Add lua_table and lua_value abstractions

Improve dump handler, bytecode, and base traits
Fix tolua on bad calls, fix interop handler changes
We are now truly done with all feature requests...

examples/interop/tolua/source/tolua.cpp

@@ -29,8 +29,16 @@ inline bool sol_lua_interop_check(sol::types<T>, lua_State* L, int relindex, sol
 	(void)handler;
 	int index = lua_absindex(L, relindex);
 	std::string name = sol::detail::short_demangle<T>();
-	tolua_Error tolua_err;
+	tolua_Error tolua_err{};
-	return tolua_isusertype(L, index, name.c_str(), 0, &tolua_err);
+	int r = tolua_isusertype(L, index, name.c_str(), 0, &tolua_err);
+	if (r == 0) {
+		// tolua seems to leave garbage on the stack
+		// when the check fails
+		// thanks, tolua
+		lua_pop(L, 2);
+		return false;
+	}
+	return true;
 }
 
 void register_sol_stuff(lua_State* L) {

include/sol/base_traits.hpp

@@ -39,7 +39,16 @@ namespace sol {
 		template <typename T>
 		using void_t = void;
 
+		template <typename T>
+		using unqualified = std::remove_cv<std::remove_reference_t<T>>;
+
+		template <typename T>
+		using unqualified_t = typename unqualified<T>::type;
+
 		namespace meta_detail {
+			template <typename T>
+			struct unqualified_non_alias : unqualified<T> {};
+
 			template <template <class...> class Test, class, class... Args>
 			struct is_detected : std::false_type {};
 
@@ -92,12 +101,6 @@ namespace sol {
 		template <typename T>
 		using identity_t = typename identity<T>::type;
 
-		template <typename T>
-		using is_tuple = is_specialization_of<T, std::tuple>;
-
-		template <typename T>
-		constexpr inline bool is_tuple_v = is_tuple<T>::value;
-
 		template <typename T>
 		using is_builtin_type = std::integral_constant<bool, std::is_arithmetic<T>::value || std::is_pointer<T>::value || std::is_array<T>::value>;
 

include/sol/bytecode.hpp

@@ -38,6 +38,17 @@ namespace sol {
 		using base_t = std::vector<std::byte, Allocator>;
 
 	public:
+		using base_t::allocator_type;
+		using base_t::const_iterator;
+		using base_t::const_pointer;
+		using base_t::const_reference;
+		using base_t::const_reverse_iterator;
+		using base_t::difference_type;
+		using base_t::iterator;
+		using base_t::pointer;
+		using base_t::reference;
+		using base_t::reverse_iterator;
+		using base_t::size_type;
 		using base_t::value_type;
 
 		using base_t::base_t;
@@ -81,11 +92,11 @@ namespace sol {
 		}
 	};
 
-	using bytecode = basic_bytecode<>;
+	template <typename Container>
-
+	inline int basic_insert_dump_writer(lua_State*, const void* memory, size_t memory_size, void* userdata) {
-	inline int bytecode_dump_writer(lua_State*, const void* memory, size_t memory_size, void* userdata) {
+		using storage_t = Container;
 		const std::byte* p_code = static_cast<const std::byte*>(memory);
-		bytecode& bc = *static_cast<bytecode*>(userdata);
+		storage_t& bc = *static_cast<storage_t*>(userdata);
 		try {
 			bc.insert(bc.cend(), p_code, p_code + memory_size);
 		}
@@ -95,6 +106,10 @@ namespace sol {
 		return 0;
 	}
 
+	using bytecode = basic_bytecode<>;
+
+	constexpr inline auto bytecode_dump_writer = &basic_insert_dump_writer<bytecode>;
+
 } // namespace sol
 
 #endif // SOL_BYTECODE_HPP

include/sol/dump_handler.hpp

@@ -24,6 +24,8 @@
 #ifndef SOL_DUMP_HANDLER_HPP
 #define SOL_DUMP_HANDLER_HPP
 
+#include "compatibility.hpp"
+
 #include <cstdint>
 #include <exception>
 
@@ -42,19 +44,29 @@ namespace sol {
 		}
 	};
 
-	inline int dump_pass_on_error(int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+	inline int dump_pass_on_error(lua_State* L, int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+		(void)L;
 		(void)writer_function;
 		(void)userdata;
 		(void)strip;
 		return result_code;
 	}
 
-	inline int dump_throw_on_error(int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+	inline int dump_throw_on_error(lua_State* L, int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+		(void)L;
 		(void)writer_function;
 		(void)userdata;
 		(void)strip;
 		throw dump_error(result_code);
-	}	
+	}
+
+	inline int dump_panic_on_error(lua_State* L, int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+		(void)L;
+		(void)writer_function;
+		(void)userdata;
+		(void)strip;
+		return luaL_error(L, "a non-zero error code (%d) was returned by the lua_Writer for the dump function", result_code);
+	}
 
 } // namespace sol
 

include/sol/forward.hpp

@@ -48,13 +48,15 @@ namespace sol {
 	template <typename A>
 	class basic_bytecode;
 
+	struct lua_value;
+
 	struct proxy_base_tag;
-	template <typename Super>
+	template <typename>
 	struct proxy_base;
-	template <typename Table, typename Key>
+	template <typename, typename>
 	struct proxy;
 
-	template <bool, typename base_type>
+	template <bool, typename>
 	class basic_table_core;
 	template <bool b>
 	using table_core = basic_table_core<b, reference>;
@@ -71,6 +73,11 @@ namespace sol {
 	using stack_table = stack_table_core<false>;
 	using stack_global_table = stack_table_core<true>;
 
+	template <typename>
+	struct basic_lua_table;
+	using lua_table = basic_lua_table<reference>;
+	using stack_lua_table = basic_lua_table<stack_reference>;
+
 	template <typename T, typename base_type>
 	class basic_usertype;
 	template <typename T>

include/sol/function.hpp

@@ -27,6 +27,7 @@
 #include "stack.hpp"
 #include "unsafe_function.hpp"
 #include "protected_function.hpp"
+#include "bytecode.hpp"
 #include <functional>
 
 namespace sol {
@@ -117,8 +118,7 @@ namespace sol {
 			}
 
 			static std::function<Signature> get(lua_State* L, int index, record& tracking) {
-				tracking.last = 1;
+				tracking.use(1);
-				tracking.used += 1;
 				type t = type_of(L, index);
 				if (t == type::none || t == type::lua_nil) {
 					return nullptr;
@@ -126,6 +126,15 @@ namespace sol {
 				return get_std_func(return_types(), L, index);
 			}
 		};
+
+		template <typename Allocator>
+		struct unqualified_getter<basic_bytecode<Allocator>> {
+			static basic_bytecode<Allocator> get(lua_State* L, int index, record& tracking) {
+				tracking.use(1);
+				stack_function sf(L, index);
+				return sf.dump(&dump_panic_on_error);
+			}
+		};
 	} // namespace stack
 
 } // namespace sol

include/sol/function_types.hpp

@@ -114,7 +114,7 @@ namespace sol {
 				stack::push(L, c_closure(freefunc, upvalues));
 			}
 			else if constexpr (sizeof...(Args) < 2) {
-				using Tu = typename meta::unqualified<Args...>::type;
+				using Tu = typename meta::meta_detail::unqualified_non_alias<Args...>::type;
 				constexpr bool is_reference = meta::is_specialization_of_v<Tu, std::reference_wrapper> || std::is_pointer_v<Tu>;
 				if constexpr (meta::is_specialization_of_v<Tu, function_detail::class_indicator>) {
 					lua_CFunction freefunc = &function_detail::upvalue_this_member_variable<typename Tu::type, Fx, is_yielding>::call;

include/sol/lua_table.hpp

@@ -0,0 +1,95 @@
+// sol3
+
+// The MIT License (MIT)
+
+// Copyright (c) 2013-2019 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#ifndef SOL_LUA_TABLE_HPP
+#define SOL_LUA_TABLE_HPP
+
+#include "table_core.hpp"
+
+namespace sol {
+
+	template <typename ref_t>
+	struct basic_lua_table : basic_table_core<false, ref_t> {
+	private:
+		using base_t = basic_table_core<false, ref_t>;
+
+		friend class state;
+		friend class state_view;
+
+	public:
+		using base_t::lua_state;
+
+		basic_lua_table() noexcept = default;
+		basic_lua_table(const basic_lua_table&) = default;
+		basic_lua_table(basic_lua_table&&) = default;
+		basic_lua_table& operator=(const basic_lua_table&) = default;
+		basic_lua_table& operator=(basic_lua_table&&) = default;
+		basic_lua_table(const stack_reference& r) : basic_lua_table(r.lua_state(), r.stack_index()) {
+		}
+		basic_lua_table(stack_reference&& r) : basic_lua_table(r.lua_state(), r.stack_index()) {
+		}
+		template <typename T, meta::enable_any<is_lua_reference<meta::unqualified_t<T>>> = meta::enabler>
+		basic_lua_table(lua_State* L, T&& r) : base_t(L, std::forward<T>(r)) {
+#if defined(SOL_SAFE_REFERENCES) && SOL_SAFE_REFERENCES
+			auto pp = stack::push_pop(*this);
+			constructor_handler handler{};
+			stack::check<basic_lua_table>(lua_state(), -1, handler);
+#endif // Safety
+		}
+		basic_lua_table(lua_State* L, const new_table& nt) : base_t(L, nt) {
+			if (!is_stack_based<meta::unqualified_t<ref_t>>::value) {
+				lua_pop(L, 1);
+			}
+		}
+		basic_lua_table(lua_State* L, int index = -1) : base_t(detail::no_safety, L, index) {
+#if defined(SOL_SAFE_REFERENCES) && SOL_SAFE_REFERENCES
+			constructor_handler handler{};
+			stack::check<basic_lua_table>(L, index, handler);
+#endif // Safety
+		}
+		basic_lua_table(lua_State* L, ref_index index) : base_t(detail::no_safety, L, index) {
+#if defined(SOL_SAFE_REFERENCES) && SOL_SAFE_REFERENCES
+			auto pp = stack::push_pop(*this);
+			constructor_handler handler{};
+			stack::check<basic_lua_table>(lua_state(), -1, handler);
+#endif // Safety
+		}
+		template <typename T,
+		     meta::enable<meta::neg<meta::any_same<meta::unqualified_t<T>, basic_lua_table>>, meta::neg<std::is_same<ref_t, stack_reference>>,
+		          meta::neg<std::is_same<lua_nil_t, meta::unqualified_t<T>>>, is_lua_reference<meta::unqualified_t<T>>> = meta::enabler>
+		basic_lua_table(T&& r) noexcept : basic_lua_table(detail::no_safety, std::forward<T>(r)) {
+#if defined(SOL_SAFE_REFERENCES) && SOL_SAFE_REFERENCES
+			if (!is_table<meta::unqualified_t<T>>::value) {
+				auto pp = stack::push_pop(*this);
+				constructor_handler handler{};
+				stack::check<basic_lua_table>(lua_state(), -1, handler);
+			}
+#endif // Safety
+		}
+		basic_lua_table(lua_nil_t r) noexcept : basic_lua_table(detail::no_safety, r) {
+		}
+	};
+
+}
+
+#endif // SOL_LUA_TABLE_HPP

