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Swift Concurrency Proposal Index
https://developer.apple.com/forums/thread/768776 Swift concurrency is an important part of my day-to-day job. I created the following document for an internal presentation, and I figured that it might be helpful for others. If you have questions or comments, put them in a new thread here on DevForums. Use the App & System Services > Processes & Concurrency topic area and tag it with both Swift and Concurrency. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" Swift Concurrency Proposal Index This post summarises the Swift Evolution proposals that went into the Swift concurrency design. It covers the proposal that are implemented in Swift 6.2, plus a few additional ones that aren’t currently available. The focus is here is the Swift Evolution proposals. For general information about Swift concurrency, see the documentation referenced by Concurrency Resources. Swift 6.0 The following Swift Evolution proposals form the basis of the Swift 6.0 concurrency design. SE-0176 Enforce Exclusive Access to Memory link: SE-0176 notes: This defines the “Law of Exclusivity”, a critical foundation for both serial and concurrent code. SE-0282 Clarify the Swift memory consistency model ⚛︎ link: SE-0282 notes: This defines Swift’s memory model, that is, the rules about what is and isn’t allowed when it comes to concurrent memory access. SE-0296 Async/await link: SE-0296 introduces: async functions, async, await SE-0297 Concurrency Interoperability with Objective-C link: SE-0297 notes: Specifies how Swift imports an Objective-C method with a completion handler as an async method. Explicitly allows @objc actors. SE-0298 Async/Await: Sequences link: SE-0298 introduces: AsyncSequence, for await syntax notes: This just defines the AsyncSequence protocol. For one concrete implementation of that protocol, see SE-0314. SE-0300 Continuations for interfacing async tasks with synchronous code link: SE-0300 introduces: CheckedContinuation, UnsafeContinuation notes: Use these to create an async function that wraps a legacy request-reply concurrency construct. SE-0302 Sendable and @Sendable closures link: SE-0302 introduces: Sendable, @Sendable closures, marker protocols SE-0304 Structured concurrency link: SE-0304 introduces: unstructured and structured concurrency, Task, cancellation, CancellationError, withTaskCancellationHandler(…), sleep(…), withTaskGroup(…), withThrowingTaskGroup(…) notes: For the async let syntax, see SE-0317. For more ways to sleep, see SE-0329 and SE-0374. For discarding task groups, see SE-0381. SE-0306 Actors link: SE-0306 introduces: actor syntax notes: For actor-isolated parameters and the nonisolated keyword, see SE-0313. For global actors, see SE-0316. For custom executors and the Actor protocol, see SE-0392. SE-0311 Task Local Values link: SE-0311 introduces: TaskLocal SE-0313 Improved control over actor isolation link: SE-0313 introduces: isolated parameters, nonisolated SE-0314 AsyncStream and AsyncThrowingStream link: SE-0314 introduces: AsyncStream, AsyncThrowingStream, onTermination notes: These are super helpful when you need to publish a legacy notification construct as an async stream. For a simpler API to create a stream, see SE-0388. SE-0316 Global actors link: SE-0316 introduces: GlobalActor, MainActor notes: This includes the @MainActor syntax for closures. SE-0317 async let bindings link: SE-0317 introduces: async let syntax SE-0323 Asynchronous Main Semantics link: SE-0323 SE-0327 On Actors and Initialization link: SE-0327 notes: For a proposal to allow access to non-sendable isolated state in a deinitialiser, see SE-0371. SE-0329 Clock, Instant, and Duration link: SE-0329 introduces: Clock, InstantProtocol, DurationProtocol, Duration, ContinuousClock, SuspendingClock notes: For another way to sleep, see SE-0374. SE-0331 Remove Sendable conformance from unsafe pointer types link: SE-0331 SE-0337 Incremental migration to concurrency checking link: SE-0337 introduces: @preconcurrency, explicit unavailability of Sendable notes: This introduces @preconcurrency on declarations, on imports, and on Sendable protocols. For @preconcurrency conformances, see SE-0423. SE-0338 Clarify the Execution of Non-Actor-Isolated Async Functions link: SE-0338 note: This change has caught a