From b0c74207d8d86b6d6b6137252bb6494f33947a25 Mon Sep 17 00:00:00 2001
From: ThePhD <phdofthehouse@gmail.com>
Date: Sun, 1 Dec 2019 17:40:16 -0500
Subject: [PATCH] Force constness on ostream operator. Automatically disable
 magic for variant types.

---
 include/sol/traits.hpp         | 1307 ++++++++++++++++---------------
 include/sol/types.hpp          |    8 +-
 include/sol/usertype_core.hpp  |    8 +-
 single/include/sol/forward.hpp |    4 +-
 single/include/sol/sol.hpp     | 1327 ++++++++++++++++----------------
 5 files changed, 1330 insertions(+), 1324 deletions(-)

diff --git a/include/sol/traits.hpp b/include/sol/traits.hpp
index b47fdc94..ca2b8ff2 100644
--- a/include/sol/traits.hpp
+++ b/include/sol/traits.hpp
@@ -39,670 +39,667 @@
 #include <iosfwd>
 
 
-namespace sol {
-	namespace meta {
-		template <typename T>
-		struct unwrapped {
-			typedef T type;
+namespace sol { namespace meta {
+	template <typename T>
+	struct unwrapped {
+		typedef T type;
+	};
+
+	template <typename T>
+	struct unwrapped<std::reference_wrapper<T>> {
+		typedef T type;
+	};
+
+	template <typename T>
+	using unwrapped_t = typename unwrapped<T>::type;
+
+	template <typename T>
+	struct unwrap_unqualified : unwrapped<unqualified_t<T>> {};
+
+	template <typename T>
+	using unwrap_unqualified_t = typename unwrap_unqualified<T>::type;
+
+	template <typename T>
+	struct remove_member_pointer;
+
+	template <typename R, typename T>
+	struct remove_member_pointer<R T::*> {
+		typedef R type;
+	};
+
+	template <typename R, typename T>
+	struct remove_member_pointer<R T::*const> {
+		typedef R type;
+	};
+
+	template <typename T>
+	using remove_member_pointer_t = remove_member_pointer<T>;
+
+	template <typename T, typename...>
+	struct all_same : std::true_type {};
+
+	template <typename T, typename U, typename... Args>
+	struct all_same<T, U, Args...> : std::integral_constant<bool, std::is_same<T, U>::value && all_same<T, Args...>::value> {};
+
+	template <typename T, typename...>
+	struct any_same : std::false_type {};
+
+	template <typename T, typename U, typename... Args>
+	struct any_same<T, U, Args...> : std::integral_constant<bool, std::is_same<T, U>::value || any_same<T, Args...>::value> {};
+
+	template <typename T, typename... Args>
+	constexpr inline bool any_same_v = any_same<T, Args...>::value;
+
+	template <bool B>
+	using boolean = std::integral_constant<bool, B>;
+
+	template <bool B>
+	constexpr inline bool boolean_v = boolean<B>::value;
+
+	template <typename T>
+	using neg = boolean<!T::value>;
+
+	template <typename T>
+	constexpr inline bool neg_v = neg<T>::value;
+
+	template <typename... Args>
+	struct all : boolean<true> {};
+
+	template <typename T, typename... Args>
+	struct all<T, Args...> : std::conditional_t<T::value, all<Args...>, boolean<false>> {};
+
+	template <typename... Args>
+	struct any : boolean<false> {};
+
+	template <typename T, typename... Args>
+	struct any<T, Args...> : std::conditional_t<T::value, boolean<true>, any<Args...>> {};
+
+	template <typename T, typename... Args>
+	constexpr inline bool all_v = all<T, Args...>::value;
+
+	template <typename T, typename... Args>
+	constexpr inline bool any_v = any<T, Args...>::value;
+
+	enum class enable_t { _ };
+
+	constexpr const auto enabler = enable_t::_;
+
+	template <bool value, typename T = void>
+	using disable_if_t = std::enable_if_t<!value, T>;
+
+	template <typename... Args>
+	using enable = std::enable_if_t<all<Args...>::value, enable_t>;
+
+	template <typename... Args>
+	using disable = std::enable_if_t<neg<all<Args...>>::value, enable_t>;
+
+	template <typename... Args>
+	using enable_any = std::enable_if_t<any<Args...>::value, enable_t>;
+
+	template <typename... Args>
+	using disable_any = std::enable_if_t<neg<any<Args...>>::value, enable_t>;
+
+	template <typename V, typename... Vs>
+	struct find_in_pack_v : boolean<false> {};
+
+	template <typename V, typename Vs1, typename... Vs>
+	struct find_in_pack_v<V, Vs1, Vs...> : any<boolean<(V::value == Vs1::value)>, find_in_pack_v<V, Vs...>> {};
+
+	namespace meta_detail {
+		template <std::size_t I, typename T, typename... Args>
+		struct index_in_pack : std::integral_constant<std::size_t, SIZE_MAX> {};
+
+		template <std::size_t I, typename T, typename T1, typename... Args>
+		struct index_in_pack<I, T, T1, Args...>
+		: conditional_t<std::is_same<T, T1>::value, std::integral_constant<std::ptrdiff_t, I>, index_in_pack<I + 1, T, Args...>> {};
+	} // namespace meta_detail
+
+	template <typename T, typename... Args>
+	struct index_in_pack : meta_detail::index_in_pack<0, T, Args...> {};
+
+	template <typename T, typename List>
+	struct index_in : meta_detail::index_in_pack<0, T, List> {};
+
+	template <typename T, typename... Args>
+	struct index_in<T, types<Args...>> : meta_detail::index_in_pack<0, T, Args...> {};
+
+	template <std::size_t I, typename... Args>
+	struct at_in_pack {};
+
+	template <std::size_t I, typename... Args>
+	using at_in_pack_t = typename at_in_pack<I, Args...>::type;
+
+	template <std::size_t I, typename Arg, typename... Args>
+	struct at_in_pack<I, Arg, Args...> : std::conditional<I == 0, Arg, at_in_pack_t<I - 1, Args...>> {};
+
+	template <typename Arg, typename... Args>
+	struct at_in_pack<0, Arg, Args...> {
+		typedef Arg type;
+	};
+
+	namespace meta_detail {
+		template <typename, typename TI>
+		using on_even = meta::boolean<(TI::value % 2) == 0>;
+
+		template <typename, typename TI>
+		using on_odd = meta::boolean<(TI::value % 2) == 1>;
+
+		template <typename, typename>
+		using on_always = std::true_type;
+
+		template <template <typename...> class When, std::size_t Limit, std::size_t I, template <typename...> class Pred, typename... Ts>
+		struct count_when_for_pack : std::integral_constant<std::size_t, 0> {};
+		template <template <typename...> class When, std::size_t Limit, std::size_t I, template <typename...> class Pred, typename T, typename... Ts>
+			          struct count_when_for_pack<When, Limit, I, Pred, T, Ts...> : conditional_t < sizeof...(Ts)
+			     == 0
+			|| Limit<2, std::integral_constant<std::size_t, I + static_cast<std::size_t>(Limit != 0 && Pred<T>::value)>,
+			        count_when_for_pack<When, Limit - static_cast<std::size_t>(When<T, std::integral_constant<std::size_t, I>>::value),
+			             I + static_cast<std::size_t>(When<T, std::integral_constant<std::size_t, I>>::value&& Pred<T>::value), Pred, Ts...>> {};
+	} // namespace meta_detail
+
+	template <template <typename...> class Pred, typename... Ts>
+	struct count_for_pack : meta_detail::count_when_for_pack<meta_detail::on_always, sizeof...(Ts), 0, Pred, Ts...> {};
+
+	template <template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_for_pack_v = count_for_pack<Pred, Ts...>::value;
+
+	template <template <typename...> class Pred, typename List>
+	struct count_for;
+
+	template <template <typename...> class Pred, typename... Args>
+	struct count_for<Pred, types<Args...>> : count_for_pack<Pred, Args...> {};
+
+	template <std::size_t Limit, template <typename...> class Pred, typename... Ts>
+	struct count_for_to_pack : meta_detail::count_when_for_pack<meta_detail::on_always, Limit, 0, Pred, Ts...> {};
+
+	template <std::size_t Limit, template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_for_to_pack_v = count_for_to_pack<Limit, Pred, Ts...>::value;
+
+	template <template <typename...> class When, std::size_t Limit, template <typename...> class Pred, typename... Ts>
+	struct count_when_for_to_pack : meta_detail::count_when_for_pack<When, Limit, 0, Pred, Ts...> {};
+
+	template <template <typename...> class When, std::size_t Limit, template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_when_for_to_pack_v = count_when_for_to_pack<When, Limit, Pred, Ts...>::value;
+
+	template <template <typename...> class Pred, typename... Ts>
+	using count_even_for_pack = count_when_for_to_pack<meta_detail::on_even, sizeof...(Ts), Pred, Ts...>;
+
+	template <template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_even_for_pack_v = count_even_for_pack<Pred, Ts...>::value;
+
+	template <template <typename...> class Pred, typename... Ts>
+	using count_odd_for_pack = count_when_for_to_pack<meta_detail::on_odd, sizeof...(Ts), Pred, Ts...>;
+
+	template <template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_odd_for_pack_v = count_odd_for_pack<Pred, Ts...>::value;
+
+	template <typename... Args>
+	struct return_type {
+		typedef std::tuple<Args...> type;
+	};
+
+	template <typename T>
+	struct return_type<T> {
+		typedef T type;
+	};
+
+	template <>
+	struct return_type<> {
+		typedef void type;
+	};
+
+	template <typename... Args>
+	using return_type_t = typename return_type<Args...>::type;
+
+	namespace meta_detail {
+		template <typename>
+		struct always_true : std::true_type {};
+		struct is_invokable_tester {
+			template <typename Fun, typename... Args>
+			static always_true<decltype(std::declval<Fun>()(std::declval<Args>()...))> test(int);
+			template <typename...>
+			static std::false_type test(...);
 		};
+	} // namespace meta_detail
 
-		template <typename T>
-		struct unwrapped<std::reference_wrapper<T>> {
-			typedef T type;
-		};
+	template <typename T>
+	struct is_invokable;
+	template <typename Fun, typename... Args>
+	struct is_invokable<Fun(Args...)> : decltype(meta_detail::is_invokable_tester::test<Fun, Args...>(0)) {};
 
