error: this pattern takes a reference on something that is being de-referenced
  --> $DIR/needless_borrowed_ref.rs:18:34
   |
18 |     let _ = v.iter_mut().filter(|&ref a| a.is_empty());
   |                                  ^^^^^^ help: try removing the `&ref` part and just keep: `a`
   |
   = note: `-D clippy::needless-borrowed-reference` implied by `-D warnings`

error: this pattern takes a reference on something that is being de-referenced
  --> $DIR/needless_borrowed_ref.rs:23:17
   |
23 |     if let Some(&ref v) = thingy {
   |                 ^^^^^^ help: try removing the `&ref` part and just keep: `v`

error: this pattern takes a reference on something that is being de-referenced
  --> $DIR/needless_borrowed_ref.rs:52:27
   |
52 |         (&Animal::Cat(v), &ref k) | (&ref k, &Animal::Cat(v)) => (), // lifetime mismatch error if there is no '&ref'
   |                           ^^^^^^ help: try removing the `&ref` part and just keep: `k`

error: this pattern takes a reference on something that is being de-referenced
  --> $DIR/needless_borrowed_ref.rs:52:38
   |
52 |         (&Animal::Cat(v), &ref k) | (&ref k, &Animal::Cat(v)) => (), // lifetime mismatch error if there is no '&ref'
   |                                      ^^^^^^ help: try removing the `&ref` part and just keep: `k`

error: aborting due to 4 previous errors