pan class="identifier">T</span><span class="special">&amp;,</span> <span class="keyword">const</span> <span class="identifier">P</span><span class="special">&amp;)</span>      <span class="special">&amp;=</span> <span class="special">|</span> <span class="identifier">e</span> <span class="identifier">b</span> <span class="identifier">s</span> <span class="identifier">m</span>            <span class="special">&amp;=</span> <span class="special">|</span> <span class="identifier">e</span> <span class="identifi