Union in c++ are they feasible

Question

Can a union in C++ have a member function? How do union with data members and member functions exist if an object is created?

If I suppose yes, then are they feasible an

Answer 1

I don't know if it's valid. Codepad accepts, runs, and gives the expected output from this program

union x {
  int t;
  int k() { return 42;};
};

int main() {
  x y;
  y.t = y.k();
  std::cout << y.t << std::endl;
}