OptionSet RawValue constraint

The documentation for OptionSet states that

The rawValue property must be of a type that conforms to the FixedWidthInteger protocol, such as Int or UInt8.

But this is seemingly not enforced:

public protocol OptionSet : SetAlgebra, RawRepresentable {

Is this an oversight, or is there some deeper implementation reason that I don't understand? As far as I can tell, the type could be declared as

public protocol OptionSet : SetAlgebra, RawRepresentable where RawValue: FixedWidthInteger {


That's an oversight, thanks!


I think there was a different hidden constraint before the where clause feature landed, no? That‘s why there is still a extension like extension OptionSet where RawValue : FixedWidthInteger. So the missing constraint is just a historical oversight.