"computeroutput"><span class="identifier">ref</span><span class="special">()</span></code>:
        </p>
<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">X</span> <span class="special">:</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">noncopyable</span>
<span class="special">{</span>
   <span class="special">...</span>
<span class="special">};</span>

<span class="keyword">void</span> <span class="identifier">apply</s