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//@ run-pass
// Test overloading of the `[]` operator. In particular test that it
// takes its argument *by reference*.
use std::ops::Index;
struct AssociationList<K,V> {
pairs: Vec<AssociationPair<K,V>> }
#[derive(Clone)]
struct AssociationPair<K,V> {
key: K,
value: V
}
impl<K,V> AssociationList<K,V> {
fn push(&mut self, key: K, value: V) {
self.pairs.push(AssociationPair {key: key, value: value});
}
}
impl<'a, K: PartialEq + std::fmt::Debug, V:Clone> Index<&'a K> for AssociationList<K,V> {
type Output = V;
fn index(&self, index: &K) -> &V {
for pair in &self.pairs {
if pair.key == *index {
return &pair.value
}
}
panic!("No value found for key: {:?}", index);
}
}
pub fn main() {
let foo = "foo".to_string();
let bar = "bar".to_string();
let mut list = AssociationList {pairs: Vec::new()};
list.push(foo.clone(), 22);
list.push(bar.clone(), 44);
assert_eq!(list[&foo], 22);
assert_eq!(list[&bar], 44);
assert_eq!(list[&foo], 22);
assert_eq!(list[&bar], 44);
}
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