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)
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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.
We have FrameworkA which needs to use another FrameworkB internally to fetch a token.
Now when I try to use this FrameworkA, we are seeing an issue with internal framework i.e. No such module 'FrameworkB'.
But when I use @_implementationOnly import for the internal FrameworkB, I didn't see any issues.
So just wanted to check If I can go ahead and use this @_implementationOnly import flag in Production?
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.
Crash Log
We have a issue with our watch app. When we do a release build with xcode 16 the watch app will not launch and crashes on watchOS 10 and below devices.
It does not do this on debug builds...and it does not do this on xcode 15 release/debug builds.
Anybody running into watch crashes on xcode 16?
Thanks
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 ?
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?
Hello together,
since Xcode Version > 15 the following error handling causes following error "Pattern of type 'DecodingError' cannot match 'Never'
func getSupportedCountries() async {
// fetch all documents from collection "seasons" from firestore
let queryCountries = try? await db.collection("countries").getDocuments()
if queryCountries != nil {
self.countries = (queryCountries!.documents.compactMap({ (queryDocumentSnapshot) -> Country? in
let result = Result { try? queryDocumentSnapshot.data(as: Country.self) }
switch result {
case .success(let country):
if let country = country {
// A country value was successfully initialized from the DocumentSnapshot
self.errorMessage = nil
return country
}
else {
// A nil value was successfully initialized from the DocumentSnapshot,
// or the DocumentSnapshot was nil
self.errorMessage = "Document doesn't exist."
return nil
}
case .failure(let error):
// A Country value could not be initialized from the DocumentSnapshot
switch error {
case DecodingError.typeMismatch(_, let context):
self.errorMessage = "\(error.localizedDescription): \(context.debugDescription)"
case DecodingError.valueNotFound(_, let context):
self.errorMessage = "\(error.localizedDescription): \(context.debugDescription)"
case DecodingError.keyNotFound(_, let context):
self.errorMessage = "\(error.localizedDescription): \(context.debugDescription)"
case DecodingError.dataCorrupted(let key):
self.errorMessage = "\(error.localizedDescription): \(key)"
default:
self.errorMessage = "Error decoding document: \(error.localizedDescription)"
}
return nil
}
}))
} else {
self.errorMessage = "No documents in 'countries' collection"
return
}
}
the interesting part of the code where XCODE shows an error is from "switch error" downwards.
Does anyone of you have an idea what's wrong?
Ay help appreciated !
Thx, Peter
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?
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.
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 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..
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.
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?
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
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?
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
Hello,
This test code for creating an array using a loop works:
var quotes: [(id: String, name: String)] {
var output: [(id: String, name: String)] = []
for i in 1...numberOfRows {
let item: (id: String, name: String) = ("\(i)", "Name \(i)")
output.append(item)
}
return output
}
But if I try to apply this logic to retrieving data from a web service using the below code I am getting 2 errors:
For the line “quotes.append(item)” I am getting the error message “Cannot use mutating member on immutable value: ‘quotes’ is a get-only property."
For the line “return output” I am getting the error message “Cannot find ‘output’ in scope."
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
var item: (id: String, name: String) = ("test id value", "test name value")
quotes.append(item)
}
return output
}
}
}
}
Topic:
Programming Languages
SubTopic:
Swift
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 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.
Topic:
Programming Languages
SubTopic:
Swift