casting error on xcode when using address book delegate method

Question

I copied this method, line by line from the apple dev library and getting casting errors for the two NSString casts. How can those be resolved? (I am using ARC)

- (BOOL)peoplePickerNavigationController:
        (ABPeoplePickerNavigationController *)peoplePicker
  shouldContinueAfterSelectingPerson:(ABRecordRef)person {

NSString* name = (NSString *)ABRecordCopyValue(person,
                                         kABPersonFirstNameProperty);
self.firstName.text = name;

name = (NSString *)ABRecordCopyValue(person, kABPersonLastNameProperty);
self.lastName.text = name;

[self dismissModalViewControllerAnimated:YES];

return NO;
}

Thank you for your help!

Answer 1

It sounds like you are using ARC.

ARC forbids standard casts between pointers to Objective-C objects and pointers of other types, including pointers to CoreFoundation objects.

The following code, which is correct under manual memory management, does not compile with ARC:

NSString* name = (NSString *)ABRecordCopyValue(person,
                             kABPersonFirstNameProperty);

To make it compile with ARC, you need to annotate the cast. See bridged casts.

NSString* name = (__bridge_transfer NSString *)ABRecordCopyValue(person,
                                               kABPersonFirstNameProperty);

The __bridge_transfer annotation moves the value into ARC and transfers ownership, i.e., it tells ARC that this object is already retained, and that ARC doesn't need to retain it again.