...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::enable_move_utility_emulation
// In header: <boost/move/utility.hpp> template<typename T> struct enable_move_utility_emulation { // public data members static const bool value; };
This trait's internal boolean `value` is false in compilers with rvalue references and true in compilers without rvalue references.
A user can specialize this trait for a type T to false to SFINAE out `move` and `forward` so that the user can define a different move emulation for that type in namespace boost (e.g. another Boost library for its types) and avoid any overload ambiguity.