| // Copyright 2018 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. |
| |
| #![feature(specialization)] |
| |
| trait Iterate<'a> { |
| type Ty: Valid; |
| fn iterate(self); |
| } |
| impl<'a, T> Iterate<'a> for T where T: Check { |
| default type Ty = (); |
| default fn iterate(self) {} |
| } |
| |
| trait Check {} |
| impl<'a, T> Check for T where <T as Iterate<'a>>::Ty: Valid {} |
| |
| trait Valid {} |
| |
| fn main() { |
| Iterate::iterate(0); |
| } |
