f&lt;tag::weighted_p_square_quantile&gt;">feature_of</a><span class="special">&lt;</span><span class="identifier">tag</span><span class="special">::</span><span class="identifier">weighted_p_square_quantile</span><span class="special">&gt;</span> <span class="special">:</span>
  <span class="keyword">public</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">accumulators</span><span class="special">::</span><span class="identifier">feature_of</span><span class