1 // { dg-options "-std=gnu++0x" }
3 // A basic implementation of TR1's mem_fn using variadic teplates
4 // Contributed by Douglas Gregor <doug.gregor@gmail.com>
7 template<typename R, typename Class, typename... Args>
11 explicit Mem_fn(R (Class::*pmf)(Args...)) : pmf(pmf) { }
13 R operator()(Class& object, Args... args)
15 return (object.*pmf)(args...);
18 R operator()(Class* object, Args... args)
20 return (object->*pmf)(args...);
23 R (Class::*pmf)(Args...);
26 template<typename R, typename Class, typename... Args>
27 inline Mem_fn<R, Class, Args...>
28 mem_fn(R (Class::* pmf)(Args...))
30 return Mem_fn<R, Class, Args...>(pmf);
35 int negate(int x) { return -x; }
36 int plus(int x, int y) { return x + y; }
44 assert(mem_fn(&X::negate)(x, 17) == -17);
45 assert(mem_fn(&X::negate)(xp, 17) == -17);
46 assert(mem_fn(&X::plus)(x, 17, 25) == 42);
47 assert(mem_fn(&X::plus)(xp, 17, 25) == 42);