/span><span class="special">;</span>      
  <span class="keyword">typedef</span> <span class="identifier">DifferenceType</span> <a name="boost.type_erasure.iterator.difference_type"></a><span class="identifier">difference_type</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="id-1.3.41.13.23.3.4"></a><h2>Description</h2>
<p>The <a class="link" href="iterator.html" title="Struct template iterator">iterator</a> concep