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If your question is about the SwiftUI framework, start in UI Frameworks > SwiftUI.
If your question is specific to the Swift Playground app, ask over in Developer Tools & Services > Swift Playground
If you’re interested in the Swift open source effort — that includes the evolution of the language, the open source tools and libraries, and Swift on non-Apple platforms — check out Swift Forums
If your question is about the Swift language, that’s on topic for Programming Languages > Swift, but you might have more luck asking it in Swift Forums > Using Swift.
General:
Forums topic: Programming Languages
Swift:
Forums subtopic: Programming Languages > Swift
Forums tags: Swift
Developer > Swift website
Swift Programming Language website
The Swift Programming Language documentation
Swift Forums website, and specifically Swift Forums > Using Swift
Swift Package Index website
Concurrency Resources, which covers Swift concurrency
How to think properly about binding memory Swift Forums thread
Other:
Forums subtopic: Programming Languages > Generic
Forums tags: Objective-C
Programming with Objective-C archived documentation
Objective-C Runtime documentation
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var testTwo: Double = 0
testDouble = 80
testTwo = 200
var testThree: Int = 0
testThree = Int(testTwo/testDouble)
var testDate: Date = .now
var dateComponent = DateComponents()
dateComponent.day = testThree
var newDate: Date = Calendar.current.date(byAdding: dateComponentwith a thread error , to: testDate)!
This code works in a playground. However, when I try to use it in Xcode for my app it fails with the following error:
Thread 1: Fatal error: Double value cannot be converted to Int because it is either infinite or NaN
I printed the value being converted to Int and it was not NAN or infinite.
Hi There,
I have been using my Mac Studio to complete some work in Python (which I normally do in Linux) and recently I got this error which has completely stopped all development as venvs will no longer work correctly:
WARNING: Ignoring invalid distribution ... (and then whichever apps are currently installed in the venv
This occurs for me on every install of any version of Python installed using any of the standard methods (installer). I've tried all the main points of advice on knowledgeable forums, but the difference between Python on Sequoia and Python on Linux is enough such that I am at an end of my debugging knowledge. I've even attempted to blast away any System Python changes with a recovery reinstall, but the problem persists. I've done almost exactly the same setup on my MacBook Air and it is fine ... but the Studio is now unavailable for Python development.
I know I have probably dropped the ball somewhere but can't see the error myself so, I'm wondering if I should just blast away everything on the machine and go through the process of doing a clean install. Asking the experts in MacOS here so I can avoid the pain of doing that!
Topic:
Programming Languages
SubTopic:
General
I have implemented the Game Center for authentication and saving player's game data. Both authentication and saving player's data works correctly all the time, but there is a problem with fetching and loading the data.
The game works like this:
At the startup, I start the authentication
After the player successfully logs in, I start loading the player's data by calling fetchSavedGames method
If a game data exists for the player, I receive a list of SavedGame object containing the player's data
The problem is that after I uninstall the game and install it again, sometimes the SavedGame list is empty(step 3). But if I don't uninstall the game and reopen the game, this process works fine.
Here's the complete code of Game Center implementation:
class GameCenterHandler {
public func signIn() {
GKLocalPlayer.local.authenticateHandler = { viewController, error in
if let viewController = viewController {
viewController.present(viewController, animated: false)
return
}
if error != nil {
// Player could not be authenticated.
// Disable Game Center in the game.
return
}
// Auth successfull
self.load(filename: "TestFileName")
}
}
public func save(filename: String, data: String) {
if GKLocalPlayer.local.isAuthenticated {
GKLocalPlayer.local.saveGameData(Data(data.utf8), withName: filename) { savedGame, error in
if savedGame != nil {
// Data saved successfully
}
if error != nil {
// Error in saving game data!
}
}
} else {
// Error in saving game data! User is not authenticated"
}
}
public func load(filename: String) {
if GKLocalPlayer.local.isAuthenticated {
GKLocalPlayer.local.fetchSavedGames { games, error in
if let game = games?.first(where: {$0.name == filename}){
game.loadData { data, error in
if data != nil {
// Data loaded successfully
}
if error != nil {
// Error in loading game data!
}
}
} else {
// Error in loading game data! Filename not found
}
}
} else {
// Error in loading game data! User is not authenticated
}
}
}
I have also added Game Center and iCloud capabilities in xcode. Also in the iCloud section, I selected the iCloud Documents and added a container.
I found a simillar question here but it doesn't make things clearer.
Hello!
Can you tell me why UIImageWriteToSavedPhotosAlbum stopped working on Mac Catalyst?
This method used to save photos to the library. Now I get an error when trying to save with the same code that previously worked.
error NSError domain: "ALAssetsLibraryErrorDomain" - code: -1 0x0000000cb00b4810
Hello,
After upgrading to macOS 26.2, I’ve noticed a significant performance regression when calling evaluateJavaScript in an iOS App running on Mac (WKWebView, Swift project).
