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Function types as return types
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
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164
Aug ’25
Odd Shell Echo Output...
I have a simple shell script as follows: #!/bin/bash OUTPUT="network.$(date +'%d-%m-%y').info.txt" SUPPORT_ID="emailaddress" echo "---------------------------------------------------" > $OUTPUT echo "Run date and time: $(date)" >> $OUTPUT echo "---------------------------------------------------" >> $OUTPUT ifconfig >> $OUTPUT echo "---------------------------------------------------" >> $OUTPUT echo "Network info written to file: $OUTPUT." echo "Please email this file to: $SUPPORT_ID." It just dumps the network config into a file. At some point I will have the file emailed out, but right now I'm just trying to figure out why the output looks like the following? bash ./test.sh .etwork info written to file: network.26-01-25.info.txt .lease email this file to: emailaddress Why in the world does the initial character of the last couple of "echo" commands get clipped and turned into periods? The echos for the output of the commands piped into the output file are fine. Strange... Any ideas?
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512
Jan ’25
Type ReferenceWritableKeyPath does not conform to the 'Sendable' protocol
This is not a question but more of a hint where I was having trouble with. In my SwiftData App I wanted to move from Swift 5 to Swift 6, for that, as recommended, I stayed in Swift 5 language mode and set 'Strict Concurrency Checking' to 'Complete' within my build settings. It marked all the places where I was using predicates with the following warning: Type '' does not conform to the 'Sendable' protocol; this is an error in the Swift 6 language mode I had the same warnings for SortDescriptors. I spend quite some time searching the web and wrapping my head around how to solve that issue to be able to move to Swift 6. In the end I found this existing issue in the repository of the Swift Language https://github.com/swiftlang/swift/issues/68943. It says that this is not a warning that should be seen by the developer and in fact when turning Swift 6 language mode on those issues are not marked as errors. So if anyone is encountering this when trying to fix all issues while staying in Swift 5 language mode, ignore those, fix the other issues and turn on Swift 6 language mode and hopefully they are gone.
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1
1k
Jun ’25
Compiler exception when using Binding and Swift 6
In my code I use a binding that use 2 methods to get and get a value. There is no problem with swift 5 but when I swift to swift 6 the compiler fails : Here a sample example of code to reproduce the problem : `import SwiftUI struct ContentView: View { @State private var isOn = false var body: some View { VStack { Image(systemName: "globe") .imageScale(.large) .foregroundStyle(.tint) Text("Hello, world!") Toggle("change it", isOn: Binding(get: getValue, set: setValue(_:))) } .padding() } private func getValue() -> Bool { isOn } private func setValue(_ value: Bool) { isOn = value } }` Xcode compiler log error : 1. Apple Swift version 6.1.2 (swiftlang-6.1.2.1.2 clang-1700.0.13.5) 2. Compiling with the current language version 3. While evaluating request IRGenRequest(IR Generation for file "/Users/xavierrouet/Developer/TestCompilBindingSwift6/TestCompilBindingSwift6/ContentView.swift") 4. While emitting IR SIL function "@$sSbScA_pSgIeAghyg_SbIeAghn_TR". for <<debugloc at "<compiler-generated>":0:0>>Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var LLVM_SYMBOLIZER_PATH` to point to it): 0 swift-frontend 0x000000010910ae24 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56 1 swift-frontend 0x0000000109108c5c llvm::sys::RunSignalHandlers() + 112 2 swift-frontend 0x000000010910b460 SignalHandler(int) + 360 3 libsystem_platform.dylib 0x0000000188e60624 _sigtramp + 56 4 libsystem_pthread.dylib 0x0000000188e2688c pthread_kill + 296 5 libsystem_c.dylib 0x0000000188d2fc60 abort + 124 6 swift-frontend 0x00000001032ff9a8 swift::DiagnosticHelper::~DiagnosticHelper() + 0 7 swift-frontend 0x000000010907a878 llvm::report_fatal_error(llvm::Twine const&, bool) + 280 8 swift-frontend 0x00000001090aef6c report_at_maximum_capacity(unsigned