I have a Settings class that conform to the TestProtocol. From the function of the protocol I need to call the setString function and this function needs to be on the MainActor. Is there a way of make this work in Swift6, without making the protocol functions running on @MainActor
The calls are as follows:
class Settings: TestProtocol{
var value:String = ""
@MainActor func setString( _ string:String ){
value = string
}
func passString(string: String) {
Task{
await setString(string)
}
}
}
protocol TestProtocol{
func passString( string:String )
}
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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!
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.
Hello,
While watching WWDC25: Code-along: Elevate an app with Swift concurrency at timestamp 25:48, I noticed something in the slide/diagram that might be incorrect.
The diagram shows ExtractSticker twice, but based on the code context and spoken explanation, I think it was meant to be ExtractSticker and ExtractColor.
Reasoning:
The surrounding code and narration describe the use of async let and a Sendable Data object.
From the flow, one task extracts a sticker while the other extracts a color, so it seems like the diagram is inconsistent.
I do understand that with @concurrent, having two ExtractSticker operations on the same Data is technically possible (with two concurrent process executing their respective ExtractSticker) — but that would be a different meaning than what the talk was describing.
Since concurrency is already a subtle and error-prone topic, I thought it was worth pointing this out. If I’m mistaken, I’d love clarification. Otherwise, this could be a small correction to keep things aligned and clearer for everyone.
Minor point overall, but Swift 6’s concurrency model is doing a fantastic job at helping us write safer code—so thank you to the team for that!
(Attaching screenshots for reference)
I’m creating an app using SwiftUI, and I would like to incorporate a small Java codebase that I created for the Android version of the app. Is there a way to package the Java code to work on iOS and macOS
Topic:
Programming Languages
SubTopic:
General
Hi the below array and code to output a list item works fine:
var quotes = [
[
"quote": "I live you the more ...",
"order": "1"
],
[
"quote": "There is nothing permanent ...",
"order": "2"
],
[
"quote": "You cannot shake hands ...",
"order": "3"
],
[
"quote": "Lord, make me an instrument...",
"order": "4"
]
]
cell.textLabel?.text = quotes[indexPath.row]["quote"]
However if I change the "order" values to be numbers rather than text like below then for the above line I get an error message in Xcode "No exact matches in call to subscript". Please could someone tell me how to make it work with the numbers stored as numbers? (I'm wondering if creating an any array type and using the .text function has caused a conflict but I can't find how to resolve)
[
"quote": "I live you the more ...",
"order": 1
],
[
"quote": "There is nothing permanent ...",
"order": 2
],
[
"quote": "You cannot shake hands ...",
"order": 3
],
[
"quote": "Lord, make me an instrument...",
"order": 4
]
]
Thank you for any pointers :-)
i am trying to build my code and have ran into this error.
"Trailing closure passed to parameter of type 'DispatchWorkItem' that does not accept a closure"
i have been trying to figure it out for so long, and even ai cant figure it out. is this a bug, or am i missing some obvious way to fix this ?
func loadUser(uid: String, completion: (() -> Void)? = nil) {
db.collection("users").document(uid).getDocument { [weak self] snapshot, error in
guard let data = snapshot?.data(), error == nil else { completion?(); return }
DispatchQueue.main.async {
self?.currentUser = User(
username: data["username"] as? String ?? "Learner",
email: data["email"] as? String ?? "",
profileImageName: "person.circle.fill",
totalXP: data["totalXP"] as? Int ?? 0,
currentStreak: data["currentStreak"] as? Int ?? 0,
longestStreak: data["longestStreak"] as? Int ?? 0,
level: data["level"] as? Int ?? 1,
levelProgress: data["levelProgress"] as? Double ?? 0.0,
xpToNextLevel: data["xpToNextLevel"] as? Int ?? 100,
completedLessons: data["completedLessons"] as? [String] ?? []
)
self?.saveUser()
completion?()
}
}
}
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
Hey everyone,
I have a problem with an app im creating. The code doesn't have any errors but the console has this that pops up:
Snapshot request 0x1054191d0 complete with error: <NSError: 0x10541a970; domain: FBSSceneSnapshotErrorDomain; code: 4; "an unrelated condition or state was not satisfied"> {
NSLocalizedDescription = an error occurred during a scene snapshotting operation;
}
For my app I've created a Dictionary that I want to persist using AppStorage
In order to be able to do this, I added RawRepresentable conformance for my specific type of Dictionary. (see code below)
typealias ScriptPickers = [Language: Bool]
extension ScriptPickers: @retroactive RawRepresentable where Key == Language, Value == Bool {
public init?(rawValue: String) {
guard let data = rawValue.data(using: .utf8),
let result = try? JSONDecoder().decode(ScriptPickers.self, from: data)
else {
return nil
}
self = result
}
public var rawValue: String {
guard let data = try? JSONEncoder().encode(self), // data is Data type
let result = String(data: data, encoding: .utf8) // coerce NSData to String
else {
return "{}" // empty Dictionary represented as String
}
return result
}
}
public enum Language: String, Codable, {
case en = "en"
case fr = "fr"
case ja = "ja"
case ko = "ko"
case hr = "hr"
case de = "de"
}
This all works fine in my app, however trying to run any tests, the build fails with the following:
Conflicting conformance of 'Dictionary<Key, Value>' to protocol 'RawRepresentable'; there cannot be more than one conformance, even with different conditional bounds
But then when I comment out my RawRepresentable implementation, I get the following error when attempting to run tests:
Value of type 'ScriptPickers' (aka 'Dictionary<Language, Bool>') has no member 'rawValue'
I hope Joseph Heller is out there somewhere chuckling at my predicament
any/all ideas greatly appreciated
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.
