User Basel has 1/2 warnings; be careful! The latest warn was because: Read the rules: no screen photo.
— Read about lvalue& type. Method returns a reference type of Point class.
— That means that you need to use normal language instead of c++
— Returning a reference in such cases is a good way to UB. Like Point& a = Point(10, 20).setX(15); Or in more sophisticated case: Point& a = (b + c).setX(15); Or Point& a = functionThatReturnsPoint().setX();