long) + 0 9 swift-frontend 0x00000001090aec7c llvm::SmallVectorBase::grow_pod(void*, unsigned long, unsigned long) + 384 10 swift-frontend 0x000000010339c418 (anonymous namespace)::SyncCallEmission::setArgs(swift::irgen::Explosion&, bool, swift::irgen::WitnessMetadata*) + 892 11 swift-frontend 0x00000001035f8104 (anonymous namespace)::IRGenSILFunction::visitFullApplySite(swift::FullApplySite) + 4792 12 swift-frontend 0x00000001035c876c (anonymous namespace)::IRGenSILFunction::visitSILBasicBlock(swift::SILBasicBlock*) + 2636 13 swift-frontend 0x00000001035c6614 (anonymous namespace)::IRGenSILFunction::emitSILFunction() + 15860 14 swift-frontend 0x00000001035c2368 swift::irgen::IRGenModule::emitSILFunction(swift::SILFunction*) + 2788 15 swift-frontend 0x00000001033e7c1c swift::irgen::IRGenerator::emitLazyDefinitions() + 5288 16 swift-frontend 0x0000000103573d6c swift::IRGenRequest::evaluate(swift::Evaluator&, swift::IRGenDescriptor) const + 4528 17 swift-frontend 0x00000001035c15c4 swift::SimpleRequest<swift::IRGenRequest, swift::GeneratedModule (swift::IRGenDescriptor), (swift::RequestFlags)17>::evaluateRequest(swift::IRGenRequest const&, swift::Evaluator&) + 180 18 swift-frontend 0x000000010357d1b0 swift::IRGenRequest::OutputType swift::Evaluator::getResultUncached<swift::IRGenRequest, swift::IRGenRequest::OutputType swift::evaluateOrFatalswift::IRGenRequest(swift::Evaluator&, swift::IRGenRequest)::'lambda'()>(swift::IRGenRequest const&, swift::IRGenRequest::OutputType swift::evaluateOrFatalswift::IRGenRequest(swift::Evaluator&, swift::IRGenRequest)::'lambda'()) + 812 19 swift-frontend 0x0000000103576910 swift::performIRGeneration(swift::FileUnit*, swift::IRGenOptions const&, swift::TBDGenOptions const&, std::__1::unique_ptr<swift::SILModule, std::__1::default_deleteswift::SILModule>, llvm::StringRef, swift::PrimarySpecificPaths const&, llvm::StringRef, llvm::GlobalVariable**) + 176 20 swift-frontend 0x0000000102f61af0 generateIR(swift::IRGenOptions const&, swift::TBDGenOptions const&, std::__1::unique_ptr<swift::SILModule, std::__1::default_deleteswift::SILModule>, swift::PrimarySpecificPaths const&, llvm::StringRef, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, llvm::GlobalVariable*&, llvm::ArrayRef<std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator>>) + 156 21 swift-frontend 0x0000000102f5d07c performCompileStepsPostSILGen(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_deleteswift::SILModule>, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) + 2108 22 swift-frontend 0x0000000102f5c0a8 swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 1036 23 swift-frontend 0x0000000102f5f654 performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 1764 24 swift-frontend 0x0000000102f5dfd8 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 3716 25 swift-frontend 0x0000000102ee20bc swift::mainEntry(int, char const**) + 5428 26 dyld 0x0000000188a86b98 start + 6076 Using Xcode 16.4 / Mac OS 16.4
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226
Aug ’25
Bridging Headers is unsupported or Module compiled with Swift 5.5.1 cannot be imported by the Swift 5.6 complier
Hello guys! I faced a problem with building... My device suddenly updated to iOS 15.4.1, my Xcode was 13.2 and I had to update it to the latest version (13.3.1) to build the app. After the update, I had a few problems which were successfully solved but one of them stopped me for a few hours. The problem is with Bridging Headers or Swift Compiler, I really don't know what I did badly, and what causes problems. On several forums I often read that is important to set: Build Settings > Build Options > Build Libraries for Distribution But in any case it doesn't work, on yes: error: using bridging headers with module interfaces is unsupported on no: (line with import framework SWXMLHash) /Users/blablabla/SSLModel.swift:9:8: error: module compiled with Swift 5.5.1 cannot be imported by the Swift 5.6 compiler: /Users/blablabla2/Build/Products/Debug-iphoneos/SWXMLHash.framework/Modules/SWXMLHash.swiftmodule/arm64-apple-ios.swiftmodule import SWXMLHash It will be important that I use Carthage. What should I do? Clone all 10 frameworks that I use and re-build them with a new Xcode which includes compiler 5.6? That may be a bad solution... Any answers on similar topics don't help..
