...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::promote_base<ToFrom, ToFrom, void>
// In header: <boost/accumulators/numeric/functional.hpp> template<typename ToFrom> struct promote_base<ToFrom, ToFrom, void> : public std::unary_function< ToFrom, ToFrom > { // public member functions ToFrom & operator()(ToFrom &) ; };