Protocols & assign properties in iOS 5

Question

I'm trying to create my own Custom Delegates in iOS 5. In iOS 4, I usually used the 'Assign' property:

@property(nonatomic, assign) id<AnyProtocol> delegate;

Now, when I try to synthesize, I get the following error message:

error: Automatic Reference Counting Issue: Existing ivar 'delegate' for unsafe_unretained property 'delegate' must be __unsafe_unretained

Any ideas ?

Answer 1

This error is because under ARC ivars default to strong

What this error is telling you that you've declared a property with __unsafe_unretained (assign) ownership, but by default ivar have __strong ownership, so they can't be in one. You can

1. Omit the ivar, which will be automatically created

2. Define the ivar to match your (assign) property declaration:

   __unsafe_unretained id <FileListDelegate> delegate;
   

3. Define the property to match the ivar's implicit __strong ownership:

    @property (weak) id <FileListDelegate> delegate;
   

The three options shamelessly copied from user chrispix's answer in this thread..Credit goes there