In this particular case: it is possible to access first_type::type parameter. It depends what the caller expects from the static interface. Maybe there other types having getSomething(...) or other getSomething-overloads, which return std::pair template instantiations and all provide first_type::type. In such a case you don't have to apply additional meta-functions to grab the underlying type from the first_type. But there should be more info about the callers... On the other hand, callers can make specialized compile time dispatching for boost::reference_wrapper<T> but not T&.

With Kind Regards,
Ovanes