al">,</span> <span class="keyword">const</span> <a class="link" href="../boost/function.html" title="Class template function">function</a><span class="special">&lt;</span><span class="identifier">Signature</span><span class="special">&gt;</span><span class="special">&amp;</span><span class="special">)</span><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> Signature<span class="special">,</span> <span class="keyword">