error[E0277]: the trait bound `&mut Baz: Happy` is not satisfied --> $DIR/multiple-1.rs:52:9 | LL | foo(&mut baz); | --- ^^^^^^^^ the trait `Happy` is not implemented for `&mut Baz` | | | required by a bound introduced by this call | = help: the trait `Happy` is implemented for `&mut LDM` note: required by a bound in `foo` --> $DIR/multiple-1.rs:45:26 | LL | fn foo(_: T) where T: Happy {} | ^^^^^ required by this bound in `foo` error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.