diff --git a/source/mijin/types/script_value.hpp b/source/mijin/types/script_value.hpp
index 96933ee..9459f8d 100644
--- a/source/mijin/types/script_value.hpp
+++ b/source/mijin/types/script_value.hpp
@@ -12,18 +12,10 @@
 
 #include "../container/optional.hpp"
 #include "../util/traits.hpp"
+#include "../util/variant.hpp"
 
 namespace mijin
 {
-//
-// public traits
-//
-
-template<typename TSearch, typename TVariant>
-inline constexpr bool variant_contains_v = false;
-
-template<typename TSearch, typename... TVariantTypes>
-inline constexpr bool variant_contains_v<TSearch, std::variant<TVariantTypes...>> = mijin::is_any_type_v<TSearch, TVariantTypes...>;
 
 //
 // public types
diff --git a/source/mijin/util/variant.hpp b/source/mijin/util/variant.hpp
new file mode 100644
index 0000000..42d6df1
--- /dev/null
+++ b/source/mijin/util/variant.hpp
@@ -0,0 +1,29 @@
+
+#pragma once
+
+#if !defined(MIJIN_UTIL_VARIANT_HPP_INCLUDED)
+#define MIJIN_UTIL_VARIANT_HPP_INCLUDED 1
+
+namespace mijin
+{
+
+//
+// public traits
+//
+
+template<typename TSearch, typename TVariant>
+inline constexpr bool variant_contains_v = false;
+
+template<typename TSearch, typename... TVariantTypes>
+inline constexpr bool variant_contains_v<TSearch, std::variant<TVariantTypes...>> = mijin::is_any_type_v<TSearch, TVariantTypes...>;
+
+//
+// public types
+//
+template<typename... TCallable>
+struct Visitor : TCallable ...
+{
+    using TCallable::operator()...;
+};
+}
+#endif // !defined(MIJIN_UTIL_VARIANT_HPP_INCLUDED)