Index: include/__refstring
===================================================================
--- include/__refstring
+++ include/__refstring
@@ -27,6 +27,10 @@
 
     typedef int count_t;
 
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wpadded"
+#endif
     struct _Rep_base
     {
         std::size_t len;
@@ -34,6 +38,10 @@
         count_t     count;
     };
 
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
     static
     _Rep_base*
     rep_from_data(const char *data_) _NOEXCEPT