/span><span class="special">(</span><span class="identifier">First</span><span class="special">,</span> <span class="identifier">Second</span><span class="special">)</span><span class="special">&gt;</span> <span class="special">{</span>
  <span class="comment">// types</span>
  <span class="keyword">typedef</span> std::pair<span class="special">&lt;</span> <span class="keyword">typename</span> <span class="identifier">remove_const</span><span class="special">&lt;</span> <span class="keyword">typename</span>