On Wed, Aug 18, 2010 at 5:23 PM, Kyle Sluder <kyle.slu...@gmail.com> wrote: > On Wed, Aug 18, 2010 at 2:08 PM, Sherm Pendley <sherm.pend...@gmail.com> > wrote: > >> Indeed, on that very page, at >> <http://developer.apple.com/mac/library/documentation/cocoa/conceptual/MemoryMgmt/Articles/mmAccessorMethods.html#//apple_ref/doc/uid/TP40003539-SW6>, >> it gives this example: > > It gives it as one example of three, the other two not having > performing an immediate retain/autorelease pair.
The second example avoids having a retain/autorelease in the getter, by moving the autorelease to the setter instead; while valid for accessors, it's not really applicable to -stringByReplacing..., since that's not an accessor method. The third example avoids autorelease, but has precisely the same problem that "return self" would have: "Its disadvantage is that the old value may be deallocated immediately (if there are no other owners), which will cause a problem if another object is maintaining a non-owning reference to it. For example: NSString *oldTitle = [anObject title]; [anObject setTitle:@"New Title"]; NSLog(@"Old title was: %@", oldTitle); If anObject was the only object that owned the original title string, then the string will be deallocated after the new title is set. The log statement would then cause a crash as oldTitle is a freed object." sherm-- -- Cocoa programming in Perl: http://camelbones.sourceforge.net _______________________________________________ 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: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
