rust/src/test/run-pass/overloaded-index.rs
Patrick Walton 7e4e99123a librustc (RFC #34): Implement the new Index and IndexMut traits.
This will break code that used the old `Index` trait. Change this code
to use the new `Index` traits. For reference, here are their signatures:

    pub trait Index<Index,Result> {
        fn index<'a>(&'a self, index: &Index) -> &'a Result;
    }
    pub trait IndexMut<Index,Result> {
        fn index_mut<'a>(&'a mut self, index: &Index) -> &'a mut Result;
    }

Closes #6515.

[breaking-change]
2014-07-07 11:43:23 -07:00

54 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.
struct Foo {
x: int,
y: int,
}
impl Index<int,int> for Foo {
fn index<'a>(&'a self, z: &int) -> &'a int {
if *z == 0 {
&self.x
} else {
&self.y
}
}
}
impl IndexMut<int,int> for Foo {
fn index_mut<'a>(&'a mut self, z: &int) -> &'a mut int {
if *z == 0 {
&mut self.x
} else {
&mut self.y
}
}
}
fn main() {
let mut f = Foo {
x: 1,
y: 2,
};
assert_eq!(f[1], 2);
f[0] = 3;
assert_eq!(f[0], 3);
{
let p = &mut f[1];
*p = 4;
}
{
let p = &f[1];
assert_eq!(*p, 4);
}
}