error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:10:12
   |
10 | fn fun(x : &mut &mut u32) -> bool {
   |            ^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:24:17
   |
24 |     let mut x = &mut &mut 1u32;
   |                 ^^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:19:20
   |
19 |     ($p:expr) => { &mut $p }
   |                    ^^^^^^^
...
39 |     let mut z = mut_ptr!(&mut 3u32);
   |                 ------------------- in this macro invocation
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: this expression mutably borrows a mutable reference. Consider reborrowing
  --> mut_mut.rs:26:21
   |
26 |         let mut y = &mut x;
   |                     ^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:30:17
   |
30 |         let y : &mut &mut u32 = &mut &mut 2;
   |                 ^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:30:33
   |
30 |         let y : &mut &mut u32 = &mut &mut 2;
   |                                 ^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:30:17
   |
30 |         let y : &mut &mut u32 = &mut &mut 2;
   |                 ^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:35:17
   |
35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
   |                 ^^^^^^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:35:22
   |
35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
   |                      ^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:35:38
   |
35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
   |                                      ^^^^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:35:17
   |
35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
   |                 ^^^^^^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:35:22
   |
35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
   |                      ^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: generally you want to avoid `&mut &mut _` if possible
  --> mut_mut.rs:35:22
   |
35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
   |                      ^^^^^^^^^^^^^
   |
   = note: `-D mut-mut` implied by `-D warnings`

error: aborting due to 13 previous errors

error: Could not compile `clippy_tests`.

To learn more, run the command again with --verbose.