1#import "objc-ivar-offsets.h" 2 3@implementation BaseClass 4@synthesize backed_int = _backed_int; 5#if __OBJC2__ 6@synthesize unbacked_int; 7#else 8@synthesize unbacked_int = _unbacked_int; 9#endif 10@end 11 12@implementation DerivedClass 13@synthesize derived_backed_int = _derived_backed_int; 14#if __OBJC2__ 15@synthesize derived_unbacked_int; 16#else 17@synthesize derived_unbacked_int = _derived_unbacked_int; 18#endif 19@end 20