error[E0277]: the trait bound `Discriminant<::Assoc>: Bar` is not satisfied --> $DIR/projection-discr-kind.rs:14:15 | LL | needs_bar(std::mem::discriminant(&x)); | --------- ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Bar` is not implemented for `Discriminant<::Assoc>` | | | required by a bound introduced by this call | help: this trait has no implementations, consider adding one --> $DIR/projection-discr-kind.rs:10:1 | LL | trait Bar {} | ^^^^^^^^^ note: required by a bound in `needs_bar` --> $DIR/projection-discr-kind.rs:11:22 | LL | fn needs_bar(_: impl Bar) {} | ^^^ required by this bound in `needs_bar` error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0277`.