-		template <typename T>
-		using unwrapped_t = typename unwrapped<T>::type;
-
-		template <typename T>
-		struct unwrap_unqualified : unwrapped<unqualified_t<T>> {};
-
-		template <typename T>
-		using unwrap_unqualified_t = typename unwrap_unqualified<T>::type;
-
-		template <typename T>
-		struct remove_member_pointer;
-
-		template <typename R, typename T>
-		struct remove_member_pointer<R T::*> {
-			typedef R type;
-		};
-
-		template <typename R, typename T>
-		struct remove_member_pointer<R T::*const> {
-			typedef R type;
-		};
-
-		template <typename T>
-		using remove_member_pointer_t = remove_member_pointer<T>;
-
-		template <typename T, typename...>
-		struct all_same : std::true_type {};
-
-		template <typename T, typename U, typename... Args>
-		struct all_same<T, U, Args...> : std::integral_constant<bool, std::is_same<T, U>::value && all_same<T, Args...>::value> {};
-
-		template <typename T, typename...>
-		struct any_same : std::false_type {};
-
-		template <typename T, typename U, typename... Args>
-		struct any_same<T, U, Args...> : std::integral_constant<bool, std::is_same<T, U>::value || any_same<T, Args...>::value> {};
-
-		template <typename T, typename... Args>
-		constexpr inline bool any_same_v = any_same<T, Args...>::value;
-
-		template <bool B>
-		using boolean = std::integral_constant<bool, B>;
-
-		template <bool B>
-		constexpr inline bool boolean_v = boolean<B>::value;
-
-		template <typename T>
-		using neg = boolean<!T::value>;
-
-		template <typename T>
-		constexpr inline bool neg_v = neg<T>::value;
-
-		template <typename... Args>
-		struct all : boolean<true> {};
-
-		template <typename T, typename... Args>
-		struct all<T, Args...> : std::conditional_t<T::value, all<Args...>, boolean<false>> {};
-
-		template <typename... Args>
-		struct any : boolean<false> {};
-
-		template <typename T, typename... Args>
-		struct any<T, Args...> : std::conditional_t<T::value, boolean<true>, any<Args...>> {};
-
-		template <typename T, typename... Args>
-		constexpr inline bool all_v = all<T, Args...>::value;
-
-		template <typename T, typename... Args>
-		constexpr inline bool any_v = any<T, Args...>::value;
-
-		enum class enable_t { _ };
-
-		constexpr const auto enabler = enable_t::_;
-
-		template <bool value, typename T = void>
-		using disable_if_t = std::enable_if_t<!value, T>;
-
-		template <typename... Args>
-		using enable = std::enable_if_t<all<Args...>::value, enable_t>;
-
-		template <typename... Args>
-		using disable = std::enable_if_t<neg<all<Args...>>::value, enable_t>;
-
-		template <typename... Args>
-		using enable_any = std::enable_if_t<any<Args...>::value, enable_t>;
-
-		template <typename... Args>
-		using disable_any = std::enable_if_t<neg<any<Args...>>::value, enable_t>;
-
-		template <typename V, typename... Vs>
-		struct find_in_pack_v : boolean<false> {};
-
-		template <typename V, typename Vs1, typename... Vs>
-		struct find_in_pack_v<V, Vs1, Vs...> : any<boolean<(V::value == Vs1::value)>, find_in_pack_v<V, Vs...>> {};
-
-		namespace meta_detail {
-			template <std::size_t I, typename T, typename... Args>
-			struct index_in_pack : std::integral_constant<std::size_t, SIZE_MAX> {};
-
-			template <std::size_t I, typename T, typename T1, typename... Args>
-			struct index_in_pack<I, T, T1, Args...>
-			: conditional_t<std::is_same<T, T1>::value, std::integral_constant<std::ptrdiff_t, I>, index_in_pack<I + 1, T, Args...>> {};
-		} // namespace meta_detail
-
-		template <typename T, typename... Args>
-		struct index_in_pack : meta_detail::index_in_pack<0, T, Args...> {};
-
-		template <typename T, typename List>
-		struct index_in : meta_detail::index_in_pack<0, T, List> {};
-
-		template <typename T, typename... Args>
-		struct index_in<T, types<Args...>> : meta_detail::index_in_pack<0, T, Args...> {};
-
-		template <std::size_t I, typename... Args>
-		struct at_in_pack {};
-
-		template <std::size_t I, typename... Args>
-		using at_in_pack_t = typename at_in_pack<I, Args...>::type;
-
-		template <std::size_t I, typename Arg, typename... Args>
-		struct at_in_pack<I, Arg, Args...> : std::conditional<I == 0, Arg, at_in_pack_t<I - 1, Args...>> {};
-
-		template <typename Arg, typename... Args>
-		struct at_in_pack<0, Arg, Args...> {
-			typedef Arg type;
-		};
-
-		namespace meta_detail {
-			template <typename, typename TI>
-			using on_even = meta::boolean<(TI::value % 2) == 0>;
-
-			template <typename, typename TI>
-			using on_odd = meta::boolean<(TI::value % 2) == 1>;
-
-			template <typename, typename>
-			using on_always = std::true_type;
-
-			template <template <typename...> class When, std::size_t Limit, std::size_t I, template <typename...> class Pred, typename... Ts>
-			struct count_when_for_pack : std::integral_constant<std::size_t, 0> {};
-			template <template <typename...> class When, std::size_t Limit, std::size_t I, template <typename...> class Pred, typename T, typename... Ts>
-			struct count_when_for_pack<When, Limit, I, Pred, T, Ts...> : conditional_t<
-				sizeof...(Ts) == 0 || Limit < 2,
-					std::integral_constant<std::size_t, I + static_cast<std::size_t>(Limit != 0 && Pred<T>::value)>,
-			     	count_when_for_pack<When, Limit - static_cast<std::size_t>(When<T, std::integral_constant<std::size_t, I>>::value), I + static_cast<std::size_t>(When<T, std::integral_constant<std::size_t, I>>::value && Pred<T>::value), Pred, Ts...>
-			> {};
-		} // namespace meta_detail
-
-		template <template <typename...> class Pred, typename... Ts>
-		struct count_for_pack : meta_detail::count_when_for_pack<meta_detail::on_always, sizeof...(Ts), 0, Pred, Ts...> {};
-
-		template <template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_for_pack_v = count_for_pack<Pred, Ts...>::value;
-
-		template <template <typename...> class Pred, typename List>
-		struct count_for;
-
-		template <template <typename...> class Pred, typename... Args>
-		struct count_for<Pred, types<Args...>> : count_for_pack<Pred, Args...> {};
-
-		template <std::size_t Limit, template <typename...> class Pred, typename... Ts>
-		struct count_for_to_pack : meta_detail::count_when_for_pack<meta_detail::on_always, Limit, 0, Pred, Ts...> {};
-
-		template <std::size_t Limit, template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_for_to_pack_v = count_for_to_pack<Limit, Pred, Ts...>::value;
-
-		template <template <typename...> class When, std::size_t Limit, template <typename...> class Pred, typename... Ts>
-		struct count_when_for_to_pack : meta_detail::count_when_for_pack<When, Limit, 0, Pred, Ts...> {};
-
-		template <template <typename...> class When, std::size_t Limit, template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_when_for_to_pack_v = count_when_for_to_pack<When, Limit, Pred, Ts...>::value;
-
-		template <template <typename...> class Pred, typename... Ts>
-		using count_even_for_pack = count_when_for_to_pack<meta_detail::on_even, sizeof...(Ts), Pred, Ts...>;
-
-		template <template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_even_for_pack_v = count_even_for_pack<Pred, Ts...>::value;
-
-		template <template <typename...> class Pred, typename... Ts>
-		using count_odd_for_pack = count_when_for_to_pack<meta_detail::on_odd, sizeof...(Ts), Pred, Ts...>;
-
-		template <template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_odd_for_pack_v = count_odd_for_pack<Pred, Ts...>::value;
-
-		template <typename... Args>
-		struct return_type {
-			typedef std::tuple<Args...> type;
-		};
-
-		template <typename T>
-		struct return_type<T> {
-			typedef T type;
-		};
-
-		template <>
-		struct return_type<> {
-			typedef void type;
-		};
-
-		template <typename... Args>
-		using return_type_t = typename return_type<Args...>::type;
-
-		namespace meta_detail {
-			template <typename>
-			struct always_true : std::true_type {};
-			struct is_invokable_tester {
-				template <typename Fun, typename... Args>
-				static always_true<decltype(std::declval<Fun>()(std::declval<Args>()...))> test(int);
-				template <typename...>
-				static std::false_type test(...);
-			};
-		} // namespace meta_detail
-
-		template <typename T>
-		struct is_invokable;
-		template <typename Fun, typename... Args>
-		struct is_invokable<Fun(Args...)> : decltype(meta_detail::is_invokable_tester::test<Fun, Args...>(0)) {};
-
-		namespace meta_detail {
-
-			template <typename T, typename = void>
-			struct is_callable : std::is_function<std::remove_pointer_t<T>> {};
-
-			template <typename T>
-			struct is_callable<T,
-			     std::enable_if_t<std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
-			          && std::is_same<decltype(void(&T::operator())), void>::value>> {};
-
-			template <typename T>
-			struct is_callable<T,
-			     std::enable_if_t<!std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
-			          && std::is_destructible<unqualified_t<T>>::value>> {
-				struct F {
-					void operator()() {};
-				};
-				struct Derived : T, F {};
-				template <typename U, U>
-				struct Check;
-
-				template <typename V>
-				static sfinae_no_t test(Check<void (F::*)(), &V::operator()>*);
-
-				template <typename>
-				static sfinae_yes_t test(...);
-
-				static constexpr bool value = std::is_same_v<decltype(test<Derived>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct is_callable<T,
-			     std::enable_if_t<!std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
-			          && !std::is_destructible<unqualified_t<T>>::value>> {
-				struct F {
-					void operator()() {};
-				};
-				struct Derived : T, F {
-					~Derived() = delete;
-				};
-				template <typename U, U>
-				struct Check;
-
-				template <typename V>
-				static sfinae_no_t test(Check<void (F::*)(), &V::operator()>*);
-
-				template <typename>
-				static sfinae_yes_t test(...);
-
-				static constexpr bool value = std::is_same_v<decltype(test<Derived>(0)), sfinae_yes_t>;
-			};
-
-			struct has_begin_end_impl {
-				template <typename T, typename U = unqualified_t<T>, typename B = decltype(std::declval<U&>().begin()),
-				     typename E = decltype(std::declval<U&>().end())>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_key_type_impl {
-				template <typename T, typename U = unqualified_t<T>, typename V = typename U::key_type>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_key_comp_impl {
-				template <typename T, typename V = decltype(std::declval<unqualified_t<T>>().key_comp())>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_load_factor_impl {
-				template <typename T, typename V = decltype(std::declval<unqualified_t<T>>().load_factor())>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_mapped_type_impl {
-				template <typename T, typename V = typename unqualified_t<T>::mapped_type>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_value_type_impl {
-				template <typename T, typename V = typename unqualified_t<T>::value_type>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_iterator_impl {
-				template <typename T, typename V = typename unqualified_t<T>::iterator>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_key_value_pair_impl {
-				template <typename T, typename U = unqualified_t<T>, typename V = typename U::value_type, typename F = decltype(std::declval<V&>().first),
-				     typename S = decltype(std::declval<V&>().second)>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			template <typename T>
-			struct has_push_back_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().push_back(std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_insert_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().insert(std::declval<std::add_rvalue_reference_t<typename C::const_iterator>>(),
-				     std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_insert_after_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().insert_after(std::declval<std::add_rvalue_reference_t<typename C::const_iterator>>(),
-				     std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_size_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().size())*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_max_size_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().max_size())*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_to_string_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().to_string())*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-#if defined(_MSC_VER) && _MSC_VER <= 1910
-			template <typename T, typename U, typename = decltype(std::declval<T&>() < std::declval<U&>())>
-			std::true_type supports_op_less_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
-			std::false_type supports_op_less_test(...);
-			template <typename T, typename U, typename = decltype(std::declval<T&>() == std::declval<U&>())>
-			std::true_type supports_op_equal_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
-			std::false_type supports_op_equal_test(...);
-			template <typename T, typename U, typename = decltype(std::declval<T&>() <= std::declval<U&>())>
-			std::true_type supports_op_less_equal_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
-			std::false_type supports_op_less_equal_test(...);
-			template <typename T, typename OS, typename = decltype(std::declval<OS&>() << std::declval<T&>())>
-			std::true_type supports_ostream_op(std::reference_wrapper<T>, std::reference_wrapper<OS>);
-			std::false_type supports_ostream_op(...);
-			template <typename T, typename = decltype(to_string(std::declval<T&>()))>
-			std::true_type supports_adl_to_string(std::reference_wrapper<T>);
-			std::false_type supports_adl_to_string(...);
-#else
-			template <typename T, typename U, typename = decltype(std::declval<T&>() < std::declval<U&>())>
-			std::true_type supports_op_less_test(const T&, const U&);
-			std::false_type supports_op_less_test(...);
-			template <typename T, typename U, typename = decltype(std::declval<T&>() == std::declval<U&>())>
-			std::true_type supports_op_equal_test(const T&, const U&);
-			std::false_type supports_op_equal_test(...);
-			template <typename T, typename U, typename = decltype(std::declval<T&>() <= std::declval<U&>())>
-			std::true_type supports_op_less_equal_test(const T&, const U&);
-			std::false_type supports_op_less_equal_test(...);
-			template <typename T, typename OS, typename = decltype(std::declval<OS&>() << std::declval<T&>())>
-			std::true_type supports_ostream_op(const T&, const OS&);
-			std::false_type supports_ostream_op(...);
-			template <typename T, typename = decltype(to_string(std::declval<T&>()))>
-			std::true_type supports_adl_to_string(const T&);
-			std::false_type supports_adl_to_string(...);
-#endif
-
-			template <typename T, bool b>
-			struct is_matched_lookup_impl : std::false_type {};
-			template <typename T>
-			struct is_matched_lookup_impl<T, true> : std::is_same<typename T::key_type, typename T::value_type> {};
-
-			template <typename T>
-			using non_void_t = meta::conditional_t<std::is_void_v<T>, ::sol::detail::unchecked_t, T>;
-		} // namespace meta_detail
-
-		template <typename T, typename U = T>
-		using supports_op_less
-		     = decltype(meta_detail::supports_op_less_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
-		template <typename T, typename U = T>
-		using supports_op_equal
-		     = decltype(meta_detail::supports_op_equal_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
-		template <typename T, typename U = T>
-		using supports_op_less_equal
-		     = decltype(meta_detail::supports_op_less_equal_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
-		template <typename T, typename U = std::ostream>
-		using supports_ostream_op
-		     = decltype(meta_detail::supports_ostream_op(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
-		template <typename T>
-		using supports_adl_to_string = decltype(meta_detail::supports_adl_to_string(std::declval<meta_detail::non_void_t<T>&>()));
-
-		template <typename T>
-		using supports_to_string_member = meta::boolean<meta_detail::has_to_string_test<meta_detail::non_void_t<T>>::value>;
-
-		template <typename T>
-		using is_callable = boolean<meta_detail::is_callable<T>::value>;
-
-		template <typename T>
-		constexpr inline bool is_callable_v = is_callable<T>::value;
-
-		template <typename T>
-		struct has_begin_end : decltype(meta_detail::has_begin_end_impl::test<T>(0)) {};
-
-		template <typename T>
-		constexpr inline bool has_begin_end_v = has_begin_end<T>::value;
-
-		template <typename T>
-		struct has_key_value_pair : decltype(meta_detail::has_key_value_pair_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_key_type : decltype(meta_detail::has_key_type_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_key_comp : decltype(meta_detail::has_key_comp_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_load_factor : decltype(meta_detail::has_load_factor_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_mapped_type : decltype(meta_detail::has_mapped_type_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_iterator : decltype(meta_detail::has_iterator_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_value_type : decltype(meta_detail::has_value_type_impl::test<T>(0)) {};
-
-		template <typename T>
-		using has_push_back = meta::boolean<meta_detail::has_push_back_test<T>::value>;
-
-		template <typename T>
-		using has_max_size = meta::boolean<meta_detail::has_max_size_test<T>::value>;
-
-		template <typename T>
-		using has_insert = meta::boolean<meta_detail::has_insert_test<T>::value>;
-
-		template <typename T>
-		using has_insert_after = meta::boolean<meta_detail::has_insert_after_test<T>::value>;
-
-		template <typename T>
-		using has_size = meta::boolean<meta_detail::has_size_test<T>::value>;
-
-		template <typename T>
-		using is_associative = meta::all<has_key_type<T>, has_key_value_pair<T>, has_mapped_type<T>>;
-
-		template <typename T>
-		using is_lookup = meta::all<has_key_type<T>, has_value_type<T>>;
-
-		template <typename T>
-		using is_ordered = meta::all<has_key_comp<T>, meta::neg<has_load_factor<T>>>;
-
-		template <typename T>
-		using is_matched_lookup = meta_detail::is_matched_lookup_impl<T, is_lookup<T>::value>;
-
-		template <typename T>
-		using is_initializer_list = meta::is_specialization_of<T, std::initializer_list>;
-
-		template <typename T>
-		constexpr inline bool is_initializer_list_v = is_initializer_list<T>::value;
-
-		template <typename T, typename CharT = char>
-		using is_string_literal_array_of = boolean<std::is_array_v<T> && std::is_same_v<std::remove_all_extents_t<T>, CharT>>;
-
-		template <typename T, typename CharT = char>
-		constexpr inline bool is_string_literal_array_of_v = is_string_literal_array_of<T, CharT>::value;
-
-		template <typename T>
-		using is_string_literal_array = boolean<std::is_array_v<T> && any_same_v<std::remove_all_extents_t<T>, char, char16_t, char32_t, wchar_t>>;
-
-		template <typename T>
-		constexpr inline bool is_string_literal_array_v = is_string_literal_array<T>::value;
-
-		template <typename T, typename CharT>
-		struct is_string_of : std::false_type {};
-
-		template <typename CharT, typename CharTargetT, typename TraitsT, typename AllocT>
-		struct is_string_of<std::basic_string<CharT, TraitsT, AllocT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
-
-		template <typename T, typename CharT>
-		constexpr inline bool is_string_of_v = is_string_of<T, CharT>::value;
-
-		template <typename T, typename CharT>
-		struct is_string_view_of : std::false_type {};
-
-#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
-		template <typename CharT, typename CharTargetT, typename TraitsT>
-		struct is_string_view_of<std::basic_string_view<CharT, TraitsT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
-#else
-		template <typename CharT, typename CharTargetT, typename TraitsT>
-		struct is_string_view_of<basic_string_view<CharT, TraitsT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
-#endif
-
-		template <typename T, typename CharT>
-		constexpr inline bool is_string_view_of_v = is_string_view_of<T, CharT>::value;
-
-		template <typename T>
-		using is_string_like = meta::boolean<is_specialization_of_v<T, std::basic_string>
-#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
-		     || is_specialization_of_v<T, std::basic_string_view>
-#else
-		     || is_specialization_of_v<T, basic_string_view>
-#endif
-		     || is_string_literal_array_v<T>>;
-
-		template <typename T>
-		constexpr inline bool is_string_like_v = is_string_like<T>::value;
-
-		template <typename T, typename CharT = char>
-		using is_string_constructible = meta::boolean<
-		     is_string_literal_array_of_v<T,
-		          CharT> || std::is_same_v<T, const CharT*> || std::is_same_v<T, CharT> || is_string_of_v<T, CharT> || std::is_same_v<T, std::initializer_list<CharT>>
-#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
-		     || is_string_view_of_v<T, CharT>
-#endif
-		     >;
-
-		template <typename T, typename CharT = char>
-		constexpr inline bool is_string_constructible_v = is_string_constructible<T, CharT>::value;
-
-		template <typename T>
-		using is_string_like_or_constructible = meta::boolean<is_string_like_v<T> || is_string_constructible_v<T>>;
-
-		template <typename T>
-		struct is_pair : std::false_type {};
-
-		template <typename T1, typename T2>
-		struct is_pair<std::pair<T1, T2>> : std::true_type {};
-
-		template <typename T, typename Char>
-		using is_c_str_of = any<std::is_same<T, const Char*>, std::is_same<T, Char const* const>, std::is_same<T, Char*>, is_string_of<T, Char>,
-		     is_string_literal_array_of<T, Char>>;
-
-		template <typename T, typename Char>
-		constexpr inline bool is_c_str_of_v = is_c_str_of<T, Char>::value;
-
-		template <typename T>
-		using is_c_str = is_c_str_of<T, char>;
-
-		template <typename T>
-		constexpr inline bool is_c_str_v = is_c_str<T>::value;
-
-		template <typename T>
-		struct is_move_only
-		: all<neg<std::is_reference<T>>, neg<std::is_copy_constructible<unqualified_t<T>>>, std::is_move_constructible<unqualified_t<T>>> {};
-
-		template <typename T>
-		using is_not_move_only = neg<is_move_only<T>>;
-
-		namespace meta_detail {
-			template <typename T>
-			decltype(auto) force_tuple(T&& x) {
-				if constexpr (meta::is_specialization_of_v<meta::unqualified_t<T>, std::tuple>) {
-					return std::forward<T>(x);
-				}
-				else {
-					return std::tuple<T>(std::forward<T>(x));
-				}
-			}
-		} // namespace meta_detail
-
-		template <typename... X>
-		decltype(auto) tuplefy(X&&... x) {
-			return std::tuple_cat(meta_detail::force_tuple(std::forward<X>(x))...);
-		}
+	namespace meta_detail {
 
