&lt;</span><span class="identifier">tag</span><span class="special">::</span><span class="identifier">variance</span><span class="special">&gt;</span> <span class="special">{</span>
  <span class="comment">// types</span>
  <span class="keyword">typedef</span> <a class="link" href="tag/weighted_variance.html" title="Struct weighted_variance">tag::weighted_variance</a> <a name="boost.accumulators.as_weig_1_3_2_6_3_38_1_1_4.type"></a><span class="identifier">type</span><span class="special">;</span>
<span cla