how to copy SubClass object in BaseClass copy constructor

Question

I would like to make copy of SubClass object in BaseClass constructor. I need that the following code execute correctly.

class BaseClass{
    BaseClass() {}
             


        

Answer 1

It's not possible. A constructor of class A gives you an instance of A, no way to circumvent this. Why not instantiate the subclass explicitly?

Another possibility might involve a static factory method like:

public static BaseClass create(BaseClass input) {
       // return BaseClass or subclass
}