error[E0599]: no method named `foo` found for reference `&B` in the current scope --> $DIR/issue-10465.rs:17:15 | LL | b.foo(); | ^^^ method not found in `&B` | = help: items from traits can only be used if the trait is in scope help: the following trait is implemented but not in scope; perhaps add a `use` for it: | LL | use a::A; | error: aborting due to previous error For more information about this error, try `rustc --explain E0599`.