bunch of folks by surprise and there’s a discussion underway as to whether to adjust it. SE-0340 Unavailable From Async Attribute link: SE-0340 introduces: noasync availability kind SE-0343 Concurrency in Top-level Code link: SE-0343 notes: For how strict concurrency applies to global variables, see SE-0412. SE-0374 Add sleep(for:) to Clock link: SE-0374 notes: This builds on SE-0329. SE-0381 DiscardingTaskGroups link: SE-0381 introduces: DiscardingTaskGroup, ThrowingDiscardingTaskGroup notes: Use this for task groups that can run indefinitely, for example, a network server. SE-0388 Convenience Async[Throwing]Stream.makeStream methods link: SE-0388 notes: This builds on SE-0314. SE-0392 Custom Actor Executors link: SE-0392 introduces: Actor protocol, Executor, SerialExecutor, ExecutorJob, assumeIsolated(…) notes: For task executors, a closely related concept, see SE-0417. For custom isolation checking, see SE-0424. SE-0395 Observation link: SE-0395 introduces: Observation module, Observable notes: While this isn’t directly related to concurrency, it’s relationship to Combine, which is an important exising concurrency construct, means I’ve included it in this list. SE-0401 Remove Actor Isolation Inference caused by Property Wrappers link: SE-0401, commentary availability: upcoming feature flag: DisableOutwardActorInference SE-0410 Low-Level Atomic Operations ⚛︎ link: SE-0410 introduces: Synchronization module, Atomic, AtomicLazyReference, WordPair SE-0411 Isolated default value expressions link: SE-0411, commentary SE-0412 Strict concurrency for global variables link: SE-0412 introduces: nonisolated(unsafe) notes: While this is a proposal about globals, the introduction of nonisolated(unsafe) applies to “any form of storage”. SE-0414 Region based Isolation link: SE-0414, commentary notes: To send parameters and results across isolation regions, see SE-0430. SE-0417 Task Executor Preference link: SE-0417, commentary introduces: withTaskExecutorPreference(…), TaskExecutor, globalConcurrentExecutor notes: This is closely related to the custom actor executors defined in SE-0392. SE-0418 Inferring Sendable for methods and key path literals link: SE-0418, commentary availability: upcoming feature flag: InferSendableFromCaptures notes: The methods part of this is for “partial and unapplied methods”. SE-0420 Inheritance of actor isolation link: SE-0420, commentary introduces: #isolation, optional isolated parameters notes: This is what makes it possible to iterate over an async stream in an isolated async function. SE-0421 Generalize effect polymorphism for AsyncSequence and AsyncIteratorProtocol link: SE-0421, commentary notes: Previously AsyncSequence used an experimental mechanism to support throwing and non-throwing sequences. This moves it off that. Instead, it uses an extra Failure generic parameter and typed throws to achieve the same result. This allows it to finally support a primary associated type. Yay! SE-0423 Dynamic actor isolation enforcement from non-strict-concurrency contexts link: SE-0423, commentary introduces: @preconcurrency conformance notes: This adds a number of dynamic actor isolation checks (think assumeIsolated(…)) to close strict concurrency holes that arise when you interact with legacy code. SE-0424 Custom isolation checking for SerialExecutor link: SE-0424, commentary introduces: checkIsolation() notes: This extends the custom actor executors introduced in SE-0392 to support isolation checking. SE-0430 sending parameter and result values link: SE-0430, commentary introduces: sending notes: Adds the ability to send parameters and results between the isolation regions introduced by SE-0414. SE-0431 @isolated(any) Function Types link: SE-0431, commentary, commentary introduces: @isolated(any) attribute on function types, isolation property of functions values notes: This is laying the groundwork for SE-NNNN Closure isolation control. That, in turn, aims to bring the currently experimental @_inheritActorContext attribute into the language officially. SE-0433 Synchronous Mutual Exclusion Lock 🔒 link: SE-0433 introduces: Mutex SE-0434 Usability of global-actor-isolated types link: SE-0434, commentary availability: upcoming feature flag: GlobalActorIsolatedTypesUsability notes: This loosen strict concurrency checking in a number of subtle ways. Swift 6.1 