7e4e99123a
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]
58 lines
1.5 KiB
Rust
58 lines
1.5 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// Test overloading of the `[]` operator. In particular test that it
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// takes its argument *by reference*.
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extern crate debug;
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use std::ops::Index;
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struct AssociationList<K,V> {
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pairs: Vec<AssociationPair<K,V>> }
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#[deriving(Clone)]
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struct AssociationPair<K,V> {
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key: K,
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value: V
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}
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impl<K,V> AssociationList<K,V> {
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fn push(&mut self, key: K, value: V) {
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self.pairs.push(AssociationPair {key: key, value: value});
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}
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}
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impl<K:PartialEq,V:Clone> Index<K,V> for AssociationList<K,V> {
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fn index<'a>(&'a self, index: &K) -> &'a V {
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for pair in self.pairs.iter() {
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if pair.key == *index {
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return &pair.value
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}
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}
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fail!("No value found for key: {:?}", index);
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}
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}
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pub fn main() {
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let foo = "foo".to_string();
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let bar = "bar".to_string();
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let mut list = AssociationList {pairs: Vec::new()};
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list.push(foo.clone(), 22i);
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list.push(bar.clone(), 44i);
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assert!(list[foo] == 22)
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assert!(list[bar] == 44)
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assert!(list[foo] == 22)
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assert!(list[bar] == 44)
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}
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