[boost] [result_of] vs decltype

From: shunsuke (pstade.mb_at_[hidden])
Date: 2007-11-26 06:35:21

Hi,

What happens if result_of is not consistent with decltype?

struct my_fun_t
{
    template<class Sig>
    struct result;

    template<class This>
    struct result<This(int)>
    {
        typedef int type; // avoid dangling.
    };

    template<class This>
    struct result<This(int const &)>
    {
        typedef int const & type;
    };

    int const & operator()(int const &i) const
    {
        return i;
    }
};

my_fun_t const my_fun = {};

int main()
{
     boost::result_of<my_fun_t const(int)>::type x = my_fun(10); // ok in C++98.
     decltype(my_fun(10)) x_ = my_fun(10); // dangling in C++0x.
}

BTW, result_of implementation of my_fun_t is allowed in C++98?

Regards,

-- 
Shunsuke Sogame