include/sol/lua_value.hpp

@@ -0,0 +1,130 @@
+// sol3
+
+// The MIT License (MIT)
+
+// Copyright (c) 2013-2019 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#ifndef SOL_LUA_VALUE_HPP
+#define SOL_LUA_VALUE_HPP
+
+#include "stack.hpp"
+#include "reference.hpp"
+#include "make_reference.hpp"
+
+namespace sol {
+	namespace detail {
+		template <typename T>
+		using is_reference_or_lua_value_init_list = meta::any<meta::is_specialization_of<T, std::initializer_list>, std::is_same<T, reference>>;
+
+		template <typename T>
+		using is_lua_value_single_constructible = meta::any<std::is_same<T, lua_value>, is_reference_or_lua_value_init_list<T>>;
+	}
+
+	struct lua_value {
+	private:
+		static lua_State*& thread_local_lua_state() {
+			static thread_local lua_State* L = nullptr;
+			return L;
+		}
+
+		reference ref_value;
+
+	public:
+		static void set_lua_state(lua_State* L) {
+			thread_local_lua_state() = L;
+		}
+
+		template <typename T, meta::disable<detail::is_reference_or_lua_value_init_list<meta::unqualified_t<T>>> = meta::enabler>
+		lua_value(lua_State* L_, T&& value) : lua_value(((set_lua_state(L_)), std::forward<T>(value))) {
+		}
+
+		template <typename T, meta::disable<detail::is_lua_value_single_constructible<meta::unqualified_t<T>>> = meta::enabler>
+		lua_value(T&& value) : ref_value(make_reference(thread_local_lua_state(), std::forward<T>(value))) {
+		}
+
+		lua_value(lua_State* L_, std::initializer_list<lua_value> il) : lua_value(((set_lua_state(L_)), std::move(il))) {
+		}
+
+		lua_value(std::initializer_list<lua_value> il) : ref_value(make_reference(thread_local_lua_state(), std::move(il))) {
+		}
+
+		lua_value(lua_State* L_, reference r) : lua_value(((thread_local_lua_state() = L_), std::move(r))) {
+		}
+
+		lua_value(reference r) : ref_value(std::move(r)) {
+		}
+
+		lua_value(const lua_value&) noexcept = default;
+		lua_value(lua_value&&) = default;
+		lua_value& operator=(const lua_value&) = default;
+		lua_value& operator=(lua_value&&) = default;
+
+		const reference& value() const& {
+			return ref_value;
+		}
+
+		reference& value() & {
+			return ref_value;
+		}
+
+		reference&& value() && {
+			return std::move(ref_value);
+		}
+
+		template <typename T>
+		decltype(auto) as() const {
+			ref_value.push();
+			return stack::pop<T>(ref_value.lua_state());
+		}
+
+		template <typename T>
+		bool is() const {
+			int r = ref_value.registry_index();
+			if (r == LUA_REFNIL)
+				return meta::any_same<meta::unqualified_t<T>, lua_nil_t, nullopt_t, std::nullptr_t>::value ? true : false;
+			if (r == LUA_NOREF)
+				return false;
+			auto pp = stack::push_pop(ref_value);
+			return stack::check<T>(ref_value.lua_state(), -1, no_panic);
+		}
+	};
+
+	namespace stack {
+		template <>
+		struct unqualified_pusher<lua_value> {
+			static int push(lua_State* L, const lua_value& lv) {
+				return stack::push(L, lv.value());
+			}
+
+			static int push(lua_State* L, lua_value&& lv) {
+				return stack::push(L, std::move(lv).value());
+			}
+		};
+
+		template <>
+		struct unqualified_getter<lua_value> {
+			static lua_value get(lua_State* L, int index, record& tracking) {
+				return lua_value(L, stack::get<reference>(L, index, tracking));
+			}
+		};
+	}
+} // namespace sol
+
+#endif // SOL_LUA_VALUE_HPP

include/sol/protected_function.hpp

@@ -265,10 +265,11 @@ namespace sol {
 
 		template <typename Fx>
 		int dump(lua_Writer writer, void* userdata, bool strip, Fx&& on_error) const {
-			auto pp = stack::push_pop(*this);
+			this->push();
+			auto ppn = stack::push_popper_n<false>(this->lua_state(), 1);
 			int r = lua_dump(this->lua_state(), writer, userdata, strip ? 1 : 0);
 			if (r != 0) {
-				return on_error(r, writer, userdata, strip);
+				return on_error(this->lua_state(), r, writer, userdata, strip);
 			}
 			return r;
 		}
@@ -277,9 +278,17 @@ namespace sol {
 			return dump(writer, userdata, strip, &dump_pass_on_error);
 		}
 
-		bytecode dump() const {
+		template <typename Container = bytecode>
-			bytecode bc;
+		Container dump() const {
-			(void)dump(&bytecode_dump_writer, static_cast<void*>(&bc), false, &dump_throw_on_error);
+			Container bc;
+			(void)dump(static_cast<lua_Writer>(&basic_insert_dump_writer<Container>), static_cast<void*>(&bc), false, &dump_throw_on_error);
+			return bc;
+		}
+
+		template <typename Container = bytecode, typename Fx>
+		Container dump(Fx&& on_error) const {
+			Container bc;
+			(void)dump(static_cast<lua_Writer>(&basic_insert_dump_writer<Container>), static_cast<void*>(&bc), false, std::forward<Fx>(on_error));
 			return bc;
 		}
 

include/sol/sol.hpp

@@ -50,6 +50,7 @@
 
 #include "forward.hpp"
 #include "forward_detail.hpp"
+#include "bytecode.hpp"
 #include "stack.hpp"
 #include "object.hpp"
 #include "function.hpp"
@@ -64,6 +65,7 @@
 #include "as_args.hpp"
 #include "variadic_args.hpp"
 #include "variadic_results.hpp"
+#include "lua_value.hpp"
 
 #if defined(__GNUC__)
 #pragma GCC diagnostic pop

include/sol/stack_check_qualified.hpp

@@ -29,7 +29,7 @@
 namespace sol {
 namespace stack {
 
-	template <typename X, type expected = lua_type_of_v<meta::unqualified_t<X>>, typename = void>
+	template <typename X, type expected, typename>
 	struct qualified_checker {
 		template <typename Handler>
 		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {

include/sol/stack_check_unqualified.hpp

@@ -86,7 +86,7 @@ namespace sol { namespace stack {
 		}
 	};
 
-	template <typename T, type expected = lua_type_of_v<T>, typename = void>
+	template <typename T, type expected, typename>
 	struct unqualified_checker {
 		template <typename Handler>
 		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
@@ -251,6 +251,24 @@ namespace sol { namespace stack {
 			else if constexpr (std::is_same_v<T, detail::non_lua_nil_t>) {
 				return !stack::unqualified_check<lua_nil_t>(L, index, std::forward<Handler>(handler), tracking);
 			}
+			else if constexpr (meta::is_specialization_of_v<T, basic_lua_table>) {
+				tracking.use(1);
+				type t = type_of(L, index);
+				if (t != type::table) {
+					handler(L, index, type::table, t, "value is not a table");
+					return false;
+				}
+				return true;
+			}
+			else if constexpr (meta::is_specialization_of_v<T, basic_bytecode>) {
+				tracking.use(1);
+				type t = type_of(L, index);
+				if (t != type::function) {
+					handler(L, index, type::function, t, "value is not a function that can be dumped");
+					return false;
+				}
+				return true;
+			}
 			else if constexpr(meta::is_specialization_of_v<T, basic_environment>) {
 				tracking.use(1);
 				if (lua_getmetatable(L, index) == 0) {
@@ -297,7 +315,7 @@ namespace sol { namespace stack {
 					return success;
 				}
 				else if constexpr (meta::is_specialization_of_v<T, user>) {
-					unqualified_checker<lightuserdata_value> c;
+					unqualified_checker<lightuserdata_value, type::userdata> c;
 					(void)c;
 					return c.check(L, index, std::forward<Handler>(handler), tracking);
 				}
@@ -415,51 +433,59 @@ namespace sol { namespace stack {
 
 		template <typename U, typename Handler>
 		static bool check(types<U>, lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
-#if defined(SOL_ENABLE_INTEROP) && SOL_ENABLE_INTEROP
+			if constexpr (std::is_same_v<T, lightuserdata_value> || std::is_same_v<T, userdata_value> || std::is_same_v<T, userdata> || std::is_same_v<T, lightuserdata>) {
-			if (stack_detail::interop_check<U>(L, index, indextype, handler, tracking)) {
+				tracking.use(1);
-				return true;
+				if (indextype != type::userdata) {
-			}
+					handler(L, index, type::userdata, indextype, "value is not a valid userdata");
-#endif // interop extensibility
+					return false;
-			tracking.use(1);
-			if (indextype != type::userdata) {
-				handler(L, index, type::userdata, indextype, "value is not a valid userdata");
-				return false;
-			}
-			if (meta::any<std::is_same<T, lightuserdata_value>, std::is_same<T, userdata_value>, std::is_same<T, userdata>, std::is_same<T, lightuserdata>>::value)
-				return true;
-			if (lua_getmetatable(L, index) == 0) {
-				return true;
-			}
-			int metatableindex = lua_gettop(L);
-			if (stack_detail::check_metatable<U>(L, metatableindex))
-				return true;
-			if (stack_detail::check_metatable<U*>(L, metatableindex))
-				return true;
-			if (stack_detail::check_metatable<detail::unique_usertype<U>>(L, metatableindex))
-				return true;
-			if (stack_detail::check_metatable<as_container_t<U>>(L, metatableindex))
-				return true;
-			bool success = false;
-			bool has_derived = derive<T>::value || weak_derive<T>::value;
-			if (has_derived) {
-#if defined(SOL_SAFE_STACK_CHECK) && SOL_SAFE_STACK_CHECK
-				luaL_checkstack(L, 1, detail::not_enough_stack_space_string);
-#endif // make sure stack doesn't overflow
-				auto pn = stack::pop_n(L, 1);
-				lua_pushstring(L, &detail::base_class_check_key()[0]);
-				lua_rawget(L, metatableindex);
-				if (type_of(L, -1) != type::lua_nil) {
-					void* basecastdata = lua_touserdata(L, -1);
-					detail::inheritance_check_function ic = reinterpret_cast<detail::inheritance_check_function>(basecastdata);
-					success = ic(usertype_traits<T>::qualified_name());
 				}
+				return true;
 			}
-			lua_pop(L, 1);
+			else {
-			if (!success) {
+#if defined(SOL_ENABLE_INTEROP) && SOL_ENABLE_INTEROP
-				handler(L, index, type::userdata, indextype, "value at this index does not properly reflect the desired type");
+				if (stack_detail::interop_check<U>(L, index, indextype, handler, tracking)) {
-				return false;
+					return true;
+				}
+#endif // interop extensibility
+				tracking.use(1);
+				if (indextype != type::userdata) {
+					handler(L, index, type::userdata, indextype, "value is not a valid userdata");
+					return false;
+				}
+				if (lua_getmetatable(L, index) == 0) {
+					return true;
+				}
+				int metatableindex = lua_gettop(L);
+				if (stack_detail::check_metatable<U>(L, metatableindex))
+					return true;
+				if (stack_detail::check_metatable<U*>(L, metatableindex))
+					return true;
+				if (stack_detail::check_metatable<detail::unique_usertype<U>>(L, metatableindex))
+					return true;
+				if (stack_detail::check_metatable<as_container_t<U>>(L, metatableindex))
+					return true;
+				bool success = false;
+				bool has_derived = derive<T>::value || weak_derive<T>::value;
+				if (has_derived) {
+	#if defined(SOL_SAFE_STACK_CHECK) && SOL_SAFE_STACK_CHECK
+					luaL_checkstack(L, 1, detail::not_enough_stack_space_string);
+	#endif // make sure stack doesn't overflow
+					auto pn = stack::pop_n(L, 1);
+					lua_pushstring(L, &detail::base_class_check_key()[0]);
+					lua_rawget(L, metatableindex);
+					if (type_of(L, -1) != type::lua_nil) {
+						void* basecastdata = lua_touserdata(L, -1);
+						detail::inheritance_check_function ic = reinterpret_cast<detail::inheritance_check_function>(basecastdata);
+						success = ic(usertype_traits<T>::qualified_name());
+					}
+				}
+				lua_pop(L, 1);
+				if (!success) {
+					handler(L, index, type::userdata, indextype, "value at this index does not properly reflect the desired type");
+					return false;
+				}
+				return true;
 			}
-			return true;
 		}
 	};
 

include/sol/stack_core.hpp

@@ -597,9 +597,9 @@ namespace sol {
 		template <typename T, typename = void>
 		struct unqualified_pusher;
 
