Extending an enum via inheritance

Question

I know this rather goes against the idea of enums, but is it possible to extend enums in C#/Java? I mean \"extend\" in both the sense of adding new values to an enum, but a

Answer 1

The reason you can't extend Enums is because it would lead to problems with polymorphism.

Say you have an enum MyEnum with values A, B, and C , and extend it with value D as MyExtEnum.

Suppose a method expects a myEnum value somewhere, for instance as a parameter. It should be legal to supply a MyExtEnum value, because it's a subtype, but now what are you going to do when it turns out the value is D?

To eliminate this problem, extending enums is illegal