an> <span class="identifier">cb</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">files</span><span class="special">,</span> <span class="keyword">bool</span> <span class="identifier">recurse</span> <span class="special">=</span> <span class="keyword">false</span><span class="special">,</span>
                          <span class="identifier">boost</span><span class="special">::</span><span class=