[boost] [tr1/result of] and l/r values

From: Tobias Schwinger (tschwinger_at_[hidden])
Date: 2006-12-27 07:55:23

Hi,

here's another result_of question:

Given a function object

    struct f
    {
        template< typename T >
        r<T> operator()(T const &) const;

        template< typename T >
        r<T&> operator()(T &) const;

        template< typename Sig >
        struct result;
    };

,

    result_of< f(some_obj &) >::type      // is r<T&>
    result_of< f(some_obj const & >::type // is r<T>

but what about:

    result_of< f(some_obj) >::type        // is r<T>?

That's what I'd do intuitively. I also found an example (written by Dave) on the net that seems to do the same:

    http://tinyurl.com/yzeenu

But wait: the TR1 text is talking about lvalues so I probably should let F::result return r<T&>?!

Thanks a lot for clarification.

Regards,
Tobias