Declaration and initialization of the same object name

[playincard]

Hi all,

I'm reviewing some C++ notes and came across this line of code in a section demonstrating copy/assignment constructor use:

struct D {
  int i;
  B b1, b2;
};

int main() {
  D d = d;	// bitwise/memberwise copy
  d = d;	// bitwise/memberwise assignment
}

The second line in main() makes sense to me because the instance with name 'd' has already been defined.

However, in the first line of main(), what is happening exactly? ? How can an instance of D with name 'd' be initialized with an instance of D also with name 'd'? Chicken or the egg?

Thanks in advance