ss="special">{</span>
  <span class="keyword">class</span> <a class="link" href="../boost/bad_function_call.html" title="Class bad_function_call">bad_function_call</a><span class="special">;</span>
  <span class="keyword">class</span> <a class="link" href="../boost/function_base.html" title="Class function_base">function_base</a><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> R<span class="special">,</span> <span cl