ial">;</span>
  <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a class="link" href="signal.html#id-1_3_37_6_9_3_1_2_24_6-bb"><span class="identifier">num_slots</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>

  <span class="comment">// <a class="link" href="signal.html#id-1_3_37_6_9_3_1_2_25-bb">invocation</a></span>
  <span class="identifier">result_type</span> 