 		template <typename T, typename = void>
-		struct iterator_tag {
-			using type = std::input_iterator_tag;
+		struct is_callable : std::is_function<std::remove_pointer_t<T>> {};
+
+		template <typename T>
+		struct is_callable<T,
+			std::enable_if_t<std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
+			     && std::is_same<decltype(void(&T::operator())), void>::value>> {};
+
+		template <typename T>
+		struct is_callable<T,
+			std::enable_if_t<!std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
+			     && std::is_destructible<unqualified_t<T>>::value>> {
+			struct F {
+				void operator()(){};
+			};
+			struct Derived : T, F {};
+			template <typename U, U>
+			struct Check;
+
+			template <typename V>
+			static sfinae_no_t test(Check<void (F::*)(), &V::operator()>*);
+
+			template <typename>
+			static sfinae_yes_t test(...);
+
+			static constexpr bool value = std::is_same_v<decltype(test<Derived>(0)), sfinae_yes_t>;
 		};
 
 		template <typename T>
-		struct iterator_tag<T, conditional_t<false, typename std::iterator_traits<T>::iterator_category, void>> {
-			using type = typename std::iterator_traits<T>::iterator_category;
+		struct is_callable<T,
+			std::enable_if_t<!std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
+			     && !std::is_destructible<unqualified_t<T>>::value>> {
+			struct F {
+				void operator()(){};
+			};
+			struct Derived : T, F {
+				~Derived() = delete;
+			};
+			template <typename U, U>
+			struct Check;
+
+			template <typename V>
+			static sfinae_no_t test(Check<void (F::*)(), &V::operator()>*);
+
+			template <typename>
+			static sfinae_yes_t test(...);
+
+			static constexpr bool value = std::is_same_v<decltype(test<Derived>(0)), sfinae_yes_t>;
 		};
 
