...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::accumulators::as_weighted_feature<tag::sum>
// In header: <boost/accumulators/statistics/sum.hpp> struct as_weighted_feature<tag::sum> { // types typedef tag::weighted_sum type; };