// revisions: edition2015 edition2021 //[edition2021]edition:2021 #![allow(warnings)] fn ice() -> impl AsRef { //[edition2015]~^ ERROR: the trait bound `(): AsRef<(dyn for<'a> Fn(&'a ()) + 'static)>` is not satisfied [E0277] //[edition2021]~^^ ERROR: trait objects must include the `dyn` keyword [E0782] todo!() } fn main() {}