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

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  26 <div class="titlepage"><div><div><h3 class="title">
  27 <a name="boost_typetraits.reference.floating_point_promotion"></a><a class="link" href="floating_point_promotion.html" title="floating_point_promotion">floating_point_promotion</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">&gt;</span>
  30 <span class="keyword">struct</span> <span class="identifier">floating_point_promotion</span>
  31 <span class="special">{</span>
  32    <span class="keyword">typedef</span> <em class="replaceable"><code>see-below</code></em> <span class="identifier">type</span><span class="special">;</span>
  33 <span class="special">};</span>
  34 </pre>
  35 <p>
  36         <span class="bold"><strong>type:</strong></span> If floating point promotion can be
  37         applied to an rvalue of type <code class="computeroutput"><span class="identifier">T</span></code>,
  38         then applies floating point promotion to <code class="computeroutput"><span class="identifier">T</span></code>
  39         and keeps cv-qualifiers of <code class="computeroutput"><span class="identifier">T</span></code>,
  40         otherwise leaves <code class="computeroutput"><span class="identifier">T</span></code> unchanged.
  41       </p>
  42 <p>
  43         <span class="bold"><strong>C++ Standard Reference:</strong></span> 4.6.
  44       </p>
  45 <p>
  46         <span class="bold"><strong>Header:</strong></span> <code class="computeroutput"> <span class="preprocessor">#include</span>
  47         <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">floating_point_promotion</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
  48         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>
  49       </p>
  50 <div class="table">
  51 <a name="boost_typetraits.reference.floating_point_promotion.examples"></a><p class="title"><b>Table&#160;1.19.&#160;Examples</b></p>
  52 <div class="table-contents"><table class="table" summary="Examples">
  53 <colgroup>
  54 <col>
  55 <col>
  56 </colgroup>
  57 <thead><tr>
  58 <th>
  59                 <p>
  60                   Expression
  61                 </p>
  62               </th>
  63 <th>
  64                 <p>
  65                   Result Type
  66                 </p>
  67               </th>
  68 </tr></thead>
  69 <tbody>
  70 <tr>
  71 <td>
  72                 <p>
  73                   <code class="computeroutput"><span class="identifier">floating_point_promotion</span><span class="special">&lt;</span><span class="keyword">float</span>
  74                   <span class="keyword">const</span><span class="special">&gt;::</span><span class="identifier">type</span></code>
  75                 </p>
  76               </td>
  77 <td>
  78                 <p>
  79                   <code class="computeroutput"><span class="keyword">double</span> <span class="keyword">const</span></code>
  80                 </p>
  81               </td>
  82 </tr>
  83 <tr>
  84 <td>
  85                 <p>
  86                   <code class="computeroutput"><span class="identifier">floating_point_promotion</span><span class="special">&lt;</span><span class="keyword">float</span><span class="special">&amp;&gt;::</span><span class="identifier">type</span></code>
  87                 </p>
  88               </td>
  89 <td>
  90                 <p>
  91                   <code class="computeroutput"><span class="keyword">float</span><span class="special">&amp;</span></code>
  92                 </p>
  93               </td>
  94 </tr>
  95 <tr>
  96 <td>
  97                 <p>
  98                   <code class="computeroutput"><span class="identifier">floating_point_promotion</span><span class="special">&lt;</span><span class="keyword">short</span><span class="special">&gt;::</span><span class="identifier">type</span></code>
  99                 </p>
 100               </td>
 101 <td>
 102                 <p>
 103                   <code class="computeroutput"><span class="keyword">short</span></code>
 104                 </p>
 105               </td>
 106 </tr>
 107 </tbody>
 108 </table></div>
 109 </div>
 110 <br class="table-break"><p>
 111         <span class="bold"><strong>Compiler Compatibility:</strong></span> All current compilers
 112         are supported by this trait.
 113       </p>
 114 </div>
 115 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 116 <td align="left"></td>
 117 <td align="right"><div class="copyright-footer">Copyright &#169; 2000, 2011 Adobe Systems Inc, David Abrahams,
 118       Frederic Bron, Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant,
 119       Jesse Jones, Mat Marcus, Itay Maman, John Maddock, Alexander Nasonov, Thorsten
 120       Ottosen, Roman Perepelitsa, Robert Ramey, Jeremy Siek, Robert Stewart and Steven
 121       Watanabe<p>
 122         Distributed under the Boost Software License, Version 1.0. (See accompanying
 123         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>)
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