automatic-ref-counting

My project contains XMPPFramework which contains a file that has to be used with ARC. But my project is Non ARC and cannot be converted due to certain other libraries linked to it. How do I force the compiler to use ARC only on a certain class ? justin It is the inverse problem of this question . The difference is that you would use -fobjc-arc instead of -fno-objc-arc . 来源： https://stackoverflow.com/questions/13392521/how-to-force-xcode-to-use-arc-on-a-specific-file

I am new to iphone development . I am using ARC for my project. As far as I understood using ARC we don't have to release any object manually. But , I have observed in some places , people explicitly set their object to nil in the ViewDidUnload even after using ARC. For example, in .h file I have something like this: @property (unsafe_unretained, nonatomic) IBOutlet MKMapView *mapViewOutlet; @property (unsafe_unretained, nonatomic) IBOutlet UIToolbar *toolBar; @property (strong,nonatomic) NSMutableArray *dataArray; And .m as follows: - (void)viewDidUnload { [self setMapViewOutlet:nil]; [self

I could not find an objective study regarding ARC performance impact in a real life project. The official doc says The compiler efficiently eliminates many extraneous retain/release calls and much effort has been invested in speeding up the Objective-C runtime in general. In particular, the common “return a retain/autoreleased object” pattern is much faster and does not actually put the object into the autorelease pool, when the caller of the method is ARC code. which has been relayed/deformed by tech-fanboys into "ARC is faster". What I know for sure is what I measured. We recently migrated

I thought I understood the usage of self in a block that is copied is a no no . But in an attempt to clean my code i enabled a bunch of warnings in Xcode, one called "Sending messages to weak pointers" so now in all my blocks, every time I use my created weakself reference __weak typeof(self) weakself = self; I get this warning: Weak receiver may be unpredictably set to nil a trivial example: __weak typeof(self) weakself = self; [aClass doSomethingInABlock:^{ [weakself doSomething]; //warning. }]; I have seen answers which define a version of self within the block like so: __weak typeof(self)