an><span class="special">.</span><span class="identifier">size</span><span class="special">();</span> <span class="special">}</span>
<span class="special">};</span>
</pre>
<p>
          and these functors are used thus:
        </p>
<pre class="programlisting"><span class="identifier">string_sort</span><span class="special">(</span><span class="identifier">array</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">array</span><spa