span class="identifier">as_child</span><span class="special">(</span><span class="identifier">T</span> <span class="special">&amp;</span> t<span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> 
  <span class="keyword">typename</span> <a class="link" href="result_of/as_child.html" title="Struct template as_child">proto::result_of::as_child</a><span class="speci