1 // { dg-do run { target c++11 } }
2 // A basic implementation of TR1's mem_fn using variadic teplates
3 // Contributed by Douglas Gregor <doug.gregor@gmail.com>
6 template<typename R, typename Class, typename... Args>
10 explicit Mem_fn(R (Class::*pmf)(Args...)) : pmf(pmf) { }
12 R operator()(Class& object, Args... args)
14 return (object.*pmf)(args...);
17 R operator()(Class* object, Args... args)
19 return (object->*pmf)(args...);
22 R (Class::*pmf)(Args...);
25 template<typename R, typename Class, typename... Args>
26 inline Mem_fn<R, Class, Args...>
27 mem_fn(R (Class::* pmf)(Args...))
29 return Mem_fn<R, Class, Args...>(pmf);
34 int negate(int x) { return -x; }
35 int plus(int x, int y) { return x + y; }
43 assert(mem_fn(&X::negate)(x, 17) == -17);
44 assert(mem_fn(&X::negate)(xp, 17) == -17);
45 assert(mem_fn(&X::plus)(x, 17, 25) == 42);
46 assert(mem_fn(&X::plus)(xp, 17, 25) == 42);