-		template <typename T, type t, typename>
+		template <typename T, type t, typename = void>
 		struct unqualified_checker;
-		template <typename T, type t, typename>
+		template <typename T, type t, typename = void>
 		struct qualified_checker;
 
 		template <typename T, typename = void>
@@ -925,7 +925,7 @@ namespace sol {
 				return sol_lua_check(types<Tu>(), L, index, std::forward<Handler>(handler), tracking);
 			}
 			else {
-				unqualified_checker<Tu> c;
+				unqualified_checker<Tu, lua_type_of_v<Tu>> c;
 				// VC++ has a bad warning here: shut it up
 				(void)c;
 				return c.check(L, index, std::forward<Handler>(handler), tracking);
@@ -950,7 +950,8 @@ namespace sol {
 				return sol_lua_check(types<T>(), L, index, std::forward<Handler>(handler), tracking);
 			}
 			else {
-				qualified_checker<T> c;
+				using Tu = meta::unqualified_t<T>;
+				qualified_checker<T, lua_type_of_v<Tu>> c;
 				// VC++ has a bad warning here: shut it up
 				(void)c;
 				return c.check(L, index, std::forward<Handler>(handler), tracking);
@@ -1049,6 +1050,11 @@ namespace sol {
 
 		namespace stack_detail {
 
+			template <typename Handler>
+			inline bool check_types(lua_State*, int, Handler&&, record&) {
+				return true;
+			}
+
 			template <typename T, typename... Args, typename Handler>
 			inline bool check_types(lua_State* L, int firstargument, Handler&& handler, record& tracking) {
 				if (!stack::check<T>(L, firstargument + tracking.used, handler, tracking))
@@ -1056,13 +1062,8 @@ namespace sol {
 				return check_types<Args...>(L, firstargument, std::forward<Handler>(handler), tracking);
 			}
 
-			template <typename Handler>
-			static bool check_types(lua_State*, int, Handler&&, record&) {
-				return true;
-			}
-
 			template <typename... Args, typename Handler>
-			bool check_types(types<Args...>, lua_State* L, int index, Handler&& handler, record& tracking) {
+			inline bool check_types(types<Args...>, lua_State* L, int index, Handler&& handler, record& tracking) {
 				return check_types<Args...>(L, index, std::forward<Handler>(handler), tracking);
 			}
 

include/sol/stack_push.hpp

@@ -1146,6 +1146,24 @@ namespace sol {
 			}
 		};
 
+		template <typename Allocator>
+		struct unqualified_pusher<basic_bytecode<Allocator>> {
+			template <typename T>
+			static int push(lua_State* L, T&& bc, const char* bytecode_name) {
+				const auto first = bc.data();
+				const auto bcsize = bc.size();
+				// pushes either the function, or an error
+				// if it errors, shit goes south, and people can test that upstream
+				(void)luaL_loadbuffer(L, reinterpret_cast<const char*>(first), static_cast<std::size_t>(bcsize * (sizeof(*first) / sizeof(const char))), bytecode_name);
+				return 1;
+			}
+
+			template <typename T>
+			static int push(lua_State* L, T&& bc) {
+				return push(L, std::forward<bc>(bc), "bytecode");
+			}
+		};
+
 #if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
 		template <typename O>
 		struct unqualified_pusher<std::optional<O>> {

include/sol/state_handling.hpp

@@ -28,6 +28,7 @@
 #include "stack.hpp"
 #include "function.hpp"
 #include "object.hpp"
+#include "lua_value.hpp"
 
 #if defined(SOL_PRINT_ERRORS) && SOL_PRINT_ERRORS
 #include <iostream>
@@ -97,6 +98,7 @@ namespace sol {
 		set_default_exception_handler(L, exf);
 		register_main_thread(L);
 		stack::luajit_exception_handler(L);
+		lua_value::set_lua_state(L);
 	}
 
 	inline std::size_t total_memory_used(lua_State* L) {

include/sol/table.hpp

@@ -25,6 +25,7 @@
 #define SOL_TABLE_HPP
 
 #include "table_core.hpp"
+#include "lua_table.hpp"
 #include "usertype.hpp"
 
 namespace sol {

include/sol/tuple.hpp

@@ -25,6 +25,7 @@
 #define SOL_TUPLE_HPP
 
 #include "forward.hpp"
+#include "base_traits.hpp"
 
 #include <tuple>
 #include <cstddef>
@@ -35,6 +36,12 @@ namespace sol {
 	} // namespace detail
 
 	namespace meta {
+		template <typename T>
+		using is_tuple = is_specialization_of<T, std::tuple>;
+
+		template <typename T>
+		constexpr inline bool is_tuple_v = is_tuple<T>::value;
+
 		namespace detail {
 			template <typename... Args>
 			struct tuple_types_ { typedef types<Args...> type; };
@@ -43,12 +50,6 @@ namespace sol {
 			struct tuple_types_<std::tuple<Args...>> { typedef types<Args...> type; };
 		} // namespace detail
 
-		template <typename T>
-		struct unqualified : std::remove_cv<std::remove_reference_t<T>> {};
-
-		template <typename T>
-		using unqualified_t = typename unqualified<T>::type;
-
 		template <typename... Args>
 		using tuple_types = typename detail::tuple_types_<Args...>::type;
 

include/sol/types.hpp

@@ -1006,6 +1006,9 @@ namespace sol {
 		template <>
 		struct lua_type_of<nullopt_t> : std::integral_constant<type, type::lua_nil> {};
 
+		template <>
+		struct lua_type_of<lua_value> : std::integral_constant<type, type::poly> {};
+
 		template <>
 		struct lua_type_of<detail::non_lua_nil_t> : std::integral_constant<type, type::poly> {};
 
@@ -1018,6 +1021,9 @@ namespace sol {
 		template <bool b, typename Base>
 		struct lua_type_of<basic_table_core<b, Base>> : std::integral_constant<type, type::table> {};
 
+		template <typename Base>
+		struct lua_type_of<basic_lua_table<Base>> : std::integral_constant<type, type::table> {};
+
 		template <typename Base>
 		struct lua_type_of<basic_metatable<Base>> : std::integral_constant<type, type::table> {};
 

include/sol/unsafe_function.hpp

@@ -124,10 +124,11 @@ namespace sol {
 
 		template <typename Fx>
 		int dump(lua_Writer writer, void* userdata, bool strip, Fx&& on_error) const {
-			auto pp = stack::push_pop(*this);
+			this->push();
+			auto ppn = stack::push_popper_n<false>(this->lua_state(), 1);
 			int r = lua_dump(this->lua_state(), writer, userdata, strip ? 1 : 0);
 			if (r != 0) {
-				return on_error(r, writer, userdata, strip);
+				return on_error(this->lua_state(), r, writer, userdata, strip);
 			}
 			return r;
 		}
@@ -136,9 +137,17 @@ namespace sol {
 			return dump(writer, userdata, strip, &dump_throw_on_error);
 		}
 
-		bytecode dump() const {
+		template <typename Container = bytecode>
-			bytecode bc;
+		Container dump() const {
-			(void)dump(&bytecode_dump_writer, static_cast<void*>(&bc), strip, &dump_throw_on_error);
+			Container bc;
+			(void)dump(static_cast<lua_Writer>(&basic_insert_dump_writer<Container>), static_cast<void*>(&bc), false, &dump_panic_on_error);
+			return bc;
+		}
+
+		template <typename Container = bytecode, typename Fx>
+		Container dump(Fx&& on_error) const {
+			Container bc;
+			(void)dump(static_cast<lua_Writer>(&basic_insert_dump_writer<Container>), static_cast<void*>(&bc), false, std::forward<Fx>(on_error));
 			return bc;
 		}
 

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 2019-03-14 20:15:14.754895 UTC
+// Generated 2019-03-18 11:40:51.752769 UTC
-// This header was generated with sol v3.0.0 (revision c1a8cb1)
+// This header was generated with sol v3.0.0 (revision 70bc111)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_FORWARD_HPP
@@ -264,13 +264,15 @@ namespace sol {
 	template <typename A>
 	class basic_bytecode;
 
+	struct lua_value;
+
 	struct proxy_base_tag;
-	template <typename Super>
+	template <typename>
 	struct proxy_base;
-	template <typename Table, typename Key>
+	template <typename, typename>
 	struct proxy;
 
-	template <bool, typename base_type>
+	template <bool, typename>
 	class basic_table_core;
 	template <bool b>
 	using table_core = basic_table_core<b, reference>;
@@ -287,6 +289,11 @@ namespace sol {
 	using stack_table = stack_table_core<false>;
 	using stack_global_table = stack_table_core<true>;
 
+	template <typename>
+	struct basic_lua_table;
+	using lua_table = basic_lua_table<reference>;
+	using stack_lua_table = basic_lua_table<stack_reference>;
+
 	template <typename T, typename base_type>
 	class basic_usertype;
 	template <typename T>

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 2019-03-14 20:15:14.455770 UTC
+// Generated 2019-03-18 11:40:51.457664 UTC
-// This header was generated with sol v3.0.0 (revision c1a8cb1)
+// This header was generated with sol v3.0.0 (revision 70bc111)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_HPP
@@ -289,13 +289,15 @@ namespace sol {
 	template <typename A>
 	class basic_bytecode;
 
+	struct lua_value;
+
 	struct proxy_base_tag;
-	template <typename Super>
+	template <typename>
 	struct proxy_base;
-	template <typename Table, typename Key>
+	template <typename, typename>
 	struct proxy;
 
-	template <bool, typename base_type>
+	template <bool, typename>
 	class basic_table_core;
 	template <bool b>
 	using table_core = basic_table_core<b, reference>;
@@ -312,6 +314,11 @@ namespace sol {
 	using stack_table = stack_table_core<false>;
 	using stack_global_table = stack_table_core<true>;
 
+	template <typename>
+	struct basic_lua_table;
+	using lua_table = basic_lua_table<reference>;
+	using stack_lua_table = basic_lua_table<stack_reference>;
+
 	template <typename T, typename base_type>
 	class basic_usertype;
 	template <typename T>
@@ -498,69 +505,6 @@ namespace sol {
 
