error: you seem to be trying to use `&Box`. Consider using just `&T` --> borrow_box.rs:9:19 | 9 | pub fn test1(foo: &mut Box) { | ^^^^^^^^^^^^^^ help: try `&mut bool` | note: lint level defined here --> borrow_box.rs:4:9 | 4 | #![deny(borrowed_box)] | ^^^^^^^^^^^^ error: you seem to be trying to use `&Box`. Consider using just `&T` --> borrow_box.rs:14:14 | 14 | let foo: &Box; | ^^^^^^^^^^ help: try `&bool` error: you seem to be trying to use `&Box`. Consider using just `&T` --> borrow_box.rs:18:10 | 18 | foo: &'a Box | ^^^^^^^^^^^^^ help: try `&'a bool` error: you seem to be trying to use `&Box`. Consider using just `&T` --> borrow_box.rs:22:17 | 22 | fn test4(a: &Box); | ^^^^^^^^^^ help: try `&bool` error: aborting due to 4 previous errors To learn more, run the command again with --verbose.