-	} // namespace meta
-} // namespace sol
+		struct has_begin_end_impl {
+			template <typename T, typename U = unqualified_t<T>, typename B = decltype(std::declval<U&>().begin()),
+				typename E = decltype(std::declval<U&>().end())>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_key_type_impl {
+			template <typename T, typename U = unqualified_t<T>, typename V = typename U::key_type>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_key_comp_impl {
+			template <typename T, typename V = decltype(std::declval<unqualified_t<T>>().key_comp())>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_load_factor_impl {
+			template <typename T, typename V = decltype(std::declval<unqualified_t<T>>().load_factor())>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_mapped_type_impl {
+			template <typename T, typename V = typename unqualified_t<T>::mapped_type>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_value_type_impl {
+			template <typename T, typename V = typename unqualified_t<T>::value_type>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_iterator_impl {
+			template <typename T, typename V = typename unqualified_t<T>::iterator>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_key_value_pair_impl {
+			template <typename T, typename U = unqualified_t<T>, typename V = typename U::value_type, typename F = decltype(std::declval<V&>().first),
+				typename S = decltype(std::declval<V&>().second)>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		template <typename T>
+		struct has_push_back_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().push_back(std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_insert_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().insert(std::declval<std::add_rvalue_reference_t<typename C::const_iterator>>(),
+				std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_insert_after_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().insert_after(std::declval<std::add_rvalue_reference_t<typename C::const_iterator>>(),
+				std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_size_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().size())*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_max_size_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().max_size())*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_to_string_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().to_string())*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+#if defined(_MSC_VER) && _MSC_VER <= 1910
+		template <typename T, typename U, typename = decltype(std::declval<T&>() < std::declval<U&>())>
+		std::true_type supports_op_less_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
+		std::false_type supports_op_less_test(...);
+		template <typename T, typename U, typename = decltype(std::declval<T&>() == std::declval<U&>())>
+		std::true_type supports_op_equal_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
+		std::false_type supports_op_equal_test(...);
+		template <typename T, typename U, typename = decltype(std::declval<T&>() <= std::declval<U&>())>
+		std::true_type supports_op_less_equal_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
+		std::false_type supports_op_less_equal_test(...);
+		template <typename T, typename OS, typename = decltype(std::declval<OS&>() << std::declval<const T&>())>
+		std::true_type supports_ostream_op(std::reference_wrapper<const T>, std::reference_wrapper<OS>);
+		std::false_type supports_ostream_op(...);
+		template <typename T, typename = decltype(to_string(std::declval<T&>()))>
+		std::true_type supports_adl_to_string(std::reference_wrapper<T>);
+		std::false_type supports_adl_to_string(...);
+#else
+		template <typename T, typename U, typename = decltype(std::declval<T&>() < std::declval<U&>())>
+		std::true_type supports_op_less_test(const T&, const U&);
+		std::false_type supports_op_less_test(...);
+		template <typename T, typename U, typename = decltype(std::declval<T&>() == std::declval<U&>())>
+		std::true_type supports_op_equal_test(const T&, const U&);
+		std::false_type supports_op_equal_test(...);
+		template <typename T, typename U, typename = decltype(std::declval<T&>() <= std::declval<U&>())>
+		std::true_type supports_op_less_equal_test(const T&, const U&);
+		std::false_type supports_op_less_equal_test(...);
+		template <typename T, typename OS, typename = decltype(std::declval<OS&>() << std::declval<const T&>())>
+		std::true_type supports_ostream_op(const T&, const OS&);
+		std::false_type supports_ostream_op(...);
+		template <typename T, typename = decltype(to_string(std::declval<T&>()))>
+		std::true_type supports_adl_to_string(const T&);
+		std::false_type supports_adl_to_string(...);
+#endif
+
+		template <typename T, bool b>
+		struct is_matched_lookup_impl : std::false_type {};
+		template <typename T>
+		struct is_matched_lookup_impl<T, true> : std::is_same<typename T::key_type, typename T::value_type> {};
+
+		template <typename T>
+		using non_void_t = meta::conditional_t<std::is_void_v<T>, ::sol::detail::unchecked_t, T>;
+	} // namespace meta_detail
+
+	template <typename T, typename U = T>
+	using supports_op_less
+		= decltype(meta_detail::supports_op_less_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
+	template <typename T, typename U = T>
+	using supports_op_equal
+		= decltype(meta_detail::supports_op_equal_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
+	template <typename T, typename U = T>
+	using supports_op_less_equal
+		= decltype(meta_detail::supports_op_less_equal_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
+	template <typename T, typename U = std::ostream>
+	using supports_ostream_op
+		= decltype(meta_detail::supports_ostream_op(std::declval<meta_detail::non_void_t<T>&>(), std::declval<const meta_detail::non_void_t<U>&>()));
+	template <typename T>
+	using supports_adl_to_string = decltype(meta_detail::supports_adl_to_string(std::declval<meta_detail::non_void_t<T>&>()));
+
+	template <typename T>
+	using supports_to_string_member = meta::boolean<meta_detail::has_to_string_test<meta_detail::non_void_t<T>>::value>;
+
+	template <typename T>
+	using is_callable = boolean<meta_detail::is_callable<T>::value>;
+
+	template <typename T>
+	constexpr inline bool is_callable_v = is_callable<T>::value;
+
+	template <typename T>
+	struct has_begin_end : decltype(meta_detail::has_begin_end_impl::test<T>(0)) {};
+
+	template <typename T>
+	constexpr inline bool has_begin_end_v = has_begin_end<T>::value;
+
+	template <typename T>
+	struct has_key_value_pair : decltype(meta_detail::has_key_value_pair_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_key_type : decltype(meta_detail::has_key_type_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_key_comp : decltype(meta_detail::has_key_comp_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_load_factor : decltype(meta_detail::has_load_factor_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_mapped_type : decltype(meta_detail::has_mapped_type_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_iterator : decltype(meta_detail::has_iterator_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_value_type : decltype(meta_detail::has_value_type_impl::test<T>(0)) {};
+
+	template <typename T>
+	using has_push_back = meta::boolean<meta_detail::has_push_back_test<T>::value>;
+
+	template <typename T>
+	using has_max_size = meta::boolean<meta_detail::has_max_size_test<T>::value>;
+
+	template <typename T>
+	using has_insert = meta::boolean<meta_detail::has_insert_test<T>::value>;
+
+	template <typename T>
+	using has_insert_after = meta::boolean<meta_detail::has_insert_after_test<T>::value>;
+
+	template <typename T>
+	using has_size = meta::boolean<meta_detail::has_size_test<T>::value>;
+
+	template <typename T>
+	using is_associative = meta::all<has_key_type<T>, has_key_value_pair<T>, has_mapped_type<T>>;
+
+	template <typename T>
+	using is_lookup = meta::all<has_key_type<T>, has_value_type<T>>;
+
+	template <typename T>
+	using is_ordered = meta::all<has_key_comp<T>, meta::neg<has_load_factor<T>>>;
+
+	template <typename T>
+	using is_matched_lookup = meta_detail::is_matched_lookup_impl<T, is_lookup<T>::value>;
+
+	template <typename T>
+	using is_initializer_list = meta::is_specialization_of<T, std::initializer_list>;
+
+	template <typename T>
+	constexpr inline bool is_initializer_list_v = is_initializer_list<T>::value;
+
+	template <typename T, typename CharT = char>
+	using is_string_literal_array_of = boolean<std::is_array_v<T> && std::is_same_v<std::remove_all_extents_t<T>, CharT>>;
+
+	template <typename T, typename CharT = char>
+	constexpr inline bool is_string_literal_array_of_v = is_string_literal_array_of<T, CharT>::value;
+
+	template <typename T>
+	using is_string_literal_array = boolean<std::is_array_v<T> && any_same_v<std::remove_all_extents_t<T>, char, char16_t, char32_t, wchar_t>>;
+
+	template <typename T>
+	constexpr inline bool is_string_literal_array_v = is_string_literal_array<T>::value;
+
+	template <typename T, typename CharT>
+	struct is_string_of : std::false_type {};
+
+	template <typename CharT, typename CharTargetT, typename TraitsT, typename AllocT>
+	struct is_string_of<std::basic_string<CharT, TraitsT, AllocT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
+
+	template <typename T, typename CharT>
+	constexpr inline bool is_string_of_v = is_string_of<T, CharT>::value;
+
+	template <typename T, typename CharT>
+	struct is_string_view_of : std::false_type {};
+
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
+	template <typename CharT, typename CharTargetT, typename TraitsT>
+	struct is_string_view_of<std::basic_string_view<CharT, TraitsT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
+#else
+	template <typename CharT, typename CharTargetT, typename TraitsT>
+	struct is_string_view_of<basic_string_view<CharT, TraitsT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
+#endif
+
+	template <typename T, typename CharT>
+	constexpr inline bool is_string_view_of_v = is_string_view_of<T, CharT>::value;
+
+	template <typename T>
+	using is_string_like = meta::boolean<is_specialization_of_v<T, std::basic_string>
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
+		|| is_specialization_of_v<T, std::basic_string_view>
+#else
+		|| is_specialization_of_v<T, basic_string_view>
+#endif
+		|| is_string_literal_array_v<T>>;
+
+	template <typename T>
+	constexpr inline bool is_string_like_v = is_string_like<T>::value;
+
+	template <typename T, typename CharT = char>
+	using is_string_constructible = meta::boolean<
+		is_string_literal_array_of_v<T,
+		     CharT> || std::is_same_v<T, const CharT*> || std::is_same_v<T, CharT> || is_string_of_v<T, CharT> || std::is_same_v<T, std::initializer_list<CharT>>
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
+		|| is_string_view_of_v<T, CharT>
+#endif
+		>;
+
+	template <typename T, typename CharT = char>
+	constexpr inline bool is_string_constructible_v = is_string_constructible<T, CharT>::value;
+
+	template <typename T>
+	using is_string_like_or_constructible = meta::boolean<is_string_like_v<T> || is_string_constructible_v<T>>;
+
+	template <typename T>
+	struct is_pair : std::false_type {};
+
+	template <typename T1, typename T2>
+	struct is_pair<std::pair<T1, T2>> : std::true_type {};
+
+	template <typename T, typename Char>
+	using is_c_str_of = any<std::is_same<T, const Char*>, std::is_same<T, Char const* const>, std::is_same<T, Char*>, is_string_of<T, Char>,
+		is_string_literal_array_of<T, Char>>;
+
+	template <typename T, typename Char>
+	constexpr inline bool is_c_str_of_v = is_c_str_of<T, Char>::value;
+
+	template <typename T>
+	using is_c_str = is_c_str_of<T, char>;
+
+	template <typename T>
+	constexpr inline bool is_c_str_v = is_c_str<T>::value;
+
+	template <typename T>
+	struct is_move_only : all<neg<std::is_reference<T>>, neg<std::is_copy_constructible<unqualified_t<T>>>, std::is_move_constructible<unqualified_t<T>>> {};
+
+	template <typename T>
+	using is_not_move_only = neg<is_move_only<T>>;
+
+	namespace meta_detail {
+		template <typename T>
+		decltype(auto) force_tuple(T&& x) {
+			if constexpr (meta::is_specialization_of_v<meta::unqualified_t<T>, std::tuple>) {
+				return std::forward<T>(x);
+			}
+			else {
+				return std::tuple<T>(std::forward<T>(x));
+			}
+		}
+	} // namespace meta_detail
+
+	template <typename... X>
+	decltype(auto) tuplefy(X&&... x) {
+		return std::tuple_cat(meta_detail::force_tuple(std::forward<X>(x))...);
+	}
+
+	template <typename T, typename = void>
+	struct iterator_tag {
+		using type = std::input_iterator_tag;
+	};
+
+	template <typename T>
+	struct iterator_tag<T, conditional_t<false, typename std::iterator_traits<T>::iterator_category, void>> {
+		using type = typename std::iterator_traits<T>::iterator_category;
+	};
+
+}} // namespace sol::meta
 
 #endif // SOL_TRAITS_HPP
diff --git a/include/sol/types.hpp b/include/sol/types.hpp
index 96c62e82..7607e531 100644
--- a/include/sol/types.hpp
+++ b/include/sol/types.hpp
@@ -1308,7 +1308,13 @@ namespace sol {
 	template <typename T>
 	struct is_automagical
 	: std::integral_constant<bool,
-	       std::is_array_v<meta::unqualified_t<T>> || !std::is_same_v<meta::unqualified_t<T>, state> || !std::is_same_v<meta::unqualified_t<T>, state_view>> {
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
+#if defined(SOL_STD_VARIANT) && SOL_STD_VARIANT != 0
+	       !meta::is_specialization_of_v<meta::unqualified_t<T>, std::variant> &&
+#endif // std::variant borked in places
+#endif // C++17 Features
+	                 std::is_array_v<
+	                      meta::unqualified_t<T>> || (!std::is_same_v<meta::unqualified_t<T>, state> && !std::is_same_v<meta::unqualified_t<T>, state_view>)> {
 	};
 
 	template <typename T>
diff --git a/include/sol/usertype_core.hpp b/include/sol/usertype_core.hpp
index cb57a041..8ab3a67c 100644
--- a/include/sol/usertype_core.hpp
+++ b/include/sol/usertype_core.hpp
@@ -172,11 +172,11 @@ namespace sol {
 		template <typename X>
 		void set_undefined_methods_on(stack_reference t) {
 			using T = std::remove_pointer_t<X>;
-			
+
 			lua_State* L = t.lua_state();
-			
+
 			t.push();
-			
+
 			detail::lua_reg_table l{};
 			int index = 0;
 			detail::indexed_insert insert_fx(l, index);
@@ -185,7 +185,7 @@ namespace sol {
 				l[index] = luaL_Reg{ to_string(meta_function::garbage_collect).c_str(), detail::make_destructor<T>() };
 			}
 			luaL_setfuncs(L, l, 0);
-			
+
 			// __type table
 			lua_createtable(L, 0, 2);
 			const std::string& name = detail::demangle<T>();
diff --git a/single/include/sol/forward.hpp b/single/include/sol/forward.hpp
index 35c478a4..140acb94 100644
--- a/single/include/sol/forward.hpp
+++ b/single/include/sol/forward.hpp
@@ -20,8 +20,8 @@
 // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 // This file was generated with a script.
-// Generated 2019-11-29 18:08:19.653548 UTC
-// This header was generated with sol v3.0.3 (revision 21c0309)
+// Generated 2019-12-01 22:39:33.269777 UTC
+// This header was generated with sol v3.2.0 (revision e26475e)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_FORWARD_HPP
diff --git a/single/include/sol/sol.hpp b/single/include/sol/sol.hpp
index 2758aad3..d68bfd25 100644
--- a/single/include/sol/sol.hpp
+++ b/single/include/sol/sol.hpp
@@ -20,8 +20,8 @@
 // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 // This file was generated with a script.
-// Generated 2019-11-29 18:08:19.142496 UTC
-// This header was generated with sol v3.0.3 (revision 21c0309)
+// Generated 2019-12-01 22:39:31.432773 UTC
+// This header was generated with sol v3.2.0 (revision e26475e)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_HPP
@@ -1413,671 +1413,668 @@ namespace sol {
 #include <iterator>
 #include <iosfwd>
 
