I believe the @ is used only by the obj-c keywords and not the ones from C. So it'll be something more like this @autoreleasepool{ for (int index =

I believe the @ is used only by the obj-c keywords and not the ones from C. So it'll be something more like this @autoreleasepool{ for (int index = 0; index < 100; index++){ int error = [MyObject performSelector:@selector(addCoolFilterToImage:)]; if (error) { return 32; } } }