| // Copyright 2014 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. |
| |
| // Uncovered during work on new scoping rules for safe destructors |
| // as an important use case to support properly. |
| |
| |
| pub struct E<'a> { |
| pub f: &'a u8, |
| } |
| impl<'b> E<'b> { |
| pub fn m(&self) -> &'b u8 { self.f } |
| } |
| |
| pub struct P<'c> { |
| pub g: &'c u8, |
| } |
| pub trait M { |
| fn n(&self) -> u8; |
| } |
| impl<'d> M for P<'d> { |
| fn n(&self) -> u8 { *self.g } |
| } |
| |
| fn extension<'e>(x: &'e E<'e>) -> Box<M+'e> { |
| loop { |
| let p = P { g: x.m() }; |
| return Box::new(p) as Box<M+'e>; |
| } |
| } |
| |
| fn main() { |
| let w = E { f: &10 }; |
| let o = extension(&w); |
| assert_eq!(o.n(), 10); |
| } |
