rust/src/test/run-pass/overloaded-index-in-field.rs

// 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.

// Test using overloaded indexing when the "map" is stored in a
// field. This caused problems at some point.

use std::ops::Index;

struct Foo {
    x: int,
    y: int,
}

struct Bar {
    foo: Foo
}

impl Index<int> for Foo {
    type Output = int;

    fn index(&self, z: &int) -> &int {
        if *z == 0 {
            &self.x
        } else {
            &self.y
        }
    }
}

trait Int {
    fn get(self) -> int;
    fn get_from_ref(&self) -> int;
    fn inc(&mut self);
}

impl Int for int {
    fn get(self) -> int { self }
    fn get_from_ref(&self) -> int { *self }
    fn inc(&mut self) { *self += 1; }
}

fn main() {
    let f = Bar { foo: Foo {
        x: 1,
        y: 2,
    } };
    assert_eq!(f.foo[1].get(), 2);
}