 // beginning of sol/tuple.hpp
 
-#include <tuple>
-#include <cstddef>
-
-namespace sol {
-	namespace detail {
-		using swallow = std::initializer_list<int>;
-	} // namespace detail
-
-	namespace meta {
-		namespace detail {
-			template <typename... Args>
-			struct tuple_types_ { typedef types<Args...> type; };
-
-			template <typename... Args>
-			struct tuple_types_<std::tuple<Args...>> { typedef types<Args...> type; };
-		} // namespace detail
-
-		template <typename T>
-		struct unqualified : std::remove_cv<std::remove_reference_t<T>> {};
-
-		template <typename T>
-		using unqualified_t = typename unqualified<T>::type;
-
-		template <typename... Args>
-		using tuple_types = typename detail::tuple_types_<Args...>::type;
-
-		template <typename Arg>
-		struct pop_front_type;
-
-		template <typename Arg>
-		using pop_front_type_t = typename pop_front_type<Arg>::type;
-
-		template <typename... Args>
-		struct pop_front_type<types<Args...>> {
-			typedef void front_type;
-			typedef types<Args...> type;
-		};
-
-		template <typename Arg, typename... Args>
-		struct pop_front_type<types<Arg, Args...>> {
-			typedef Arg front_type;
-			typedef types<Args...> type;
-		};
-
-		template <std::size_t N, typename Tuple>
-		using tuple_element = std::tuple_element<N, std::remove_reference_t<Tuple>>;
-
-		template <std::size_t N, typename Tuple>
-		using tuple_element_t = std::tuple_element_t<N, std::remove_reference_t<Tuple>>;
-
-		template <std::size_t N, typename Tuple>
-		using unqualified_tuple_element = unqualified<tuple_element_t<N, Tuple>>;
-
-		template <std::size_t N, typename Tuple>
-		using unqualified_tuple_element_t = unqualified_t<tuple_element_t<N, Tuple>>;
-
-	} // namespace meta
-} // namespace sol
-
-// end of sol/tuple.hpp
-
-// beginning of sol/bind_traits.hpp
-
 // beginning of sol/base_traits.hpp
 
 namespace sol {
@@ -576,7 +520,16 @@ namespace sol {
 		template <typename T>
 		using void_t = void;
 
+		template <typename T>
+		using unqualified = std::remove_cv<std::remove_reference_t<T>>;
+
+		template <typename T>
+		using unqualified_t = typename unqualified<T>::type;
+
 		namespace meta_detail {
+			template <typename T>
+			struct unqualified_non_alias : unqualified<T> {};
+
 			template <template <class...> class Test, class, class... Args>
 			struct is_detected : std::false_type {};
 
@@ -629,12 +582,6 @@ namespace sol {
 		template <typename T>
 		using identity_t = typename identity<T>::type;
 
-		template <typename T>
-		using is_tuple = is_specialization_of<T, std::tuple>;
-
-		template <typename T>
-		constexpr inline bool is_tuple_v = is_tuple<T>::value;
-
 		template <typename T>
 		using is_builtin_type = std::integral_constant<bool, std::is_arithmetic<T>::value || std::is_pointer<T>::value || std::is_array<T>::value>;
 
@@ -643,6 +590,69 @@ namespace sol {
 
 // end of sol/base_traits.hpp
 
+#include <tuple>
+#include <cstddef>
+
+namespace sol {
+	namespace detail {
+		using swallow = std::initializer_list<int>;
+	} // namespace detail
+
+	namespace meta {
+		template <typename T>
+		using is_tuple = is_specialization_of<T, std::tuple>;
+
+		template <typename T>
+		constexpr inline bool is_tuple_v = is_tuple<T>::value;
+
+		namespace detail {
+			template <typename... Args>
+			struct tuple_types_ { typedef types<Args...> type; };
+
+			template <typename... Args>
+			struct tuple_types_<std::tuple<Args...>> { typedef types<Args...> type; };
+		} // namespace detail
+
+		template <typename... Args>
+		using tuple_types = typename detail::tuple_types_<Args...>::type;
+
+		template <typename Arg>
+		struct pop_front_type;
+
+		template <typename Arg>
+		using pop_front_type_t = typename pop_front_type<Arg>::type;
+
+		template <typename... Args>
+		struct pop_front_type<types<Args...>> {
+			typedef void front_type;
+			typedef types<Args...> type;
+		};
+
+		template <typename Arg, typename... Args>
+		struct pop_front_type<types<Arg, Args...>> {
+			typedef Arg front_type;
+			typedef types<Args...> type;
+		};
+
+		template <std::size_t N, typename Tuple>
+		using tuple_element = std::tuple_element<N, std::remove_reference_t<Tuple>>;
+
+		template <std::size_t N, typename Tuple>
+		using tuple_element_t = std::tuple_element_t<N, std::remove_reference_t<Tuple>>;
+
+		template <std::size_t N, typename Tuple>
+		using unqualified_tuple_element = unqualified<tuple_element_t<N, Tuple>>;
+
+		template <std::size_t N, typename Tuple>
+		using unqualified_tuple_element_t = unqualified_t<tuple_element_t<N, Tuple>>;
+
+	} // namespace meta
+} // namespace sol
+
+// end of sol/tuple.hpp
+
+// beginning of sol/bind_traits.hpp
+
 namespace sol {
 namespace meta {
 	namespace meta_detail {
@@ -2041,13 +2051,7 @@ namespace sol {
 #endif // SOL_FORWARD_DETAIL_HPP
 // end of sol/forward_detail.hpp
 
-// beginning of sol/stack.hpp
+// beginning of sol/bytecode.hpp
-
-// beginning of sol/trampoline.hpp
-
-// beginning of sol/types.hpp
-
-// beginning of sol/error.hpp
 
 // beginning of sol/compatibility.hpp
 
@@ -3369,6 +3373,99 @@ COMPAT53_API void luaL_requiref(lua_State *L, const char *modname,
 
 // end of sol/compatibility.hpp
 
+#include <vector>
+
+namespace sol {
+
+	template <typename Allocator = std::allocator<std::byte>>
+	class basic_bytecode : private std::vector<std::byte, Allocator> {
+	private:
+		using base_t = std::vector<std::byte, Allocator>;
+
+	public:
+		using base_t::allocator_type;
+		using base_t::const_iterator;
+		using base_t::const_pointer;
+		using base_t::const_reference;
+		using base_t::const_reverse_iterator;
+		using base_t::difference_type;
+		using base_t::iterator;
+		using base_t::pointer;
+		using base_t::reference;
+		using base_t::reverse_iterator;
+		using base_t::size_type;
+		using base_t::value_type;
+
+		using base_t::base_t;
+		using base_t::operator=;
+
+		using base_t::data;
+		using base_t::empty;
+		using base_t::max_size;
+		using base_t::size;
+
+		using base_t::at;
+		using base_t::operator[];
+		using base_t::back;
+		using base_t::front;
+
+		using base_t::begin;
+		using base_t::cbegin;
+		using base_t::cend;
+		using base_t::end;
+
+		using base_t::crbegin;
+		using base_t::crend;
+		using base_t::rbegin;
+		using base_t::rend;
+
+		using base_t::swap;
+		using base_t::get_allocator;
+
+		using base_t::emplace;
+		using base_t::emplace_back;
+		using base_t::insert;
+		using base_t::pop_back;
+		using base_t::push_back;
+		using base_t::reserve;
+		using base_t::resize;
+		using base_t::shrink_to_fit;
+
+		string_view as_string_view () const {
+			return string_view(reinterpret_cast<const char*>(this->data()), this->size());
+		}
+	};
+
+	template <typename Container>
+	inline int basic_insert_dump_writer(lua_State*, const void* memory, size_t memory_size, void* userdata) {
+		using storage_t = Container;
+		const std::byte* p_code = static_cast<const std::byte*>(memory);
+		storage_t& bc = *static_cast<storage_t*>(userdata);
+		try {
+			bc.insert(bc.cend(), p_code, p_code + memory_size);
+		}
+		catch ( ... ) {
+			return -1;
+		}
+		return 0;
+	}
+
+	using bytecode = basic_bytecode<>;
+
+	constexpr inline auto bytecode_dump_writer = &basic_insert_dump_writer<bytecode>;
+
+} // namespace sol
+
+// end of sol/bytecode.hpp
+
+// beginning of sol/stack.hpp
+
+// beginning of sol/trampoline.hpp
+
+// beginning of sol/types.hpp
+
+// beginning of sol/error.hpp
+
 #include <stdexcept>
 
 namespace sol {
@@ -7017,6 +7114,9 @@ namespace sol {
 		template <>
 		struct lua_type_of<nullopt_t> : std::integral_constant<type, type::lua_nil> {};
 
+		template <>
+		struct lua_type_of<lua_value> : std::integral_constant<type, type::poly> {};
+
 		template <>
 		struct lua_type_of<detail::non_lua_nil_t> : std::integral_constant<type, type::poly> {};
 
@@ -7029,6 +7129,9 @@ namespace sol {
 		template <bool b, typename Base>
 		struct lua_type_of<basic_table_core<b, Base>> : std::integral_constant<type, type::table> {};
 
+		template <typename Base>
+		struct lua_type_of<basic_lua_table<Base>> : std::integral_constant<type, type::table> {};
+
 		template <typename Base>
 		struct lua_type_of<basic_metatable<Base>> : std::integral_constant<type, type::table> {};
 
@@ -8917,7 +9020,6 @@ namespace sol {
 
 // end of sol/stack_guard.hpp
 
-#include <vector>
 #include <bitset>
 #include <forward_list>
 #include <algorithm>
@@ -9476,9 +9578,9 @@ namespace sol {
 		template <typename T, typename = void>
 		struct unqualified_pusher;
 
-		template <typename T, type t, typename>
+		template <typename T, type t, typename = void>
 		struct unqualified_checker;
-		template <typename T, type t, typename>
+		template <typename T, type t, typename = void>
 		struct qualified_checker;
 
 		template <typename T, typename = void>
@@ -9803,7 +9905,7 @@ namespace sol {
 				return sol_lua_check(types<Tu>(), L, index, std::forward<Handler>(handler), tracking);
 			}
 			else {
-				unqualified_checker<Tu> c;
+				unqualified_checker<Tu, lua_type_of_v<Tu>> c;
 				// VC++ has a bad warning here: shut it up
 				(void)c;
 				return c.check(L, index, std::forward<Handler>(handler), tracking);
@@ -9828,7 +9930,8 @@ namespace sol {
 				return sol_lua_check(types<T>(), L, index, std::forward<Handler>(handler), tracking);
 			}
 			else {
-				qualified_checker<T> c;
+				using Tu = meta::unqualified_t<T>;
+				qualified_checker<T, lua_type_of_v<Tu>> c;
 				// VC++ has a bad warning here: shut it up
 				(void)c;
 				return c.check(L, index, std::forward<Handler>(handler), tracking);
@@ -9927,6 +10030,11 @@ namespace sol {
 
 		namespace stack_detail {
 
+			template <typename Handler>
+			inline bool check_types(lua_State*, int, Handler&&, record&) {
+				return true;
+			}
+
 			template <typename T, typename... Args, typename Handler>
 			inline bool check_types(lua_State* L, int firstargument, Handler&& handler, record& tracking) {
 				if (!stack::check<T>(L, firstargument + tracking.used, handler, tracking))
@@ -9934,13 +10042,8 @@ namespace sol {
 				return check_types<Args...>(L, firstargument, std::forward<Handler>(handler), tracking);
 			}
 
-			template <typename Handler>
-			static bool check_types(lua_State*, int, Handler&&, record&) {
-				return true;
-			}
-
 			template <typename... Args, typename Handler>
-			bool check_types(types<Args...>, lua_State* L, int index, Handler&& handler, record& tracking) {
+			inline bool check_types(types<Args...>, lua_State* L, int index, Handler&& handler, record& tracking) {
 				return check_types<Args...>(L, index, std::forward<Handler>(handler), tracking);
 			}
 
@@ -10323,7 +10426,7 @@ namespace sol { namespace stack {
 		}
 	};
 
