terator</a> <span class="special">{</span>
  <span class="comment">// types</span>
  <span class="keyword">typedef</span> <span class="emphasis"><em><span class="identifier">unspecified</span></em></span>    <a name="boost.type_erasure.iterator.value_type"></a><span class="identifier">value_type</span><span class="special">;</span>     
  <span class="keyword">typedef</span> <span class="identifier">Reference</span>      <a name="boost.type_erasure.iterator.reference"></a><span class="identifier">reference<