A type that provides the collection's iteration interface and encapsulates its iteration state.
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
- Xcode 8.0+
By default, a collection conforms to the
Sequence protocol by supplying an
Indexing as its associated Iterator type.