I have an @objC used for notification. kTag is an Int constant, fieldBeingEdited is an Int variable. The following code fails at compilation with error: Command CompileSwift failed with a nonzero exit code if I capture self (I edited code, to have minimal case) @objc func keyboardDone(_ sender : UIButton) { DispatchQueue.main.async { [self] () -> Void in switch fieldBeingEdited { case kTag : break default : break } } } If I explicitly use self, it compiles, even with self captured: @objc func keyboardDone(_ sender : UIButton) { DispatchQueue.main.async { [self] () -> Void in switch fieldBeingEdited { // <<-- no need for self here case self.kTag : break // <<-- self here default : break } } } This compiles as well: @objc func keyboardDone(_ sender : UIButton) { DispatchQueue.main.async { () -> Void in switch self.fieldBeingEdited { // <<-- no need for self here case self.kTag : break // <<-- self here default : break } } } Is it a compiler bug or am I missing something ?

Hello, I was expecting the code below to print the test message "line 25" because the class "API" is being called on line 57. But "line 25" is not being displayed in the debug window, please could you tell me why? This is the debugging window: line 93 0 line 93 0 line 93 0 import UIKit // not sure these 2 below are needed import SwiftUI import Combine struct NewsFeed: Codable { var id: String var name: String var country: String var type: String var situation: String var timestamp: String } let urlString = "https://www.notafunnyname.com/jsonmockup.php" let url = URL(string: urlString) let session = URLSession.shared class API: ObservableObject { let dataTask = session.dataTask(with: url!) { (data, response, error) in print("line 25") var dataString = String(data: data!, encoding: String.Encoding.utf8) if error == nil && data != nil { // Parse JSON let decoder = JSONDecoder() do { var newsFeed = try decoder.decode([NewsFeed].self, from: data!) print("line 38") // print(newsFeed) // print("line 125") // print(newsFeed.count) print(error) } catch{ print("Line 46, Error in JSON parsing") print(error) } } }.resume // Make the API Call - not sure why but error clears if moved to line above // dataTask.resume() } let myAPIarray = API() class QuoteTableViewController: UITableViewController { var newsFeed: [[String: String]] = [] override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) { // let selectedQuote = quotes[indexPath.row] // performSegue(withIdentifier: "moveToQuoteDetail", sender: selectedQuote) } override func viewDidLoad() { super.viewDidLoad() // tableView.dataSource = self } // Uncomment the following line to preserve selection between presentations // self.clearsSelectionOnViewWillAppear = false // Uncomment the following line to display an Edit button in the navigation bar for this view controller. // self.navigationItem.rightBarButtonItem = self.editButtonItem // MARK: - Table view data source override func numberOfSections(in tableView: UITableView) -> Int { // #warning Incomplete implementation, return the number of sections return 1 } override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { // (viewDidLoad loads after tableView) // #warning Incomplete implementation, return the number of rows print("line 93") print(newsFeed.count) return 10 } override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { // let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier", for: indexPath) let cell = UITableViewCell () cell.textLabel?.text = "test" return cell } /* // Override to support conditional editing of the table view. override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool { // Return false if you do not want the specified item to be editable. return true } */ /* // Override to support editing the table view. override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) { if editingStyle == .delete { // Delete the row from the data source tableView.deleteRows(at: [indexPath], with: .fade) } else if editingStyle == .insert { // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view } } */ /* // Override to support rearranging the table view. override func tableView(_ tableView: UITableView, moveRowAt fromIndexPath: IndexPath, to: IndexPath) { } */ /* // Override to support conditional rearranging of the table view. override func tableView(_ tableView: UITableView, canMoveRowAt indexPath: IndexPath) -> Bool { // Return false if you do not want the item to be re-orderable. return true } */ // MARK: - Navigation // In a storyboard-based application, you will often want to do a little preparation before navigation override func prepare(for segue: UIStoryboardSegue, sender: Any?) { // Get the new view controller using segue.destination. // Pass the selected object to the new view controller. // getPrice() print("test_segue") if let quoteViewController = segue.destination as? QuoteDetailViewController{ if let selectedQuote = sender as? String { quoteViewController.title = selectedQuote } } } }

