Making a copy of an object of abstract base class

Question

If I have a pointer to an object that derives from an abstract base class (so I cannot create an new object of that class), and I wish to make a deep copy of said object, is there a more concise way of accomplishing that than to have the abstract base class create a new pure virtual copy function that every inheriting class has to implement?

Answer 1

No, but the copy method does not have to be painful:

class Derived : public Base
{
  public:
    Base *copy() const
    {
        return new Derived(*this);
    }
};

(assuming you already have a copy constructor, which, if you need a deep copy, you'll have).