Question

I have a method that returns an integer and I now also want to return a small struct or class. If I was using C++ I would pass a reference to the struct in as a parameter. In iOS using ARC, I think the equivalent is to use a pointer to a pointer that has the __autoreleasing attribute which I find a bit cumbersome.

I could return an array containing the two values but then think I would be alloc’ing more than necessary and I could be using this a lot (100,000 calls).

Answer 1

Even with ARC, you can just pass in a struct by reference or an object pointer…

Pass the struct by ref just like you would in C++, e.g. &aStruct

-(int)getStuffOut:(SomeStruct *)aStruct {
   if(!aStruct) {
      return 0;
   }
   aStruct->myInt = 12345;
   aStruct->myFloat = 12.345f;
   return 1;
}

Or:

-(int)getStuffOut:(SomeClass *)anObject {
   if(!anObject) {
      return 0;
   }
   anObject.myIntProperty = 12345;
   anObject.myFloatProperty = 12.345f;
   return 1;
}