-	template <typename T, type expected = lua_type_of_v<T>, typename = void>
+	template <typename T, type expected, typename>
 	struct unqualified_checker {
 		template <typename Handler>
 		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
@@ -10488,6 +10591,24 @@ namespace sol { namespace stack {
 			else if constexpr (std::is_same_v<T, detail::non_lua_nil_t>) {
 				return !stack::unqualified_check<lua_nil_t>(L, index, std::forward<Handler>(handler), tracking);
 			}
+			else if constexpr (meta::is_specialization_of_v<T, basic_lua_table>) {
+				tracking.use(1);
+				type t = type_of(L, index);
+				if (t != type::table) {
+					handler(L, index, type::table, t, "value is not a table");
+					return false;
+				}
+				return true;
+			}
+			else if constexpr (meta::is_specialization_of_v<T, basic_bytecode>) {
+				tracking.use(1);
+				type t = type_of(L, index);
+				if (t != type::function) {
+					handler(L, index, type::function, t, "value is not a function that can be dumped");
+					return false;
+				}
+				return true;
+			}
 			else if constexpr(meta::is_specialization_of_v<T, basic_environment>) {
 				tracking.use(1);
 				if (lua_getmetatable(L, index) == 0) {
@@ -10534,7 +10655,7 @@ namespace sol { namespace stack {
 					return success;
 				}
 				else if constexpr (meta::is_specialization_of_v<T, user>) {
-					unqualified_checker<lightuserdata_value> c;
+					unqualified_checker<lightuserdata_value, type::userdata> c;
 					(void)c;
 					return c.check(L, index, std::forward<Handler>(handler), tracking);
 				}
@@ -10652,51 +10773,59 @@ namespace sol { namespace stack {
 
 		template <typename U, typename Handler>
 		static bool check(types<U>, lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
-#if defined(SOL_ENABLE_INTEROP) && SOL_ENABLE_INTEROP
+			if constexpr (std::is_same_v<T, lightuserdata_value> || std::is_same_v<T, userdata_value> || std::is_same_v<T, userdata> || std::is_same_v<T, lightuserdata>) {
-			if (stack_detail::interop_check<U>(L, index, indextype, handler, tracking)) {
+				tracking.use(1);
-				return true;
+				if (indextype != type::userdata) {
-			}
+					handler(L, index, type::userdata, indextype, "value is not a valid userdata");
-#endif // interop extensibility
+					return false;
-			tracking.use(1);
-			if (indextype != type::userdata) {
-				handler(L, index, type::userdata, indextype, "value is not a valid userdata");
-				return false;
-			}
-			if (meta::any<std::is_same<T, lightuserdata_value>, std::is_same<T, userdata_value>, std::is_same<T, userdata>, std::is_same<T, lightuserdata>>::value)
-				return true;
-			if (lua_getmetatable(L, index) == 0) {
-				return true;
-			}
-			int metatableindex = lua_gettop(L);
-			if (stack_detail::check_metatable<U>(L, metatableindex))
-				return true;
-			if (stack_detail::check_metatable<U*>(L, metatableindex))
-				return true;
-			if (stack_detail::check_metatable<detail::unique_usertype<U>>(L, metatableindex))
-				return true;
-			if (stack_detail::check_metatable<as_container_t<U>>(L, metatableindex))
-				return true;
-			bool success = false;
-			bool has_derived = derive<T>::value || weak_derive<T>::value;
-			if (has_derived) {
-#if defined(SOL_SAFE_STACK_CHECK) && SOL_SAFE_STACK_CHECK
-				luaL_checkstack(L, 1, detail::not_enough_stack_space_string);
-#endif // make sure stack doesn't overflow
-				auto pn = stack::pop_n(L, 1);
-				lua_pushstring(L, &detail::base_class_check_key()[0]);
-				lua_rawget(L, metatableindex);
-				if (type_of(L, -1) != type::lua_nil) {
-					void* basecastdata = lua_touserdata(L, -1);
-					detail::inheritance_check_function ic = reinterpret_cast<detail::inheritance_check_function>(basecastdata);
-					success = ic(usertype_traits<T>::qualified_name());
 				}
+				return true;
 			}
-			lua_pop(L, 1);
+			else {
-			if (!success) {
+#if defined(SOL_ENABLE_INTEROP) && SOL_ENABLE_INTEROP
-				handler(L, index, type::userdata, indextype, "value at this index does not properly reflect the desired type");
+				if (stack_detail::interop_check<U>(L, index, indextype, handler, tracking)) {
-				return false;
+					return true;
+				}
+#endif // interop extensibility
+				tracking.use(1);
+				if (indextype != type::userdata) {
+					handler(L, index, type::userdata, indextype, "value is not a valid userdata");
+					return false;
+				}
+				if (lua_getmetatable(L, index) == 0) {
+					return true;
+				}
+				int metatableindex = lua_gettop(L);
+				if (stack_detail::check_metatable<U>(L, metatableindex))
+					return true;
+				if (stack_detail::check_metatable<U*>(L, metatableindex))
+					return true;
+				if (stack_detail::check_metatable<detail::unique_usertype<U>>(L, metatableindex))
+					return true;
+				if (stack_detail::check_metatable<as_container_t<U>>(L, metatableindex))
+					return true;
+				bool success = false;
+				bool has_derived = derive<T>::value || weak_derive<T>::value;
+				if (has_derived) {
+	#if defined(SOL_SAFE_STACK_CHECK) && SOL_SAFE_STACK_CHECK
+					luaL_checkstack(L, 1, detail::not_enough_stack_space_string);
+	#endif // make sure stack doesn't overflow
+					auto pn = stack::pop_n(L, 1);
+					lua_pushstring(L, &detail::base_class_check_key()[0]);
+					lua_rawget(L, metatableindex);
+					if (type_of(L, -1) != type::lua_nil) {
+						void* basecastdata = lua_touserdata(L, -1);
+						detail::inheritance_check_function ic = reinterpret_cast<detail::inheritance_check_function>(basecastdata);
+						success = ic(usertype_traits<T>::qualified_name());
+					}
+				}
+				lua_pop(L, 1);
+				if (!success) {
+					handler(L, index, type::userdata, indextype, "value at this index does not properly reflect the desired type");
+					return false;
+				}
+				return true;
 			}
-			return true;
 		}
 	};
 
@@ -10819,7 +10948,7 @@ namespace sol { namespace stack {
 namespace sol {
 namespace stack {
 
-	template <typename X, type expected = lua_type_of_v<meta::unqualified_t<X>>, typename = void>
+	template <typename X, type expected, typename>
 	struct qualified_checker {
 		template <typename Handler>
 		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
@@ -13537,6 +13666,24 @@ namespace sol {
 			}
 		};
 
+		template <typename Allocator>
+		struct unqualified_pusher<basic_bytecode<Allocator>> {
+			template <typename T>
+			static int push(lua_State* L, T&& bc, const char* bytecode_name) {
+				const auto first = bc.data();
+				const auto bcsize = bc.size();
+				// pushes either the function, or an error
+				// if it errors, shit goes south, and people can test that upstream
+				(void)luaL_loadbuffer(L, reinterpret_cast<const char*>(first), static_cast<std::size_t>(bcsize * (sizeof(*first) / sizeof(const char))), bytecode_name);
+				return 1;
+			}
+
+			template <typename T>
+			static int push(lua_State* L, T&& bc) {
+				return push(L, std::forward<bc>(bc), "bytecode");
+			}
+		};
+
 #if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
 		template <typename O>
 		struct unqualified_pusher<std::optional<O>> {
@@ -17110,7 +17257,7 @@ namespace sol {
 				stack::push(L, c_closure(freefunc, upvalues));
 			}
 			else if constexpr (sizeof...(Args) < 2) {
-				using Tu = typename meta::unqualified<Args...>::type;
+				using Tu = typename meta::meta_detail::unqualified_non_alias<Args...>::type;
 				constexpr bool is_reference = meta::is_specialization_of_v<Tu, std::reference_wrapper> || std::is_pointer_v<Tu>;
 				if constexpr (meta::is_specialization_of_v<Tu, function_detail::class_indicator>) {
 					lua_CFunction freefunc = &function_detail::upvalue_this_member_variable<typename Tu::type, Fx, is_yielding>::call;
@@ -17574,76 +17721,6 @@ namespace sol {
 
 // end of sol/function_types.hpp
 
-// beginning of sol/bytecode.hpp
-
-namespace sol {
-
-	template <typename Allocator = std::allocator<std::byte>>
-	class basic_bytecode : private std::vector<std::byte, Allocator> {
-	private:
-		using base_t = std::vector<std::byte, Allocator>;
-
-	public:
-		using base_t::value_type;
-
-		using base_t::base_t;
-		using base_t::operator=;
-
-		using base_t::data;
-		using base_t::empty;
-		using base_t::max_size;
-		using base_t::size;
-
-		using base_t::at;
-		using base_t::operator[];
-		using base_t::back;
-		using base_t::front;
-
-		using base_t::begin;
-		using base_t::cbegin;
-		using base_t::cend;
-		using base_t::end;
-
-		using base_t::crbegin;
-		using base_t::crend;
-		using base_t::rbegin;
-		using base_t::rend;
-
-		using base_t::swap;
-		using base_t::get_allocator;
-
-		using base_t::emplace;
-		using base_t::emplace_back;
-		using base_t::insert;
-		using base_t::pop_back;
-		using base_t::push_back;
-		using base_t::reserve;
-		using base_t::resize;
-		using base_t::shrink_to_fit;
-
-		string_view as_string_view () const {
-			return string_view(reinterpret_cast<const char*>(this->data()), this->size());
-		}
-	};
-
-	using bytecode = basic_bytecode<>;
-
-	inline int bytecode_dump_writer(lua_State*, const void* memory, size_t memory_size, void* userdata) {
-		const std::byte* p_code = static_cast<const std::byte*>(memory);
-		bytecode& bc = *static_cast<bytecode*>(userdata);
-		try {
-			bc.insert(bc.cend(), p_code, p_code + memory_size);
-		}
-		catch ( ... ) {
-			return -1;
-		}
-		return 0;
-	}
-
-} // namespace sol
-
-// end of sol/bytecode.hpp
-
 // beginning of sol/dump_handler.hpp
 
 namespace sol {
@@ -17661,19 +17738,29 @@ namespace sol {
 		}
 	};
 
-	inline int dump_pass_on_error(int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+	inline int dump_pass_on_error(lua_State* L, int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+		(void)L;
 		(void)writer_function;
 		(void)userdata;
 		(void)strip;
 		return result_code;
 	}
 
-	inline int dump_throw_on_error(int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+	inline int dump_throw_on_error(lua_State* L, int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+		(void)L;
 		(void)writer_function;
 		(void)userdata;
 		(void)strip;
 		throw dump_error(result_code);
-	}	
+	}
+
+	inline int dump_panic_on_error(lua_State* L, int result_code, lua_Writer writer_function, void* userdata, bool strip) {
+		(void)L;
+		(void)writer_function;
+		(void)userdata;
+		(void)strip;
+		return luaL_error(L, "a non-zero error code (%d) was returned by the lua_Writer for the dump function", result_code);
+	}
 
