error[E0277]: the trait bound `Box: Foo` is not satisfied --> $DIR/object-does-not-impl-trait.rs:6:44 | LL | fn take_object(f: Box) { take_foo(f); } | -------- ^ the trait `Foo` is not implemented for `Box` | | | required by a bound introduced by this call | help: this trait has no implementations, consider adding one --> $DIR/object-does-not-impl-trait.rs:4:1 | LL | trait Foo {} | ^^^^^^^^^ note: required by a bound in `take_foo` --> $DIR/object-does-not-impl-trait.rs:5:15 | LL | fn take_foo(f: F) {} | ^^^ required by this bound in `take_foo` error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.