Observed behavior
On macOS 26.2, the callback of evaluateJavaScript takes around 3 seconds to return.
This happens not only for:
evaluateJavaScript("navigator.userAgent")
but also for simple or even empty scripts, for example:
evaluateJavaScript("")
On previous macOS versions, the same calls typically returned in ~200 ms.
Additional testing
I created a new, empty Objective-C project with a WKWebView and tested the same evaluateJavaScript calls.
In the Objective-C project, the callback still returns in ~200 ms, even on macOS 26.2.
Question
Is this a known issue or regression related to:
iOS Apps on Mac,
Swift + WKWebView, or
behavioral changes in evaluateJavaScript on macOS 26.2?
Any information about known issues, internal changes, or recommended workarounds would be greatly appreciated.
Thank you.
Test Code Swift
class ViewController: UIViewController {
private var tmpWebView: WKWebView?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
setupUserAgent()
}
func setupUserAgent() {
let t1 = CACurrentMediaTime()
tmpWebView = WKWebView(frame: .zero)
tmpWebView?.isInspectable = true
tmpWebView?.evaluateJavaScript("navigator.userAgent") { [weak self] result, error in
let t2 = CACurrentMediaTime()
print("[getUserAgent] \(t2 - t1)s")
self?.tmpWebView = nil
}
}
}
Test Code Objective-C
- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions {
NSTimeInterval startTime = [[NSDate date] timeIntervalSince1970];
WKWebView *webView = [[WKWebView alloc] init];
dispatch_async(dispatch_get_main_queue(), ^{
[webView evaluateJavaScript:@"navigator.userAgent" completionHandler:^(id result, NSError *error) {
NSTimeInterval endTime = [[NSDate date] timeIntervalSince1970];
NSLog(@"[getUserAgent]: %.2f s", (endTime - startTime));
}];
});
}
So I’m writing a program, as a developer would - ‘with Xcode.’
Code produced an error.
The key values were swapped. The parameters suggested were ‘optional parameters variables.’
“var name: TYPE? = (default)”
var name0: TYPE
=============================
name0 = “super cool”
‘Name is not yet declared at this point
provided with
x - incorrect argument replace
ExampleStruct(name:”supercool”)
should be
x - incorrect argument replace
ExampleStruct(name0:”supercool”)
=============================
In swift, there is a procedural prioritization within the constructor calling process.
Application calls constructor.
Constructor provides constructor signature. Signature requires parameters & throws an error if the params are not in appropriate order. - “got it compiler; thank you, very much”
Typically, when this occurs, defaults will be suggested. Often the variable type. Ie String, Bool.
such as:
StructName(param1:Int64, param2:Bool)
(Recently, I have seen a decline in @Apple’s performance in many vectors.)
As stated before, the key value pairs were out of sequence. The optionals were suggested instead of the required parameters.
This leads me to believe that there is an order of operations in the calling procedure that is being mismanaged.
I.e. regular expression, matching with optional. This confuses these with [forced, required] parameters, and the mismanagement of ‘key: value’ pairs.
this is a superficial prognosis and would like to know if anyone has any insight as to why this may occur.
Could it be a configuration setting? Is it possibly the network I connected to bumped into something. Etc..
I appreciate any and all feedback.
Please take into consideration the Apple developer forum, guidelines before posting comments.
#dev_div
When I try to invoke the tkinter module in Python 3 that is bundled with Xcode Developer Tools, I get a message saying that my system version is too low:
$ /usr/bin/python3 -m tkinter
macOS 26 (2602) or later required, have instead 16 (1602) !
zsh: abort /usr/bin/python3 -m tkinter
It seems like the system version reported is macOS 16, which I assume is the version code before the decision to rename all OS platforms to 26. This is a very low level mistake and should be fixed as soon as possible.
Topic:
Programming Languages
SubTopic:
General
Can I use Xcode to create a playbook for soccer to design exercises and then show the exercise to the players later at practice or a game?
I need to integrate the roster with game plans and designed exercises with practice.
Hi all,
I'm working on a Call Directory Extension using CXCallDirectoryExtensionContext. I want to add a list of numbers to be blocked. Here's the function I use:
override func beginRequest(with context: CXCallDirectoryExtensionContext) {
context.delegate = self
let blockedNumbers = loadNumberEntries(forKey: blockedKey)
let identifiedNumbers = loadNumberEntries(forKey: identifiedKey)
addAllBlocking(blockedNumbers, to: context)
addAllIdentification(identifiedNumbers, to: context)
context.completeRequest()
}
private func addAllBlocking(_ entries: [NumberEntry], to context: CXCallDirectoryExtensionContext) {
let numbers: [Int64] = entries.compactMap {
Int64($0.countryCode + $0.phone)
}.sorted()
for number in numbers {
context.addBlockingEntry(withNextSequentialPhoneNumber: number)
print("# Added blocking entry: \(number)")
}
}
When I run this, I see in the console:
# Added blocking entry: (*my number with country code*)
So it seems the number is added correctly. However, in practice, the number is not blocked on the device.
