pan class="identifier">T</span><span class="special">&amp;&gt;</span></code>
          forwarding assignment to the referenced object (thus changing the referenced
          object value but not rebinding), and consider the following code:
        </p>
<pre class="programlisting"><span class="identifier">optional</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&amp;&gt;</span> <span class="identifier">a</span> <span class="special">=</span> <span class="identifie