optional< T& > is a useful thing when you want to apply operators (such as relation operators or streaming) to the referred value. In generic code you don't have to specialize for pointers to do the right thing. I'm going to use this property in my Boost.Log library.
Andrey, would you mind giving us a short example of how you want to use an optional reference? I am in the middle of designing the new optional interface for TR2, and came to the conclusion that in order to avoid counter-intuitive semantics for optional reference assignment, I had better remove it at all; that is, optional references are to be limited: they should provide no assignment. You could still use optional values and optional references in generic code but with reduced interface: template <typename T> // T is a ref or a value void use( std::tr2::optional<T> opt, T nval ) { if (opt) { std::cout << *out; // fine *opt = nval; // fine, assigning T's not optionals opt = nval; // invalid if T is a ref opt = opt; // invalid if T is a ref } if (needToRebindAReference()) { opt.emplace(nval); // valid - always rebinds } }; Would such a limited interface as I described above be enough for your generic usage of optional? Regards, &rzej