[Fusion] Add tr1_result_of specialization

[Michel Morin]

To make result_of and tr1_result_of equivalent, we have to add specialization of tr1_result_of. (Boost.Fusion already has specialization of result_of.)

Also, it would be nice to avoid specialization of result_of, when we use decltype-based result_of. (As for tr1_result_of, it should be specialized even when decltype-based result_of is used.)

So, instead of

template <...>
struct result_of<F()>
{
    typedef XXXX type;
};

we should write

#if !defined(BOOST_RESULT_OF_USE_DECLTYPE) || defined(BOOST_NO_DECLTYPE)
template <...>
struct result_of<F()>
{
    typedef XXXX type;
};
#endif

template <...>
struct tr1_result_of<F()>
{
    typedef XXXX type;
};

A quick grep said the following files specialize result_of.

• fusion/functional/adapter/unfused.hpp
• fusion/functional/adapter/unfused_typed.hpp

[Joel de Guzman]

If you can prepare a patch, I'd be willing to apply it.

[Michel Morin]

Patch attached.

[Joel de Guzman]

patch applied.