Derive Eq for RandomState

src/libstd/collections/hash/map.rs

@@ -1662,7 +1662,7 @@ impl<'a, K, V, S> Extend<(&'a K, &'a V)> for HashMap<K, V, S>
 /// A particular instance `RandomState` will create the same instances of
 /// `Hasher`, but the hashers created by two different `RandomState`
 /// instances are unlikely to produce the same result for the same values.
-#[derive(Clone)]
+#[derive(Clone, PartialEq, Eq)]
 #[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
 pub struct RandomState {
     k0: u64,
@@ -1732,6 +1732,8 @@ mod test_map {
 
     use super::HashMap;
     use super::Entry::{Occupied, Vacant};
+    use super::RandomState;
+    use hash::{Hash, BuildHasher, Hasher};
     use cell::RefCell;
     use rand::{thread_rng, Rng};
 
@@ -2454,4 +2456,20 @@ mod test_map {
         a.insert(item, 0);
         assert!(a.capacity() > a.len());
     }
+
+
+    #[test]
+    fn test_randomstate_eq() {
+        let a = RandomState::new();
+        let b = a.clone();
+        assert!(a == b);
+
+        let mut a_hasher = a.build_hasher();
+        let mut b_hasher = b.build_hasher();
+
+        1u32.hash(&mut a_hasher);
+        1u32.hash(&mut b_hasher);
+
+        assert_eq!(a_hasher.finish(), b_hasher.finish())
+    }
 }