| // Copyright 2015 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(default_type_parameter_fallback)] |
| |
| use std::marker::PhantomData; |
| |
| trait Id { |
| type This; |
| } |
| |
| impl<A> Id for A { |
| type This = A; |
| } |
| |
| struct Foo<X: Default = usize, Y = <X as Id>::This> { |
| data: PhantomData<(X, Y)> |
| } |
| |
| impl<X: Default, Y> Foo<X, Y> { |
| fn new() -> Foo<X, Y> { |
| Foo { data: PhantomData } |
| } |
| } |
| |
| fn main() { |
| let foo = Foo::new(); |
| } |