As far as I understand it, you need to apply result_type to your F and parameter_types to F. From there you can model your function. Or am I wrong?

template<class F>

some_return_type make_function(F f)

{

  typedef typename result_type<F>::type result_type;

  typedef typename parameter_types<F>::type mpl_seq_params;

  //insert the result type to the mpl_seq_params => fct_sig;

  ...

}

But I am not sure if it works, this is my assumption only.

Regards,

Ovanes