ate</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">BidirectionalIterator</span><span class="special">,</span>
         <span class="keyword">class</span> <span class="identifier">Allocator</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">allocator</span><span class="special">&lt;</span><span class="identifier">sub_match</span><span class="special">&lt;</span><span class="ident