error[E0277]: the trait bound `&mut usize: Default` is not satisfied --> $DIR/suggest-adding-reference-to-trait-assoc-item.rs:13:9 | LL | foo(Default::default()); | ^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `&mut usize` | help: consider mutably borrowing here | LL | foo(&mut Default::default()); | ++++ error[E0277]: the trait bound `&usize: Default` is not satisfied --> $DIR/suggest-adding-reference-to-trait-assoc-item.rs:14:9 | LL | bar(Default::default()); | ^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `&usize` | help: consider borrowing here | LL | bar(&Default::default()); | + error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0277`.