error[E0277]: the trait bound `(): AsRef<(dyn for<'r> Fn(&'r ()) + 'static)>` is not satisfied --> $DIR/generic-with-implicit-hrtb-without-dyn.rs:6:13 | LL | fn ice() -> impl AsRef { | ^^^^^^^^^^^^^^^^^^^ the trait `AsRef<(dyn for<'r> Fn(&'r ()) + 'static)>` is not implemented for `()` error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.