al">&amp;</span> visitor<span class="special">,</span> <span class="identifier">Variant</span><span class="special">&amp;&amp;</span> operand<span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> BinaryVisitor<span class="special">,</span> <span class="keyword">typename</span> Variant1<span class="special">,</span> <span class="keyword">typename</span> Variant2<span class="special">&gt;</span> 
