ecial">)</span></a><span class="special">(</span><span class="identifier">Expr</span> <span class="special">&amp;</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <a class="link" href="../../../Expr.html" title="Concept Expr">Expr</a><span class="special">&gt;</span> 
    <span class="keyword">typename</span> <a class="link" href="../result_of/val