Question

I have an enum with a Flags attribute.

My question is, I’d like to get an integer bitmask of all of the options without manually combining all the bits myself.
I want to do this to compare to some other int field, and I want to protect in case a future developer ads more bit options to the enum.

Another thing is the bits in my enum flags will be all manually assigned, so I cannot simply get the next value and subtract 1.

Answer 1

If I understood what you asked correctly this should work for you:

Enum.GetValues(typeof(Enum)).Cast<int>().Sum();

You can then cast it back to your typeof(Enum):

[Flags]
public enum Values
{
    Value_1 = 1,
    Value_2 = 2,
    Value_3 = 4,
    Value_4 = 8,
    Value_5 = 16,
    Value_6 = 32,
    Value_7 = 64,
    Value_8 = 128,
    Value_9 = 256
}

static void Main(string[] args)
{
    Values values = (Values)Enum.GetValues(typeof(Values)).Cast<int>().Sum();
}