an><span class="special">;</span>
  <a class="link" href="unordered_set_base_hook.html#idp65844208-bb"><span class="identifier">unordered_set_base_hook</span></a><span class="special">(</span><span class="keyword">const</span> <a class="link" href="unordered_set_base_hook.html" title="Class template unordered_set_base_hook">unordered_set_base_hook</a> <span class="special">&amp;</span><span class="special">)</span><span class="special">;</span>
  <a class="link" href="unordered_set_base_hook.html" title="Cl