">reference</span><span class="special">;</span>
   <span class="keyword">typedef</span>          <span class="identifier">implementation</span> <span class="identifier">defined</span>                                  <span class="identifier">const_iterator</span><span class="special">;</span>
   <span class="keyword">typedef</span>          <span class="identifier">const_iterator</span>                                          <span class="identifier">iterator</span><span class="special">;</span>
   <span 