 } // namespace sol
 
@@ -17770,10 +17857,11 @@ namespace sol {
 
 		template <typename Fx>
 		int dump(lua_Writer writer, void* userdata, bool strip, Fx&& on_error) const {
-			auto pp = stack::push_pop(*this);
+			this->push();
+			auto ppn = stack::push_popper_n<false>(this->lua_state(), 1);
 			int r = lua_dump(this->lua_state(), writer, userdata, strip ? 1 : 0);
 			if (r != 0) {
-				return on_error(r, writer, userdata, strip);
+				return on_error(this->lua_state(), r, writer, userdata, strip);
 			}
 			return r;
 		}
@@ -17782,9 +17870,17 @@ namespace sol {
 			return dump(writer, userdata, strip, &dump_throw_on_error);
 		}
 
-		bytecode dump() const {
+		template <typename Container = bytecode>
-			bytecode bc;
+		Container dump() const {
-			(void)dump(&bytecode_dump_writer, static_cast<void*>(&bc), strip, &dump_throw_on_error);
+			Container bc;
+			(void)dump(static_cast<lua_Writer>(&basic_insert_dump_writer<Container>), static_cast<void*>(&bc), false, &dump_panic_on_error);
+			return bc;
+		}
+
+		template <typename Container = bytecode, typename Fx>
+		Container dump(Fx&& on_error) const {
+			Container bc;
+			(void)dump(static_cast<lua_Writer>(&basic_insert_dump_writer<Container>), static_cast<void*>(&bc), false, std::forward<Fx>(on_error));
 			return bc;
 		}
 
@@ -18125,10 +18221,11 @@ namespace sol {
 
 		template <typename Fx>
 		int dump(lua_Writer writer, void* userdata, bool strip, Fx&& on_error) const {
-			auto pp = stack::push_pop(*this);
+			this->push();
+			auto ppn = stack::push_popper_n<false>(this->lua_state(), 1);
 			int r = lua_dump(this->lua_state(), writer, userdata, strip ? 1 : 0);
 			if (r != 0) {
-				return on_error(r, writer, userdata, strip);
+				return on_error(this->lua_state(), r, writer, userdata, strip);
 			}
 			return r;
 		}
@@ -18137,9 +18234,17 @@ namespace sol {
 			return dump(writer, userdata, strip, &dump_pass_on_error);
 		}
 
-		bytecode dump() const {
+		template <typename Container = bytecode>
-			bytecode bc;
+		Container dump() const {
-			(void)dump(&bytecode_dump_writer, static_cast<void*>(&bc), false, &dump_throw_on_error);
+			Container bc;
+			(void)dump(static_cast<lua_Writer>(&basic_insert_dump_writer<Container>), static_cast<void*>(&bc), false, &dump_throw_on_error);
+			return bc;
+		}
+
+		template <typename Container = bytecode, typename Fx>
+		Container dump(Fx&& on_error) const {
+			Container bc;
+			(void)dump(static_cast<lua_Writer>(&basic_insert_dump_writer<Container>), static_cast<void*>(&bc), false, std::forward<Fx>(on_error));
 			return bc;
 		}
 
@@ -18288,8 +18393,7 @@ namespace sol {
 			}
 
 			static std::function<Signature> get(lua_State* L, int index, record& tracking) {
-				tracking.last = 1;
+				tracking.use(1);
-				tracking.used += 1;
 				type t = type_of(L, index);
 				if (t == type::none || t == type::lua_nil) {
 					return nullptr;
@@ -18297,6 +18401,15 @@ namespace sol {
 				return get_std_func(return_types(), L, index);
 			}
 		};
+
+		template <typename Allocator>
+		struct unqualified_getter<basic_bytecode<Allocator>> {
+			static basic_bytecode<Allocator> get(lua_State* L, int index, record& tracking) {
+				tracking.use(1);
+				stack_function sf(L, index);
+				return sf.dump(&dump_panic_on_error);
+			}
+		};
 	} // namespace stack
 
 } // namespace sol
@@ -22479,6 +22592,76 @@ namespace sol {
 
 // beginning of sol/table.hpp
 
+// beginning of sol/lua_table.hpp
+
+namespace sol {
+
+	template <typename ref_t>
+	struct basic_lua_table : basic_table_core<false, ref_t> {
+	private:
+		using base_t = basic_table_core<false, ref_t>;
+
+		friend class state;
+		friend class state_view;
+
+	public:
+		using base_t::lua_state;
+
+		basic_lua_table() noexcept = default;
+		basic_lua_table(const basic_lua_table&) = default;
+		basic_lua_table(basic_lua_table&&) = default;
+		basic_lua_table& operator=(const basic_lua_table&) = default;
+		basic_lua_table& operator=(basic_lua_table&&) = default;
+		basic_lua_table(const stack_reference& r) : basic_lua_table(r.lua_state(), r.stack_index()) {
+		}
+		basic_lua_table(stack_reference&& r) : basic_lua_table(r.lua_state(), r.stack_index()) {
+		}
+		template <typename T, meta::enable_any<is_lua_reference<meta::unqualified_t<T>>> = meta::enabler>
+		basic_lua_table(lua_State* L, T&& r) : base_t(L, std::forward<T>(r)) {
+#if defined(SOL_SAFE_REFERENCES) && SOL_SAFE_REFERENCES
+			auto pp = stack::push_pop(*this);
+			constructor_handler handler{};
+			stack::check<basic_lua_table>(lua_state(), -1, handler);
+#endif // Safety
+		}
+		basic_lua_table(lua_State* L, const new_table& nt) : base_t(L, nt) {
+			if (!is_stack_based<meta::unqualified_t<ref_t>>::value) {
+				lua_pop(L, 1);
+			}
+		}
+		basic_lua_table(lua_State* L, int index = -1) : base_t(detail::no_safety, L, index) {
+#if defined(SOL_SAFE_REFERENCES) && SOL_SAFE_REFERENCES
+			constructor_handler handler{};
+			stack::check<basic_lua_table>(L, index, handler);
+#endif // Safety
+		}
+		basic_lua_table(lua_State* L, ref_index index) : base_t(detail::no_safety, L, index) {
+#if defined(SOL_SAFE_REFERENCES) && SOL_SAFE_REFERENCES
+			auto pp = stack::push_pop(*this);
+			constructor_handler handler{};
+			stack::check<basic_lua_table>(lua_state(), -1, handler);
+#endif // Safety
+		}
+		template <typename T,
+		     meta::enable<meta::neg<meta::any_same<meta::unqualified_t<T>, basic_lua_table>>, meta::neg<std::is_same<ref_t, stack_reference>>,
+		          meta::neg<std::is_same<lua_nil_t, meta::unqualified_t<T>>>, is_lua_reference<meta::unqualified_t<T>>> = meta::enabler>
+		basic_lua_table(T&& r) noexcept : basic_lua_table(detail::no_safety, std::forward<T>(r)) {
+#if defined(SOL_SAFE_REFERENCES) && SOL_SAFE_REFERENCES
+			if (!is_table<meta::unqualified_t<T>>::value) {
+				auto pp = stack::push_pop(*this);
+				constructor_handler handler{};
+				stack::check<basic_lua_table>(lua_state(), -1, handler);
+			}
+#endif // Safety
+		}
+		basic_lua_table(lua_nil_t r) noexcept : basic_lua_table(detail::no_safety, r) {
+		}
+	};
+
+}
+
+// end of sol/lua_table.hpp
+
 namespace sol {
 	typedef table_core<false> table;
 
@@ -22878,6 +23061,109 @@ namespace sol {
 
 // beginning of sol/state_handling.hpp
 
+// beginning of sol/lua_value.hpp
+
+namespace sol {
+	namespace detail {
+		template <typename T>
+		using is_reference_or_lua_value_init_list = meta::any<meta::is_specialization_of<T, std::initializer_list>, std::is_same<T, reference>>;
+
+		template <typename T>
+		using is_lua_value_single_constructible = meta::any<std::is_same<T, lua_value>, is_reference_or_lua_value_init_list<T>>;
+	}
+
+	struct lua_value {
+	private:
+		static lua_State*& thread_local_lua_state() {
+			static thread_local lua_State* L = nullptr;
+			return L;
+		}
+
+		reference ref_value;
+
+	public:
+		static void set_lua_state(lua_State* L) {
+			thread_local_lua_state() = L;
+		}
+
+		template <typename T, meta::disable<detail::is_reference_or_lua_value_init_list<meta::unqualified_t<T>>> = meta::enabler>
+		lua_value(lua_State* L_, T&& value) : lua_value(((set_lua_state(L_)), std::forward<T>(value))) {
+		}
+
+		template <typename T, meta::disable<detail::is_lua_value_single_constructible<meta::unqualified_t<T>>> = meta::enabler>
+		lua_value(T&& value) : ref_value(make_reference(thread_local_lua_state(), std::forward<T>(value))) {
+		}
+
+		lua_value(lua_State* L_, std::initializer_list<lua_value> il) : lua_value(((set_lua_state(L_)), std::move(il))) {
+		}
+
+		lua_value(std::initializer_list<lua_value> il) : ref_value(make_reference(thread_local_lua_state(), std::move(il))) {
+		}
+
+		lua_value(lua_State* L_, reference r) : lua_value(((thread_local_lua_state() = L_), std::move(r))) {
+		}
+
+		lua_value(reference r) : ref_value(std::move(r)) {
+		}
+
+		lua_value(const lua_value&) noexcept = default;
+		lua_value(lua_value&&) = default;
+		lua_value& operator=(const lua_value&) = default;
+		lua_value& operator=(lua_value&&) = default;
+
+		const reference& value() const& {
+			return ref_value;
+		}
+
+		reference& value() & {
+			return ref_value;
+		}
+
+		reference&& value() && {
+			return std::move(ref_value);
+		}
+
+		template <typename T>
+		decltype(auto) as() const {
+			ref_value.push();
+			return stack::pop<T>(ref_value.lua_state());
+		}
+
+		template <typename T>
+		bool is() const {
+			int r = ref_value.registry_index();
+			if (r == LUA_REFNIL)
+				return meta::any_same<meta::unqualified_t<T>, lua_nil_t, nullopt_t, std::nullptr_t>::value ? true : false;
+			if (r == LUA_NOREF)
+				return false;
+			auto pp = stack::push_pop(ref_value);
+			return stack::check<T>(ref_value.lua_state(), -1, no_panic);
+		}
+	};
+
+	namespace stack {
+		template <>
+		struct unqualified_pusher<lua_value> {
+			static int push(lua_State* L, const lua_value& lv) {
+				return stack::push(L, lv.value());
+			}
+
+			static int push(lua_State* L, lua_value&& lv) {
+				return stack::push(L, std::move(lv).value());
+			}
+		};
+
+		template <>
+		struct unqualified_getter<lua_value> {
+			static lua_value get(lua_State* L, int index, record& tracking) {
+				return lua_value(L, stack::get<reference>(L, index, tracking));
+			}
+		};
+	}
+} // namespace sol
+
+// end of sol/lua_value.hpp
+
 #if defined(SOL_PRINT_ERRORS) && SOL_PRINT_ERRORS
 #endif
 
