n> <span class="identifier">time_duration_type_</span>                             <a name="boost.date_time.us_dst_rules.time_duration_type"></a><span class="identifier">time_duration_type</span><span class="special">;</span>
  <span class="keyword">typedef</span> <span class="identifier">date_type_</span>                                      <a name="boost.date_time.us_dst_rules.date_type"></a><span class="identifier">date_type</span><span class="special">;</span>         
  <span class="keyword">typedef</