Automatic Reference Counting Issue: Passing address of non-local object to __autoreleasing parameter for write-back

问题

I'm trying to pass pointer to pointer to a method, but apparently ARC has some issues with how I'm doing it. Here the two methods:

+ (NSString *)personPropertyNameForIndex:(kSHLPersonDetailsTableRowIndex)index 
{
    static NSArray *propertyNames = nil;

    (nil == propertyNames) ? 
        [self SHL_initPersonPropertyNamesWithArray:&propertyNames] : NULL;
}

+ (void)SHL_initPersonPropertyNamesWithArray:(NSArray **)theArray
{
    *theArray = [[NSArray alloc] 
                 initWithObjects:@"name", @"email", @"birthdate", @"phone", nil];
}

I receive the following error:

Automatic Reference Counting Issue: Passing address of non-local object to __autoreleasing parameter for write-back

On the line which the following command appears:

[self SHL_initPersonPropertyNamesWithArray:&propertyNames] : NULL;

回答1:

The __strong storage qualifier is needed for this case.

+ (void)SHL_initPersonPropertyNamesWithArray:(NSArray * __strong *)theArray

However, this code doesn't follow the Basic Memory Management Rules.

You own any object you create

You create an object using a method whose name begins with “alloc”, “new”, “copy”, or “mutableCopy” (for example, alloc, newObject, or mutableCopy).

For what reason do you want to do this?

来源：https://stackoverflow.com/questions/7415301/automatic-reference-counting-issue-passing-address-of-non-local-object-to-aut