I’m working with Swift and encountered an issue when using the contains method on an array. The following code works fine: let result = ["hello", "world"].contains(Optional("hello")) // ✅ Works fine However, when I try to use the same contains method with the array declared in a separate constant(or variable), I get a compile-time error: let stringArray = ["hello", "world"] let result = stringArray.contains(Optional("hello")) // ❌ Compile-time error The compiler produces the following error message: Cannot convert value of type 'Optional<String>' to expected argument type 'String' Both examples seem conceptually similar, but the second one causes a compile-time error, while the first one works fine. This confuses me because I know that Swift automatically promotes a non-optional value to an optional when comparing it with an optional value. This means "hello" should be implicitly converted to Optional("hello") for the comparison. What I understand so far: The contains(_:) method is defined as: func contains(_ element: Element) -> Bool Internally, it calls contains(where:), as seen in the Swift source code: 🔗 Reference contains(where:) takes a closure that applies the == operator for comparison. Since Swift allows comparing String and String? directly (String is implicitly promoted to String? when compared with an optional), I expected contains(where:) to work the same way. My Questions: Why does the first example work, but the second one fails with a compile-time error? What exactly causes this error in the second case, even though both cases involve comparing an optional value with a non-optional value? Does contains(_:) behave differently when used with an explicit array variable rather than a direct array literal? If so, why? I know that there are different ways to resolve this, like using nil coalescing or optional binding, but what I’m really looking for is a detailed explanation of why this issue occurs at the compile-time level. Can anyone explain the underlying reason for this behavior?

Just read about the new @concurrent option coming to Swift 6.2 and lover it, but... It just me, but I which these options would pick a case and stick with it... @Sendable @unchecked @MainActor @concurrent @Observable @ObservationIgnored

I came across One Sided Range Example: [...2] [2...] [..<2] Half Open Range [..<2] Can not the last use case be separated [..<2] of One Sided Range for Brevity as it is already included in Half Open Range?

I want to understand what the recommended way is for string interoperability between swift and c++. Below are the 3 ways to achieve it. Approach 2 is not allowed at work due to restrictions with using std libraries. Approach 1: In C++: char arr[] = "C++ String"; void * cppstring = arr; std::cout<<"before:"<<(char*)cppstring<<std::endl;           // C++ String // calling swift function and passing the void buffer to it, so that swift can update the buffer content Module1::SwiftClass:: ReceiveString (cppstring, length);   std::cout<<"after:"<<(char*)cppstring<<std::endl;             // SwiftStr      In Swift: func ReceiveString (pBuffer : UnsafeMutableRawPointer , pSize : UInt ) -> Void { // to convert cpp-str to swift-str: let swiftStr = String (cString: pBuffer.assumingMemoryBound(to: Int8.self)); print("pBuffer content: \(bufferAsString)"); // to modify cpp-str without converting: let swiftstr:String = "SwiftStr"      _ =  swiftstr.withCString { (cString: UnsafePointer<Int8>) in pBuffer.initializeMemory(as: Int8.self, from: cString, count: swiftstr.count+1) } }  Approach 2:  The ‘String’ type returned from a swift function is received as ‘swift::String’ type in cpp. This is implicitly casted to std::string type. The std::string has the method available to convert it to char *. void TWCppClass::StringConversion () {     // GetSwiftString() is a swift call that returns swift::String which can be received in std::string type     std::string stdstr = Module1::SwiftClass::GetSwiftString ();     char * cstr = stdstr.data ();     const char * conststr= stdstr.c_str (); }    Approach 3: The swift::String type that is obtained from a swift function can be received in char * by directly casting the address of the swift::String. We cannot directly receive a swift::String into a char *. void TWCppClass::StringConversion () {    // GetSwiftString() is a swift call that returns swift::String    swift::String swiftstr = Module1::SwiftClass::GetSwiftString ();    // obtaining the address of swift string and casting it into char *    char * cstr = (char*)&swiftstr; }

I’m aware that Xcode version 26 beta 3 provides an option to enable Swift’s Approachable Concurrency feature at the project level. However, I’d like to achieve the same for a Swift Package. Could you please advise on how to enable Approachable Concurrency support specifically for a Swift Package?

I'm developing an audio unit for use on iOS. The AUv3 worked fine with xcode 15.X and swift 5.X. I recently tried to submit an update to my plug-in but Apple refused submission because my Xcode was not the latest. Now that I'm on Xcode 16.4 I can't get my project to compile, even when following all of the same previous steps. As one example of a change, Xcode doesn't appear to include the “C++ and Objective-C interoperability” build setting that it used to. This setting is noted in the Swift documentation and I used to need it, https://www.swift.org/documentation/cxx-interop/project-build-setup/#mixing-swift-and-c-using-xcode Currently my C++ code can't see anything from Swift, and I get a "Use of undeclared identifier 'project_name'". I've selected Switch support for version 5.0 in an attempt to minimize changes from Apple. My process is I generate an Xcode project file from my audio plugin support, JUCE. Then I add in the swift files, click yes to create bridging headers, but c++ doesn't see swift anymore. I'd greatly appreciate any suggestions.

