an><span class="special">&lt;</span> <span class="identifier">char_type</span> <span class="special">&gt;</span> <a name="boost.log.expressions.format_terminal.string_type"></a><span class="identifier">string_type</span><span class="special">;</span>  <span class="comment">// String type. </span>
  <span class="keyword">typedef</span> <span class="identifier">format_type</span><span class="special">::</span><span class="identifier">pump</span>              <a name="boost.log.expressions.format_terminal.resu