le="Struct template transform_impl">proto::transform_impl</a>&lt;Expr, State, Data&gt; <span class="special">{</span>
  <span class="comment">// <a class="link" href="impl.html#boost.proto.lazy.impltypes">types</a></span>
  <span class="keyword">typedef</span> <em class="replaceable"><code><span class="identifier">see</span><span class="special">-</span><span class="identifier">below</span></code></em> <a class="link" href="impl.html#boost.proto.lazy.impl.result_type"><span class="identifier">result_type</s