# relative(to:) Returns the range of indices described by this range expression within the given collection. ``` func relative(to collection: C) -> Range where Bound == C.Index, C : Collection ``` ## Parameters `collection` The collection to evaluate this range expression in relation to. ## Return Value A range suitable for slicing `collection`. The returned range is *not* guaranteed to be inside the bounds of `collection`. Callers should apply the same preconditions to the return value as they would to a range provided directly by the user. --- 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)