class="identifier">boost</span><span class="special">::</span><span class="identifier">begin</span><span class="special">(</span><span class="identifier">tree</span><span class="special">),</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">end</span><span class="special">(</span><span class="identifier">tree</span><span class="special">),</span> <span class="identifier">do_something</span><span class="special">());</span>
</pre>
<p>
          </p>
<h6>
<a na