error[E0277]: the trait bound `std::boxed::Box: Foo` is not satisfied --> $DIR/object-does-not-impl-trait.rs:6:31 | LL | fn take_object(f: Box) { take_foo(f); } | ^^^^^^^^ the trait `Foo` is not implemented for `std::boxed::Box` | note: required by `take_foo` --> $DIR/object-does-not-impl-trait.rs:5:1 | LL | fn take_foo(f: F) {} | ^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.