Swift 6.1 has the following additions. Vision: Improving the approachability of data-race safety link: vision SE-0442 Allow TaskGroup’s ChildTaskResult Type To Be Inferred link: SE-0442, commentary notes: This represents a small quality of life improvement for withTaskGroup(…) and withThrowingTaskGroup(…). SE-0449 Allow nonisolated to prevent global actor inference link: SE-0449, commentary notes: This is a straightforward extension to the number of places you can apply nonisolated. Swift 6.2 Xcode 26 beta has two new build settings: Approachable Concurrency enables the following feature flags: DisableOutwardActorInference, GlobalActorIsolatedTypesUsability, InferIsolatedConformances, InferSendableFromCaptures, and NonisolatedNonsendingByDefault. Default Actor Isolation controls SE-0466 Swift 6.2, still in beta, has the following additions. SE-0371 Isolated synchronous deinit link: SE-0371, commentary introduces: isolated deinit notes: Allows a deinitialiser to access non-sendable isolated state, lifting a restriction imposed by SE-0327. SE-0457 Expose attosecond representation of Duration link: SE-0457 introduces: attoseconds, init(attoseconds:) SE-0461 Run nonisolated async functions on the caller’s actor by default link: SE-0461 availability: upcoming feature flag: NonisolatedNonsendingByDefault introduces: nonisolated(nonsending), @concurrent notes: This represents a significant change to how Swift handles actor isolation by default, and introduces syntax to override that default. SE-0462 Task Priority Escalation APIs link: SE-0462 introduces: withTaskPriorityEscalationHandler(…) notes: Code that uses structured concurrency benefits from priority boosts automatically. This proposal exposes APIs so that code using unstructured concurrency can do the same. SE-0463 Import Objective-C completion handler parameters as @Sendable link: SE-0463 notes: This is a welcome resolution to a source of much confusion. SE-0466 Control default actor isolation inference link: SE-0466, commentary availability: not officially approved, but a de facto part of Swift 6.2 introduces: -default-isolation compiler flag notes: This is a major component of the above-mentioned vision document. SE-0468 Hashable conformance for Async(Throwing)Stream.Continuation link: SE-0468 notes: This is an obvious benefit when you’re juggling a bunch of different async streams. SE-0469 Task Naming link: SE-0469 introduces: name, init(name:…) SE-0470 Global-actor isolated conformances link: SE-0470 availability: upcoming feature flag: InferIsolatedConformances introduces: @SomeActor protocol conformance notes: This is particularly useful when you want to conform an @MainActor type to Equatable, Hashable, and so on. SE-0471 Improved Custom SerialExecutor isolation checking for Concurrency Runtime link: SE-0471 notes: This is a welcome extension to SE-0424. SE-0472 Starting tasks synchronously from caller context link: SE-0472 introduces: immediate[Detached](…), addImmediateTask[UnlessCancelled](…), notes: This introduces the concept of an immediate task, one that initially uses the calling execution context. This is one of those things where, when you need it, you really need it. But it’s hard to summary when you might need it, so you’ll just have to read the proposal (-: In Progress The proposals in this section didn’t make Swift 6.2. SE-0406 Backpressure support for AsyncStream link: SE-0406 availability: returned for revision notes: Currently AsyncStream has very limited buffering options. This was a proposal to improve that. This feature is still very much needed, but the outlook for this proposal is hazy. My best guess is that something like this will land first in the Swift Async Algorithms package. See this thread. SE-NNNN Closure isolation control link: SE-NNNN introduces: @inheritsIsolation availability: not yet approved notes: This aims to bring the currently experimental @_inheritActorContext attribute into the language officially. It’s not clear how this will play out given the changes in SE-0461. Revision History 2025-09-02 Updated for the upcoming release Swift 6.2. 2025-04-07 Updated for the release of Swift 6.1, including a number of things that are still in progress. 2024-11-09 First post.
0
0
1.5k
Sep ’25
AVExportSession in Xcode16 - "exportAsynchronouslyWithCompletionHandler: more than once."
