swift-concurrency-6-2

# Swift 6.2 Approachable Concurrency Patterns for adopting Swift 6.2's concurrency model where code runs single-threaded by default and concurrency is introduced explicitly. Eliminates common data-race errors without sacrificing performance. ## When to Activate - Migrating Swift 5.x or 6.0/6.1 projects to Swift 6.2 - Resolving data-race safety compiler errors - Designing MainActor-based app architecture - Offloading CPU-intensive work to background threads - Implementing protocol conformances on MainActor-isolated types - Enabling Approachable Concurrency build settings in Xcode 26 ## Core Problem: Implicit Background Offloading In Swift 6.1 and earlier, async functions could be implicitly offloaded to background threads, causing data-race errors even in seemingly safe code: ```swift // Swift 6.1: ERROR @MainActor final class StickerModel { let photoProcessor = PhotoProcessor() func extractSticker(_ item: PhotosPickerItem) async throws -> Sticker? { guard let data = try await item.loadTransferable(type: Data.self) else { return nil } // Error: Sending 'self.photoProcessor' risks causing data races return await photoProcessor.extractSticker(data: data, with: item.itemIdentifier) } } ``` Swift 6.2 fixes this: async functions stay on the calling actor by default. ```swift // Swift 6.2: OK — async stays on MainActor, no data race @MainActor final class StickerModel { let photoProcessor = PhotoProcessor() func extractSticker(_...