s="special">(!</span><span class="identifier">r</span> <span class="special">||</span> <span class="identifier">first</span> <span class="special">!=</span> <span class="identifier">last</span><span class="special">)</span> <span class="comment">// fail if we did not get a full match</span>
            <span class="keyword">return</span> <span class="keyword">false</span><span class="special">;</span>
        <span class="identifier">c</span> <span class="special">=</span> <span class="identifier">std</span