...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::is_reference_wrapper — Determine if a type `T` is an instantiation of `reference_wrapper`.
// In header: <boost/core/ref.hpp> template<typename T> struct is_reference_wrapper { // public data members static constexpr bool value; };