I’m experiencing a crash at runtime when trying to extract audio from a video. This issue occurs on both iOS 18 and earlier versions. The crash is caused by the following error: *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '*** -[AVAssetExportSession exportAsynchronouslyWithCompletionHandler:] Cannot call exportAsynchronouslyWithCompletionHandler: more than once. (0x1851435ec 0x1826dd244 0x1970c09c0 0x214d8f358 0x214d95899 0x190a1c8b9 0x214d8efd9 0x30204cef5 0x302053ab9 0x190a5ae39) libc++abi: terminating due to uncaught exception of type NSException My previous code worked fine, but it's crashing with Swift 6. Does anyone know a solution for this? Previous code: func extractAudioFromVideo(from videoURL: URL, exportHandler: ((AVAssetExportSession, CurrentValueSubject<Float, Never>?) -> Void)? = nil, completion: @escaping (Swift.Result<URL, Error>) -> Void) { let asset = AVAsset(url: videoURL) // Create an AVAssetExportSession to export the audio track guard let exportSession = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetAppleM4A) else { completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Failed to create AVAssetExportSession"]))) return } // Set the output file type and path guard let filename = videoURL.lastPathComponent.components(separatedBy: ["."]).first else { return } let outputURL = VideoUtils.getTempAudioExportUrl(filename) VideoUtils.deleteFileIfExists(outputURL.path) exportSession.outputFileType = .m4a exportSession.outputURL = outputURL let audioExportProgressPublisher = CurrentValueSubject<Float, Never>(0.0) if let exportHandler = exportHandler { exportHandler(exportSession, audioExportProgressPublisher) } // Periodically check the progress of the export session let timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { _ in audioExportProgressPublisher.send(exportSession.progress) } // Export the audio track asynchronously exportSession.exportAsynchronously { switch exportSession.status { case .completed: completion(.success(outputURL)) case .failed: completion(.failure(exportSession.error ?? NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Unknown error occurred while exporting audio"]))) case .cancelled: completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Export session was cancelled"]))) default: completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Unknown export session status"]))) } // Invalidate the timer when the export session completes or is cancelled timer.invalidate() } } ## New Code: func extractAudioFromVideo(from videoURL: URL, exportHandler: ((AVAssetExportSession, CurrentValueSubject<Float, Never>?) -> Void)? = nil, completion: @escaping (Swift.Result<URL, Error>) -> Void) { let asset = AVAsset(url: videoURL) // Create an AVAssetExportSession to export the audio track guard let exportSession = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetAppleM4A) else { completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Failed to create AVAssetExportSession"]))) return } // Set the output file type and path guard let filename = videoURL.lastPathComponent.components(separatedBy: ["."]).first else { return } let outputURL = VideoUtils.getTempAudioExportUrl(filename) VideoUtils.deleteFileIfExists(outputURL.path) exportSession.outputFileType = .m4a exportSession.outputURL = outputURL let audioExportProgressPublisher = CurrentValueSubject<Float, Never>(0.0) if let exportHandler { exportHandler(exportSession, audioExportProgressPublisher) } let task = Task { if #available(iOS 18.0, *) { // Handle export for iOS 18 and later let states = exportSession.states(updateInterval: 0.1) for await state in states { switch state { case .pending, .waiting: break case .exporting(progress: let progress): print("Exporting: \(progress.fractionCompleted)") if progress.isFinished { completion(.success(outputURL)) } else if progress.isCancelled { completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Export session was cancelled"]))) } else { audioExportProgressPublisher.send(Float(progress.fractionCompleted)) } } } try await exportSession.export(to: outputURL, as: .m4a) // Only call export once } else { // Handle export for iOS versions below 18 let publishTimer = Timer.publish(every: 0.1, on: .main, in: .common) .autoconnect() .sink { [weak exportSession] _ in guard let exportSession = exportSession else { return } audioExportProgressPublisher.send(exportSession.progress) } // Only call export once await exportSession.export() // Handle the export session's status switch exportSession.status { case .completed: completion(.success(outputURL)) case .failed: completion(.failure(exportSession.error ?? NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Unknown error occurred while exporting audio"]))) case .cancelled: completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Export session was cancelled"]))) default: completion(.failure(NSError(domain: "com.example.app", code: -1, userInfo: [NSLocalizedDescriptionKey: "Unknown export session status"]))) } // Invalidate the timer when the export session completes or is cancelled publishTimer.cancel() } } task.cancel() }
