On Mon, 13 Feb 2012 20:08:34 +0100, Frank Birbacher <bloodymir.crap@gmx.net> wrote:
So this is the point: I need a signature from a member function. There is no type trait that does this. Any other suggestions?
The code example below compiles and runs nicely with gcc 4.7. A note: if you substitute using signature = R (Arg...); with: typedef R (Arg...) signature; you get a compile time error. Cheers, -- Marco #include <iostream> #include <utility> #include <boost/function.hpp> using boost::function; ////////////////////////////////////////////////////////////// // member function traits template<typename MembFuncPtr> struct memb_func_traits {}; template< typename ClassT, typename R, typename... Arg> struct memb_func_traits<R ClassT::* (Arg...)> { using class_type = ClassT; using signature = R (Arg...); }; template< typename ClassT, typename R, typename... Arg> struct memb_func_traits<R (ClassT::*) (Arg...) const> { using class_type = ClassT; using signature = R (Arg...); }; template<typename F> struct function_type { typedef typename memb_func_traits< decltype(&F::operator()) >::signature signature; typedef function<signature> type; }; template<typename F> typename function_type<F>::type make_function(F && f) { typedef typename function_type<F>::type result_type; return result_type(std::forward<F>(f)); } int main() { auto a = make_function([](int){ return 4; }); assert( a(1) == 4 ); std::cout << a(1) << std::endl; } -- Using Opera's revolutionary e-mail client: http://www.opera.com/mail/