diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs index 1e5c012e7d808..4ad8fce8120aa 100644 --- a/src/libstd/collections/hash/map.rs +++ b/src/libstd/collections/hash/map.rs @@ -1583,6 +1583,14 @@ impl Extend<(K, V)> for HashMap } } +#[stable(feature = "hash_extend_copy", since = "1.4.0")] +impl<'a, K, V, S> Extend<(&'a K, &'a V)> for HashMap + where K: Eq + Hash + Copy, V: Copy, S: HashState +{ + fn extend>(&mut self, iter: T) { + self.extend(iter.into_iter().map(|(&key, &value)| (key, value))); + } +} /// `RandomState` is the default state for `HashMap` types. /// @@ -2347,4 +2355,20 @@ mod test_map { check(&m); } } + + #[test] + fn test_extend_ref() { + let mut a = HashMap::new(); + a.insert(1, "one"); + let mut b = HashMap::new(); + b.insert(2, "two"); + b.insert(3, "three"); + + a.extend(&b); + + assert_eq!(a.len(), 3); + assert_eq!(a[&1], "one"); + assert_eq!(a[&2], "two"); + assert_eq!(a[&3], "three"); + } } diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs index 1f19a72371c9a..7264b5827c4fb 100644 --- a/src/libstd/collections/hash/set.rs +++ b/src/libstd/collections/hash/set.rs @@ -654,6 +654,16 @@ impl Extend for HashSet } } +#[stable(feature = "hash_extend_copy", since = "1.4.0")] +impl<'a, T, S> Extend<&'a T> for HashSet + where T: 'a + Eq + Hash + Copy, + S: HashState, +{ + fn extend>(&mut self, iter: I) { + self.extend(iter.into_iter().cloned()); + } +} + #[stable(feature = "rust1", since = "1.0.0")] impl Default for HashSet where T: Eq + Hash, @@ -1325,4 +1335,32 @@ mod test_set { assert_eq!(it.next(), Some(&Foo("a", 2))); assert_eq!(it.next(), None); } + + #[test] + fn test_extend_ref() { + let mut a = HashSet::new(); + a.insert(1); + + a.extend(&[2, 3, 4]); + + assert_eq!(a.len(), 4); + assert!(a.contains(&1)); + assert!(a.contains(&2)); + assert!(a.contains(&3)); + assert!(a.contains(&4)); + + let mut b = HashSet::new(); + b.insert(5); + b.insert(6); + + a.extend(&b); + + assert_eq!(a.len(), 6); + assert!(a.contains(&1)); + assert!(a.contains(&2)); + assert!(a.contains(&3)); + assert!(a.contains(&4)); + assert!(a.contains(&5)); + assert!(a.contains(&6)); + } }