0
0
462
Dec ’24
Working correctly with actor annotated class
Hi, I have a complex structure of classes, and I'm trying to migrate to swift6 For this classes I've a facade that creates the classes for me without disclosing their internals, only conforming to a known protocol I think I've hit a hard wall in my knowledge of how the actors can exchange data between themselves. I've created a small piece of code that can trigger the error I've hit import SwiftUI import Observation @globalActor actor MyActor { static let shared: some Actor = MyActor() init() { } } @MyActor protocol ProtocolMyActor { var value: String { get } func set(value: String) } @MyActor func make(value: String) -> ProtocolMyActor { return ImplementationMyActor(value: value) } class ImplementationMyActor: ProtocolMyActor { private(set) var value: String init(value: String) { self.value = value } func set(value: String) { self.value = value } } @MainActor @Observable class ViewObserver { let implementation: ProtocolMyActor var value: String init() async { let implementation = await make(value: "Ciao") self.implementation = implementation self.value = await implementation.value } func set(value: String) { Task { await implementation.set(value: value) self.value = value } } } struct MyObservedView: View { @State var model: ViewObserver? var body: some View { if let model { Button("Loaded \(model.value)") { model.set(value: ["A", "B", "C"].randomElement()!) } } else { Text("Loading") .task { self.model = await ViewObserver() } } } } The error Non-sendable type 'any ProtocolMyActor' passed in implicitly asynchronous call to global actor 'MyActor'-isolated property 'value' cannot cross actor boundary Occurs in the init on the line "self.value = await implementation.value" I don't know which concurrency error happens... Yes the init is in the MainActor , but the ProtocolMyActor data can only be accessed in a MyActor queue, so no data races can happen... and each access in my ImplementationMyActor uses await, so I'm not reading or writing the object from a different actor, I just pass sendable values as parameter to a function of the object.. can anybody help me understand better this piece of concurrency problem? Thanks
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0
597
Nov ’24
Do i need to put any OS Error handling for Unmanaged.passRetain (obj) or Unmanaged.takeRetain (objptr)
In below Swift code , is there any possiblities of failure of Unmanaged.passRetain and Unmanaged.takeRetain calls ? // can below call fail (constructor returns nil due to OS or language error) and do i need to do explicit error handling here? let str = TWSwiftString(pnew) // Increasing RC by 1 // can below call fail (assuming str is valid) and do i need to do explicit error handling for the same ? let ptr:UnsafeMutableRawPointer? = Unmanaged.passRetained(str).toOpaque() // decrease RC by 1 // can below call fail (assuming ptr is valid) ? and do i need to do explicit error handling Unmanaged<TWSwiftString>.fromOpaque(pStringptr).release()
1
0
545
Nov ’24
UIViewRepresentable is not working
I have been trying to integrate a UIKit view into SwiftUI, specifically a WKWebView. However, I keep encountering a does not conform to protocol error. Here's my code: import SwiftUI import WebKit struct SimpleWebView: View { var body: some View { WebViewContainerRepresentable() .edgesIgnoringSafeArea(.all) } } struct WebViewContainerRepresentable: UIViewRepresentable { typealias UIViewType = WKWebView func makeUIView(context: Context) -> WKWebView { let webView = WKWebView() if let url = Bundle.main.url(forResource: "index", withExtension: "html") { webView.loadFileURL(url, allowingReadAccessTo: url.deletingLastPathComponent()) } return webView } func updateUIView(_ uiView: WKWebView, context: Context) { // Updates not required for this use case } } I tried this with other views as well, and it turns out this is not WKWebView-specific. The minimum deployment version is iOS 15. Any help would be much appreciated. Let me know if I need to add any more information.
