error: unnecessary map of the identity function
  --> $DIR/map_identity.rs:7:47
   |
LL |     let _: Vec<_> = x.iter().map(not_identity).map(|x| return x).collect();
   |                                               ^^^^^^^^^^^^^^^^^^ help: remove the call to `map`
   |
   = note: `-D clippy::map-identity` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::map_identity)]`

error: unnecessary map of the identity function
  --> $DIR/map_identity.rs:8:57
   |
LL |     let _: Vec<_> = x.iter().map(std::convert::identity).map(|y| y).collect();
   |                                                         ^^^^^^^^^^^ help: remove the call to `map`

error: unnecessary map of the identity function
  --> $DIR/map_identity.rs:8:29
   |
LL |     let _: Vec<_> = x.iter().map(std::convert::identity).map(|y| y).collect();
   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the call to `map`

error: unnecessary map of the identity function
  --> $DIR/map_identity.rs:9:32
   |
LL |     let _: Option<u8> = Some(3).map(|x| x);
   |                                ^^^^^^^^^^^ help: remove the call to `map`

error: unnecessary map of the identity function
  --> $DIR/map_identity.rs:10:36
   |
LL |       let _: Result<i8, f32> = Ok(-3).map(|x| {
   |  ____________________________________^
LL | |         return x;
LL | |     });
   | |______^ help: remove the call to `map`

error: unnecessary map of the identity function
  --> $DIR/map_identity.rs:20:36
   |
LL |     let _: Result<u32, u32> = Ok(1).map_err(|a| a);
   |                                    ^^^^^^^^^^^^^^^ help: remove the call to `map_err`

error: aborting due to 6 previous errors