Question

Take this enum for example:

public enum PersonName : short
{
    Mike = 1,
    Robert= 2
}

I wnat to have en extension method like this:

PersonName person = PersonName.Robert;
short personId = person.GetId();
//Instead of:
short personId = (short)person;

Any idea how to implement this?

it need to be generic to int, short etc…, and to generic enums as well, not limited to PersonName.

Answer 1

This is completely impossible.

You cannot constrain a method based on an enum‘s underlying type.

Explanation:

Here is how you might try to do this:

public static TNumber GetId<TEnum, TNumber>(this TEnum val) 
       where TEnum : Enum 
       where TEnum based on TNumber

The first constraint is unfortunately not allowed by C#, and the second constraint is not supported by the CLR.