1
0
627
Dec ’24
Error about "swift for windows" at windows11
谁能告诉我为什么? “[正在运行] swift ”d:\vscode object\swift object\ceshi.swift” JIT 会话错误:未找到符号:[ $ss 27_allocateUninitializedArrayySayxG_BptBwlFyp_Tg5 ] 未能具体化符号: { (main, { main, $sSa 12_endMutationyyF, $ss 5print_9separator10terminatoryypd_S2StFfA0_, $ss 5print_9separator10terminatoryypd_S2StFfA1_, $ss 27_finalizeUninitializedArrayySayxGABnlF }) } [完成] 在 0.47 秒内退出并带有 code=4294967295” 当“Swift for Windows”在 VSCode for Windows 上运行时。 路径为 true,“Package-swift-lsp: Path”为 true。 谁能告诉我为什么?
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0
826
Jul ’25
TaskExecutor and Swift 6 question
I have the following TaskExecutor code in Swift 6 and is getting the following error: //Error Passing closure as a sending parameter risks causing data races between main actor-isolated code and concurrent execution of the closure. May I know what is the best way to approach this? This is the default code generated by Xcode when creating a Vision Pro App using Metal as the Immersive Renderer. Renderer @MainActor static func startRenderLoop(_ layerRenderer: LayerRenderer, appModel: AppModel) { Task(executorPreference: RendererTaskExecutor.shared) { //Error let renderer = Renderer(layerRenderer, appModel: appModel) await renderer.startARSession() await renderer.renderLoop() } } final class RendererTaskExecutor: TaskExecutor { private let queue = DispatchQueue(label: "RenderThreadQueue", qos: .userInteractive) func enqueue(_ job: UnownedJob) { queue.async { job.runSynchronously(on: self.asUnownedSerialExecutor()) } } func asUnownedSerialExecutor() -&gt; UnownedTaskExecutor { return UnownedTaskExecutor(ordinary: self) } static let shared: RendererTaskExecutor = RendererTaskExecutor() }
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0
834
Dec ’24
Open any Swift view from C++
I've narrowed down my question after many rabbit holes - how can C++ code open any view in Swift. I can call functions in swift from C++ (works great), but not async or main actor (or actor at all) functions. And if I'm not mistaken all views are actors if not main actors? When calling from C+ I think its necessary that the first view be the main actor? I've implemented the code from the WWDC23 C++ interop video (Zoe's image picker) where I made a view in a struct, and just want to call it and let the view do the work. The compiler immediately gives me 'cannot expose main actors to C++'. If I'm not mistaken, doesn't this block the opening of any kind of swift view from C++? Hopefully I'm missing something obvious, which is likely :) In Zoe's code was his entry point into the program still Swift and not actually C++ app? Thanks! Thanks!
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1
117
May ’25
Module compiled with Swift 6.0.3 cannot be imported by the Swift 6.1 compiler
Module compiled with Swift 6.0.3 cannot be imported by the Swift 6.1 compiler: /private/var/tmp/_bazel_xx/8b7c61ad484d9da1bf94a11f12ae6ffd/rules_xcodeproj.noindex/build_output_base/execroot/main/CustomModules/BIYThred/CocoaLumberjack/framework/CocoaLumberjack.framework/Modules/CocoaLumberjack.swiftmodule/arm64-apple-ios.swiftmodule
1
0
718
Jul ’25
'init(coordinateRegion:interactionModes:showsUserLocation:userTrackingMode:annotationItems:annotationContent:)' was deprecated in iOS 17.0: Use Map initializers that t
I am currently encountering two deprecated errors in my code. Could someone please identify the issues with the code? Errors: 'init(coordinateRegion:interactionModes:showsUserLocation:userTrackingMode:annotationItems:annotationContent:)' was deprecated in iOS 17.0: Use Map initializers that take a MapContentBuilder instead. 'MapAnnotation' was deprecated in iOS 17.0: Use Annotation along with Map initializers that take a MapContentBuilder instead. Code: // MARK: - Stores Map (Dynamic) struct StoresMapView: View { @State private var storeLocations: [StoreLocation] = [] @State private var region = MKCoordinateRegion( center: CLLocationCoordinate2D(latitude: -31.95, longitude: 115.86), span: MKCoordinateSpan(latitudeDelta: 0.5, longitudeDelta: 0.5) ) var body: some View { Map(coordinateRegion: $region, interactionModes: .all, annotationItems: storeLocations) { store in MapAnnotation(coordinate: CLLocationCoordinate2D(latitude: store.latitude, longitude: store.longitude)) { VStack(spacing: 4) { Image(systemName: "leaf.circle.fill") .font(.title) .foregroundColor(.green) Text(store.name) .font(.caption) .fixedSize() } } } .onAppear(perform: loadStoreData) .navigationTitle("Store Locator") } private func loadStoreData() { guard let url = URL(string: "https://example.com/cop092/StoreLocations.json") else { return } URLSession.shared.dataTask(with: url) { data, _, _ in if let data = data, let decoded = try? JSONDecoder().decode([StoreLocation].self, from: data) { DispatchQueue.main.async { self.storeLocations = decoded if let first = decoded.first { self.region.center = CLLocationCoordinate2D(latitude: first.latitude, longitude: first.longitude) } } } }.resume() } }
