// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

pub trait Foo {
    type Out;
}

impl Foo for () {
    type Out = bool;
}

fn main() {
    type Bool = <() as Foo>::Out;

    let x: Bool = true;
    assert!(x);

    let y: Option<Bool> = None;
    assert_eq!(y, None);
}