rust/src/test/run-pass/overloaded-autoderef-vtable.rs
Alex Crichton ec7c800d2f Remove pretty-expanded from failing tests
This commit removes pretty-expanded from all tests that wind up calling panic!
one way or another now that its internals are unstable.
2015-04-08 17:21:34 -07:00

48 lines
1.1 KiB
Rust

// 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.
use std::ops::Deref;
struct DerefWithHelper<H, T> {
helper: H,
value: T
}
trait Helper<T> {
fn helper_borrow(&self) -> &T;
}
impl<T> Helper<T> for Option<T> {
fn helper_borrow(&self) -> &T {
self.as_ref().unwrap()
}
}
impl<T, H: Helper<T>> Deref for DerefWithHelper<H, T> {
type Target = T;
fn deref(&self) -> &T {
self.helper.helper_borrow()
}
}
struct Foo {x: isize}
impl Foo {
fn foo(&self) -> isize {self.x}
}
pub fn main() {
let x: DerefWithHelper<Option<Foo>, Foo> =
DerefWithHelper { helper: Some(Foo {x: 5}), value: Foo { x: 2 } };
assert!(x.foo() == 5);
}