span> <span class="identifier">when</span> <span class="identifier">the</span> <span class="char">'name'</span> <span class="keyword">enum</span> <span class="identifier">exists</span> 
            <span class="identifier">within</span> <span class="identifier">the</span> <span class="identifier">enclosing</span> <span class="identifier">type</span> <span class="identifier">BOOST_TTI_TP_T</span><span class="special">.</span>
</pre>
<p>Example usage:</p>
<pre class="programlisting"><span class="identifier">B