...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::root_typeof_helper
template<typename Radicand, typename Index> struct root_typeof_helper { // types typedef unspecified type; // specifies the result type // public static functions static type value(const BaseType &) ; };