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0
2.9k
Jul ’25
Memory leak and a crash when swizzling NSURLRequest initialiser
When swizzling NSURLRequest initialiser and returning a mutable copy, the original instance does not get deallocated and eventually gets leaked and a crash follows after that. Here's the swizzling setup: static func swizzleInit() { let initSel = NSSelectorFromString("initWithURL:cachePolicy:timeoutInterval:") guard let initMethod = class_getInstanceMethod(NSClassFromString("NSURLRequest"), initSel) else { return } let origInitImp = method_getImplementation(initMethod) let block: @convention(block) (AnyObject, Any, NSURLRequest.CachePolicy, TimeInterval) -> NSURLRequest = { _self, url, policy, interval in typealias OrigInit = @convention(c) (AnyObject, Selector, Any, NSURLRequest.CachePolicy, TimeInterval) -> NSURLRequest let origFunc = unsafeBitCast(origInitImp, to: OrigInit.self) let request = origFunc(_self, initSel, url, policy, interval) return request.tagged() } let newImplementation = imp_implementationWithBlock(block as Any) method_setImplementation(initMethod, newImplementation) } // create a mutable copy if needed and add a header private func tagged() -> NSURLRequest { guard let mutableRequest = self as? NSMutableURLRequest ?? self.mutableCopy() as? NSMutableURLRequest else { return self } mutableRequest.setValue("test", forHTTPHeaderField: "test") return mutableRequest } Then, we have a few test cases: // memory leak and crash func testSwizzleNSURLRequestInit() { let request = NSURLRequest(url: URL(string: "https://example.com")!) XCTAssertEqual(request.value(forHTTPHeaderField: "test"), "test") } // no crash, as the request is mutable, so no copy is created func testSwizzleNSURLRequestInit2() { let request = URLRequest(url: URL(string: "https://example.com")!) XCTAssertEqual(request.value(forHTTPHeaderField: "test"), "test") } // no crash, as the request is mutable, so no copy is created func testSwizzleNSURLRequestInit3() { let request = NSMutableURLRequest(url: URL(string: "https://example.com")!) XCTAssertEqual(request.value(forHTTPHeaderField: "test"), "test") } // no crash, as the new instance does not get deallocated // when the test method completes (?) var request: NSURLRequest? func testSwizzleNSURLRequestInit4() { request = NSURLRequest(url: URL(string: "https://example.com")!) XCTAssertEqual(request?.value(forHTTPHeaderField: "test"), "test") } It appears a memory leak occurs only when any other instance except for the original one is being returned from the initialiser. Is there a workaround to prevent the leak, while allowing for modifications of all requests?
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582
Nov ’24
Confusion About Objective-C's Memory Management (Cocoa)
Hello everyone, There is one thing about Objective-C's memory management that confuses me, which is a returned object's lifetime from methods with names doesn't start with "alloc", "new", "copy", or "mutableCopy". Take this as an example, when using NSBitmapImageRep's representationUsingType:properties: method, it returns an NSData object (reference: https://developer.apple.com/documentation/appkit/nsbitmapimagerep/representation(using:properties:)?language=objc). While testing this out, the NSData seemed to be an owned object (it doesn't get released until the end of the program). From what I understand, this may be an auto-released object which is released at the end of an autorelease pool block. Could someone explain this in more detail? What if I want to release that NSData object before the end of the autorelease pool block? How can I know which object is autoreleased, borrowed, or owned?
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606
Jan ’25
In app purchase goes to Entered Billing Retry after free trail
I have a VPN application published in the app store. Used Ikev2 for this personal VPN. There are two in-app purchases. One is 'Monthly' and another is 'Yearly' with 3 days free trial. We have seen something strange for the yearly subscriptions which has free trail, the cancellation reason through the billing issue is too high like 70-80% due to billing retry state. Some other apps which have billing issues under 10% always. We have done some research and found that if the user doesn't cancel and Apple is unable to charge then it goes to a billing retry state. If users don't like the app, they could cancel their subscription/free trail easily but they are not doing this and why Apple unable to charge the bill after the trial ends. Am i missing something in the developer end?
