Index: include/utility
===================================================================
--- include/utility
+++ include/utility
@@ -178,6 +178,7 @@
 #include <__config>
 #include <__tuple>
 #include <type_traits>
+#include <initializer_list>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header