diff --git a/src/libcore/to_bytes.rs b/src/libcore/to_bytes.rs
index b0e445c1b198..900cc97066c5 100644
--- a/src/libcore/to_bytes.rs
+++ b/src/libcore/to_bytes.rs
@@ -208,19 +208,22 @@ impl<A: IterBytes> &[A]: IterBytes {
 impl<A: IterBytes, B: IterBytes> (A,B): IterBytes {
   #[inline(always)]
   pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
-    let &(ref a, ref b) = self;
-    a.iter_bytes(lsb0, f);
-    b.iter_bytes(lsb0, f);
+    match *self {
+      (ref a, ref b) => {
+        iter_bytes_2(a, b, lsb0, f);
+      }
+    }
   }
 }
 
 impl<A: IterBytes, B: IterBytes, C: IterBytes> (A,B,C): IterBytes {
   #[inline(always)]
   pure fn iter_bytes(&self, lsb0: bool, f: Cb) {
-    let &(ref a, ref b, ref c) = self;
-    a.iter_bytes(lsb0, f);
-    b.iter_bytes(lsb0, f);
-    c.iter_bytes(lsb0, f);
+    match *self {
+      (ref a, ref b, ref c) => {
+        iter_bytes_3(a, b, c, lsb0, f);
+      }
+    }
   }
 }