rust/tests/ui/impl-trait/in-trait/auxiliary/rpitit.rs

// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty

#![feature(return_position_impl_trait_in_trait)]

use std::ops::Deref;

pub trait Foo {
    fn bar() -> impl Deref<Target = impl Sized>;
}

pub struct Foreign;
impl Foo for Foreign {
    fn bar() -> &'static () { &() }
}