error: The function/method `takes_an_immutable_reference` doesn't need a mutable reference --> $DIR/mut_reference.rs:26:34 | LL | takes_an_immutable_reference(&mut 42); | ^^^^^^^ | = note: `-D clippy::unnecessary-mut-passed` implied by `-D warnings` error: The function/method `as_ptr` doesn't need a mutable reference --> $DIR/mut_reference.rs:28:12 | LL | as_ptr(&mut 42); | ^^^^^^^ error: The function/method `takes_an_immutable_reference` doesn't need a mutable reference --> $DIR/mut_reference.rs:32:44 | LL | my_struct.takes_an_immutable_reference(&mut 42); | ^^^^^^^ error: aborting due to 3 previous errors