| warning: method `clone_first` is never used | |
| --> $DIR/issue-23485.rs:20:8 | |
| | | |
| LL | trait Iterator { | |
| | -------- method in this trait | |
| ... | |
| LL | fn clone_first(mut self) -> Option<<Self::Item as Deref>::Target> where | |
| | ^^^^^^^^^^^ | |
| | | |
| = note: `#[warn(dead_code)]` on by default | |
| warning: 1 warning emitted | |