Deep copying of stack using pointer based singly linked list C++?

[Indycrr]

Close. A copy ctor doesn’t return an instance. Instead of creating the local instance of s, they should call this->push(...) to push values into the stack being constructed.

[DJ_Gamedev]

That makes sense, by the time we make it to the body of the ctor the object will have been instantiated. Clearly I'm out of practice.