">
  84 <tr><th class="head">Expression</th>
  85 <th class="head">Semantics</th>
  86 </tr>
  87 </thead>
  88 <tbody valign="top">
  89 <tr><td><pre class="first last literal-block">
  90 <a href="./filter-view.html" class="identifier">filter_view</a>&lt;s,pred&gt;
  91 <a href="./filter-view.html" class="identifier">filter_view</a>&lt;s,pred&gt;::type
  92 </pre>
  93 </td>
  94 <td>A lazy <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a> sequence of all the elements in
  95 the range [<tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a>&lt;s&gt;::type</span></tt>, <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a>&lt;s&gt;::type</span></tt>) that satisfy the predicate
  96 <tt class="literal"><span class="pre">pred</span></tt>.</td>
  97 </tr>
  98 <tr><td><tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a>&lt;v&gt;::type</span></tt></td>
  99 <td>The size of <tt class="literal"><span class="pre">v</span></tt>;
 100 <tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a>&lt;v&gt;::value</span> <span class="pre">==</span> <span class="pre"><a href="./count-if.html" class="identifier">count_if</a>&lt;s,pred&gt;::value</span></tt>;
 101 linear complexity; see <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a>.</td>
 102 </tr>
 103 </tbody>
 104 </table>
 105 </div>
 106 <div class="section" id="id131">
 107 <h3><a class="subsection-title" href="#example" name="example">Example</a></h3>
 108 <p>Find the largest floating type in a sequence.</p>
 109 <pre class="literal-block">
 110 typedef <a href="./vector.html" class="identifier">vector</a>&lt;int,float,long,float,char[50],long double,char&gt; types;
 111 typedef <a href="./max-element.html" class="identifier">max_element</a>&lt;
 112       <a href="./transform-view.html" class="identifier">transform_view</a>&lt; <a href="./filter-view.html" class="identifier">filter_view</a>&lt; types,boost::is_float&lt;_&gt; &gt;, size_of&lt;_&gt; &gt;
 113     &gt;::type iter;
 114
 115 <a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( is_same&lt; <a href="./deref.html" class="identifier">deref</a>&lt;iter::base&gt;::type, long double > ));
 116 </pre>
 117 </div>
 118 <div class="section" id="id132">
 119 <h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3>
 120 <p><a class="reference internal" href="./sequences.html">Sequences</a>, <a class="reference internal" href="./views.html">Views</a>, <a class="reference internal" href="./transform-view.html">transform_view</a>, <a class="reference internal" href="./joint-view.html">joint_view</a>, <a class="reference internal" href="./zip-view.html">zip_view</a>, <a class="reference internal" href="./iterator-range.html">iterator_range</a></p>
 121 <!-- Sequences/Views//iterator_range -->
 122 </div>
 123 </div>
 124
 125 <div class="footer-separator"></div>
 126 <table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./empty-sequence.html" class="navigation-link">Prev</a>&nbsp;<a href="./iterator-range.html" class="navigation-link">Next</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./empty-sequence.html" class="navigation-link">Back</a>&nbsp;<a href="./iterator-range.html" class="navigation-link">Along</a></span><span class="navigation-group-separator">&nbsp;|&nbsp;</span><span class="navigation-group"><a href="./views.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>
 127 <td><div class="copyright-footer"><div class="copyright">Copyright ©  2001-2009 Aleksey Gurtovoy and David Abrahams</div>
 128 Distributed under the Boost Software License, Version 1.0. (See accompanying
 129 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>
 130 </html>