alue_manip">add_value_manip</a> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
  <span class="comment">// types</span>
  <span class="keyword">typedef</span> <span class="identifier">RefT</span>                                                                 <a name="boost.log.add_value_manip.reference_type"></a><span class="identifier">reference_type</span><span class="special">;</span>  <span class="comment">// Stored reference type. </span>
  <span class=