On Jun 11, 2012, at 13:20 , cocoa-dev-requ...@lists.apple.com wrote: > Date: Mon, 11 Jun 2012 12:35:13 +0300 > From: Oleg Krupnov <oleg.krup...@gmail.com> > Message-ID: > <cak83q-b44u6dh5hx7gdjj676_vot_6c-+dngxsabgihpjh3...@mail.gmail.com> > > I'm solving the following problem. I have a huge array of items of the > same class MyItem. All items need to share a certain global "context" > variable. Normally, I would wrap access to this variable in a > class-level (+) method of MyItem, like +[MyItem getContext]. > > Now the problem is that I need multiple arrays of MyItems have > different contexts. The solution could be to add the context pointer > as an ivar to each MyItem instance, but I would not like to waste > memory on that (the arrays are huge).
You could subclass NSArray (tricky because it's a class cluster), adding the context variable as an ivar to that; or make your own class containing that context and the actual array, and implementing all the proper methods. However, what I used in a similar situation is objc_getAssociatedObject() and objc_setAssociatedObject() in objc/runtime.h. Look them up. HTH, -- Rainer Brockerhoff <rai...@brockerhoff.net> Belo Horizonte, Brazil "In the affairs of others even fools are wise In their own business even sages err." Weblog: http://www.brockerhoff.net/blog _______________________________________________ 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
