yword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> ContextT<span class="special">&gt;</span> <span class="identifier">result_type</span> <a name="idm46093047178432-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">ContextT</span> <span class="keyword">const</span> <span class="special">&amp;</span> ctx<span class="special">)</span> <span class="keyword">cons