error: this argument is a mutable reference, but not used mutably
  --> $DIR/needless_pass_by_ref_mut.rs:6:11
   |
LL | fn foo(s: &mut Vec<u32>, b: &u32, x: &mut u32) {
   |           ^^^^^^^^^^^^^ help: consider changing to: `&Vec<u32>`
   |
   = note: `-D clippy::needless-pass-by-ref-mut` implied by `-D warnings`

error: this argument is a mutable reference, but not used mutably
  --> $DIR/needless_pass_by_ref_mut.rs:31:12
   |
LL | fn foo6(s: &mut Vec<u32>) {
   |            ^^^^^^^^^^^^^ help: consider changing to: `&Vec<u32>`

error: this argument is a mutable reference, but not used mutably
  --> $DIR/needless_pass_by_ref_mut.rs:44:29
   |
LL |     fn mushroom(&self, vec: &mut Vec<i32>) -> usize {
   |                             ^^^^^^^^^^^^^ help: consider changing to: `&Vec<i32>`

error: this argument is a mutable reference, but not used mutably
  --> $DIR/needless_pass_by_ref_mut.rs:49:31
   |
LL |     fn badger(&mut self, vec: &mut Vec<i32>) -> usize {
   |                               ^^^^^^^^^^^^^ help: consider changing to: `&Vec<i32>`

error: aborting due to 4 previous errors