I have my project running perfectly fine on Xcode 16. However, in Xcode 26 it doesn't build due to an error that I do not understand. I have three files that pertain to this error:
// FriendListResponse.swift
import Foundation
struct FriendListResponse: Decodable {
var friendships: [Friendship]
var collections: [FriendCollection]
}
// Friendship.swift
import Foundation
struct Friendship: Decodable {
var createdAt: String
var friendId: Int
var friendUserId: Int // user ID of the friend
var friendUsername: String
var id: Int
var tagNames: [String]
}
// FriendCollection.swift
struct FriendCollection: Decodable {
var id: Int
var permalink: String
var tagNames: [String]
var title: String
}
On the first file, FriendListResponse.swift, I am the simple error message "circular reference." I do not understand how these self-contained structs could create a circular reference. Although I have other data types in my project, none of them are even referenced in these files except for Friendship and FriendCollection.
The FriendListResponse is a struct that is created from JSON values that are fetched from an API. This is the function that fetches the JSON:
public static func listFriends(username: String) async throws -> [Friendship] {
let data = try await sendGETRequest(
url: "people/\(username)/friends/list.json"
)
print(String(data: data, encoding: .utf8)!)
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
let wrapper = try decoder.decode(FriendListResponse.self, from: data)
return wrapper.friendships
}
// Note: the function sendGETRequest is just
// a function that I have created that takes a set
// of parameters and returns a data object
// using the HTTP GET protocol. I don't think
// that it is related to this issue. However, if you
// think that it is, I can share the code for that.
This error has also happened in a few other cases within contained networks of my data structure.
I do not know why this error is only appearing once I launch Xcode 26 beta with my project files. I would think that this error also would appear in Xcode 16.4.
Any help would be greatly appreciated in my process to compile my project on Xcode 26!
After ther Mac application is launched:
Log error: CGSWindowShmemCreateWithPort failed on port 0
and when the application quit:
No error handler for XPC error: Connection invalid
Appear with Xcode 15.4 but not with 12.4
As repported by Steve4442 in "Can someone explain this message" https://Forums.Developer.Apple.com/Forums/Thread/727803
.
The code don't use "windowNumbersWithOptions"
Can I ignore this log message ?
NSPredicate(format: "SELF MATCHES %@", "^[0-9A-Z]+$").evaluate(with: "126𝒥ℰℬℬ𝒢𝒦𝒮33")
Returns true, and I don't know why. 𝒥ℰℬℬ𝒢𝒦𝒮 is not between 0-9 and A-Z, and why it returns true? How to avoid similar problem like this when using NSPredicate?
PLATFORM AND VERSION
iOS
Development environment: Xcode 26, macOS 26
Run-time configuration: iOS 18 and up
DESCRIPTION OF PROBLEM
I am on the beta version of os 26 for both Xcode and macOS. When I try to run my project, which has the Swift OpenAPI Generator from apple, it gives the error "unsupported configuration: the aggregate target 'OpenAPIGenerator' has package dependencies, but targets that build for different platforms depend on it"
STEPS TO REPRODUCE
Install macOS 26 and Xcode 26 and try running an iOS app built for iOS 18.0 and up wit the OpenAPIGenerator package on a physical iPhone running iOS 26
Topic:
Programming Languages
SubTopic:
Swift
Hello,
Please can you tell me how to create an array of dictionaries? This code below should create 4 dictionaries in an array, but I'm getting these errors:
For line "var output = [id: "testID", name: "testName"]":
cannot find 'name' in scope
Type '(any AnyObject).Type'
cannot conform to 'Hashable'
For line "return output":
Type '(any AnyObject).Type' cannot conform to 'Hashable'
var quotes: [(id: String, name: String)] {
var output = [[(id: String, name: String)]] ()
for i in 1...4 {
var output = [id: "testID", name: "testName"]
}
return output
}
Topic:
Programming Languages
SubTopic:
Swift
Hi, I would like to modify an associated value of an existing enum instance of the the following enum:
enum FilterItem: Equatable, Hashable {
case work(isSelected: Bool)
...
var filterName: String {
switch self {
case .work: return "Work"
...
}
}
var isSelected: Bool {
switch self {
case .work(let isSelected): return isSelected
...
}
}
I want to be able to switch on the FilterItem type and then to be able to modify the isSelected property of the instance like:
let itemToChange: FilterItem
switch item {
case .work(let isSelected):
itemToChange.isSelected = !isSelected
I know the above code doesn't compile, but I was wondering if there was a way I could modify my enum instance without creating a totally new enum instance.
Topic:
Programming Languages
SubTopic:
Swift
I have a transformation function that takes in data, executes some instructions, and returns an output. This function is dynamic and not shipped with the binary. Currently, I’m executing it using JavaScriptCore.JSContext, which works well, but the function itself is written in JavaScript.
Is there a way to achieve something similar using Swift – such as executing a dynamic Swift script, either directly or through other means? I know this is possible on macOS, but I’m not sure about iOS. I’ve also heard that extensions might open up some possibilities here. Any insights or alternative approaches would be appreciated.
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?
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?
Topic:
Programming Languages
SubTopic:
Swift