nst</span> Type &amp;, <span class="keyword">const</span> Type &amp;);</div>
<div class="line">bool(<span class="keyword">const</span> Entity, <span class="keyword">const</span> Entity);</div>
</div><!-- fragment --><p>Where <code>Type</code> are either owned types or not but still such that they are iterated by the group.<br  />
 Moreover, the comparison function object shall induce a <em>strict weak ordering</em> on the values.</p>
<p>The sort function object must offer a member function template <code>op