What retain policy should be used for a block as an object property?

Question

I have the following initializer:

- (id) initWithBlock:(void(^)void) block;

and within the initializer I want to assign the block to a property so that it can be executed at a later time.

typedef void(^block)(void);
@interface myClass()
@property (X, nonatomic)    block theBlock;
@end

What should X be and why? (using ARC)

I have just taken a look to this [question](http://stackoverflow.com/questions/3935574/can-i-use-objective-c-blocks-as-properties). I'm not sure 100% but maybe `copy` is the best approach. — Jonathan Naguin, Apr 25 '12 at 19:29
`copy` and `strong` are definitely *not* equivalent under ARC. — BJ Homer, Apr 25 '12 at 19:30

score 1 · Accepted Answer · answered Apr 25 '12 at 20:43

1

You need to copy a block.

If you want details, please see an article by Mike Ash on the topic. Even if you don't want the details you should read it.

answered Apr 25 '12 at 20:43

Jody Hagins

score 0 · Answer 2 · answered Apr 25 '12 at 19:42

0

You should use copy. A block which has not been copied lives on the stack. Retaining something on the stack would be meaningless.

answered Apr 25 '12 at 19:42

Heiberg

2 Answers2