4-bit Enum in C#

I know that its possible to make enums that use signed or unsigned 64, 32, 16, and 8 bit values as their underlying valud type using (:ulong, :uint, :ushort, :byte). But is it possible to create a 4 bit enum?

(I'm writing some code tha开发者_如何转开发t will interop with C++ and the struct that I have in C# for a return type has one field that would be most natural as a 4-bit struct.)

From the C# spec:

The approved types for an enum are byte, sbyte, short, ushort, int, uint, long, or ulong.

None of these are 4-bit types. You'd have the same problem on the C++ side as well.

But is it possible to create a 4 bit enum?

No, mostly because that would be awkward and slow. And syntactically there exists no 4-bit type to specify as base type.

with C++ and the struct that I have in C# for a return type has one field that would be most natural as a 4-bit struct.

I doubt that very much, C++ can deal with bit fields but this is very efficient (except maybe in space).

Interop with C++ is difficult enough, when the return-type is your choice then don't make it any harder than it has to be.