swift-concurrency-6-2

Swift 6.2 keeps async functions on the calling actor by default, so most implicit offloading data races disappear. Enable the Approachable Concurrency build settings in Xcode's Swift Compiler Concurrency section, then annotate remaining shared state with @MainActor.

Mark the containing type as nonisolated, add @concurrent to the function, ensure it is async, and use await at call sites. Use this only for expensive work like image processing or compression after profiling with Instruments.

An isolated conformance lets a MainActor type conform to a non-isolated protocol by writing `extension MyType: @MainActor MyProtocol`. The compiler guarantees the conformance is only used on the main actor, rejecting use from nonisolated contexts.

No. Swift 6.2 keeps async functions on the calling actor by default, unlike Swift 6.1 which could implicitly offload them. Background execution requires explicit opt-in via the @concurrent attribute.

Enable it for apps, scripts, and other executable targets that are mostly single-threaded. It implicitly applies @MainActor to types, properties, and conformances, removing boilerplate annotations while keeping code data-race safe.