diff --git a/beast/cxx14/type_traits.h b/beast/cxx17/type_traits.h
similarity index 87%
rename from beast/cxx14/type_traits.h
rename to beast/cxx17/type_traits.h
index be11f51f9..31bec59f6 100644
--- a/beast/cxx14/type_traits.h
+++ b/beast/cxx17/type_traits.h
@@ -17,8 +17,8 @@
 */
 //==============================================================================
 
-#ifndef BEAST_CXX14_TYPE_TRAITS_H_INCLUDED
-#define BEAST_CXX14_TYPE_TRAITS_H_INCLUDED
+#ifndef BEAST_CXX17_TYPE_TRAITS_H_INCLUDED
+#define BEAST_CXX17_TYPE_TRAITS_H_INCLUDED
 
 #include <tuple>
 #include <type_traits>
@@ -26,6 +26,16 @@
 
 namespace std {
 
+#ifndef _MSC_VER
+
+template<class...>
+using void_t = void;
+
+template<bool B>
+using bool_constant = std::integral_constant<bool, B>;
+
+#endif
+
 // Ideas from Howard Hinnant
 //
 // Specializations of is_constructible for pair and tuple which
@@ -41,6 +51,6 @@ struct is_constructible <pair <T, U>>
 {
 };
 
-}
+} // std
 
 #endif