# next(isolation:) Produces the next element in the filter sequence. ``` mutating func next(isolation actor: isolated (any Actor)?) async throws(AsyncFilterSequence.Failure) -> Base.Element? ``` ## Discussion This iterator calls `next(isolation:)` on its base iterator; if this call returns `nil`, `next(isolation:)` returns nil. Otherwise, `next(isolation:)` evaluates the result with the `predicate` closure. If the closure returns `true`, `next(isolation:)` returns the received element; otherwise it awaits the next element from the base iterator. --- 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)