@@ -22945,6 +23231,7 @@ namespace sol {
 		set_default_exception_handler(L, exf);
 		register_main_thread(L);
 		stack::luajit_exception_handler(L);
+		lua_value::set_lua_state(L);
 	}
 
 	inline std::size_t total_memory_used(lua_State* L) {

tests/compile_tests/source/lua_table.cpp

@@ -0,0 +1,26 @@
+// sol3
+
+// The MIT License (MIT)
+
+// Copyright (c) 2013-2019 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#include "sol_defines.hpp"
+
+#include <sol/lua_table.hpp>

tests/compile_tests/source/lua_value.cpp

@@ -0,0 +1,26 @@
+// sol3
+
+// The MIT License (MIT)
+
+// Copyright (c) 2013-2019 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#include "sol_defines.hpp"
+
+#include <sol/lua_value.hpp>

tests/runtime_tests/source/container_semantics.cpp

@@ -255,6 +255,7 @@ end
 TEST_CASE("containers/sequence containers", "check all of the functinos for every single container") {
 	SECTION("vector") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		std::vector<int> items{ 11, 12, 13, 14, 15 };
@@ -263,6 +264,7 @@ TEST_CASE("containers/sequence containers", "check all of the functinos for ever
 	}
 	SECTION("list") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		std::list<int> items{ 11, 12, 13, 14, 15 };
@@ -271,6 +273,7 @@ TEST_CASE("containers/sequence containers", "check all of the functinos for ever
 	}
 	SECTION("forward_list") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		std::forward_list<int> items{ 11, 12, 13, 14, 15 };
@@ -279,6 +282,7 @@ TEST_CASE("containers/sequence containers", "check all of the functinos for ever
 	}
 	SECTION("deque") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		std::deque<int> items{ 11, 12, 13, 14, 15 };
@@ -290,6 +294,7 @@ TEST_CASE("containers/sequence containers", "check all of the functinos for ever
 TEST_CASE("containers/fixed containers", "check immutable container types") {
 	SECTION("array") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		std::array<int, 5> items{ { 11, 12, 13, 14, 15 } };
@@ -298,6 +303,7 @@ TEST_CASE("containers/fixed containers", "check immutable container types") {
 	}
 	SECTION("array ref") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		std::array<int, 5> items{ { 11, 12, 13, 14, 15 } };
@@ -306,6 +312,7 @@ TEST_CASE("containers/fixed containers", "check immutable container types") {
 	}
 	SECTION("c array") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		int items[5] = { 11, 12, 13, 14, 15 };
@@ -314,6 +321,7 @@ TEST_CASE("containers/fixed containers", "check immutable container types") {
 	}
 	SECTION("c array ref") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		int items[5] = { 11, 12, 13, 14, 15 };
@@ -324,6 +332,7 @@ TEST_CASE("containers/fixed containers", "check immutable container types") {
 
 TEST_CASE("containers/auxiliary functions test", "make sure the manipulation functions are present and usable and working across various container types") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries();
 
 	auto result1 = lua.safe_script(R"(
@@ -407,6 +416,8 @@ TEST_CASE("containers/indices test", "test indices on fixed array types") {
 #if 0
 	SECTION("zero index test") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
+
 		lua["c_arr"] = std::array<int, 5>{ { 2, 4, 6, 8, 10 } };
 		auto result = lua.safe_script(R"(
 c_arr[0] = 7
@@ -416,6 +427,8 @@ c_arr[0] = 7
 
 	SECTION("negative index test") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
+
 		lua["c_arr"] = std::array<int, 5>{ { 2, 4, 6, 8, 10 } };
 		auto result = lua.safe_script(R"(
 c_arr[-1] = 7

tests/runtime_tests/source/coroutines.cpp

@@ -100,6 +100,8 @@ end
 )";
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	lua.open_libraries(sol::lib::base, sol::lib::coroutine);
 	auto result1 = lua.safe_script(script);
 	REQUIRE(result1.valid());
@@ -127,6 +129,8 @@ end
 )";
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	lua.open_libraries(sol::lib::base, sol::lib::coroutine);
 	auto result = lua.safe_script(code, sol::script_pass_on_error);
 	REQUIRE(result.valid());
@@ -146,6 +150,8 @@ end
 TEST_CASE("coroutines/transfer", "test that things created inside of a coroutine can have their state transferred using lua_xmove constructors") {
 	for (std::size_t tries = 0; tries < 200; ++tries) {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
+	
 		lua.open_libraries();
 		{
 			sol::function f2;

tests/runtime_tests/source/customizations_private.cpp

@@ -60,7 +60,7 @@ namespace sol {
 	namespace stack {
 
 		template <>
-		struct unqualified_checker<two_things> {
+		struct unqualified_checker<two_things, type::poly> {
 			template <typename Handler>
 			static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
 				bool success = stack::check<int>(L, index, handler) && stack::check<bool>(L, index + 1, handler);
@@ -89,7 +89,7 @@ namespace sol {
 		};
 
 		template <>
-		struct unqualified_checker<number_shim> {
+		struct unqualified_checker<number_shim, type::poly> {
 			template <typename Handler>
 			static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
 				if (!check_usertype<number_shim>(L, index) && !stack::check<double>(L, index)) {

tests/runtime_tests/source/dump.cpp

@@ -25,19 +25,97 @@
 
 #include <catch.hpp>
 
-TEST_CASE("dump/dump transfer", "test that a function can be transferred from one place to another") {
+#include <list>
-	sol::state lua;
+#include <vector>
-	sol::state lua2;
+#include <deque>
-	lua2.open_libraries(sol::lib::base);
 
-	sol::load_result lr = lua.load("a = function (v) print(v) return v end");
+int dump_always_fail_number = -32;
-	REQUIRE(lr.valid());
-	sol::protected_function target = lr;
-	sol::bytecode target_bc = target.dump();
 
-	auto result2 = lua2.safe_script(target_bc.as_string_view(), sol::script_pass_on_error);
+int dump_always_fail(lua_State*, const void*, size_t, void*) {
-	REQUIRE(result2.valid());
+	return dump_always_fail_number;
-	sol::protected_function pf = lua2["a"];
+}
-	int v = pf(25557);
+
-	REQUIRE(v == 25557);
+TEST_CASE("dump/dump transfer", "test that a function can be transferred from one place to another") {
+	SECTION("safe") {
+		sol::state lua;
+		sol::state lua2;
+		lua2.open_libraries(sol::lib::base);
+
+		sol::load_result lr = lua.load("a = function (v) print(v) return v end");
+		REQUIRE(lr.valid());
+		sol::protected_function target = lr;
+		sol::bytecode target_bc = target.dump();
+
+		auto result2 = lua2.safe_script(target_bc.as_string_view(), sol::script_pass_on_error);
+		REQUIRE(result2.valid());
+		sol::protected_function pf = lua2["a"];
+		int v = pf(25557);
+		REQUIRE(v == 25557);
+	}
+	SECTION("unsafe") {
+		sol::state lua;
+		sol::state lua2;
+		lua2.open_libraries(sol::lib::base);
+
+		sol::load_result lr = lua.load("a = function (v) print(v) return v end");
+		REQUIRE(lr.valid());
+		sol::unsafe_function target = lr;
+		sol::bytecode target_bc = target.dump();
+
+		auto result2 = lua2.safe_script(target_bc.as_string_view(), sol::script_pass_on_error);
+		REQUIRE(result2.valid());
+		sol::unsafe_function pf = lua2["a"];
+		int v = pf(25557);
+		REQUIRE(v == 25557);
+	}
+}
+
+TEST_CASE("dump/failure", "test that failure is properly propagated") {
+	SECTION("safe") {
+		sol::state lua;
+		sol::load_result lr = lua.load("a = function (v) print(v) return v end");
+		REQUIRE(lr.valid());
+		sol::protected_function target = lr;
+		int err = target.dump(&dump_always_fail, nullptr, false, sol::dump_pass_on_error);
+		REQUIRE(err == dump_always_fail_number);
+	}
+	SECTION("unsafe") {
+		sol::state lua;
+		sol::load_result lr = lua.load("a = function (v) print(v) return v end");
+		REQUIRE(lr.valid());
+		sol::unsafe_function target = lr;
+		int err = target.dump(&dump_always_fail, nullptr, false, sol::dump_pass_on_error);
+		REQUIRE(err == dump_always_fail_number);
+	}
+}
+
+TEST_CASE("dump/different containers", "test that dump inserter works for various kinds of containers") {
+	SECTION("safe") {
+		sol::state lua;
+
+		sol::load_result lr = lua.load("a = function (v) print(v) return v end");
+		REQUIRE(lr.valid());
+		sol::protected_function target = lr;
+		sol::bytecode bytecode_dump = target.dump();
+		std::list<std::byte> list_dump = target.dump<std::list<std::byte>>();
+		std::vector<std::byte> vector_dump = target.dump<std::vector<std::byte>>();
+		std::deque<std::byte> deque_dump = target.dump<std::deque<std::byte>>();
+		REQUIRE(std::equal(bytecode_dump.cbegin(), bytecode_dump.cend(), vector_dump.cbegin(), vector_dump.cend()));
+		REQUIRE(std::equal(bytecode_dump.cbegin(), bytecode_dump.cend(), list_dump.cbegin(), list_dump.cend()));
+		REQUIRE(std::equal(bytecode_dump.cbegin(), bytecode_dump.cend(), deque_dump.cbegin(), deque_dump.cend()));
+	}
+	SECTION("unsafe") {
+		sol::state lua;
+
+		sol::load_result lr = lua.load("a = function (v) print(v) return v end");
+		REQUIRE(lr.valid());
+		sol::unsafe_function target = lr;
+		sol::bytecode bytecode_dump = target.dump();
+		std::list<std::byte> list_dump = target.dump<std::list<std::byte>>();
+		std::vector<std::byte> vector_dump = target.dump<std::vector<std::byte>>();
+		std::deque<std::byte> deque_dump = target.dump<std::deque<std::byte>>();
+		REQUIRE(std::equal(bytecode_dump.cbegin(), bytecode_dump.cend(), vector_dump.cbegin(), vector_dump.cend()));
+		REQUIRE(std::equal(bytecode_dump.cbegin(), bytecode_dump.cend(), list_dump.cbegin(), list_dump.cend()));
+		REQUIRE(std::equal(bytecode_dump.cbegin(), bytecode_dump.cend(), deque_dump.cbegin(), deque_dump.cend()));
+	}
 }

tests/runtime_tests/source/environments.cpp

@@ -30,6 +30,7 @@
 TEST_CASE("environments/get", "Envronments can be taken out of things like Lua functions properly") {
 	sol::state lua;
 	sol::stack_guard luasg(lua);
+
 	lua.open_libraries(sol::lib::base);
 
 	auto result1 = lua.safe_script("f = function() return test end", sol::script_pass_on_error);
@@ -62,7 +63,7 @@ TEST_CASE("environments/get", "Envronments can be taken out of things like Lua f
 
 	lua.set_function("check_f_env",
 		[&lua, &env_f](sol::object target) {
-			sol::stack_guard sg(lua);
+			sol::stack_guard luasg(lua);
 			sol::environment target_env(sol::env_key, target);
 			int test_env_f = env_f["test"];
 			int test_target_env = target_env["test"];
@@ -72,7 +73,7 @@ TEST_CASE("environments/get", "Envronments can be taken out of things like Lua f
 		});
 	lua.set_function("check_g_env",
 		[&lua, &env_g](sol::function target) {
-			sol::stack_guard sg(lua);
+			sol::stack_guard luasg(lua);
 			sol::environment target_env = sol::get_environment(target);
 			int test_env_g = env_g["test"];
 			int test_target_env = target_env["test"];
@@ -82,7 +83,7 @@ TEST_CASE("environments/get", "Envronments can be taken out of things like Lua f
 		});
 	lua.set_function("check_h_env",
 		[&lua](sol::function target) {
-			sol::stack_guard sg(lua);
+			sol::stack_guard luasg(lua);
 			sol::environment target_env = sol::get_environment(target);
 		});
 
@@ -97,6 +98,8 @@ TEST_CASE("environments/get", "Envronments can be taken out of things like Lua f
 TEST_CASE("environments/shadowing", "Environments can properly shadow and fallback on variables") {
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	lua["b"] = 2142;
 
