...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::numeric::functional::average_base
// In header: <boost/accumulators/numeric/functional.hpp> template<typename Left, typename Right, typename EnableIf> struct average_base : public boost::numeric::functional::divides< Left, Right > { };