I’ve made sure that:
The number is stored with the country code prefix.
The extension is enabled in Settings → Phone → Call Blocking & Identification.
The extension is reloaded after adding numbers.
The array of numbers is sorted in ascending order before calling addBlockingEntry.
Despite all this, the number still isn’t blocked.
Does anyone know why the print shows the number added, but it doesn’t actually block the call? Am I missing something in the way CXCallDirectoryExtensionContext works?
Thanks for any advice!
Consider this Swift struct:
public struct Example
{
public func foo(callback: ()->Void)
{
....
}
public func blah(i: Int)
{
....
}
....
}
Using Swift/C++ interop, I can create Example objects and call methods like blah. But I can't call foo because Swift/C++ interop doesn't currently support passing closures (right?).
On the other hand, Swift/objC does support passing objC blocks to Swift functions. But I can't use that here because Example is a Swift struct, not a class. So I could change it to a class, and update everything to work with reference rather than value semantics; but then I also have to change the objC++ code to create the object and call its methods using objC syntax. I'd like to avoid that.
Is there some hack that I can use to make this possible? I'm hoping that I can wrap a C++ std::function in some sort of opaque wrapper and pass that to swift, or something.
Thanks for any suggestions!
I'm dealing with a strange bug where I am requesting read access for 'appleExerciseTime' and 'activitySummaryType', and despite enabling both in the permission sheet, they are being set to 'sharingDenied'.
I'm writing a Swift Test for making sure permissions are being granted.
@Test
func PermissionsGranted() {
try await self.manager.getPermissions()
for type in await manager.allHealthTypes {
let status = await manager.healthStore.authorizationStatus(for: type)
#expect(status == .sharingAuthorized, "\(type) authorization status is \(status)")
}
}
let healthTypesToShare: Set<HKSampleType> = [
HKQuantityType(.bodyMass),
HKQuantityType(.bodyFatPercentage),
HKQuantityType(.leanBodyMass),
HKQuantityType(.activeEnergyBurned),
HKQuantityType(.basalEnergyBurned),
HKObjectType.workoutType()
]
let allHealthTypes: Set<HKObjectType> = [
HKQuantityType(.bodyMass),
HKQuantityType(.bodyFatPercentage),
HKQuantityType(.leanBodyMass),
HKQuantityType(.activeEnergyBurned),
HKQuantityType(.basalEnergyBurned),
HKQuantityType(.appleExerciseTime),
HKObjectType.activitySummaryType()
]
let healthStore = HKHealthStore()
func getPermissions() async throws {
try await healthStore.requestAuthorization(toShare: self.healthTypesToShare, read: self.allHealthTypes)
}
After 'getPermissions' runs, the permission sheet shows up on the Simulator, and I accept all. I've double checked that the failing permissions show up on the sheet and are enabled. Then the test fails with:
Expectation failed: (status → HKAuthorizationStatus(rawValue: 1)) == (.sharingAuthorized → HKAuthorizationStatus(rawValue: 2)) HKActivitySummaryTypeIdentifier authorization status is HKAuthorizationStatus(rawValue: 1)
Expectation failed: (status → HKAuthorizationStatus(rawValue: 1)) == (.sharingAuthorized → HKAuthorizationStatus(rawValue: 2)) HKActivitySummaryTypeIdentifier authorization status is HKAuthorizationStatus(rawValue: 1)
With the rawValue of '1' being 'sharingDenied'. All other permissions are granted. Is there a workaround here, or something I'm potentially doing wrong?
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!!!
I want to build a Swift library package that uses modified build of OpenSSL and Curl.
I have already statically compiled both and verified I can use them in an Objective-C framework on my target platform (iOS & iOS Simulator). I'm using XCFramework files that contain the static library binaries and headers:
openssl.xcframework/
ios-arm64/
openssl.framework/
Headers/
[...]
openssl
ios-arm64_x86_64-simulator/
openssl.framework/
Headers/
[...]
openssl
Info.plist
I'm not sure how I'm supposed to set up my Swift package to import these libraries.
I can use .systemLibrary but that seems to use the embedded copies of libssl and libcurl on my system, and I can't figure out how to use the path: parameter to that.
I also tried using a .binaryTarget pointing to the XCFramework files, but that didn't seem to work as there is no module generated and I'm not sure how to make one myself.
