<span class="identifier">iterator_adaptor</span></code>
        creates a class derived from an instantiation of <code class="computeroutput"><span class="identifier">iterator_adaptor</span></code>
        and then selectively redefines some of the core member functions described
        in the <code class="computeroutput"><span class="identifier">iterator_facade</span></code> core
        requirements table. The <code class="computeroutput"><span class="identifier">Base</span></code>
        type need not 