Greetings, func stepForward(_ input: Int) -> Int { return input + 1 } func stepBackward(_ input: Int) -> Int { return input - 1 } func chooseStepFunction(backward: Bool) -> (Int) -> Int { return backward ? stepBackward : stepForward /* Error type of expression is ambiguous without a type annotation */ } Why am I getting this error. If I change the function to func chooseStepFunction(backward: Bool) -> (Int) -> Int { if backward { return stepBackward else { return stepForward } } Why is the previous chooseStepFunction giving me an error ? Thx in advance

I filed the following issue on swiftlang/swift on GitHub (Aug 8th), and a followup the swift.org forums, but not getting any replies. As we near the release of Swift 6.2, I want to know if what I'm seeing below is expected, or if it's another case where the compiler needs a fix. protocol P1: Equatable { } struct S1: P1 { } // Error: Conformance of 'S1' to protocol 'P1' crosses into main actor-isolated code an can cause data races struct S1Workaround: @MainActor P1 { } // OK // Another potential workaround if `Equatable` conformance can be moved to the conforming type. protocol P2 { } struct S2: Equatable, P2 { } // OK There was a prior compiler bug fix which addressed inhereted protocols regarding @MainActor. For Equatable, one still has to use @MainActoreven when the default actor isolation is MainActor. Also affects Hashable and any other protocol inheriting from Equatable.

I am writing a SPM based project for MacOS. In this project? I need to access MacOS Keychain. I am write a swift test built by SPM testTarget(). I can see it generates a bundle ./.build/x86_64-apple-macosx/debug/MyProjectTests.xctest with an executable: % file ./.build/x86_64-apple-macosx/debug/MyProjectPackageTests.xctest/Contents/MacOS/MyProjectPackageTests ./.build/x86_64-apple-macosx/debug/MyProjectPackageTests.xctest/Contents/MacOS/MyProjectPackageTests: Mach-O 64-bit bundle x86_64 This bundle file cannot be executed. How can I execute its tests? I tried with xcodebuild test-without-building -xctestrun ./.build/x86_64-apple-macosx/debug/MyProjectPackageTests.xctest -destination 'platform=macOS' without any chance. Obviously the next question is can I 'simply' add entitlement to this bundle with codesign to fix my enttilement error. My error when running the test is A required entitlement isn't present.

According to the doc: The value returned is the same as the value returned in the kEventParamKeyCode when using Carbon Events. So where can I find kEventParamKeyCode?

Why doesn’t deinit support async? At the end of a test, I want to wipe data from HealthKit, and it’s delete function is asynchronous.

I get this red warning in Xcode every time my app is syncing to the iCloud. My model has only basic types and enum that conform to Codable so i'm not sure what is the problem. App is working well, synchronization works. But the warning doesn't look good. Maybe someone has idea how to debug it.

Given the below code with Swift 6 language mode, Xcode 16.2 If running with iOS 18+: the app crashes due to _dispatch_assert_queue_fail If running with iOS 17 and below: there is a warning: warning: data race detected: @MainActor function at Swift6Playground/PublishedValuesView.swift:12 was not called on the main thread Could anyone please help explain what's wrong here? import SwiftUI import Combine @MainActor class PublishedValuesViewModel: ObservableObject { @Published var count = 0 @Published var content: String = "NA" private var cancellables: Set<AnyCancellable> = [] func start() async { let publisher = $count .map { String(describing: $0) } .removeDuplicates() for await value in publisher.values { content = value } } } struct PublishedValuesView: View { @ObservedObject var viewModel: PublishedValuesViewModel var body: some View { Text("Published Values: \(viewModel.content)") .task { await viewModel.start() } } }

I have been recently getting the following error seemingly randomly, when an event handler of a SwiftUI view accesses a relationship of a SwiftData model the view holds a reference to. I haven't yet found a reliable way of reproducing it: SwiftData/BackingData.swift:866: Fatal error: This model instance was invalidated because its backing data could no longer be found the store. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: COREDATA_ID_URL), implementation: SwiftData.PersistentIdentifierImplementation) What could cause this error? Could you suggest me a workaround?