-namespace sol {
-	namespace meta {
-		template <typename T>
-		struct unwrapped {
-			typedef T type;
+namespace sol { namespace meta {
+	template <typename T>
+	struct unwrapped {
+		typedef T type;
+	};
+
+	template <typename T>
+	struct unwrapped<std::reference_wrapper<T>> {
+		typedef T type;
+	};
+
+	template <typename T>
+	using unwrapped_t = typename unwrapped<T>::type;
+
+	template <typename T>
+	struct unwrap_unqualified : unwrapped<unqualified_t<T>> {};
+
+	template <typename T>
+	using unwrap_unqualified_t = typename unwrap_unqualified<T>::type;
+
+	template <typename T>
+	struct remove_member_pointer;
+
+	template <typename R, typename T>
+	struct remove_member_pointer<R T::*> {
+		typedef R type;
+	};
+
+	template <typename R, typename T>
+	struct remove_member_pointer<R T::*const> {
+		typedef R type;
+	};
+
+	template <typename T>
+	using remove_member_pointer_t = remove_member_pointer<T>;
+
+	template <typename T, typename...>
+	struct all_same : std::true_type {};
+
+	template <typename T, typename U, typename... Args>
+	struct all_same<T, U, Args...> : std::integral_constant<bool, std::is_same<T, U>::value && all_same<T, Args...>::value> {};
+
+	template <typename T, typename...>
+	struct any_same : std::false_type {};
+
+	template <typename T, typename U, typename... Args>
+	struct any_same<T, U, Args...> : std::integral_constant<bool, std::is_same<T, U>::value || any_same<T, Args...>::value> {};
+
+	template <typename T, typename... Args>
+	constexpr inline bool any_same_v = any_same<T, Args...>::value;
+
+	template <bool B>
+	using boolean = std::integral_constant<bool, B>;
+
+	template <bool B>
+	constexpr inline bool boolean_v = boolean<B>::value;
+
+	template <typename T>
+	using neg = boolean<!T::value>;
+
+	template <typename T>
+	constexpr inline bool neg_v = neg<T>::value;
+
+	template <typename... Args>
+	struct all : boolean<true> {};
+
+	template <typename T, typename... Args>
+	struct all<T, Args...> : std::conditional_t<T::value, all<Args...>, boolean<false>> {};
+
+	template <typename... Args>
+	struct any : boolean<false> {};
+
+	template <typename T, typename... Args>
+	struct any<T, Args...> : std::conditional_t<T::value, boolean<true>, any<Args...>> {};
+
+	template <typename T, typename... Args>
+	constexpr inline bool all_v = all<T, Args...>::value;
+
+	template <typename T, typename... Args>
+	constexpr inline bool any_v = any<T, Args...>::value;
+
+	enum class enable_t { _ };
+
+	constexpr const auto enabler = enable_t::_;
+
+	template <bool value, typename T = void>
+	using disable_if_t = std::enable_if_t<!value, T>;
+
+	template <typename... Args>
+	using enable = std::enable_if_t<all<Args...>::value, enable_t>;
+
+	template <typename... Args>
+	using disable = std::enable_if_t<neg<all<Args...>>::value, enable_t>;
+
+	template <typename... Args>
+	using enable_any = std::enable_if_t<any<Args...>::value, enable_t>;
+
+	template <typename... Args>
+	using disable_any = std::enable_if_t<neg<any<Args...>>::value, enable_t>;
+
+	template <typename V, typename... Vs>
+	struct find_in_pack_v : boolean<false> {};
+
+	template <typename V, typename Vs1, typename... Vs>
+	struct find_in_pack_v<V, Vs1, Vs...> : any<boolean<(V::value == Vs1::value)>, find_in_pack_v<V, Vs...>> {};
+
+	namespace meta_detail {
+		template <std::size_t I, typename T, typename... Args>
+		struct index_in_pack : std::integral_constant<std::size_t, SIZE_MAX> {};
+
+		template <std::size_t I, typename T, typename T1, typename... Args>
+		struct index_in_pack<I, T, T1, Args...>
+		: conditional_t<std::is_same<T, T1>::value, std::integral_constant<std::ptrdiff_t, I>, index_in_pack<I + 1, T, Args...>> {};
+	} // namespace meta_detail
+
+	template <typename T, typename... Args>
+	struct index_in_pack : meta_detail::index_in_pack<0, T, Args...> {};
+
+	template <typename T, typename List>
+	struct index_in : meta_detail::index_in_pack<0, T, List> {};
+
+	template <typename T, typename... Args>
+	struct index_in<T, types<Args...>> : meta_detail::index_in_pack<0, T, Args...> {};
+
+	template <std::size_t I, typename... Args>
+	struct at_in_pack {};
+
+	template <std::size_t I, typename... Args>
+	using at_in_pack_t = typename at_in_pack<I, Args...>::type;
+
+	template <std::size_t I, typename Arg, typename... Args>
+	struct at_in_pack<I, Arg, Args...> : std::conditional<I == 0, Arg, at_in_pack_t<I - 1, Args...>> {};
+
+	template <typename Arg, typename... Args>
+	struct at_in_pack<0, Arg, Args...> {
+		typedef Arg type;
+	};
+
+	namespace meta_detail {
+		template <typename, typename TI>
+		using on_even = meta::boolean<(TI::value % 2) == 0>;
+
+		template <typename, typename TI>
+		using on_odd = meta::boolean<(TI::value % 2) == 1>;
+
+		template <typename, typename>
+		using on_always = std::true_type;
+
+		template <template <typename...> class When, std::size_t Limit, std::size_t I, template <typename...> class Pred, typename... Ts>
+		struct count_when_for_pack : std::integral_constant<std::size_t, 0> {};
+		template <template <typename...> class When, std::size_t Limit, std::size_t I, template <typename...> class Pred, typename T, typename... Ts>
+			          struct count_when_for_pack<When, Limit, I, Pred, T, Ts...> : conditional_t < sizeof...(Ts)
+			     == 0
+			|| Limit<2, std::integral_constant<std::size_t, I + static_cast<std::size_t>(Limit != 0 && Pred<T>::value)>,
+			        count_when_for_pack<When, Limit - static_cast<std::size_t>(When<T, std::integral_constant<std::size_t, I>>::value),
+			             I + static_cast<std::size_t>(When<T, std::integral_constant<std::size_t, I>>::value&& Pred<T>::value), Pred, Ts...>> {};
+	} // namespace meta_detail
+
+	template <template <typename...> class Pred, typename... Ts>
+	struct count_for_pack : meta_detail::count_when_for_pack<meta_detail::on_always, sizeof...(Ts), 0, Pred, Ts...> {};
+
+	template <template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_for_pack_v = count_for_pack<Pred, Ts...>::value;
+
+	template <template <typename...> class Pred, typename List>
+	struct count_for;
+
+	template <template <typename...> class Pred, typename... Args>
+	struct count_for<Pred, types<Args...>> : count_for_pack<Pred, Args...> {};
+
+	template <std::size_t Limit, template <typename...> class Pred, typename... Ts>
+	struct count_for_to_pack : meta_detail::count_when_for_pack<meta_detail::on_always, Limit, 0, Pred, Ts...> {};
+
+	template <std::size_t Limit, template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_for_to_pack_v = count_for_to_pack<Limit, Pred, Ts...>::value;
+
+	template <template <typename...> class When, std::size_t Limit, template <typename...> class Pred, typename... Ts>
+	struct count_when_for_to_pack : meta_detail::count_when_for_pack<When, Limit, 0, Pred, Ts...> {};
+
+	template <template <typename...> class When, std::size_t Limit, template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_when_for_to_pack_v = count_when_for_to_pack<When, Limit, Pred, Ts...>::value;
+
+	template <template <typename...> class Pred, typename... Ts>
+	using count_even_for_pack = count_when_for_to_pack<meta_detail::on_even, sizeof...(Ts), Pred, Ts...>;
+
+	template <template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_even_for_pack_v = count_even_for_pack<Pred, Ts...>::value;
+
+	template <template <typename...> class Pred, typename... Ts>
+	using count_odd_for_pack = count_when_for_to_pack<meta_detail::on_odd, sizeof...(Ts), Pred, Ts...>;
+
+	template <template <typename...> class Pred, typename... Ts>
+	inline constexpr std::size_t count_odd_for_pack_v = count_odd_for_pack<Pred, Ts...>::value;
+
+	template <typename... Args>
+	struct return_type {
+		typedef std::tuple<Args...> type;
+	};
+
+	template <typename T>
+	struct return_type<T> {
+		typedef T type;
+	};
+
+	template <>
+	struct return_type<> {
+		typedef void type;
+	};
+
+	template <typename... Args>
+	using return_type_t = typename return_type<Args...>::type;
+
+	namespace meta_detail {
+		template <typename>
+		struct always_true : std::true_type {};
+		struct is_invokable_tester {
+			template <typename Fun, typename... Args>
+			static always_true<decltype(std::declval<Fun>()(std::declval<Args>()...))> test(int);
+			template <typename...>
+			static std::false_type test(...);
 		};
+	} // namespace meta_detail
 
-		template <typename T>
-		struct unwrapped<std::reference_wrapper<T>> {
-			typedef T type;
-		};
+	template <typename T>
+	struct is_invokable;
+	template <typename Fun, typename... Args>
+	struct is_invokable<Fun(Args...)> : decltype(meta_detail::is_invokable_tester::test<Fun, Args...>(0)) {};
 
