error: non-binding let on a type that implements `Drop`
  --> $DIR/map_identity.rs:8:5
   |
LL |     let _: Vec<_> = x.iter().map(not_identity).map(|x| return x).collect();
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `#[deny(clippy::let_underscore_drop)]` on by default
   = help: consider using an underscore-prefixed named binding or dropping explicitly with `std::mem::drop`

error: unnecessary map of the identity function
  --> $DIR/map_identity.rs:8:47
   |
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`

error: non-binding let on a type that implements `Drop`
  --> $DIR/map_identity.rs:9:5
   |
LL |     let _: Vec<_> = x.iter().map(std::convert::identity).map(|y| y).collect();
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider using an underscore-prefixed named binding or dropping explicitly with `std::mem::drop`

error: unnecessary map of the identity function
  --> $DIR/map_identity.rs:9:57
   |
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:9:29
   |
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:10:32
   |
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:11:36
   |
LL |       let _: Result<i8, f32> = Ok(-3).map(|x| {
   |  ____________________________________^
LL | |         return x;
LL | |     });
   | |______^ help: remove the call to `map`

error: non-binding let on a type that implements `Drop`
  --> $DIR/map_identity.rs:15:5
   |
LL |     let _: Vec<_> = x.iter().map(|x| 2 * x).collect();
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider using an underscore-prefixed named binding or dropping explicitly with `std::mem::drop`

error: non-binding let on a type that implements `Drop`
  --> $DIR/map_identity.rs:16:5
   |
LL |     let _: Vec<_> = x.iter().map(not_identity).map(|x| return x - 4).collect();
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: consider using an underscore-prefixed named binding or dropping explicitly with `std::mem::drop`

error: aborting due to 9 previous errors