I was able to duplicate your problem. This is what fixed it for me. Add QuartzCore.framework to your project and this line to your .m file. #import <QuartzCore/QuartzCore.h>
You’re right. As the official documentation explains: __autoreleasing to denote arguments that are passed by reference (id *) and are autoreleased on return. All of this is very well explained in the ARC transition guide. In your NSError example, the declaration means __strong, implicitly: NSError * e = nil; Will be transformed to: NSError * … Read more
Short answer: no, you do not have to nil out properties in dealloc under ARC. Long answer: You should never nil out properties in dealloc, even in manual memory management. In MRR, you should release your ivars. Nilling out properties means calling setters, which may invoke code that it shouldn’t touch in dealloc (e.g. if … Read more
If I decide to upgrade to iOS 5, do I need to remove all [myObject retain] and [myObject release] statements from my code? Yes, but XCode 4.2 includes a new “Migrate to Objective-C ARC” tool (in the Edit->Refactor menu), which does that for you. Calling dealloc is a different story. As mentioned in the comments … Read more
Replying to myself: My understanding of the documentation says that using keyword block and setting the variable to nil after using it inside the block should be ok, but it still shows the warning. __block ASIHTTPRequest *request = [[ASIHTTPRequest alloc] initWithURL:… [request setCompletionBlock:^{ NSDictionary *jsonDictionary = [[CJSONDeserializer deserializer] deserialize:request.responseData error:nil]; request = nil; // …. … Read more
I agree that the description is confusing. Since I just grasped them, I’ll try to summarize: (__bridge_transfer <NSType>) op or alternatively CFBridgingRelease(op) is used to consume a retain-count of a CFTypeRef while transferring it over to ARC. This could also be represented by id someObj = (__bridge <NSType>) op; CFRelease(op); (__bridge_retained <CFType>) op or alternatively … Read more
In exactly the same way that you (should) have been doing it already: + (instancetype)sharedInstance { static MyClass *sharedInstance = nil; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ sharedInstance = [[MyClass alloc] init]; // Do any other initialisation stuff here }); return sharedInstance; }
It is not very intuitive how to disable ARC on MULTIPLE files, for a while I was do it one by one until a figured out how to do that. Select desired files at Target/Build Phases/Compile Sources in Xcode (CMD+click or Shift+click) PRESS ENTER (double click will reset the selection, so it does’t work) Type … Read more
ARC doesn’t get rid of retains, releases and autoreleases, it just adds in the required ones for you. So there are still calls to retain, there are still calls to release, there are still calls to autorelease and there are still auto release pools. One of the other changes they made with the new Clang … Read more
Every new developer who comes to Objective-C has to learn the rigid rules of when to retain, release, and autorelease objects. These rules even specify naming conventions that imply the retain count of objects returned from methods. Memory management in Objective-C becomes second nature once you take these rules to heart and apply them consistently, … Read more