Overriding OBJC_ARC_UNAVAILABLE methods in Swift

Question

Bogdan Shubravyi OP

Created Jun ’15

Replies 1

Boosts 0

Participants 2

I believe I found a small bug in Swift Compiler when used one third party SDK.

Basically I have some obj-c class with overriden zone method. Swift compiler doesn't compile

zone

method as for some reason it assumes that I want to call

zone

method from

NSObject

, which can not be used in ARC environment.

I believe problem exists for all methods marked with OBJC_ARC_UNAVAILABLE flag.

Here is an example:

@interface Test : NSObject
@property (nonatomic, readonly) NSString *zone;
@end

@implementation Test
- (NSString *)zone {
    return @"Test";
}
@end

When I use this class in Swift I get Compiler error.

let test = Test()
test.zone()

Error: 'zone()' is unavailable; not available in automatic reference counting mode

To make it work I added small category with new method.

@interface Test(Extended)
- (NSString *)testZone;
@end

@implemntation Test (Extended)
- (NSString *)testZone {
    return self.zone;
}
@end

Boost

Answer 1

Monicker OP

Jun ’15

I don't think this is a bug.

It looks like you are overriding a propery of a super class for a completely different purpose, which is probably not a great idea, and the compiler has no way of knowing that.

While 'zone' is unavailable in ARC, it *still* exists in the class and is just marked as unavailable to prevent you from accidentally using it.

Until the property is completely removed from NSObject, you should use a different name for the property.

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