nal</code> 
        public
       construct/copy/destruct</h3>
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<pre class="literallayout"><a name="id-1_3_37_6_9_3_1_2_21-bb"></a><span class="identifier">signal</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">combiner_type</span><span class="special">&amp;</span> combiner <span class="special">=</span> <span class="identifier">combiner_type</span><span class="special">(</span><sp