...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::proto::functional::as_expr::result<This(T)>
// In header: <boost/proto/traits.hpp> template<typename This, typename T> struct result<This(T)> : proto::result_of::as_expr< typename remove_reference< T >::type, Domain > { };