-		template <typename T>
-		using unwrapped_t = typename unwrapped<T>::type;
-
-		template <typename T>
-		struct unwrap_unqualified : unwrapped<unqualified_t<T>> {};
-
-		template <typename T>
-		using unwrap_unqualified_t = typename unwrap_unqualified<T>::type;
-
-		template <typename T>
-		struct remove_member_pointer;
-
-		template <typename R, typename T>
-		struct remove_member_pointer<R T::*> {
-			typedef R type;
-		};
-
-		template <typename R, typename T>
-		struct remove_member_pointer<R T::*const> {
-			typedef R type;
-		};
-
-		template <typename T>
-		using remove_member_pointer_t = remove_member_pointer<T>;
-
-		template <typename T, typename...>
-		struct all_same : std::true_type {};
-
-		template <typename T, typename U, typename... Args>
-		struct all_same<T, U, Args...> : std::integral_constant<bool, std::is_same<T, U>::value && all_same<T, Args...>::value> {};
-
-		template <typename T, typename...>
-		struct any_same : std::false_type {};
-
-		template <typename T, typename U, typename... Args>
-		struct any_same<T, U, Args...> : std::integral_constant<bool, std::is_same<T, U>::value || any_same<T, Args...>::value> {};
-
-		template <typename T, typename... Args>
-		constexpr inline bool any_same_v = any_same<T, Args...>::value;
-
-		template <bool B>
-		using boolean = std::integral_constant<bool, B>;
-
-		template <bool B>
-		constexpr inline bool boolean_v = boolean<B>::value;
-
-		template <typename T>
-		using neg = boolean<!T::value>;
-
-		template <typename T>
-		constexpr inline bool neg_v = neg<T>::value;
-
-		template <typename... Args>
-		struct all : boolean<true> {};
-
-		template <typename T, typename... Args>
-		struct all<T, Args...> : std::conditional_t<T::value, all<Args...>, boolean<false>> {};
-
-		template <typename... Args>
-		struct any : boolean<false> {};
-
-		template <typename T, typename... Args>
-		struct any<T, Args...> : std::conditional_t<T::value, boolean<true>, any<Args...>> {};
-
-		template <typename T, typename... Args>
-		constexpr inline bool all_v = all<T, Args...>::value;
-
-		template <typename T, typename... Args>
-		constexpr inline bool any_v = any<T, Args...>::value;
-
-		enum class enable_t { _ };
-
-		constexpr const auto enabler = enable_t::_;
-
-		template <bool value, typename T = void>
-		using disable_if_t = std::enable_if_t<!value, T>;
-
-		template <typename... Args>
-		using enable = std::enable_if_t<all<Args...>::value, enable_t>;
-
-		template <typename... Args>
-		using disable = std::enable_if_t<neg<all<Args...>>::value, enable_t>;
-
-		template <typename... Args>
-		using enable_any = std::enable_if_t<any<Args...>::value, enable_t>;
-
-		template <typename... Args>
-		using disable_any = std::enable_if_t<neg<any<Args...>>::value, enable_t>;
-
-		template <typename V, typename... Vs>
-		struct find_in_pack_v : boolean<false> {};
-
-		template <typename V, typename Vs1, typename... Vs>
-		struct find_in_pack_v<V, Vs1, Vs...> : any<boolean<(V::value == Vs1::value)>, find_in_pack_v<V, Vs...>> {};
-
-		namespace meta_detail {
-			template <std::size_t I, typename T, typename... Args>
-			struct index_in_pack : std::integral_constant<std::size_t, SIZE_MAX> {};
-
-			template <std::size_t I, typename T, typename T1, typename... Args>
-			struct index_in_pack<I, T, T1, Args...>
-			: conditional_t<std::is_same<T, T1>::value, std::integral_constant<std::ptrdiff_t, I>, index_in_pack<I + 1, T, Args...>> {};
-		} // namespace meta_detail
-
-		template <typename T, typename... Args>
-		struct index_in_pack : meta_detail::index_in_pack<0, T, Args...> {};
-
-		template <typename T, typename List>
-		struct index_in : meta_detail::index_in_pack<0, T, List> {};
-
-		template <typename T, typename... Args>
-		struct index_in<T, types<Args...>> : meta_detail::index_in_pack<0, T, Args...> {};
-
-		template <std::size_t I, typename... Args>
-		struct at_in_pack {};
-
-		template <std::size_t I, typename... Args>
-		using at_in_pack_t = typename at_in_pack<I, Args...>::type;
-
-		template <std::size_t I, typename Arg, typename... Args>
-		struct at_in_pack<I, Arg, Args...> : std::conditional<I == 0, Arg, at_in_pack_t<I - 1, Args...>> {};
-
-		template <typename Arg, typename... Args>
-		struct at_in_pack<0, Arg, Args...> {
-			typedef Arg type;
-		};
-
-		namespace meta_detail {
-			template <typename, typename TI>
-			using on_even = meta::boolean<(TI::value % 2) == 0>;
-
-			template <typename, typename TI>
-			using on_odd = meta::boolean<(TI::value % 2) == 1>;
-
-			template <typename, typename>
-			using on_always = std::true_type;
-
-			template <template <typename...> class When, std::size_t Limit, std::size_t I, template <typename...> class Pred, typename... Ts>
-			struct count_when_for_pack : std::integral_constant<std::size_t, 0> {};
-			template <template <typename...> class When, std::size_t Limit, std::size_t I, template <typename...> class Pred, typename T, typename... Ts>
-			struct count_when_for_pack<When, Limit, I, Pred, T, Ts...> : conditional_t<
-				sizeof...(Ts) == 0 || Limit < 2,
-					std::integral_constant<std::size_t, I + static_cast<std::size_t>(Limit != 0 && Pred<T>::value)>,
-			     	count_when_for_pack<When, Limit - static_cast<std::size_t>(When<T, std::integral_constant<std::size_t, I>>::value), I + static_cast<std::size_t>(When<T, std::integral_constant<std::size_t, I>>::value && Pred<T>::value), Pred, Ts...>
-			> {};
-		} // namespace meta_detail
-
-		template <template <typename...> class Pred, typename... Ts>
-		struct count_for_pack : meta_detail::count_when_for_pack<meta_detail::on_always, sizeof...(Ts), 0, Pred, Ts...> {};
-
-		template <template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_for_pack_v = count_for_pack<Pred, Ts...>::value;
-
-		template <template <typename...> class Pred, typename List>
-		struct count_for;
-
-		template <template <typename...> class Pred, typename... Args>
-		struct count_for<Pred, types<Args...>> : count_for_pack<Pred, Args...> {};
-
-		template <std::size_t Limit, template <typename...> class Pred, typename... Ts>
-		struct count_for_to_pack : meta_detail::count_when_for_pack<meta_detail::on_always, Limit, 0, Pred, Ts...> {};
-
-		template <std::size_t Limit, template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_for_to_pack_v = count_for_to_pack<Limit, Pred, Ts...>::value;
-
-		template <template <typename...> class When, std::size_t Limit, template <typename...> class Pred, typename... Ts>
-		struct count_when_for_to_pack : meta_detail::count_when_for_pack<When, Limit, 0, Pred, Ts...> {};
-
-		template <template <typename...> class When, std::size_t Limit, template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_when_for_to_pack_v = count_when_for_to_pack<When, Limit, Pred, Ts...>::value;
-
-		template <template <typename...> class Pred, typename... Ts>
-		using count_even_for_pack = count_when_for_to_pack<meta_detail::on_even, sizeof...(Ts), Pred, Ts...>;
-
-		template <template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_even_for_pack_v = count_even_for_pack<Pred, Ts...>::value;
-
-		template <template <typename...> class Pred, typename... Ts>
-		using count_odd_for_pack = count_when_for_to_pack<meta_detail::on_odd, sizeof...(Ts), Pred, Ts...>;
-
-		template <template <typename...> class Pred, typename... Ts>
-		inline constexpr std::size_t count_odd_for_pack_v = count_odd_for_pack<Pred, Ts...>::value;
-
-		template <typename... Args>
-		struct return_type {
-			typedef std::tuple<Args...> type;
-		};
-
-		template <typename T>
-		struct return_type<T> {
-			typedef T type;
-		};
-
-		template <>
-		struct return_type<> {
-			typedef void type;
-		};
-
-		template <typename... Args>
-		using return_type_t = typename return_type<Args...>::type;
-
-		namespace meta_detail {
-			template <typename>
-			struct always_true : std::true_type {};
-			struct is_invokable_tester {
-				template <typename Fun, typename... Args>
-				static always_true<decltype(std::declval<Fun>()(std::declval<Args>()...))> test(int);
-				template <typename...>
-				static std::false_type test(...);
-			};
-		} // namespace meta_detail
-
-		template <typename T>
-		struct is_invokable;
-		template <typename Fun, typename... Args>
-		struct is_invokable<Fun(Args...)> : decltype(meta_detail::is_invokable_tester::test<Fun, Args...>(0)) {};
-
-		namespace meta_detail {
-
-			template <typename T, typename = void>
-			struct is_callable : std::is_function<std::remove_pointer_t<T>> {};
-
-			template <typename T>
-			struct is_callable<T,
-			     std::enable_if_t<std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
-			          && std::is_same<decltype(void(&T::operator())), void>::value>> {};
-
-			template <typename T>
-			struct is_callable<T,
-			     std::enable_if_t<!std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
-			          && std::is_destructible<unqualified_t<T>>::value>> {
-				struct F {
-					void operator()() {};
-				};
-				struct Derived : T, F {};
-				template <typename U, U>
-				struct Check;
-
-				template <typename V>
-				static sfinae_no_t test(Check<void (F::*)(), &V::operator()>*);
-
-				template <typename>
-				static sfinae_yes_t test(...);
-
-				static constexpr bool value = std::is_same_v<decltype(test<Derived>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct is_callable<T,
-			     std::enable_if_t<!std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
-			          && !std::is_destructible<unqualified_t<T>>::value>> {
-				struct F {
-					void operator()() {};
-				};
-				struct Derived : T, F {
-					~Derived() = delete;
-				};
-				template <typename U, U>
-				struct Check;
-
-				template <typename V>
-				static sfinae_no_t test(Check<void (F::*)(), &V::operator()>*);
-
-				template <typename>
-				static sfinae_yes_t test(...);
-
-				static constexpr bool value = std::is_same_v<decltype(test<Derived>(0)), sfinae_yes_t>;
-			};
-
-			struct has_begin_end_impl {
-				template <typename T, typename U = unqualified_t<T>, typename B = decltype(std::declval<U&>().begin()),
-				     typename E = decltype(std::declval<U&>().end())>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_key_type_impl {
-				template <typename T, typename U = unqualified_t<T>, typename V = typename U::key_type>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_key_comp_impl {
-				template <typename T, typename V = decltype(std::declval<unqualified_t<T>>().key_comp())>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_load_factor_impl {
-				template <typename T, typename V = decltype(std::declval<unqualified_t<T>>().load_factor())>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_mapped_type_impl {
-				template <typename T, typename V = typename unqualified_t<T>::mapped_type>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_value_type_impl {
-				template <typename T, typename V = typename unqualified_t<T>::value_type>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_iterator_impl {
-				template <typename T, typename V = typename unqualified_t<T>::iterator>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			struct has_key_value_pair_impl {
-				template <typename T, typename U = unqualified_t<T>, typename V = typename U::value_type, typename F = decltype(std::declval<V&>().first),
-				     typename S = decltype(std::declval<V&>().second)>
-				static std::true_type test(int);
-
-				template <typename...>
-				static std::false_type test(...);
-			};
-
-			template <typename T>
-			struct has_push_back_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().push_back(std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_insert_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().insert(std::declval<std::add_rvalue_reference_t<typename C::const_iterator>>(),
-				     std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_insert_after_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().insert_after(std::declval<std::add_rvalue_reference_t<typename C::const_iterator>>(),
-				     std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_size_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().size())*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_max_size_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().max_size())*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-			template <typename T>
-			struct has_to_string_test {
-			private:
-				template <typename C>
-				static sfinae_yes_t test(decltype(std::declval<C>().to_string())*);
-				template <typename C>
-				static sfinae_no_t test(...);
-
-			public:
-				static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
-			};
-
-#if defined(_MSC_VER) && _MSC_VER <= 1910
-			template <typename T, typename U, typename = decltype(std::declval<T&>() < std::declval<U&>())>
-			std::true_type supports_op_less_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
-			std::false_type supports_op_less_test(...);
-			template <typename T, typename U, typename = decltype(std::declval<T&>() == std::declval<U&>())>
-			std::true_type supports_op_equal_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
-			std::false_type supports_op_equal_test(...);
-			template <typename T, typename U, typename = decltype(std::declval<T&>() <= std::declval<U&>())>
-			std::true_type supports_op_less_equal_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
-			std::false_type supports_op_less_equal_test(...);
-			template <typename T, typename OS, typename = decltype(std::declval<OS&>() << std::declval<T&>())>
-			std::true_type supports_ostream_op(std::reference_wrapper<T>, std::reference_wrapper<OS>);
-			std::false_type supports_ostream_op(...);
-			template <typename T, typename = decltype(to_string(std::declval<T&>()))>
-			std::true_type supports_adl_to_string(std::reference_wrapper<T>);
-			std::false_type supports_adl_to_string(...);
-#else
-			template <typename T, typename U, typename = decltype(std::declval<T&>() < std::declval<U&>())>
-			std::true_type supports_op_less_test(const T&, const U&);
-			std::false_type supports_op_less_test(...);
-			template <typename T, typename U, typename = decltype(std::declval<T&>() == std::declval<U&>())>
-			std::true_type supports_op_equal_test(const T&, const U&);
-			std::false_type supports_op_equal_test(...);
-			template <typename T, typename U, typename = decltype(std::declval<T&>() <= std::declval<U&>())>
-			std::true_type supports_op_less_equal_test(const T&, const U&);
-			std::false_type supports_op_less_equal_test(...);
-			template <typename T, typename OS, typename = decltype(std::declval<OS&>() << std::declval<T&>())>
-			std::true_type supports_ostream_op(const T&, const OS&);
-			std::false_type supports_ostream_op(...);
-			template <typename T, typename = decltype(to_string(std::declval<T&>()))>
-			std::true_type supports_adl_to_string(const T&);
-			std::false_type supports_adl_to_string(...);
-#endif
-
-			template <typename T, bool b>
-			struct is_matched_lookup_impl : std::false_type {};
-			template <typename T>
-			struct is_matched_lookup_impl<T, true> : std::is_same<typename T::key_type, typename T::value_type> {};
-
-			template <typename T>
-			using non_void_t = meta::conditional_t<std::is_void_v<T>, ::sol::detail::unchecked_t, T>;
-		} // namespace meta_detail
-
-		template <typename T, typename U = T>
-		using supports_op_less
-		     = decltype(meta_detail::supports_op_less_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
-		template <typename T, typename U = T>
-		using supports_op_equal
-		     = decltype(meta_detail::supports_op_equal_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
-		template <typename T, typename U = T>
-		using supports_op_less_equal
-		     = decltype(meta_detail::supports_op_less_equal_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
-		template <typename T, typename U = std::ostream>
-		using supports_ostream_op
-		     = decltype(meta_detail::supports_ostream_op(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
-		template <typename T>
-		using supports_adl_to_string = decltype(meta_detail::supports_adl_to_string(std::declval<meta_detail::non_void_t<T>&>()));
-
-		template <typename T>
-		using supports_to_string_member = meta::boolean<meta_detail::has_to_string_test<meta_detail::non_void_t<T>>::value>;
-
-		template <typename T>
-		using is_callable = boolean<meta_detail::is_callable<T>::value>;
-
-		template <typename T>
-		constexpr inline bool is_callable_v = is_callable<T>::value;
-
-		template <typename T>
-		struct has_begin_end : decltype(meta_detail::has_begin_end_impl::test<T>(0)) {};
-
-		template <typename T>
-		constexpr inline bool has_begin_end_v = has_begin_end<T>::value;
-
-		template <typename T>
-		struct has_key_value_pair : decltype(meta_detail::has_key_value_pair_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_key_type : decltype(meta_detail::has_key_type_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_key_comp : decltype(meta_detail::has_key_comp_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_load_factor : decltype(meta_detail::has_load_factor_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_mapped_type : decltype(meta_detail::has_mapped_type_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_iterator : decltype(meta_detail::has_iterator_impl::test<T>(0)) {};
-
-		template <typename T>
-		struct has_value_type : decltype(meta_detail::has_value_type_impl::test<T>(0)) {};
-
-		template <typename T>
-		using has_push_back = meta::boolean<meta_detail::has_push_back_test<T>::value>;
-
-		template <typename T>
-		using has_max_size = meta::boolean<meta_detail::has_max_size_test<T>::value>;
-
-		template <typename T>
-		using has_insert = meta::boolean<meta_detail::has_insert_test<T>::value>;
-
-		template <typename T>
-		using has_insert_after = meta::boolean<meta_detail::has_insert_after_test<T>::value>;
-
-		template <typename T>
-		using has_size = meta::boolean<meta_detail::has_size_test<T>::value>;
-
-		template <typename T>
-		using is_associative = meta::all<has_key_type<T>, has_key_value_pair<T>, has_mapped_type<T>>;
-
-		template <typename T>
-		using is_lookup = meta::all<has_key_type<T>, has_value_type<T>>;
-
-		template <typename T>
-		using is_ordered = meta::all<has_key_comp<T>, meta::neg<has_load_factor<T>>>;
-
-		template <typename T>
-		using is_matched_lookup = meta_detail::is_matched_lookup_impl<T, is_lookup<T>::value>;
-
-		template <typename T>
-		using is_initializer_list = meta::is_specialization_of<T, std::initializer_list>;
-
-		template <typename T>
-		constexpr inline bool is_initializer_list_v = is_initializer_list<T>::value;
-
-		template <typename T, typename CharT = char>
-		using is_string_literal_array_of = boolean<std::is_array_v<T> && std::is_same_v<std::remove_all_extents_t<T>, CharT>>;
-
-		template <typename T, typename CharT = char>
-		constexpr inline bool is_string_literal_array_of_v = is_string_literal_array_of<T, CharT>::value;
-
-		template <typename T>
-		using is_string_literal_array = boolean<std::is_array_v<T> && any_same_v<std::remove_all_extents_t<T>, char, char16_t, char32_t, wchar_t>>;
-
-		template <typename T>
-		constexpr inline bool is_string_literal_array_v = is_string_literal_array<T>::value;
-
-		template <typename T, typename CharT>
-		struct is_string_of : std::false_type {};
-
-		template <typename CharT, typename CharTargetT, typename TraitsT, typename AllocT>
-		struct is_string_of<std::basic_string<CharT, TraitsT, AllocT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
-
-		template <typename T, typename CharT>
-		constexpr inline bool is_string_of_v = is_string_of<T, CharT>::value;
-
-		template <typename T, typename CharT>
-		struct is_string_view_of : std::false_type {};
-
-#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
-		template <typename CharT, typename CharTargetT, typename TraitsT>
-		struct is_string_view_of<std::basic_string_view<CharT, TraitsT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
-#else
-		template <typename CharT, typename CharTargetT, typename TraitsT>
-		struct is_string_view_of<basic_string_view<CharT, TraitsT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
-#endif
-
-		template <typename T, typename CharT>
-		constexpr inline bool is_string_view_of_v = is_string_view_of<T, CharT>::value;
-
-		template <typename T>
-		using is_string_like = meta::boolean<is_specialization_of_v<T, std::basic_string>
-#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
-		     || is_specialization_of_v<T, std::basic_string_view>
-#else
-		     || is_specialization_of_v<T, basic_string_view>
-#endif
-		     || is_string_literal_array_v<T>>;
-
-		template <typename T>
-		constexpr inline bool is_string_like_v = is_string_like<T>::value;
-
-		template <typename T, typename CharT = char>
-		using is_string_constructible = meta::boolean<
-		     is_string_literal_array_of_v<T,
-		          CharT> || std::is_same_v<T, const CharT*> || std::is_same_v<T, CharT> || is_string_of_v<T, CharT> || std::is_same_v<T, std::initializer_list<CharT>>
-#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
-		     || is_string_view_of_v<T, CharT>
-#endif
-		     >;
-
-		template <typename T, typename CharT = char>
-		constexpr inline bool is_string_constructible_v = is_string_constructible<T, CharT>::value;
-
-		template <typename T>
-		using is_string_like_or_constructible = meta::boolean<is_string_like_v<T> || is_string_constructible_v<T>>;
-
-		template <typename T>
-		struct is_pair : std::false_type {};
-
-		template <typename T1, typename T2>
-		struct is_pair<std::pair<T1, T2>> : std::true_type {};
-
-		template <typename T, typename Char>
-		using is_c_str_of = any<std::is_same<T, const Char*>, std::is_same<T, Char const* const>, std::is_same<T, Char*>, is_string_of<T, Char>,
-		     is_string_literal_array_of<T, Char>>;
-
-		template <typename T, typename Char>
-		constexpr inline bool is_c_str_of_v = is_c_str_of<T, Char>::value;
-
-		template <typename T>
-		using is_c_str = is_c_str_of<T, char>;
-
-		template <typename T>
-		constexpr inline bool is_c_str_v = is_c_str<T>::value;
-
-		template <typename T>
-		struct is_move_only
-		: all<neg<std::is_reference<T>>, neg<std::is_copy_constructible<unqualified_t<T>>>, std::is_move_constructible<unqualified_t<T>>> {};
-
-		template <typename T>
-		using is_not_move_only = neg<is_move_only<T>>;
-
-		namespace meta_detail {
-			template <typename T>
-			decltype(auto) force_tuple(T&& x) {
-				if constexpr (meta::is_specialization_of_v<meta::unqualified_t<T>, std::tuple>) {
-					return std::forward<T>(x);
-				}
-				else {
-					return std::tuple<T>(std::forward<T>(x));
-				}
-			}
-		} // namespace meta_detail
-
-		template <typename... X>
-		decltype(auto) tuplefy(X&&... x) {
-			return std::tuple_cat(meta_detail::force_tuple(std::forward<X>(x))...);
-		}
+	namespace meta_detail {
 
