ass="special">&gt;</span> <span class="special">&gt;</span> <a name="boost.histogram.weighted_profile_storage"></a><span class="identifier">weighted_profile_storage</span><span class="special">;</span>  <span class="comment">// Dense storage which tracks means of weighted samples in each cell. </span>
    <span class="keyword">namespace</span> <span class="identifier">axis</span> <span class="special">{</span>
      <span class="keyword">struct</span> <a class="link" href="../boost/histogram/axis/null_type.