...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::tag::lazy_weighted_variance
// In header: <boost/accumulators/statistics/weighted_variance.hpp> struct lazy_weighted_variance : public boost::accumulators::depends_on< weighted_moment< 2 >, weighted_mean > { };