operator</span> <span class="special">&amp;=</span>
                <span class="special">(</span><span class="identifier">T</span><span class="special">&amp;</span> <span class="identifier">y</span><span class="special">,</span> <span class="keyword">const</span>
                <span class="identifier">P</span><span class="special">&amp;</span>
                <span class="identifier">x</span><span class="special">)</span></code>
              </p>
              </th>
<th>
              <p>
              