impl Hasher for {&mut Hasher, Box<Hasher>}

1 files changed, 13 insertions, 0 deletions

diff --git a/src/liballoc/tests/lib.rs b/src/liballoc/tests/lib.rs
index 8f3e71ef794..61377018455 100644
--- a/src/liballoc/tests/lib.rs
+++ b/src/liballoc/tests/lib.rs
@@ -50,3 +50,16 @@ fn hash<T: Hash>(t: &T) -> u64 {
     t.hash(&mut s);
     s.finish()
 }
+
+#[test]
+fn test_boxed_hasher() {
+    let ordinary_hash = hash(&5u32);
+
+    let mut hasher_1 = Box::new(DefaultHasher::new());
+    5u32.hash(&mut hasher_1);
+    assert_eq!(ordinary_hash, hasher_1.finish());
+
+    let mut hasher_2 = Box::new(DefaultHasher::new()) as Box<Hasher>;
+    5u32.hash(&mut hasher_2);
+    assert_eq!(ordinary_hash, hasher_2.finish());
+}