C++: Deep copying a Base class pointer

Question

I searched around and seems in order to perform this I need to change my Base class and want to know if this is the best approach. For example, I have a Base class:

Answer 1

I think that templates are the best way to go in this situation:

template
class DeepCopy
{
    Base *base;

    DeepCopy(Sub *sub)
    {
        base = new Sub(*sub); // use copy constructor
    }
}

This does mean that DeepCopy's are un-assignable to each other, but that's the price you pay with C++.