rd">const</span> <span class="identifier">value_type</span><span class="special">&amp;</span>                                       <span class="identifier">reference</span><span class="special">;</span>
   <span class="keyword">typedef</span>          <span class="identifier">std</span><span class="special">::</span><span class="identifier">forward_iterator_tag</span>                               <span class="identifier">iterator_category</span><span class="special">;</span>

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