Sendable
A Swift protocol that marks values as safe to pass between concurrently running tasks and actors.
Definition
The compiler only lets Sendable values cross from one concurrency domain to another. Value types made of Sendable parts are Sendable automatically, as are actors, immutable final classes and classes isolated to the main actor. In the Swift 6 language mode, sending a non-Sendable value across domains is a compile error. @unchecked Sendable turns the check off, so it must be backed by a real lock.
In practice
A struct Order with let properties can be returned from a background task to a @MainActor view model without any extra work.
Learn it in context
Lessons that use this term.