3 #[derive(Clone, Default)]
4 struct MaybeCopy<T>(T);
6 impl Copy for MaybeCopy<u8> {}
8 fn is_copy<T: Copy>(x: T) {
9 println!("{}", std::any::type_name::<T>());
13 is_copy(MaybeCopy::default());
14 [MaybeCopy::default(); 13];
15 // didn't work, because `Copy` was only checked in the mir