...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::units::reduce_unit<unit< Dim, System >> — Returns a unique type for every unit.
// In header: <boost/units/unit.hpp> template<typename Dim, typename System> struct reduce_unit<unit< Dim, System >> { // types typedef unspecified type; };