error[E0594]: cannot assign to `*input`, which is behind a `&` reference --> $DIR/issue-68049-2.rs:9:7 | LL | *input = self.0; | ^^^^^^^^^^^^^^^ `input` is a `&` reference, so the data it refers to cannot be written | help: consider changing this to be a mutable reference | LL | fn example(&self, input: &mut i32) { // should not suggest here | +++ error[E0594]: cannot assign to `self.0`, which is behind a `&` reference --> $DIR/issue-68049-2.rs:17:5 | LL | self.0 += *input; | ^^^^^^^^^^^^^^^^ `self` is a `&` reference, so the data it refers to cannot be written | help: consider changing this to be a mutable reference | LL | fn example(&mut self, input: &i32); // should suggest here | ~~~~~~~~~ error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0594`.