From fa8c4ba81175f671c3f39f1586d0a1d9067d9f89 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 7 May 2019 14:26:03 -0700
Subject: [PATCH] Minor

---
 src/hb-serialize.hh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hb-serialize.hh b/src/hb-serialize.hh
index dc9cc8226..ccb7af988 100644
--- a/src/hb-serialize.hh
+++ b/src/hb-serialize.hh
@@ -393,7 +393,7 @@ struct hb_serialize_context_t
   { return _copy (src, hb_prioritize, hb_forward<Ts> (ds)...); }
 
   template <typename Type>
-  hb_serialize_context_t &operator << (const Type &obj) { embed (obj); return *this; }
+  hb_serialize_context_t& operator << (const Type &obj) & { embed (obj); return *this; }
 
   template <typename Type>
   Type *extend_size (Type &obj, unsigned int size)