I am currently studying the Accelerate library by referring to Apple documentation. Here is the link to the referenced document: https://developer.apple.com/documentation/accelerate/veclib/vforce When I executed the sample code provided at the bottom of the document, I found a case where the results were different. let n = 10_000 let x = (0..&lt;n).map { _ in Float.random(in: 1 ... 10_000) } let y = x.map { return sqrt($0) } and let y = [Float](unsafeUninitializedCapacity: n) { buffer, initializedCount in vForce.sqrt(x, result: &amp;buffer) initializedCount = n } The code below is provided to observe the issue described above. import Accelerate Task { let n = 1//10_000 let x = (0..&lt;n).map { _ in Float(6737.015)//Float.random(in: 1 ... 10_000) } let y = x.map { return sqrt($0) } try? await Task.sleep(nanoseconds: 1_000_000_000) let z = [Float](unsafeUninitializedCapacity: n) { buffer, initializedCount in vForce.sqrt(x, result: &amp;buffer) initializedCount = n } } For a value of 6737.015 when calculating the square root: Using the sqrt(_:) function gives the result 82.07932, While using the vForce.sqrt(_:result:) function gives the result 82.07933. Using a calculator, the value comes out as 82.07932139, which shows that the result from vForce is incorrect. Could you explain the reason behind this difference?

Hey there- I'm having a quite interesting bug on Swift Playgrounds. I am trying to run my app with this following code snippet which does not compile on Swift Playgrounds, yet compiles on XCode (note: this is a Swift Playground app) if #available(iOS 18.0, *) { //simple function to get the indices of other items that have the same date as the "date" variable let indices = data!.indices(where: { item in let sameMonth = Calendar.current.component(.month, from: item.time) == Calendar.current.component(.month, from: date) let sameYear = Calendar.current.component(.year, from: item.time) == Calendar.current.component(.year, from: date) let sameDay = Calendar.current.component(.day, from: item.time) == Calendar.current.component(.year, from: date) return sameDay && sameMonth && sameYear }) However, the indices(where:) codeblock seems to stop the app from compiling (ONLY on Swift Playgrounds - it works perfectly fine on XCode). I am getting the following error: Cannot call value of non-function type 'Range<Array<Int>.Index>' (aka 'Range<Int>') Please let me know if you have any insight regarding this issue. -ColoredOwl

Using the DebugDescription macro to display an optional value produces a “String interpolation produces a debug description for an optional value” build warning. For example: @DebugDescription struct MyType: CustomDebugStringConvertible { let optionalValue: String? public var debugDescription: String { "Value: \(optionalValue)" } } The DebugDescription macro does not allow (it is an error) "Value: \(String(describing: optionalValue))" or "Value: \(optionalValue ?? "nil")" because “Only references to stored properties are allowed.” Is there a way to reconcile these? I have a build log full of these warnings, obscuring real issues.

I've got a watch app, still with storyboard, WKInterfaceController and WatchConnectivity. After updating it for swift 6 concurrency I thought I'd keep it for a little while without swift 6 concurrency dynamic runtime check. So I added -disable-dynamic-actor-isolation in OTHER_SWIFT_FLAGS, but it doesn't seem to have an effect for the Apple Watch target. Without manually marking callbacks where needed with @Sendable in dynamic checks seem to be in place. swiftc invocation is as (includes -disable-dynamic-actor-isolation): swiftc -module-name GeoCameraWatchApp -Onone -enforce-exclusivity\=checked ... GeoCameraWatchApp.SwiftFileList -DDEBUG -enable-bridging-pch -disable-dynamic-actor-isolation -D DEBUG -enable-experimental-feature DebugDescriptionMacro -sdk /Applications/Xcode.app/Contents/Developer/Platforms/WatchOS.platform/Developer/SDKs/WatchOS11.2.sdk -target arm64_32-apple-watchos7.0 -g -module-cache-path /Users/stand/Library/Developer/Xcode/DerivedData/ModuleCache.noindex -Xfrontend -serialize-debugging-options -enable-testing -index-store-path /Users/stand/Library/Developer/Xcode/DerivedData/speedo-almhjmryctkitceaufvkvhkkfvdw/Index.noindex/DataStore -enable-experimental-feature OpaqueTypeErasure -Xcc -D_LIBCPP_HARDENING_MODE\=_LIBCPP_HARDENING_MODE_DEBUG -swift-version 6 ... -disable-dynamic-actor-isolation flag seems to be working for the iOS targets, I believe. The flag is described here Am I missing something? Should the flag work for both iOS and Apple Watch targets?