At a basic high level, this is what I'm trying to accomplish:
where libcrypto & libssl come from the provided openssl.xcframework file, and libcurl from curl.xcframework
Hey everyone,
I’m learning async/await and trying to fetch an image from a URL off the main thread to avoid overloading it, while updating the UI afterward. Before starting the fetch, I want to show a loading indicator (UI-related work). I’ve implemented this in two different ways using Task and Task.detached, and I have some doubts:
Is using Task { @MainActor the better approach?
I added @MainActor because, after await, the resumed execution might not return to the Task's original actor. Is this the right way to ensure UI updates are done safely?
Does calling fetchImage() on @MainActor force it to run entirely on the main thread?
I used an async data fetch function (not explicitly marked with any actor). If I were to use a completion handler instead, would the function run on the main thread?
Is using Task.detached overkill here?
I tried Task.detached to ensure the fetch runs on a non-main actor. However, it seems to involve unnecessary actor hopping since I still need to hop back to the main actor for UI updates. Is there any scenario where Task.detached would be a better fit?
class ViewController : UIViewController{
override func viewDidLoad() {
super.viewDidLoad()
//MARK: First approch
Task{@MainActor in
showLoading()
let image = try? await fetchImage() //Will the image fetch happen on main thread?
updateImageView(image:image)
hideLoading()
}
//MARK: 2nd approch
Task{@MainActor in
showLoading()
let detachedTask = Task.detached{
try await self.fetchImage()
}
updateImageView(image:try? await detachedTask.value)
hideLoading()
}
}
func fetchImage() async throws -> UIImage {
let url = URL(string: "https://via.placeholder.com/600x400.png?text=Example+Image")!
//Async data function call
let (data, response) = try await URLSession.shared.data(from: url)
guard let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode == 200 else {
throw URLError(.badServerResponse)
}
guard let image = UIImage(data: data) else {
throw URLError(.cannotDecodeContentData)
}
return image
}
func showLoading(){
//Show Loader handling
}
func hideLoading(){
//Hides the loader
}
func updateImageView(image:UIImage?){
//Image view updated
}
}
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..<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: &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..<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: &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?
Context: SwiftUI TextField with a String for simple math using NSExpression.
I first prepare the input string to an extent but a malformed input using valid characters still fails, as expected. Let's say preparedExpression is "5--"
let expr = NSExpression(format: preparedExpression)
gives
FAULT: NSInvalidArgumentException: Unable to parse the format string "5-- == 1"; (user info absent)
How can I use NSExpression such that either the preparedExpression is pre-tested before asking for actual execution or the error is handled in a polite way that I can use to alert the user to try again.
Is there a Swift alternative to NSExpression that I've missed?
I have a class object created dynamically using Runtime, and I want to release some manually allocated memory resources when this object is deallocated. To achieve this, I added a custom implementation of the dealloc method using the following code:
SEL aSel = NSSelectorFromString(@"dealloc");
class_addMethod(kvoClass, aSel, (IMP)custom_dealloc, method_getTypeEncoding(class_getInstanceMethod(kvoClass, aSel)));
However, I encountered some issues. If I don't call the superclass's dealloc method in the cus_dealloc function, the superclass's dealloc implementation will not be executed. On the other hand, if I explicitly call the superclass's dealloc method, the program crashes.
Here is the implementation of the cus_dealloc function:
void custom_dealloc(id self, SEL _cmd) {
// Release other memory

Class superClass = class_getSuperclass(object_getClass(self));
void (*originIMP)(struct objc_super *, SEL, ...) = (void *)objc_msgSendSuper;
struct objc_super *objcSuper = &(struct objc_super){self, superClass};
originIMP(objcSuper, _cmd);
}
demo
Hello, I am a software engineer student and I have recently been getting problems on my Mac regarding the C/C++ libraries. I have used my macbook for uni work for months, but around 3 or 4 months ago my macbook could not compile my work since it couldnt find the basic libraries I was using. For example, iostream. I have been using VSCode, and what it exactly says is "cannot open source file "iostream". Please run the 'Select IntelliSense Configuration...' command to locate your system headers." I have tried researching, changing the include path, even using chatgpt, and nothing. Is anyone having this same problem, or is able to help me? If any other information is needed, please let me know!
Topic:
Programming Languages
SubTopic:
General
I’m working on a project in Xcode 16.2 and encountered an issue where getAPI() with a default implementation in a protocol extension doesn’t show up in autocomplete. Here’s a simplified version of the code:
import Foundation
public protocol Repository {
func getAPI(from url: String?)
}
extension Repository {
public func getAPI(from url: String? = "https://...") {
getAPI(from: url)
}
}
final class _Repository: Repository {
func getAPI(from url: String?) {
// Task...
}
}
let repo: Repository = _Repository()
repo.getAPI( // Autocomplete doesn't suggest getAPI()
I’ve tried the following without success:
• Clean build folder
• Restart Xcode
• Reindexing
Is there something wrong with the code, or is this a known issue with Xcode 16.2? I’d appreciate any insights or suggestions.