R'</strong></span>, and <span class="bold"><strong>D'</strong></span>
          parameters of the <code class="computeroutput"><span class="identifier">iterator_facade</span></code>
          used as a base class in the summary of <code class="computeroutput"><span class="identifier">iterator_adaptor</span></code>
          above are defined as follows:
        </p>
<pre class="programlisting">   <span class="bold"><strong>V'</strong></span> = if (Value is use_default)
             return iterator_traits&lt