error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:12:11
   |
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`
   = help: to override `-D warnings` add `#[allow(clippy::needless_pass_by_ref_mut)]`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:37:12
   |
LL | fn foo6(s: &mut Vec<u32>) {
   |            ^^^^^^^^^^^^^ help: consider changing to: `&Vec<u32>`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:50:29
   |
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
  --> tests/ui/needless_pass_by_ref_mut.rs:55:31
   |
LL |     fn badger(&mut self, vec: &mut Vec<i32>) -> usize {
   |                               ^^^^^^^^^^^^^ help: consider changing to: `&Vec<i32>`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:132:16
   |
LL | async fn a1(x: &mut i32) {
   |                ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:136:16
   |
LL | async fn a2(x: &mut i32, y: String) {
   |                ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:140:16
   |
LL | async fn a3(x: &mut i32, y: String, z: String) {
   |                ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:144:16
   |
LL | async fn a4(x: &mut i32, y: i32) {
   |                ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:148:24
   |
LL | async fn a5(x: i32, y: &mut i32) {
   |                        ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:152:24
   |
LL | async fn a6(x: i32, y: &mut i32) {
   |                        ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:156:32
   |
LL | async fn a7(x: i32, y: i32, z: &mut i32) {
   |                                ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:160:24
   |
LL | async fn a8(x: i32, a: &mut i32, y: i32, z: &mut i32) {
   |                        ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:160:45
   |
LL | async fn a8(x: i32, a: &mut i32, y: i32, z: &mut i32) {
   |                                             ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:194:16
   |
LL | fn cfg_warn(s: &mut u32) {}
   |                ^^^^^^^^ help: consider changing to: `&u32`
   |
   = note: this is cfg-gated and may require further changes

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:200:20
   |
LL |     fn cfg_warn(s: &mut u32) {}
   |                    ^^^^^^^^ help: consider changing to: `&u32`
   |
   = note: this is cfg-gated and may require further changes

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:214:39
   |
LL | async fn inner_async2(x: &mut i32, y: &mut u32) {
   |                                       ^^^^^^^^ help: consider changing to: `&u32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:222:26
   |
LL | async fn inner_async3(x: &mut i32, y: &mut u32) {
   |                          ^^^^^^^^ help: consider changing to: `&i32`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:241:34
   |
LL | pub async fn call_in_closure1(n: &mut str) {
   |                                  ^^^^^^^^ help: consider changing to: `&str`
   |
   = warning: changing this function will impact semver compatibility

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:253:25
   |
LL | pub async fn closure(n: &mut usize) -> impl '_ + FnMut() {
   |                         ^^^^^^^^^^ help: consider changing to: `&usize`
   |
   = warning: changing this function will impact semver compatibility

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:260:20
   |
LL | pub fn closure2(n: &mut usize) -> impl '_ + FnMut() -> usize {
   |                    ^^^^^^^^^^ help: consider changing to: `&usize`
   |
   = warning: changing this function will impact semver compatibility

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:271:26
   |
LL | pub async fn closure4(n: &mut usize) {
   |                          ^^^^^^^^^^ help: consider changing to: `&usize`
   |
   = warning: changing this function will impact semver compatibility

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:311:18
   |
LL | fn _empty_tup(x: &mut (())) {}
   |                  ^^^^^^^^^ help: consider changing to: `&()`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:312:19
   |
LL | fn _single_tup(x: &mut ((i32,))) {}
   |                   ^^^^^^^^^^^^^ help: consider changing to: `&(i32,)`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:313:18
   |
LL | fn _multi_tup(x: &mut ((i32, u32))) {}
   |                  ^^^^^^^^^^^^^^^^^ help: consider changing to: `&(i32, u32)`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:314:11
   |
LL | fn _fn(x: &mut (fn())) {}
   |           ^^^^^^^^^^^ help: consider changing to: `&fn()`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:316:23
   |
LL | fn _extern_rust_fn(x: &mut extern "Rust" fn()) {}
   |                       ^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&extern "Rust" fn()`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:317:20
   |
LL | fn _extern_c_fn(x: &mut extern "C" fn()) {}
   |                    ^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&extern "C" fn()`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:318:18
   |
LL | fn _unsafe_fn(x: &mut unsafe fn()) {}
   |                  ^^^^^^^^^^^^^^^^ help: consider changing to: `&unsafe fn()`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:319:25
   |
LL | fn _unsafe_extern_fn(x: &mut unsafe extern "C" fn()) {}
   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&unsafe extern "C" fn()`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:320:20
   |
LL | fn _fn_with_arg(x: &mut unsafe extern "C" fn(i32)) {}
   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&unsafe extern "C" fn(i32)`

error: this argument is a mutable reference, but not used mutably
  --> tests/ui/needless_pass_by_ref_mut.rs:321:20
   |
LL | fn _fn_with_ret(x: &mut unsafe extern "C" fn() -> (i32)) {}
   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider changing to: `&unsafe extern "C" fn() -> (i32)`

error: aborting due to 31 previous errors