 		template <typename T, typename = void>
-		struct iterator_tag {
-			using type = std::input_iterator_tag;
+		struct is_callable : std::is_function<std::remove_pointer_t<T>> {};
+
+		template <typename T>
+		struct is_callable<T,
+			std::enable_if_t<std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
+			     && std::is_same<decltype(void(&T::operator())), void>::value>> {};
+
+		template <typename T>
+		struct is_callable<T,
+			std::enable_if_t<!std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
+			     && std::is_destructible<unqualified_t<T>>::value>> {
+			struct F {
+				void operator()(){};
+			};
+			struct Derived : T, F {};
+			template <typename U, U>
+			struct Check;
+
+			template <typename V>
+			static sfinae_no_t test(Check<void (F::*)(), &V::operator()>*);
+
+			template <typename>
+			static sfinae_yes_t test(...);
+
+			static constexpr bool value = std::is_same_v<decltype(test<Derived>(0)), sfinae_yes_t>;
 		};
 
 		template <typename T>
-		struct iterator_tag<T, conditional_t<false, typename std::iterator_traits<T>::iterator_category, void>> {
-			using type = typename std::iterator_traits<T>::iterator_category;
+		struct is_callable<T,
+			std::enable_if_t<!std::is_final<unqualified_t<T>>::value && std::is_class<unqualified_t<T>>::value
+			     && !std::is_destructible<unqualified_t<T>>::value>> {
+			struct F {
+				void operator()(){};
+			};
+			struct Derived : T, F {
+				~Derived() = delete;
+			};
+			template <typename U, U>
+			struct Check;
+
+			template <typename V>
+			static sfinae_no_t test(Check<void (F::*)(), &V::operator()>*);
+
+			template <typename>
+			static sfinae_yes_t test(...);
+
+			static constexpr bool value = std::is_same_v<decltype(test<Derived>(0)), sfinae_yes_t>;
 		};
 
