n class="keyword">typename</span> VisitorT<span class="special">&gt;</span> 
  <a class="link" href="visitation_result.html" title="Class visitation_result">visitation_result</a> 
  <span class="identifier">visit</span><span class="special">(</span><span class="identifier">expressions</span><span class="special">::</span><span class="identifier">attribute_keyword</span><span class="special">&lt;</span> <span class="identifier">DescriptorT</span><span class="special">,</span> <span class="identifier">ActorT<