What is your use case? I found
Stjepan Rajko a écrit : this sort of thing useful for finding
out whether result_of would work for a specific set of arguments. Is your metafunction intended for testing whether result_of would work for _some_
(whichever) set of arguments? (it doesn't quite do that
because it doesn't check that result has a nested type typedef).
I was trying to use it as a simple traits to see if a given type fullfilled the result_of protocol whatever the arguments used. It works ok for the result_type variant but now I see it's still incomplete. The problem is that I can't see, for an arbitrary result structure, how I can see if it actually has at least one overload that has a proper nested type typedef. Typical use is : For F a given type, support_result_of_protocol<F>::type evaluates as a compile time boolean indicating if either F has a nested result structure or result_type typedef. It doesn't make any assumptions on wether or nor result is correcly implemented. As for testing if a particuliar set of arguments produces a valid result_of, one can easily do : template< class F , template<class> class T = boost::result_of<F>::type > struct valid_impl { typedef void type; }; template<class F, class EnableIf = void> struct produce_valid_result_of : boost::false_type {}; template<class F> struct produce_valid_result_of<F,typename valid_impl<F>::type> : boost::true_type {}; or did I miss something in your question ?