error: use of `flat_map` with an identity function --> $DIR/flat_map_identity.rs:8:22 | LL | let _ = iterator.flat_map(|x| x); | ^^^^^^^^^^^^^^^ help: try: `flatten()` | = note: `-D clippy::flat-map-identity` implied by `-D warnings` error: use of `flat_map` with an identity function --> $DIR/flat_map_identity.rs:11:22 | LL | let _ = iterator.flat_map(convert::identity); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `flatten()` error: use of `flat_map` with an identity function --> $DIR/flat_map_identity.rs:14:22 | LL | let _ = iterator.flat_map(|x| return x); | ^^^^^^^^^^^^^^^^^^^^^^ help: try: `flatten()` error: aborting due to 3 previous errors