How can I determine the return type of a C++11 member function

Question

I am trying to determine the return type of a various C++ member functions. I understand that decltype and std::declval can be used to do this, but I am having problems with the

Answer 1

How can I determine the return type of a C++11 member function?

Answer:

You could use decltype and std::declval like the toy example below:

#include 
#include 

struct foo {
  int    memfun1(int a) const { return a;   }
  double memfun2(double b) const { return b; }
};

int main() {
  decltype(std::declval().memfun1(1)) i = 10;
  std::cout << i << std::endl;
  decltype(std::declval().memfun2(10.0)) d = 12.9;
  std::cout << d << std::endl;
}

LIVE DEMO