rust/src/test/ui/impl-trait/in-trait/opaque-in-impl.rs

// check-pass

#![feature(return_position_impl_trait_in_trait)]
#![allow(incomplete_features)]

use std::fmt::Display;

trait Foo {
    fn bar(&self) -> impl Display;
}

impl Foo for () {
    fn bar(&self) -> impl Display {
        "Hello, world"
    }
}

fn main() {
    println!("{}", ().bar());
}