="../../../accumulators/reference.html#header.boost.accumulators.accumulators_fwd_hpp" title="Header &lt;boost/accumulators/accumulators_fwd.hpp&gt;">boost/accumulators/accumulators_fwd.hpp</a>&gt;

</span><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> Feature<span class="special">&gt;</span> 
<span class="keyword">struct</span> <a class="link" href="droppable.html" title="Struct template droppable">droppable</a> <span class="special">:</span> <sp