Correct way to use __ attribute __ ((NSObject)) with ARC?

I'm just using CFNumber as an example, so it can be any type that doesn't have the free Fundation part!

I just write test code like this:

typedef  __attribute__((NSObject)) CFNumberRef MYNumberRef;

int main(int argc, const char * argv[])
{

    @autoreleasepool {
    MYNumberRef ptr = NULL;
    double myDouble = 10.1;
    ptr = CFNumberCreate(kCFAllocatorDefault, kCFNumberDoubleType, &myDouble);
    CFIndex count = CFGetRetainCount(ptr);
    }
    return 0;
}

      

        
        
        
      

    

It's very strange that the counter is 2. But if I use CFNumberRef

, the counter is 1. It seems arc

to ignore the convention CFType

, it's just the retain

return value.

So if I use a property __attribute__((NSObject))

to declare CFType

. This post said you shouldn't have to explicitly nil them out in dealloc.

But if I use like this:

   @property (strong, nonatomic, readwrite) __attribute__((NSObject)) CFNumberRef number;

      

        
        
        
      

    

Then:

   self.number = CFNumberCreate(kCFAllocatorDefault, kCFNumberDoubleType, &myDouble);

      

        
        
        
      

    

No memory leak if I don't release it in the method dealloc

? Maybe I should use it like this:

  CFNumbeRef ref =  CFNumberCreate(kCFAllocatorDefault, kCFNumberDoubleType, &myDouble);
  self.number = ref;
  CFRelease(ref);

      

        
        
        
      

    

Does Apple say something about this?