</span>
   <span class="identifier">BOOST_STATIC_ASSERT</span><span class="special">(</span>
      <span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">is_convertible</span><span class="special">&lt;</span>
         <span class="identifier">cat</span><span class="special">,</span>
         <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">random_access_iterator_ta