   reference to an object as its argument and returning a reference to the
          bound member variable. For instance, given:
        </p>
<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">xyz</span>
<span class="special">{</span>
    <span class="keyword">int</span> <span class="identifier">v</span><span class="special">;</span>
<span class="special">};</span>
</pre>
<p>
          <code class="computeroutput"><span class="identifier">xyz</span><span class="special"