HasFlags always returns true for None (0) value in enum

Question

This is the enum definition:

[Flags]
enum Animals
{
    None = 0,
    Dog = 1,
    Cat = 2,
    Horse = 4,
    Zebra = 8,
}

Now, given the

Answer 1

There is already a plethora of answers describing WHY this happens, so I will just add that what you can do to get what you're looking for is to not use HasFlag in that case, but instead do var hasNone = myAnimals == Animals.None.

I personally really loathe extension methods, but it would be possible to put this in an extension on Enum if you really value being able to just write myOptionEnum.HasNoFlags(). I would just run with explicitly checking for the None value in this special case though.