<a class="link" href="signal.html#id-1_3_37_6_9_3_1_2_25_1_1-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">arg</span><span class="special">&lt;</span><span class="number">0</span><span class="special">&gt;</span><span class="special">::</span><span class="identifier">type</span><span class="special">,</span> <span class="identifier">arg</span><span class="special">&lt;</span><span class="number"