rust-clippy/clippy_tests/examples/needless_borrow.stderr

error: this expression borrows a reference that is immediately dereferenced by the compiler
  --> needless_borrow.rs:13:15
   |
13 |     let c = x(&&a);
   |               ^^^
   |
   = note: `-D needless-borrow` implied by `-D warnings`

error: this pattern creates a reference to a reference
  --> needless_borrow.rs:20:17
   |
20 |     if let Some(ref cake) = Some(&5) {}
   |                 ^^^^^^^^
   |
   = note: `-D needless-borrow` implied by `-D warnings`

error: this expression borrows a reference that is immediately dereferenced by the compiler
  --> needless_borrow.rs:27:15
   |
27 |         46 => &&a,
   |               ^^^
   |
   = note: `-D needless-borrow` implied by `-D warnings`

error: this pattern creates a reference to a reference
  --> needless_borrow.rs:50:31
   |
50 |     let _ = v.iter().filter(|&ref a| a.is_empty());
   |                               ^^^^^
   |
   = note: `-D needless-borrow` implied by `-D warnings`

error: aborting due to 4 previous errors

error: Could not compile `clippy_tests`.

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