On Aug 13, 2012, at 2:12 PM, Uli Kusterer <witness.of.teacht...@gmx.net> wrote: > On 09.08.2012, at 01:21, Graham Cox <graham....@bigpond.com> wrote: >> If a superclass implements copies using NSCopyObject, then any pointer ivars >> we add in a subclass need to be additionally -retained. But if the >> superclass implements copy by alloc/initing a new object and setting >> properties, then this extra step would lead to an over-retain and so leak. > > Not really. It *must* correctly do the additional retains for the ivars it > created, but yours are just copied as integers to the new object. So you > could simply rely on that if you know your base class uses NSCopyObject(). > Alternately (and more safely) you can just ignore the value in there (as you > know it either hasn't been retained, or is NIL altogether)
You don't know that. If the superclass called alloc/init, and your subclass init sets that ivar to a retained value, then the copy's ivar is retained and not nil. -- Greg Parker gpar...@apple.com Runtime Wrangler _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
