# subscript(_:) Accesses the element at `position`. ``` subscript(position: FlattenSequence.Index) -> Base.Element.Element { get } ``` ## Overview> Precondition: `position` is a valid position in `self` and > `position != endIndex`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)