Someone on Matt's site mentioned the possibility that the synthesized ivar could be implemented indirectly, say as a member of a collection. Since the implementation's opaque, we don't know if that ever can happen.
So, is self->mySynthIvar safe (both lvalue and rvalue), or should we be messaging? And does the compiler ever shortcut something like self.mySynthSimpleIntVar to self->mySynthSimpleIntVar, or does it always use the setter/getter? Thanks ScottB On Oct 11, 2011, at 10:12 , David Duncan wrote: > On Oct 11, 2011, at 9:57 AM, Matt Neuburg wrote: > >> I did everything "right" when I named an ivar "firstResponder" (property, >> synthesized ivar, synthesized accessors) and totally broke my app because >> Apple was apparently already using an undocumented ivar called >> "firstResponder". >> >> http://www.cocoabuilder.com/archive/cocoa/296662-assign-property-behaves-differently-from-simple-instance-variable.html > > The problem wasn't an undocumented ivar, it was an undocumented method. The > @synthesize thus overrode the existing method and broke your project because > parts of UIKit were expecting the default implementation and got your > implementation instead. > > As a rule, we strive to avoid this situation, but unfortunately this does > happen on occasion. > >> Also, note that there are circumstances where a synthesized ivar won't work; >> see, for instance, this note: >> >> http://www.cocoabuilder.com/archive/cocoa/298320-inherited-implicitly-created-member-is-no-member.html > > The gist of this is that synthesized ivars are private, and the public > interface (the @property) doesn't tell you about private implementation > details (the ivar). As such, subclasses can't get at synthesized ivars, > precisely because the @synthesize declaration is hidden from them. > -- > David Duncan > > _______________________________________________ > > 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/scottbayes-dev%40comcast.net > > This email sent to scottbayes-...@comcast.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
