1 files changed, 12 insertions, 0 deletions
diff --git a/src/librustc_data_structures/stable_hasher.rs b/src/librustc_data_structures/stable_hasher.rs
index 19343a9250d..c777f1fa829 100644
--- a/src/librustc_data_structures/stable_hasher.rs
+++ b/src/librustc_data_structures/stable_hasher.rs
@@ -1,6 +1,7 @@
 use std::hash::{Hash, Hasher, BuildHasher};
 use std::marker::PhantomData;
 use std::mem;
+use smallvec::SmallVec;
 use crate::sip128::SipHasher128;
 use crate::indexed_vec;
 use crate::bit_set;
@@ -318,6 +319,17 @@ impl<T: HashStable<CTX>, CTX> HashStable<CTX> for Vec<T> {
     }
 }
 
+impl<A, CTX> HashStable<CTX> for SmallVec<[A; 1]> where A: HashStable<CTX> {
+    #[inline]
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          ctx: &mut CTX,
+                                          hasher: &mut StableHasher<W>) {
+        for item in self {
+            item.hash_stable(ctx, hasher);
+        }
+    }
+}
+
 impl<T: ?Sized + HashStable<CTX>, CTX> HashStable<CTX> for Box<T> {
     #[inline]
     fn hash_stable<W: StableHasherResult>(&self,