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  26 <div class="titlepage"><div><div><h4 class="title">
  27 <a name="fusion.iterator.metafunctions.deref"></a><a class="link" href="deref.html" title="deref">deref</a>
  28 </h4></div></div></div>
  29 <h6>
  30 <a name="fusion.iterator.metafunctions.deref.h0"></a>
  31           <span class="phrase"><a name="fusion.iterator.metafunctions.deref.description"></a></span><a class="link" href="deref.html#fusion.iterator.metafunctions.deref.description">Description</a>
  32         </h6>
  33 <p>
  34           Returns the type that will be returned by dereferencing an iterator.
  35         </p>
  36 <h6>
  37 <a name="fusion.iterator.metafunctions.deref.h1"></a>
  38           <span class="phrase"><a name="fusion.iterator.metafunctions.deref.synposis"></a></span><a class="link" href="deref.html#fusion.iterator.metafunctions.deref.synposis">Synposis</a>
  39         </h6>
  40 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
  41     <span class="keyword">typename</span> <span class="identifier">I</span>
  42     <span class="special">&gt;</span>
  43 <span class="keyword">struct</span> <span class="identifier">deref</span>
  44 <span class="special">{</span>
  45     <span class="keyword">typedef</span> <span class="emphasis"><em>unspecified</em></span> <span class="identifier">type</span><span class="special">;</span>
  46 <span class="special">};</span>
  47 </pre>
  48 <div class="table">
  49 <a name="fusion.iterator.metafunctions.deref.t0"></a><p class="title"><b>Table&#160;1.13.&#160;Parameters</b></p>
  50 <div class="table-contents"><table class="table" summary="Parameters">
  51 <colgroup>
  52 <col>
  53 <col>
  54 <col>
  55 </colgroup>
  56 <thead><tr>
  57 <th>
  58                   <p>
  59                     Parameter
  60                   </p>
  61                 </th>
  62 <th>
  63                   <p>
  64                     Requirement
  65                   </p>
  66                 </th>
  67 <th>
  68                   <p>
  69                     Description
  70                   </p>
  71                 </th>
  72 </tr></thead>
  73 <tbody><tr>
  74 <td>
  75                   <p>
  76                     <code class="computeroutput"><span class="identifier">I</span></code>
  77                   </p>
  78                 </td>
  79 <td>
  80                   <p>
  81                     Model of <a class="link" href="../concepts/forward_iterator.html" title="Forward Iterator">Forward
  82                     Iterator</a>
  83                   </p>
  84                 </td>
  85 <td>
  86                   <p>
  87                     Operation's argument
  88                   </p>
  89                 </td>
  90 </tr></tbody>
  91 </table></div>
  92 </div>
  93 <br class="table-break"><h6>
  94 <a name="fusion.iterator.metafunctions.deref.h2"></a>
  95           <span class="phrase"><a name="fusion.iterator.metafunctions.deref.expression_semantics"></a></span><a class="link" href="deref.html#fusion.iterator.metafunctions.deref.expression_semantics">Expression
  96           Semantics</a>
  97         </h6>
  98 <pre class="programlisting"><a class="link" href="deref.html" title="deref"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">deref</span></code></a><span class="special">&lt;</span><span class="identifier">I</span><span class="special">&gt;::</span><span class="identifier">type</span>
  99 </pre>
 100 <p>
 101           <span class="bold"><strong>Return type</strong></span>: Any type
 102         </p>
 103 <p>
 104           <span class="bold"><strong>Semantics</strong></span>: Returns the result of dereferencing
 105           an iterator of type <code class="computeroutput"><span class="identifier">I</span></code>.
 106         </p>
 107 <h6>
 108 <a name="fusion.iterator.metafunctions.deref.h3"></a>
 109           <span class="phrase"><a name="fusion.iterator.metafunctions.deref.header"></a></span><a class="link" href="deref.html#fusion.iterator.metafunctions.deref.header">Header</a>
 110         </h6>
 111 <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">deref</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 112 <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">deref</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 113 </pre>
 114 <h6>
 115 <a name="fusion.iterator.metafunctions.deref.h4"></a>
 116           <span class="phrase"><a name="fusion.iterator.metafunctions.deref.example"></a></span><a class="link" href="deref.html#fusion.iterator.metafunctions.deref.example">Example</a>
 117         </h6>
 118 <pre class="programlisting"><span class="keyword">typedef</span> <a class="link" href="../../container/vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span><span class="keyword">int</span><span class="special">&amp;&gt;</span> <span class="identifier">vec</span><span class="special">;</span>
 119 <span class="keyword">typedef</span> <span class="keyword">const</span> <span class="identifier">vec</span> <span class="identifier">const_vec</span><span class="special">;</span>
 120 <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>
 121 <span class="keyword">typedef</span> <a class="link" href="next.html" title="next"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">next</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="identifier">second</span><span class="special">;</span>
 122
 123 <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">const_vec</span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">const_first</span><span class="special">;</span>
 124 <span class="keyword">typedef</span> <a class="link" href="next.html" title="next"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">next</span></code></a><span class="special">&lt;</span><span class="identifier">const_first</span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">const_second</span><span class="special">;</span>
 125
 126 <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="deref.html" title="deref"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">deref</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">&amp;&gt;));</span>
 127 <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="deref.html" title="deref"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">deref</span></code></a><span class="special">&lt;</span><span class="identifier">second</span><span class="special">&gt;::</span><span class="identifier">type</span><span class="special">,</span> <span class="keyword">int</span><span class="special">&amp;&gt;));</span>
 128 </pre>
 129 </div>
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 132 <td align="right"><div class="copyright-footer">Copyright &#169; 2001-2006, 2011, 2012 Joel de Guzman,
 133       Dan Marsden, Tobias Schwinger<p>
 134         Distributed under the Boost Software License, Version 1.0. (See accompanying
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