error: `into_iter` call on an empty collection --> $DIR/iter_on_empty_collections.rs:5:16 | LL | assert_eq!([].into_iter().next(), Option::<i32>::None); | ^^^^^^^^^^^^^^ help: try: `std::iter::empty()` | = note: `-D clippy::iter-on-empty-collections` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(clippy::iter_on_empty_collections)]` error: `iter_mut` call on an empty collection --> $DIR/iter_on_empty_collections.rs:6:16 | LL | assert_eq!([].iter_mut().next(), Option::<&mut i32>::None); | ^^^^^^^^^^^^^ help: try: `std::iter::empty()` error: `iter` call on an empty collection --> $DIR/iter_on_empty_collections.rs:7:16 | LL | assert_eq!([].iter().next(), Option::<&i32>::None); | ^^^^^^^^^ help: try: `std::iter::empty()` error: `into_iter` call on an empty collection --> $DIR/iter_on_empty_collections.rs:8:16 | LL | assert_eq!(None.into_iter().next(), Option::<i32>::None); | ^^^^^^^^^^^^^^^^ help: try: `std::iter::empty()` error: `iter_mut` call on an empty collection --> $DIR/iter_on_empty_collections.rs:9:16 | LL | assert_eq!(None.iter_mut().next(), Option::<&mut i32>::None); | ^^^^^^^^^^^^^^^ help: try: `std::iter::empty()` error: `iter` call on an empty collection --> $DIR/iter_on_empty_collections.rs:10:16 | LL | assert_eq!(None.iter().next(), Option::<&i32>::None); | ^^^^^^^^^^^ help: try: `std::iter::empty()` error: aborting due to 6 previous errors