This defines the structure used as contextual information in the
- iOS 2.0+
- macOS 10.5+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
A C array that you can use to hold returned values.
Arbitrary state information used to detect whether the collection has been mutated.
Arbitrary state information used by the iterator. Typically this is set to
0 at the beginning of the iteration.