...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_feature<tag::rolling_variance(lazy)>
// In header: <boost/accumulators/statistics/rolling_variance.hpp> struct as_feature<tag::rolling_variance(lazy)> { // types typedef tag::lazy_rolling_variance type; };