How to override method with derived return type in C#?

Question

I want to override a virtual method with a derived class type. What\'s the current best way to do this? So far I\'ve found two approaches:

1. Use an abstract<

Answer 1

You could make the base class generic:

public abstract class Base where TDerived : Base {
  public abstract TDerived Clone();
}

public class Derived1 : Base {
  public override Derived1 Clone() { ... }
}

public class Derived2 : Base {
  public override Derived2 Clone() { ... }
}

However this makes me wonder how useful having a common base class is. Perhaps the Clone implementations of Derived1 and Derived2 don't need to be part of a common interface.