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110
May ’25
Customization in Swift ArgumentParser's help command and error output
Hello I want to implement customisation to swift argumentparser, Here are following changes want to do it in my cli changing default footer present in help command output currently help command output coming like this OVERVIEW: clisample USAGE: clisample <subcommand> OPTIONS: --version show the version. -h, --help show the help. SUBCOMMANDS: logs (default) Export logs for clisample processes. See 'clisample --help' for more information.' so instead of See 'clisample --help' for more information.' I want my own string For more details, run 'clisample help <subcommand>' customise error string getting from validation error Error: Missing value for '-t <time>' Help: -t <time> Time window (e.g. 10h, 30m, 2d). Usage: clisample logs --time <time> See 'clisample logs --help' for more information. so I want error output with example and customised footer, like this Error: Missing value for '-t <time>' Help: -t <time> Time window (e.g. 10h, 30m, 2d). Usage: clisample logs --time <time> Example: clisample logs -t 5m For more details, run 'clisample help <subcommand>' Is this changes possible from anyway?
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505
Sep ’25
Returning One Component of Struct as Encoded Value in JSON
I have a class that I want to custom encode into JSON: class Declination: Decodable, Encodable { var asString: String var asDouble: Double init(_ asString: String) { self.asString = asString self.asDouble = raToDouble(asString) } required init(from decoder: Decoder) throws { let value = try decoder.singleValueContainer() self.asString = try value.decode(String.self) self.asDouble = declinationToDouble(asString) } } As you can see, I calculate the double form of the declination when I decode a JSON file containing the data. What I want to do now is ENCODE the class back out as a single string. Currently the standard JSON encode in Swift produces the following: "declination":{"asDouble":18.26388888888889,"asString":"+18:15:50.00"} what I want to produce is: declination:"+18:15:50.00" How can I easily do that? I've read up about custom encoders and such, and I get confused about the containers and what keys are being used. I think there might be a simple answer where I could just code: extension Coordinate: Encodable { func encode(to encoder: Encoder) throws { return encoder.encode(self.asString) } } But experienced Swift developers will immediately see that won't work. Should I do JSONSerialization instead? Can I just write a toString() extension and have JSON pick that up? Any help would be appreciated. Thanks, Robert
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325
Jan ’25
Passing compatible primitive types as reference in cpp-swift interop
I have an xcode project which has both cpp and swift code. In one of my usecase I am passing primitive type variables from swift to cpp by reference( primitives types list here as per the new cpp-swift interop documentation) swift code: // primitive check code:Bool var x : Bool = true // When we are passing a variable as a Reference, we need to use explicitly use'&' student.PassBoolAsReferenceType (&x) // interop call to cpp code print (x) Cpp code: void Student::PassBoolAsReferenceType(bool &pValue) noexcept { std::cout << pValue << std::endl; pValue = false; } The above code fails during compilation with no clear error message "Command SwiftCompile failed with a nonzero exit code" However, all the other primitive types that I tested worked for the above code like Int, Float, Double etc. Only the Bool interop fails. Can someone explain why is it not possible for bool? I m using the new interop introduced in swift 5.9.
