Enums - All options value

Question

Is there a way to add an "All values" option to an enum without having to change its value every time a new value is added to the enum?

[Flags]  public enum SomeEnum {     SomeValue =  1,     SomeValue2 = 1 << 1,     SomeValue3 = 1 << 2,     SomeValue4 = 1 << 3,     All = ? } 

Update:

Ended up inheriting from long and using long.MaxValue for All option.

Answer 1

Since you should define the empty value in a Flags enum such as None = 0, the simplest way of defining the Allvalue is by simply inverting all the bits inNone`.

[Flags] enum MyEnum {    None = 0,    A = 1,    B = 2,    C = 4,    ...    All = ~None } 

Note that ~0 instead of ~None will not work for unsigned backing types as that is -1, which is not a valid value for unsigned.

Edit: Answer was modified to use an inverted None instead of an explicit constant such as 0x7FFFFFFF or ~0, as this also works for unsigned

Answer 2

It should be like this:

[Flags]  public enum SomeEnum {     SomeValue =  1,     SomeValue2 = 1 << 1,     SomeValue3 = 1 << 2,     SomeValue4 = 1 << 3,     All = SomeValue | SomeValue2 | SomeValue3 | SomeValue4 }