ARC forbids Objective-C objects in structs or unions.
Unless you add __unsafe_unretained which means its not managed.
I was wonder what people are using in place of structs now if anything?
Or are you retaining everything manually?
-
please add some example code to your questionart-divin– art-divin2013-05-02 08:10:59 +00:00Commented May 2, 2013 at 8:10
-
possible duplicate of typedef struct vs. Object - BenefitsSulthan– Sulthan2013-05-02 08:12:02 +00:00Commented May 2, 2013 at 8:12
-
The struct vs object question is a abstract discussion about which to use in what scenario. This is a question about what you would use instead of stucts since arc does not allow stucts to contain Objective C objects. Do ppl recommend not use Objective c Objects and still use structs. do ppl just use objects? Or is there some other method i am not aware of.abe– abe2013-05-02 08:19:49 +00:00Commented May 2, 2013 at 8:19
Add a comment
|
4 Answers
It's very simple - if you want to add an object inside a struct, you are doing it wrong. Whenever you need a struct to hold an obj-c object, convert the struct into an obj-c object.
Comments
I would manage different objects in one objc-object like this:
@class MyFirst, MySecond;
@interface MyContainer : NSObject
@property (nonatomic, strong, readonly) MyFirst *firstInst;
@property (nonatomic, strong, readonly) MySecond *secondInst;
// optional: convenience initializer
+ (instancetype)containerWithFirstInst:(MyFirst *)firstInst secondInst:(MySecond *)secondInst;
@end
// required by linker: stub definition for the class declared above
@implementation MyContainer
@end
@interface SomeController : NSObject
- (void)doSomething;
@end
@implementation SomeController
- (void)doSomething {
MyFirst *firstInstance = [[MyFirst alloc] initWithSomeParameters:...];
MySecond *secondInstance = [[MySecond alloc] initWithSomeParameters:...];
MyContainer *container = [MyContainer containerWithFirstInst:firstInstance secondInst:secondInstance];
// use container as a struct (but it's definitely an object that is managed by ARC)
}
@end
9 Comments
abe
so it seems every one is going with an obj-c object
art-divin
you'll get used to it, don't worry :) Since it's a common practice and looks to me "naturally"
abe
its what im using but it feels wasteful some how...i know its not really that much memory for most things...it just urks me
iSofia
@art-divin : Sorry to bump an old thread. I'm currently using your suggested class model in lieu of C-structures. However, if in addition to properties, the class also contains methods, would it mean that every instance of the class, that is passed as a parameter, also contains all those methods as well? If so, is such an operation safe, and are the overheads high? One more question, please (if you ever read this). The instantiated class object is actually being sent as a parameter to a C-style function that resides within that same instantiated class - is that safe? Thank you.
peterflynn
Note: you also need to include an empty
@implementation MyContainer block somewhere in the .m file or else you will get a "symbol(s) not found" linker error. I will edit the answer above to include this. |
Wouldn't it be a lot easier to implement a static class and fake its properties, as shown here?
Comments
I answered to it here https://stackoverflow.com/a/28845377/1570826
maybe somebody with the right level could mark this or the other as a duplicate.
