NSData decorator example if you're putting the bytes of an object in NSData and want to make sure ARC doesn't deallocate that object before you call -[data bytes];

gistfile1.m

@interface JSObjectBytesDataDecorator : NSData

+ (instancetype)dataDecoratorWithData:(NSData *)data holdingOnToBytesOfObject:(id)object;

@end

gistfile2.m

@implementation JSObjectBytesDataDecorator
{
    NSData *_decoratedData;
    id _object;
}

+ (instancetype)dataDecoratorWithData:(NSData *)data holdingOnToBytesOfObject:(id)object
{
    JSObjectBytesDataDecorator *decorator = [[self alloc] init];
    decorator->_decoratedData = data;
    decorator->_object = object;
    
    return decorator;
}

- (id)forwardingTargetForSelector:(SEL)aSelector
{
    return _decoratedData;
}

@end