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0
1.1k
Dec ’24
Objective-C Literals inside a Swift Package
I have a Swift Package that contains an Objective-C target. The target contains Objective-C literals but unfortunately the compiler says "Initializer element is not a compile-time constant", what am I doing wrong? Based on the error triggering in the upper half, I take it that objc_array_literals is on. My target definition looks like: .target( name: "MyTarget", path: "Sources/MySourcesObjC", publicHeadersPath: "include", cxxSettings: [ .unsafeFlags("-fobjc-constant-literals") ] ), I believe Objective-C literals are enabled since a long time but I still tried passing in the -fobjc-constant-literals flag and no luck. To be clear I'm not interested in a run-time initialization, I really want it to be compile time. Does anyone know what I can do?
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142
May ’25
Open Share Extension
Hello, everyone! Help me please to find answer. I have two applications: App-1 with share extension and App-2 without it. From the second app I can open share extension via UIActivityViewController. But I need this extension in the second application to open immediately by pressing a button, and not through UIActivityViewController. Can I do this?
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1.6k
Dec ’24
C++ and Swift in Xcode 16 broke my audio unit
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.
3
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309
Aug ’25
CryptoTokenKit Network Cryptographic Tokens
Hello, It is mentioned in CryptoTokenKit documentation: You use the CryptoTokenKit framework to easily access cryptographic tokens. Tokens are physical devices built in to the system, located on attached hardware (like a smart card), or accessible through a network connection. However, it looks like there is lack of documentation with simple example, how to access network token. I have a certificates in HSM (hardware secure module), which is accessible on network, and I'd like to access certificates on HSM on my Mac. Does anybody know, where to start with implementation? Thank you.
3
0
1.4k
Mar ’25
Equatable with default actor isolation of MainActor
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.
3
0
1.1k
Aug ’25
How to convert a function into a variable?
Hello, I have a test variable here which works fine: var quotes: [(quote: String, order: Int)] = [ ("I live you the more ...", 1), ("There is nothing permanent ...", 2), ("You cannot shake hands ...", 3), ("Lord, make me an instrument...", 4) ] and I have a test function which successfully pulls data from a mysql database via a web service and displays it via the "print" function: func getPrice(){ if let url = URL(string:"https://www.TEST.com/test_connection.php"){ URLSession.shared.dataTask(with: url) { (data, response, error) in if let data = data{ if let json = try? JSONDecoder().decode([[String:String]].self, from: data){ json.forEach { row in print(row["quote"]!) print(row["order"]!) } } else{ } } else{ print("wrong :-(") } }.resume() } } Please can you tell me how to re-write the quotes variable/array so that it returns the results that are found in the getPrice() function?
3
0
447
Mar ’25
Use String Catalog and Localization with class and struct
Hi Everyone, I was able to create the String Catalog with all my strings getting automatic into the stringCatalog except the strings from my models where is not swiftUI and where all I have a class with a lot of info for my app. Some classes are short and I was able to just make the strings localizable by adding on every line: (String(localized: "Telefone")) But I have one class which has Line: 1071 and Col: 1610 and every line I have 7 strings that needs to get localized. These 7 strings are repeated on every line. So I was trying to create a localization for these 7 strings on this class without having to write (String(localized: "Telefone")) 7 times on every line. is there a way? Here is short version of my class: import Foundation class LensStructFilter: Identifiable { var description: String init(description: String) { self.description = description } } let lensEntriesFilter: [LensStructFilter] = [ LensStructFilter(description: "Focal: 24mm \nAbertura Máxima: F2.8 \nCobertura: FULL FRAME \nBocal: Nikon F \nFoco Mínimo: 0,30m \nDiâmetro Frontal: 52mm \nPeso: 275g \n\nFocal: 35mm \nAbertura Máxima: F2.0 \nCobertura: FULL FRAME \nBocal: Nikon F \nFoco Mínimo: 0,25m \nDiâmetro Frontal: 52mm \nPeso: 205g \n\nFocal: 50mm \nAbertura Máxima: F1.8 \nCobertura: FULL FRAME \nBocal: Nikon F \nFoco Mínimo: 0,45m \nDiâmetro Frontal: 52mm \nPeso: 185g \n\nFocal: 85mm \nAbertura Máxima: F1.8 \nCobertura: FULL FRAME \nBocal: Nikon F \nFoco Mínimo: 0,80m \nDiâmetro Frontal: 67mm \nPeso: 350g \n\nFocal: 105mm MACRO \nAbertura Máxima: F2.8 \nCobertura: FULL FRAME \nBocal: Nikon F \nFoco Mínimo: 0,31m \nDiâmetro Frontal: 62mm \nPeso: 720g"), LensStructFilter(description: "Focal: 16-35mm  \nAbertura Máxima: F2.8 \nCobertura: FULL FRAME  \nBocal: EF \nFoco Mínimo: 0,28m \nDiâmetro Frontal (rosca): 82mm \nPeso: 790Kg"), Thanks
3
0
375
Mar ’25
Use FormatStyle to print formatted values from a Vector structure
I'm trying to use FormatStyle from Foundation to format numbers when printing a vector structure. See code below. import Foundation struct Vector<T> { var values: [T] subscript(item: Int) -> T { get { values[item] } set { values[item] = newValue } } } extension Vector: CustomStringConvertible { var description: String { var desc = "( " desc += values.map { "\($0)" }.joined(separator: " ") desc += " )" return desc } } extension Vector { func formatted<F: FormatStyle>(_ style: F) -> String where F.FormatInput == T, F.FormatOutput == String { var desc = "( " desc += values.map { style.format($0) }.joined(separator: " ") desc += " )" return desc } } In the example below, the vector contains a mix of integer and float literals. The result is a vector with a type of Vector<Double>. Since the values of the vector are inferred as Double then I expect the print output to display as decimal numbers. However, the .number formatted output seems to ignore the vector type and print the values as a mix of integers and decimals. This is fixed by explicitly providing a format style with a fraction length. So why is the .formatted(.number) method ignoring the vector type T which is Double in this example? let vec = Vector(values: [-2, 5.5, 100, 19, 4, 8.37]) print(vec) print(vec.formatted(.number)) print(vec.formatted(.number.precision(.fractionLength(1...)))) ( -2.0 5.5 100.0 19.0 4.0 8.37 ) // correct output that uses all Double types ( -2 5.5 100 19 4 8.37 ) // wrong output that uses Int and Double types ( -2.0 5.5 100.0 19.0 4.0 8.37 ) // correct output that uses all Double types
2
0
294
Mar ’25
Use of `for await` with `AyncStream`, and yielding async closures to its continuation
Hello, I was hoping to clarify my understanding of the use of for await with an AsyncStream. My use case is, I'd like to yield async closures to the stream's continuation, with the idea that, when I use for await with the stream to process and execute the closures, it would only continue on to the following closure once the current closure has been run to completion. At a high level, I am trying to implement in-order execution of async closures in the context of re-entrancy. An example of asynchronous work I want to execute is a network call that should write to a database: func syncWithRemote() async -> Void { let data = await fetchDataFromNetwork() await writeToLocalDatabase(data) } For the sake of example, I'll call the intended manager of closure submission SingleOperationRunner. where, at a use site such as this, my desired outcome is that call 1 of syncWithRemote() is always completed before call 2 of it: let singleOperationRunner = SingleOperationRunner(priority: nil) singleOperationRunner.run { syncWithRemote() } singleOperationRunner.run { syncWithRemote() } My sketch implementation looks like this: public final class SingleOperationRunner { private let continuation: AsyncStream<() async -> Void>.Continuation public init(priority: TaskPriority?) { let (stream, continuation) = AsyncStream.makeStream(of: (() async -> Void).self) self.continuation = continuation Task.detached(priority: priority) { // Will this loop only continue when the `await operation()` completes? for await operation in stream { await operation() } } } public func run(operation: @escaping () async -> Void) { continuation.yield(operation) } deinit { continuation.finish() } } The resources I've found are https://developer.apple.com/videos/play/wwdc2022-110351/?time=1445 and https://forums.swift.org/t/swift-async-func-to-run-sequentially/60939/2 but do not think I have fully put the pieces together, so would appreciate any help!
2
0
298
Mar ’25