error: you are implementing `Iterator` on a `Copy` type --> $DIR/copy_iterator.rs:18:1 | 18 | / impl Iterator for Countdown { 19 | | type Item = u8; 20 | | 21 | | fn next(&mut self) -> Option { ... | 26 | | } 27 | | } | |_^ | = note: `-D clippy::copy-iterator` implied by `-D warnings` = note: consider implementing `IntoIterator` instead error: aborting due to previous error