ref="pass_through.html" title="Struct template pass_through">proto::pass_through</a>&lt;unary_expr&gt;::template impl&lt;Expr, State, Data&gt;
  <span class="special">{</span>
  <span class="special">}</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="id-1.3.33.5.41.67.4"></a><h2>Description</h2>
<p>
            Use <code class="computeroutput">proto::unary_expr&lt;<a class="link" href="_.html" title="Struct _">proto