ntifier">O4</span> <span class="special">&gt;</span>
<span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
  <span class="comment">// <a class="link" href="unordered_set_base_hook.html#boost.intrusive.unordered_set_base_hookconstruct-copy-destruct">construct/copy/destruct</a></span>
  <a class="link" href="unordered_set_base_hook.html#idp65840432-bb"><span class="identifier">unordered_set_base_hook</span></a><span class="special">(</span><span class="special">)</sp