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372
Dec ’24
Undefined symbol
Is anyone have this problem on xcode 26 ? Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibility50 Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibility51 Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibility56 Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibilityConcurrency Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibilityDynamicReplacements
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1
1.3k
Sep ’25
How to save a point cloud in the sample code "Capturing depth using the LiDAR camera" with the photoOutput
Hello dear community, I have the sample code from Apple “CapturingDepthUsingLiDAR” to access the LiDAR on my iPhone 12 Pro. My goal is to use the “photo output” function to generate a point cloud from a single image and then save it as a ply file. So far I have tested different approaches to create a .ply file from the depthmap, the intrinsic camera data and the rgba values. Unfortunately, I have had no success so far and the result has always been an incorrect point cloud. My question now is whether there are already approaches to this and whether anyone has any experience with it. Thank you very much in advance!!!
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0
516
Jan ’25
Undefined symbol: _main Error
I’ve been struggling with this issue for a long time. When I try to archive my app to submit it to the App Store, I encounter two errors: Linker command failed with exit code 1 (use -v to see invocation) Linker command failed with exit code 1 (use -v to see invocation)
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0
97
Jun ’25
Polynomial Coefficients calculation
How can I calculate polynomial coefficients for Tone Curve points: // • Red channel: (0, 0), (60, 39), (128, 128), (255, 255) // • Green channel: (0, 0), (63, 50), (128, 128), (255, 255) // • Blue channel: (0, 0), (60, 47), (119, 119), (255, 255) CIFilter: func colorCrossPolynomial(inputImage: CIImage) -> CIImage? { let colorCrossPolynomial = CIFilter.colorCrossPolynomial() let redfloatArr: [CGFloat] = [1, 1, 1, 1, 0, 0, 0, 0, 0, 0] let greenfloatArr: [CGFloat] = [0, 1, 1, 0, 0, 0, 0, 0, 0, 1] let bluefloatArr: [CGFloat] = [0, 0, 1, 0, 0, 0, 0, 1, 1, 0] colorCrossPolynomial.inputImage = inputImage colorCrossPolynomial.blueCoefficients = CIVector(values: bluefloatArr, count: bluefloatArr.count) colorCrossPolynomial.redCoefficients = CIVector(values: redfloatArr, count: redfloatArr.count) colorCrossPolynomial.greenCoefficients = CIVector(values: greenfloatArr, count: greenfloatArr.count) return colorCrossPolynomial.outputImage }
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0
443
Jan ’25
Issue with Swift 6 migration issues
We are migrating to swift 6 from swift 5 using Xcode 16.2. we are getting below errors in almost each of our source code files : Call to main actor-isolated initializer 'init(storyboard:bundle:)' in a synchronous non isolated context Main actor-isolated property 'delegate' can not be mutated from a nonisolated context Call to main actor-isolated instance method 'register(cell:)' in a synchronous nonisolated context Call to main actor-isolated instance method 'setup()' in a synchronous nonisolated context Few questions related to these compile errors. Some of our functions arguments have default value set but swift 6 does not allow to set any default values. This requires a lot of code changes throughout the project. This would be lot of source code re-write. Using annotations like @uncheck sendable , @Sendable on the class (Main actor) name, lot of functions within those classes , having inside some code which coming from other classes which also showing main thread issue even we using @uncheck sendable. There are so many compile errors, we are still seeing other than what we have listed here. Fixing these compile errors throughout our project, would be like a re-write of our whole application, which would take lot of time. In order for us to migrate efficiently, we have few questions where we need your help with. Below are the questions. Are there any ways we can bypass these errors using any keywords or any other way possible? Can Swift 5 and Swift 6 co-exist? so, we can slowly migrate over a period of time.
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0
160
Jun ’25