#import "Bar.h" @interface InternalClass : NSObject { @public NSString *foo; NSString *bar; } @end @implementation InternalClass @end @interface Bar () { NSString *_hidden_ivar; } @end @implementation Bar - (id)init { self = [super init]; if (self) { _hidden_ivar = [NSString stringWithFormat:@"%p: @Bar", self]; } return self; // Set breakpoint where Bar is an implementation } - (void)dealloc { [_hidden_ivar release]; [super dealloc]; } - (NSString *)description { return [_hidden_ivar copyWithZone:NULL]; } @end