C++ template determine function return type

Question

hi

How can I go about determining return type of a member generic function?

    template<class E>
    struct result<E> {
        // E has member function data(), I need to know its return type
        typedef typename &E::data type;
    };

is it possible to do it in generic way? I know there is boost:: result_of but for my purposes it lacks specializations (if I understood correctly, return type must be specialized). boost implementation would be great.

Answer 1

GCC's nonstandard typeof operator can do this, as can Boost.TypeOf.

Answer 2

If you're using VS2010 or GCC 4.3 at least you can use C++0x new keyword decltype .