...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
// In header: <boost/accumulators/numeric/functional.hpp> template<typename Left, typename Right, typename LeftTag, typename RightTag> struct average : public boost::numeric::functional::average_base< Left, Right, void > { };