Correct exception to throw for an unhandled switch case for an argument?

Question

NOTE: This is different than the proposed duplicates as this deals with an argument rather than a value. The behavior and applicable scenarios are essentially different.

Answer 1

If you were using Code Contracts (something I HIGHLY recommend), you would put this at the start of the method:

Contract.Requires(value == SomeEnum.One || value == SomeEnum.Two);

If you want to check a range of an enum which has too many individual values to write them all explicitly, you can do it like this:

Contract.Requires(SomeEnum.One <= value && value <= SomeEnum.Two);