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  26 <div class="titlepage"><div><div><h4 class="title">
  27 <a name="fusion.iterator.metafunctions.value_of_data"></a><a class="link" href="value_of_data.html" title="value_of_data">value_of_data</a>
  28 </h4></div></div></div>
  29 <h6>
  30 <a name="fusion.iterator.metafunctions.value_of_data.h0"></a>
  31           <span class="phrase"><a name="fusion.iterator.metafunctions.value_of_data.description"></a></span><a class="link" href="value_of_data.html#fusion.iterator.metafunctions.value_of_data.description">Description</a>
  32         </h6>
  33 <p>
  34           Returns the type of the data property associated with the element referenced
  35           by an associative iterator references.
  36         </p>
  37 <h6>
  38 <a name="fusion.iterator.metafunctions.value_of_data.h1"></a>
  39           <span class="phrase"><a name="fusion.iterator.metafunctions.value_of_data.synopsis"></a></span><a class="link" href="value_of_data.html#fusion.iterator.metafunctions.value_of_data.synopsis">Synopsis</a>
  40         </h6>
  41 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
  42     <span class="keyword">typename</span> <span class="identifier">I</span>
  43     <span class="special">&gt;</span>
  44 <span class="keyword">struct</span> <span class="identifier">value_of_data</span>
  45 <span class="special">{</span>
  46     <span class="keyword">typedef</span> <span class="emphasis"><em>unspecified</em></span> <span class="identifier">type</span><span class="special">;</span>
  47 <span class="special">};</span>
  48 </pre>
  49 <div class="table">
  50 <a name="fusion.iterator.metafunctions.value_of_data.t0"></a><p class="title"><b>Table&#160;1.21.&#160;Parameters</b></p>
  51 <div class="table-contents"><table class="table" summary="Parameters">
  52 <colgroup>
  53 <col>
  54 <col>
  55 <col>
  56 </colgroup>
  57 <thead><tr>
  58 <th>
  59                   <p>
  60                     Parameter
  61                   </p>
  62                 </th>
  63 <th>
  64                   <p>
  65                     Requirement
  66                   </p>
  67                 </th>
  68 <th>
  69                   <p>
  70                     Description
  71                   </p>
  72                 </th>
  73 </tr></thead>
  74 <tbody><tr>
  75 <td>
  76                   <p>
  77                     <code class="computeroutput"><span class="identifier">I</span></code>
  78                   </p>
  79                 </td>
  80 <td>
  81                   <p>
  82                     Model of <a class="link" href="../concepts/associative_iterator.html" title="Associative Iterator">Associative
  83                     Iterator</a>
  84                   </p>
  85                 </td>
  86 <td>
  87                   <p>
  88                     Operation's argument
  89                   </p>
  90                 </td>
  91 </tr></tbody>
  92 </table></div>
  93 </div>
  94 <br class="table-break"><h6>
  95 <a name="fusion.iterator.metafunctions.value_of_data.h2"></a>
  96           <span class="phrase"><a name="fusion.iterator.metafunctions.value_of_data.expression_semantics"></a></span><a class="link" href="value_of_data.html#fusion.iterator.metafunctions.value_of_data.expression_semantics">Expression
  97           Semantics</a>
  98         </h6>
  99 <pre class="programlisting"><a class="link" href="value_of_data.html" title="value_of_data"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">value_of_data</span></code></a><span class="special">&lt;</span><span class="identifier">I</span><span class="special">&gt;::</span><span class="identifier">type</span>
 100 </pre>
 101 <p>
 102           <span class="bold"><strong>Return type</strong></span>: Any type
 103         </p>
 104 <p>
 105           <span class="bold"><strong>Semantics</strong></span>: Returns the type of the data
 106           property associated with the element referenced by an associative iterator
 107           <code class="computeroutput"><span class="identifier">I</span></code>.
 108         </p>
 109 <h6>
 110 <a name="fusion.iterator.metafunctions.value_of_data.h3"></a>
 111           <span class="phrase"><a name="fusion.iterator.metafunctions.value_of_data.header"></a></span><a class="link" href="value_of_data.html#fusion.iterator.metafunctions.value_of_data.header">Header</a>
 112         </h6>
 113 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">iterator</span><span class="special">/</span><span class="identifier">value_of_data</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 114 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">value_of_data</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 115 </pre>
 116 <h6>
 117 <a name="fusion.iterator.metafunctions.value_of_data.h4"></a>
 118           <span class="phrase"><a name="fusion.iterator.metafunctions.value_of_data.example"></a></span><a class="link" href="value_of_data.html#fusion.iterator.metafunctions.value_of_data.example">Example</a>
 119         </h6>
 120 <pre class="programlisting"><span class="keyword">typedef</span> <a class="link" href="../../container/map.html" title="map"><code class="computeroutput"><span class="identifier">map</span></code></a><span class="special">&lt;</span><a class="link" href="../../support/pair.html" title="pair"><code class="computeroutput"><span class="identifier">pair</span></code></a><span class="special">&lt;</span><span class="keyword">float</span><span class="special">,</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">vec</span><span class="special">;</span>
 121 <span class="keyword">typedef</span> <a class="link" href="../../sequence/intrinsic/metafunctions/begin.html" title="begin"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">begin</span></code></a><span class="special">&lt;</span><span class="identifier">vec</span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">first</span><span class="special">;</span>
 122
 123 <span class="identifier">BOOST_MPL_ASSERT</span><span class="special">((</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">is_same</span><span class="special">&lt;</span><a class="link" href="value_of_data.html" title="value_of_data"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">value_of_data</span></code></a><span class="special">&lt;</span><span class="identifier">first</span><span class="special">&gt;::</span><span class="identifier">type</span><span class="special">,</span> <span class="keyword">int</span><span class="special">&gt;));</span>
 124 </pre>
 125 </div>
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 130         Distributed under the Boost Software License, Version 1.0. (See accompanying
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