error: this let-binding has unit value
  --> $DIR/let_unit.rs:14:5
   |
LL |     let _x = println!("x");
   |     ^^^^^^^^^^^^^^^^^^^^^^^ help: omit the `let` binding: `println!("x");`
   |
   = note: `-D clippy::let-unit-value` implied by `-D warnings`

error: this let-binding has unit value
  --> $DIR/let_unit.rs:18:9
   |
LL |         let _a = ();
   |         ^^^^^^^^^^^^ help: omit the `let` binding: `();`

error: this let-binding has unit value
  --> $DIR/let_unit.rs:53:5
   |
LL | /     let _ = v
LL | |         .into_iter()
LL | |         .map(|i| i * 2)
LL | |         .filter(|i| i % 2 == 0)
LL | |         .map(|_| ())
LL | |         .next()
LL | |         .unwrap();
   | |__________________^
   |
help: omit the `let` binding
   |
LL |     v
LL |         .into_iter()
LL |         .map(|i| i * 2)
LL |         .filter(|i| i % 2 == 0)
LL |         .map(|_| ())
LL |         .next()
 ...

error: aborting due to 3 previous errors