> On 21 May 2015, at 6:50 am, Michael David Crawford <mdcrawf...@gmail.com> > wrote: > > In my own code I started with nothing but ivars, but changed some of > them to properties while neglecting to remove the original ivar. This > leaves me somewhat in the same situation as you.
Nothing wrong with that, AS LONG as you remember to add the @synthesize foo = myOriginalIvar in your implementation. Problem is, it’s not a compile-time error if you forget. It might not even be a runtime error, but it’s very likely a bug anyway, because when you think you’re manipulating < myOriginalIvar >, in fact it’s manipulating a hidden _foo ivar. At its most benign, this is just a minor waste of space for the < myOriginalIvar > storage, but if code (and legacy code is quite likely to do this) is sometimes accessing the ivar directly, and sometimes through the property, you have a very, very definite and insidious bug. Frankly, (and I have said this before more than once) the design of autosynthesizing properties, added as it was later to properties themselves, is a nasty way to shoot yourself in the foot and not even realise it. Caught me out numerous times. You can enable the warning CLANG_WARN_OBJC_MISSING_PROPERTY_SYNTHESIS (“Implicit Synthesized Properties” in build settings) to at least be told when you pulled the trigger. —Graham _______________________________________________ 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
