2 files changed, 71 insertions, 9 deletions

diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
index 3e2c7627dbe..ee091d1786b 100644
--- a/src/libstd/collections/hash/map.rs
+++ b/src/libstd/collections/hash/map.rs
@@ -20,7 +20,7 @@ use cmp::{max, Eq, PartialEq};
 use default::Default;
 use fmt::{self, Debug};
 use hash::{self, Hash, SipHasher};
-use iter::{self, Iterator, ExactSizeIterator, IteratorExt, FromIterator, Extend, Map};
+use iter::{self, Iterator, ExactSizeIterator, IntoIterator, IteratorExt, FromIterator, Extend, Map};
 use marker::Sized;
 use mem::{self, replace};
 use num::{Int, UnsignedInt};
@@ -1385,6 +1385,42 @@ enum VacantEntryState<K, V, M> {
     NoElem(EmptyBucket<K, V, M>),
 }
 
+impl<'a, K, V, S, H> IntoIterator for &'a HashMap<K, V, S>
+    where K: Eq + Hash<H>,
+          S: HashState<Hasher=H>,
+          H: hash::Hasher<Output=u64>
+{
+    type Iter = Iter<'a, K, V>;
+
+    fn into_iter(self) -> Iter<'a, K, V> {
+        self.iter()
+    }
+}
+
+impl<'a, K, V, S, H> IntoIterator for &'a mut HashMap<K, V, S>
+    where K: Eq + Hash<H>,
+          S: HashState<Hasher=H>,
+          H: hash::Hasher<Output=u64>
+{
+    type Iter = IterMut<'a, K, V>;
+
+    fn into_iter(mut self) -> IterMut<'a, K, V> {
+        self.iter_mut()
+    }
+}
+
+impl<K, V, S, H> IntoIterator for HashMap<K, V, S>
+    where K: Eq + Hash<H>,
+          S: HashState<Hasher=H>,
+          H: hash::Hasher<Output=u64>
+{
+    type Iter = IntoIter<K, V>;
+
+    fn into_iter(self) -> IntoIter<K, V> {
+        self.into_iter()
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, K, V> Iterator for Iter<'a, K, V> {
     type Item = (&'a K, &'a V);
@@ -1539,7 +1575,7 @@ impl<K, V, S, H> Extend<(K, V)> for HashMap<K, V, S>
           S: HashState<Hasher=H>,
           H: hash::Hasher<Output=u64>
 {
-    fn extend<T: Iterator<Item=(K, V)>>(&mut self, mut iter: T) {
+    fn extend<T: Iterator<Item=(K, V)>>(&mut self, iter: T) {
         for (k, v) in iter {
             self.insert(k, v);
         }
@@ -1941,7 +1977,7 @@ mod test_map {
 
         let mut observed: u32 = 0;
 
-        for (k, v) in m.iter() {
+        for (k, v) in &m {
             assert_eq!(*v, *k * 2);
             observed |= 1 << *k;
         }
@@ -2131,7 +2167,7 @@ mod test_map {
 
         let map: HashMap<int, int> = xs.iter().map(|&x| x).collect();
 
-        for &(k, v) in xs.iter() {
+        for &(k, v) in &xs {
             assert_eq!(map.get(&k), Some(&v));
         }
     }
diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index c6dcb0d230f..ae9fb9bca77 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -18,7 +18,9 @@ use default::Default;
 use fmt::Debug;
 use fmt;
 use hash::{self, Hash};
-use iter::{Iterator, ExactSizeIterator, IteratorExt, FromIterator, Map, Chain, Extend};
+use iter::{
+    Iterator, IntoIterator, ExactSizeIterator, IteratorExt, FromIterator, Map, Chain, Extend,
+};
 use ops::{BitOr, BitAnd, BitXor, Sub};
 use option::Option::{Some, None, self};
 
@@ -634,7 +636,7 @@ impl<T, S, H> Extend<T> for HashSet<T, S>
           S: HashState<Hasher=H>,
           H: hash::Hasher<Output=u64>
 {
-    fn extend<I: Iterator<Item=T>>(&mut self, mut iter: I) {
+    fn extend<I: Iterator<Item=T>>(&mut self, iter: I) {
         for k in iter {
             self.insert(k);
         }
@@ -833,6 +835,30 @@ pub struct Union<'a, T: 'a, S: 'a> {
     iter: Chain<Iter<'a, T>, Difference<'a, T, S>>
 }
 
+impl<'a, T, S, H> IntoIterator for &'a HashSet<T, S>
+    where T: Eq + Hash<H>,
+          S: HashState<Hasher=H>,
+          H: hash::Hasher<Output=u64>
+{
+    type Iter = Iter<'a, T>;
+
+    fn into_iter(self) -> Iter<'a, T> {
+        self.iter()
+    }
+}
+
+impl<T, S, H> IntoIterator for HashSet<T, S>
+    where T: Eq + Hash<H>,
+          S: HashState<Hasher=H>,
+          H: hash::Hasher<Output=u64>
+{
+    type Iter = IntoIter<T>;
+
+    fn into_iter(self) -> IntoIter<T> {
+        self.into_iter()
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, K> Iterator for Iter<'a, K> {
     type Item = &'a K;
@@ -1007,7 +1033,7 @@ mod test_set {
             assert!(a.insert(i));
         }
         let mut observed: u32 = 0;
-        for k in a.iter() {
+        for k in &a {
             observed |= 1 << *k;
         }
         assert_eq!(observed, 0xFFFF_FFFF);
@@ -1128,7 +1154,7 @@ mod test_set {
 
         let set: HashSet<int> = xs.iter().map(|&x| x).collect();
 
-        for x in xs.iter() {
+        for x in &xs {
             assert!(set.contains(x));
         }
     }
@@ -1214,7 +1240,7 @@ mod test_set {
                 assert_eq!(last_i, 49);
             }
 
-            for _ in s.iter() { panic!("s should be empty!"); }
+            for _ in &s { panic!("s should be empty!"); }
 
             // reset to try again.
             s.extend(1..100);