#![feature(min_specialization, const_trait_impl)]

struct Dummy;

const trait One {
    fn one();
}
impl One for Dummy {
    fn one() {
        println!("wut");
    }
}

const trait Two {
    fn two();
}
impl<T: One, U> const Two for (T, U) {
    default fn two() {
        unreachable!();
    }
}
impl<T: [const] One> const Two for (T, i32) {
    fn two() {
        T::one();
    }
}

const trait Three {
    fn three();
}
impl<T: One, U> const Three for (T, U) {
    fn three() {
        <(T, U)>::two();
    }
}

const A: () = {
    <(Dummy, i32)>::three();
};

fn main() {}