an class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">charT</span><span class="special">,</span> <span class="identifier">traits</span><span class="special">&gt;&amp;</span> <span class="identifier">os</span><span class="special">,</span>
               <span class="keyword">const</span> <span class="identifier">match_results</span><span class="special">&lt;</span><span class="identifier">BidirectionalIterator</span><span class="special">,</span> <span class="id