On Sat, Apr 9, 2011 at 9:52 AM, Philipp Leusmann <m...@byteshift.eu> wrote: > Who can explain this behavior to me? Why is oWidth != object.mWidth ? How can > that happen?
It's an artifact of how Objective-C searches for selector implementations. You're calling @selector(width) on an "id", and of course "id" doesn't implement @selector(width). So what Objective-C does is search for the first implementation of @selector(width) that it finds. My guess is it finds the one in AppKit first (greping the frameworks): NSTableColumn.h:- (CGFloat)width; Then when the compiler sets up the call site it does it expecting a CGFloat return and that is handled differently than an integer. So the call site and the implementation of how your width is done disagree and you get some strange heisenvalue back. When you cast the variable to "Result*", Objective-C now knows to use YOUR implementation of @selector(width) and it sets up the call site properly. _______________________________________________ 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
