span> Tin<span class="special">,</span> <span class="keyword">typename</span> Signature<span class="special">,</span> 
         <span class="keyword">typename</span>  <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">enable_if</span><span class="special">&lt;</span><span class="identifier">detail</span><span class="special">::</span><span class="identifier">unqalified_is_same</span><span class="special">&lt;</span><span class="identif