-	} // namespace meta
-} // namespace sol
+		struct has_begin_end_impl {
+			template <typename T, typename U = unqualified_t<T>, typename B = decltype(std::declval<U&>().begin()),
+				typename E = decltype(std::declval<U&>().end())>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_key_type_impl {
+			template <typename T, typename U = unqualified_t<T>, typename V = typename U::key_type>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_key_comp_impl {
+			template <typename T, typename V = decltype(std::declval<unqualified_t<T>>().key_comp())>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_load_factor_impl {
+			template <typename T, typename V = decltype(std::declval<unqualified_t<T>>().load_factor())>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_mapped_type_impl {
+			template <typename T, typename V = typename unqualified_t<T>::mapped_type>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_value_type_impl {
+			template <typename T, typename V = typename unqualified_t<T>::value_type>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_iterator_impl {
+			template <typename T, typename V = typename unqualified_t<T>::iterator>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		struct has_key_value_pair_impl {
+			template <typename T, typename U = unqualified_t<T>, typename V = typename U::value_type, typename F = decltype(std::declval<V&>().first),
+				typename S = decltype(std::declval<V&>().second)>
+			static std::true_type test(int);
+
+			template <typename...>
+			static std::false_type test(...);
+		};
+
+		template <typename T>
+		struct has_push_back_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().push_back(std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_insert_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().insert(std::declval<std::add_rvalue_reference_t<typename C::const_iterator>>(),
+				std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_insert_after_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().insert_after(std::declval<std::add_rvalue_reference_t<typename C::const_iterator>>(),
+				std::declval<std::add_rvalue_reference_t<typename C::value_type>>()))*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_size_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().size())*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_max_size_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().max_size())*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+		template <typename T>
+		struct has_to_string_test {
+		private:
+			template <typename C>
+			static sfinae_yes_t test(decltype(std::declval<C>().to_string())*);
+			template <typename C>
+			static sfinae_no_t test(...);
+
+		public:
+			static constexpr bool value = std::is_same_v<decltype(test<T>(0)), sfinae_yes_t>;
+		};
+
+#if defined(_MSC_VER) && _MSC_VER <= 1910
+		template <typename T, typename U, typename = decltype(std::declval<T&>() < std::declval<U&>())>
+		std::true_type supports_op_less_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
+		std::false_type supports_op_less_test(...);
+		template <typename T, typename U, typename = decltype(std::declval<T&>() == std::declval<U&>())>
+		std::true_type supports_op_equal_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
+		std::false_type supports_op_equal_test(...);
+		template <typename T, typename U, typename = decltype(std::declval<T&>() <= std::declval<U&>())>
+		std::true_type supports_op_less_equal_test(std::reference_wrapper<T>, std::reference_wrapper<U>);
+		std::false_type supports_op_less_equal_test(...);
+		template <typename T, typename OS, typename = decltype(std::declval<OS&>() << std::declval<const T&>())>
+		std::true_type supports_ostream_op(std::reference_wrapper<const T>, std::reference_wrapper<OS>);
+		std::false_type supports_ostream_op(...);
+		template <typename T, typename = decltype(to_string(std::declval<T&>()))>
+		std::true_type supports_adl_to_string(std::reference_wrapper<T>);
+		std::false_type supports_adl_to_string(...);
+#else
+		template <typename T, typename U, typename = decltype(std::declval<T&>() < std::declval<U&>())>
+		std::true_type supports_op_less_test(const T&, const U&);
+		std::false_type supports_op_less_test(...);
+		template <typename T, typename U, typename = decltype(std::declval<T&>() == std::declval<U&>())>
+		std::true_type supports_op_equal_test(const T&, const U&);
+		std::false_type supports_op_equal_test(...);
+		template <typename T, typename U, typename = decltype(std::declval<T&>() <= std::declval<U&>())>
+		std::true_type supports_op_less_equal_test(const T&, const U&);
+		std::false_type supports_op_less_equal_test(...);
+		template <typename T, typename OS, typename = decltype(std::declval<OS&>() << std::declval<const T&>())>
+		std::true_type supports_ostream_op(const T&, const OS&);
+		std::false_type supports_ostream_op(...);
+		template <typename T, typename = decltype(to_string(std::declval<T&>()))>
+		std::true_type supports_adl_to_string(const T&);
+		std::false_type supports_adl_to_string(...);
+#endif
+
+		template <typename T, bool b>
+		struct is_matched_lookup_impl : std::false_type {};
+		template <typename T>
+		struct is_matched_lookup_impl<T, true> : std::is_same<typename T::key_type, typename T::value_type> {};
+
+		template <typename T>
+		using non_void_t = meta::conditional_t<std::is_void_v<T>, ::sol::detail::unchecked_t, T>;
+	} // namespace meta_detail
+
+	template <typename T, typename U = T>
+	using supports_op_less
+		= decltype(meta_detail::supports_op_less_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
+	template <typename T, typename U = T>
+	using supports_op_equal
+		= decltype(meta_detail::supports_op_equal_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
+	template <typename T, typename U = T>
+	using supports_op_less_equal
+		= decltype(meta_detail::supports_op_less_equal_test(std::declval<meta_detail::non_void_t<T>&>(), std::declval<meta_detail::non_void_t<U>&>()));
+	template <typename T, typename U = std::ostream>
+	using supports_ostream_op
+		= decltype(meta_detail::supports_ostream_op(std::declval<meta_detail::non_void_t<T>&>(), std::declval<const meta_detail::non_void_t<U>&>()));
+	template <typename T>
+	using supports_adl_to_string = decltype(meta_detail::supports_adl_to_string(std::declval<meta_detail::non_void_t<T>&>()));
+
+	template <typename T>
+	using supports_to_string_member = meta::boolean<meta_detail::has_to_string_test<meta_detail::non_void_t<T>>::value>;
+
+	template <typename T>
+	using is_callable = boolean<meta_detail::is_callable<T>::value>;
+
+	template <typename T>
+	constexpr inline bool is_callable_v = is_callable<T>::value;
+
+	template <typename T>
+	struct has_begin_end : decltype(meta_detail::has_begin_end_impl::test<T>(0)) {};
+
+	template <typename T>
+	constexpr inline bool has_begin_end_v = has_begin_end<T>::value;
+
+	template <typename T>
+	struct has_key_value_pair : decltype(meta_detail::has_key_value_pair_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_key_type : decltype(meta_detail::has_key_type_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_key_comp : decltype(meta_detail::has_key_comp_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_load_factor : decltype(meta_detail::has_load_factor_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_mapped_type : decltype(meta_detail::has_mapped_type_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_iterator : decltype(meta_detail::has_iterator_impl::test<T>(0)) {};
+
+	template <typename T>
+	struct has_value_type : decltype(meta_detail::has_value_type_impl::test<T>(0)) {};
+
+	template <typename T>
+	using has_push_back = meta::boolean<meta_detail::has_push_back_test<T>::value>;
+
+	template <typename T>
+	using has_max_size = meta::boolean<meta_detail::has_max_size_test<T>::value>;
+
+	template <typename T>
+	using has_insert = meta::boolean<meta_detail::has_insert_test<T>::value>;
+
+	template <typename T>
+	using has_insert_after = meta::boolean<meta_detail::has_insert_after_test<T>::value>;
+
+	template <typename T>
+	using has_size = meta::boolean<meta_detail::has_size_test<T>::value>;
+
+	template <typename T>
+	using is_associative = meta::all<has_key_type<T>, has_key_value_pair<T>, has_mapped_type<T>>;
+
+	template <typename T>
+	using is_lookup = meta::all<has_key_type<T>, has_value_type<T>>;
+
+	template <typename T>
+	using is_ordered = meta::all<has_key_comp<T>, meta::neg<has_load_factor<T>>>;
+
+	template <typename T>
+	using is_matched_lookup = meta_detail::is_matched_lookup_impl<T, is_lookup<T>::value>;
+
+	template <typename T>
+	using is_initializer_list = meta::is_specialization_of<T, std::initializer_list>;
+
+	template <typename T>
+	constexpr inline bool is_initializer_list_v = is_initializer_list<T>::value;
+
+	template <typename T, typename CharT = char>
+	using is_string_literal_array_of = boolean<std::is_array_v<T> && std::is_same_v<std::remove_all_extents_t<T>, CharT>>;
+
+	template <typename T, typename CharT = char>
+	constexpr inline bool is_string_literal_array_of_v = is_string_literal_array_of<T, CharT>::value;
+
+	template <typename T>
+	using is_string_literal_array = boolean<std::is_array_v<T> && any_same_v<std::remove_all_extents_t<T>, char, char16_t, char32_t, wchar_t>>;
+
+	template <typename T>
+	constexpr inline bool is_string_literal_array_v = is_string_literal_array<T>::value;
+
+	template <typename T, typename CharT>
+	struct is_string_of : std::false_type {};
+
+	template <typename CharT, typename CharTargetT, typename TraitsT, typename AllocT>
+	struct is_string_of<std::basic_string<CharT, TraitsT, AllocT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
+
+	template <typename T, typename CharT>
+	constexpr inline bool is_string_of_v = is_string_of<T, CharT>::value;
+
+	template <typename T, typename CharT>
+	struct is_string_view_of : std::false_type {};
+
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
+	template <typename CharT, typename CharTargetT, typename TraitsT>
+	struct is_string_view_of<std::basic_string_view<CharT, TraitsT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
+#else
+	template <typename CharT, typename CharTargetT, typename TraitsT>
+	struct is_string_view_of<basic_string_view<CharT, TraitsT>, CharTargetT> : std::is_same<CharT, CharTargetT> {};
+#endif
+
+	template <typename T, typename CharT>
+	constexpr inline bool is_string_view_of_v = is_string_view_of<T, CharT>::value;
+
+	template <typename T>
+	using is_string_like = meta::boolean<is_specialization_of_v<T, std::basic_string>
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
+		|| is_specialization_of_v<T, std::basic_string_view>
+#else
+		|| is_specialization_of_v<T, basic_string_view>
+#endif
+		|| is_string_literal_array_v<T>>;
+
+	template <typename T>
+	constexpr inline bool is_string_like_v = is_string_like<T>::value;
+
+	template <typename T, typename CharT = char>
+	using is_string_constructible = meta::boolean<
+		is_string_literal_array_of_v<T,
+		     CharT> || std::is_same_v<T, const CharT*> || std::is_same_v<T, CharT> || is_string_of_v<T, CharT> || std::is_same_v<T, std::initializer_list<CharT>>
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
+		|| is_string_view_of_v<T, CharT>
+#endif
+		>;
+
+	template <typename T, typename CharT = char>
+	constexpr inline bool is_string_constructible_v = is_string_constructible<T, CharT>::value;
+
+	template <typename T>
+	using is_string_like_or_constructible = meta::boolean<is_string_like_v<T> || is_string_constructible_v<T>>;
+
+	template <typename T>
+	struct is_pair : std::false_type {};
+
+	template <typename T1, typename T2>
+	struct is_pair<std::pair<T1, T2>> : std::true_type {};
+
+	template <typename T, typename Char>
+	using is_c_str_of = any<std::is_same<T, const Char*>, std::is_same<T, Char const* const>, std::is_same<T, Char*>, is_string_of<T, Char>,
+		is_string_literal_array_of<T, Char>>;
+
+	template <typename T, typename Char>
+	constexpr inline bool is_c_str_of_v = is_c_str_of<T, Char>::value;
+
+	template <typename T>
+	using is_c_str = is_c_str_of<T, char>;
+
+	template <typename T>
+	constexpr inline bool is_c_str_v = is_c_str<T>::value;
+
+	template <typename T>
+	struct is_move_only : all<neg<std::is_reference<T>>, neg<std::is_copy_constructible<unqualified_t<T>>>, std::is_move_constructible<unqualified_t<T>>> {};
+
+	template <typename T>
+	using is_not_move_only = neg<is_move_only<T>>;
+
+	namespace meta_detail {
+		template <typename T>
+		decltype(auto) force_tuple(T&& x) {
+			if constexpr (meta::is_specialization_of_v<meta::unqualified_t<T>, std::tuple>) {
+				return std::forward<T>(x);
+			}
+			else {
+				return std::tuple<T>(std::forward<T>(x));
+			}
+		}
+	} // namespace meta_detail
+
+	template <typename... X>
+	decltype(auto) tuplefy(X&&... x) {
+		return std::tuple_cat(meta_detail::force_tuple(std::forward<X>(x))...);
+	}
+
+	template <typename T, typename = void>
+	struct iterator_tag {
+		using type = std::input_iterator_tag;
+	};
+
+	template <typename T>
+	struct iterator_tag<T, conditional_t<false, typename std::iterator_traits<T>::iterator_category, void>> {
+		using type = typename std::iterator_traits<T>::iterator_category;
+	};
+
+}} // namespace sol::meta
 
 // end of sol/traits.hpp
 
@@ -7565,7 +7562,13 @@ namespace sol {
 	template <typename T>
 	struct is_automagical
 	: std::integral_constant<bool,
-	       std::is_array_v<meta::unqualified_t<T>> || !std::is_same_v<meta::unqualified_t<T>, state> || !std::is_same_v<meta::unqualified_t<T>, state_view>> {
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
+#if defined(SOL_STD_VARIANT) && SOL_STD_VARIANT != 0
+	       !meta::is_specialization_of_v<meta::unqualified_t<T>, std::variant> &&
+#endif // std::variant borked in places
+#endif // C++17 Features
+	                 std::is_array_v<
+	                      meta::unqualified_t<T>> || (!std::is_same_v<meta::unqualified_t<T>, state> && !std::is_same_v<meta::unqualified_t<T>, state_view>)> {
 	};
 
 	template <typename T>
@@ -21152,11 +21155,11 @@ namespace sol {
 		template <typename X>
 		void set_undefined_methods_on(stack_reference t) {
 			using T = std::remove_pointer_t<X>;
-			
+
 			lua_State* L = t.lua_state();
-			
+
 			t.push();
-			
+
 			detail::lua_reg_table l{};
 			int index = 0;
 			detail::indexed_insert insert_fx(l, index);
@@ -21165,7 +21168,7 @@ namespace sol {
 				l[index] = luaL_Reg{ to_string(meta_function::garbage_collect).c_str(), detail::make_destructor<T>() };
 			}
 			luaL_setfuncs(L, l, 0);
-			
+
 			// __type table
 			lua_createtable(L, 0, 2);
 			const std::string& name = detail::demangle<T>();