error[E0308]: mismatched types --> $DIR/resume-arg-late-bound.rs:19:5 | LL | test(gen); | ^^^^^^^^^ one type is more general than the other | = note: expected type `for<'a> Generator<&'a mut bool>` found type `Generator<&mut bool>` note: the lifetime requirement is introduced here --> $DIR/resume-arg-late-bound.rs:12:17 | LL | fn test(a: impl for<'a> Generator<&'a mut bool>) {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.