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// result_of example
#include <iostream>
#include <type_traits>
int fn(int) {return int();} // function
typedef int(&fn_ref)(int); // function reference
typedef int(*fn_ptr)(int); // function pointer
struct fn_class { int operator()(int i){return i;} }; // function-like class
int main() {
typedef std::result_of<decltype(fn)&(int)>::type A; // int
typedef std::result_of<fn_ref(int)>::type B; // int
typedef std::result_of<fn_ptr(int)>::type C; // int
typedef std::result_of<fn_class(int)>::type D; // int
std::cout << std::boolalpha;
std::cout << "typedefs of int:" << std::endl;
std::cout << "A: " << std::is_same<int,A>::value << std::endl;
std::cout << "B: " << std::is_same<int,B>::value << std::endl;
std::cout << "C: " << std::is_same<int,C>::value << std::endl;
std::cout << "D: " << std::is_same<int,D>::value << std::endl;
return 0;
}
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