ntifier">R</span><span class="char">'*, *D'</span><span class="special">*&gt;</span> <span class="comment">// see details</span>
<span class="special">{</span>
    <span class="keyword">friend</span> <span class="keyword">class</span> <span class="identifier">iterator_core_access</span><span class="special">;</span>
 <span class="keyword">public</span><span class="special">:</span>
    <span class="identifier">iterator_adaptor</span><span class="special">();</span>
    <span class="keyword">explicit</span> 