an class="identifier">pointer</span><span class="special">;</span>        
  <span class="keyword">typedef</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">ptrdiff_t</span> <a name="boost.intrusive.pointer_traits_idp69156352.difference_type"></a><span class="identifier">difference_type</span><span class="special">;</span>
  <span class="keyword">typedef</span> <span class="identifier">T</span> <span class="special">&amp;</span>            <a name="boost.intru