 	SECTION("no fallback") {
@@ -179,6 +182,7 @@ TEST_CASE("environments/functions", "see if environments on functions are workin
 
 	SECTION("basic") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		auto result1 = lua.safe_script("a = function() return 5 end", sol::script_pass_on_error);
 		REQUIRE(result1.valid());
@@ -196,6 +200,7 @@ TEST_CASE("environments/functions", "see if environments on functions are workin
 	}
 	SECTION("return environment value") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		auto result1 = lua.safe_script("a = function() return test end", sol::script_pass_on_error);
 		REQUIRE(result1.valid());
@@ -212,6 +217,8 @@ TEST_CASE("environments/functions", "see if environments on functions are workin
 
 	SECTION("set environment value") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
+
 		auto result1 = lua.safe_script("a = function() test = 5 end", sol::script_pass_on_error);
 		REQUIRE(result1.valid());
 
@@ -235,6 +242,7 @@ TEST_CASE("environments/this_environment", "test various situations of pulling o
 	static std::string code = "return (f(10))";
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 
 	lua["f"] = [](sol::this_environment te, int x, sol::this_state ts) {
 		if (te) {

tests/runtime_tests/source/functions.cpp

@@ -145,6 +145,8 @@ TEST_CASE("functions/tuple returns", "Make sure tuple returns are ordered proper
 
 TEST_CASE("functions/overload resolution", "Check if overloaded function resolution templates compile/work") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	lua.open_libraries(sol::lib::base);
 
 	lua.set_function("non_overloaded", non_overloaded);
@@ -188,9 +190,9 @@ TEST_CASE("functions/return order and multi get", "Check if return order is in t
 	const static std::tuple<int, int, int> triple = std::make_tuple(10, 11, 12);
 	const static std::tuple<int, float> paired = std::make_tuple(10, 10.f);
 	sol::state lua;
-	lua.set_function("f", [] {
+	sol::stack_guard luasg(lua);
-		return std::make_tuple(10, 11, 12);
+	
-	});
+	lua.set_function("f", [] { return std::make_tuple(10, 11, 12); });
 	lua.set_function("h", []() {
 		return std::make_tuple(10, 10.0f);
 	});
@@ -260,8 +262,9 @@ end )", sol::script_pass_on_error);
 
 TEST_CASE("functions/pair and tuple and proxy tests", "Check if sol::reference and sol::proxy can be passed to functions as arguments") {
 	sol::state lua;
-	lua.new_usertype<A>("A",
+	sol::stack_guard luasg(lua);
-		"bark", &A::bark);
+	
+	lua.new_usertype<A>("A", "bark", &A::bark);
 	auto result1 = lua.safe_script(R"( function f (num_value, a)
     return num_value * 2, a:bark()
 end 
@@ -302,6 +305,8 @@ nested = { variables = { no = { problem = 10 } } } )", sol::script_pass_on_error
 
 TEST_CASE("functions/sol::function to std::function", "check if conversion to std::function works properly and calls with correct arguments") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	lua.open_libraries(sol::lib::base);
 
 	lua.set_function("testFunc", test_free_func);
@@ -336,12 +341,14 @@ TEST_CASE("functions/returning functions from C++", "check to see if returning a
 }
 
 TEST_CASE("functions/function_result and protected_function_result", "Function result should be the beefy return type for sol::function that allows for error checking and error handlers") {
-	sol::state lua;
-	lua.open_libraries(sol::lib::base, sol::lib::debug);
 	static const char unhandlederrormessage[] = "true error message";
 	static const char handlederrormessage[] = "doodle";
 	static const std::string handlederrormessage_s = handlederrormessage;
 
+	sol::state lua;
+	sol::stack_guard luasg(lua);
+	lua.open_libraries(sol::lib::base, sol::lib::debug);
+
 	// Some function; just using a lambda to be cheap
 	auto doomfx = []() {
 		throw std::runtime_error(unhandlederrormessage);
@@ -512,6 +519,7 @@ TEST_CASE("functions/unsafe protected_function_result handlers",
 
 TEST_CASE("functions/all kinds", "Register all kinds of functions, make sure they all compile and work") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 
 	struct test_1 {
 		int a = 0xA;
@@ -972,14 +980,14 @@ TEST_CASE("functions/stack atomic", "make sure functions don't impede on the sta
 	//test protected_function
 	sol::protected_function Stringtest(lua["stringtest"]);
 	Stringtest.error_handler = lua["ErrorHandler"];
-	sol::stack_guard sg(lua);
+	sol::stack_guard luasg(lua);
 	{
 		sol::protected_function_result stringresult = Stringtest("protected test");
 		REQUIRE(stringresult.valid());
 		std::string s = stringresult;
 		INFO("Back in C++, protected result is : " << s);
 	}
-	REQUIRE(sg.check_stack());
+	REQUIRE(luasg.check_stack());
 
 	//test optional
 	{
@@ -994,7 +1002,7 @@ TEST_CASE("functions/stack atomic", "make sure functions don't impede on the sta
 			INFO("opt_result failed");
 		}
 	}
-	REQUIRE(sg.check_stack());
+	REQUIRE(luasg.check_stack());
 
 	{
 		sol::protected_function_result errresult = Stringtest(sol::lua_nil);
@@ -1003,7 +1011,7 @@ TEST_CASE("functions/stack atomic", "make sure functions don't impede on the sta
 		std::string msg = err.what();
 		INFO("error :" << msg);
 	}
-	REQUIRE(sg.check_stack());
+	REQUIRE(luasg.check_stack());
 }
 
 TEST_CASE("functions/stack multi-return", "Make sure the stack is protected after multi-returns") {
@@ -1011,7 +1019,7 @@ TEST_CASE("functions/stack multi-return", "Make sure the stack is protected afte
 	lua.safe_script("function f () return 1, 2, 3, 4, 5 end");
 
 	{
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		sol::stack::push(lua, double(256.78));
 		{
 			int a, b, c, d, e;
@@ -1034,7 +1042,7 @@ TEST_CASE("functions/protected stack multi-return", "Make sure the stack is prot
 	lua.safe_script("function f () return 1, 2, 3, 4, 5 end");
 
 	{
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		sol::stack::push(lua, double(256.78));
 		{
 			int a, b, c, d, e;
@@ -1060,7 +1068,7 @@ TEST_CASE("functions/function_result as arguments", "ensure that function_result
 	lua.safe_script("function g (a, b, c, d, e) assert(a == 1) assert(b == 2) assert(c == 3) assert(d == 4) assert(e == 5) end");
 
 	{
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		sol::stack::push(lua, double(256.78));
 		{
 			int a, b, c, d, e;
@@ -1089,7 +1097,7 @@ TEST_CASE("functions/protected_function_result as arguments", "ensure that prote
 	lua.safe_script("function g (a, b, c, d, e) assert(a == 1) assert(b == 2) assert(c == 3) assert(d == 4) assert(e == 5) end");
 
 	{
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		sol::stack::push(lua, double(256.78));
 		{
 			int a, b, c, d, e;

tests/runtime_tests/source/lua_value.cpp

@@ -0,0 +1,310 @@
+// sol3
+
+// The MIT License (MIT)
+
+// Copyright (c) 2013-2019 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#include "sol_test.hpp"
+
+#include <catch.hpp>
+
+#include <vector>
+#include <thread>
+#include <mutex>
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
+#include <string_view>
+#include <variant>
+#endif // C++17
+
+struct int_entry {
+	int value;
+
+	int_entry() : value(0) {
+	}
+
+	int_entry(int v) : value(v) {
+	}
+
+	bool operator==(const int_entry& e) const {
+		return value == e.value;
+	}
+};
+
+std::mutex lua_value_construct_require_mutex;
+
+void lua_value_construct_race() {
+	sol::state lua;
+	try {
+		lua.open_libraries();
+		lua["a"] = sol::lua_value(lua, 24);
+		int a = lua["a"];
+		{
+			std::lock_guard<std::mutex> lg(lua_value_construct_require_mutex);
+			REQUIRE(a == 24);
+		}
+	}
+	catch (const sol::error& e) {
+		std::lock_guard<std::mutex> lg(lua_value_construct_require_mutex);
+		INFO(e.what());
+		REQUIRE(false);
+	}
+	catch (...) {
+		std::lock_guard<std::mutex> lg(lua_value_construct_require_mutex);
+		REQUIRE(false);
+	}
+}
+
+TEST_CASE("lua_value/nested", "make nested values can be put in lua_value properly") {
+#if defined(SOL_STD_VARIANT) && SOL_STD_VARIANT
+	using mixed_table_entry = std::variant<int, int_entry, std::string>;
+	using nested_entry = std::variant<int, int_entry, std::string, std::vector<mixed_table_entry>>;
+
+	const std::vector<std::variant<int, int_entry>> mixed_table_truth = { 1, int_entry(2), 3, int_entry(4), 5 };
+	const std::vector<nested_entry> mixed_nested_table_truth = { 1, int_entry(2), 3, int_entry(4), std::vector<mixed_table_entry>{ 5, 6, int_entry(7), "8" } };
+
+	sol::state lua;
+
+	sol::lua_value lv_mixed_table(lua, { 1, int_entry(2), 3, int_entry(4), 5 });
+	sol::lua_value lv_mixed_nested_table(lua, { 1, int_entry(2), 3, int_entry(4), { 5, 6, int_entry(7), "8" } });
+
+	REQUIRE(lv_mixed_table.is<sol::table>());
+	REQUIRE(lv_mixed_nested_table.is<sol::table>());
+
+	std::vector<std::variant<int, int_entry>> mixed_table_value_lv = lv_mixed_table.as<std::vector<std::variant<int, int_entry>>>();
+	std::vector<nested_entry> mixed_nested_table_value_lv = lv_mixed_nested_table.as<std::vector<nested_entry>>();
+
+	REQUIRE(mixed_table_truth == mixed_table_value_lv);
+	REQUIRE(mixed_nested_table_truth == mixed_nested_table_value_lv);
+
+	SECTION("type check (object)") {
+		sol::object obj_mixed_table(lv_mixed_table.value());
+		sol::object obj_mixed_nested_table(lv_mixed_nested_table.value());
+		
+		REQUIRE(obj_mixed_table.is<sol::table>());
+		REQUIRE(obj_mixed_nested_table.is<sol::table>());
+		
+		std::vector<std::variant<int, int_entry>> mixed_table_value = obj_mixed_table.as<std::vector<std::variant<int, int_entry>>>();
+		std::vector<nested_entry> mixed_nested_table_value = obj_mixed_nested_table.as<std::vector<nested_entry>>();
+		
+		REQUIRE(mixed_table_truth == mixed_table_value);
+		REQUIRE(mixed_nested_table_truth == mixed_nested_table_value);
+	}
+	SECTION("pushing/popping") {
+		lua["obj_mixed_table"] = lv_mixed_table;
+		lua["obj_mixed_nested_table"] = lv_mixed_nested_table;
+
+		sol::lua_value obj_mixed_table = lua["obj_mixed_table"];
+		sol::lua_value obj_mixed_nested_table = lua["obj_mixed_nested_table"];
+
+		REQUIRE(obj_mixed_table.is<sol::table>());
+		REQUIRE(obj_mixed_nested_table.is<sol::table>());
+
+		std::vector<std::variant<int, int_entry>> mixed_table_value = obj_mixed_table.as<std::vector<std::variant<int, int_entry>>>();
+		std::vector<nested_entry> mixed_nested_table_value = obj_mixed_nested_table.as<std::vector<nested_entry>>();
+		
+		REQUIRE(mixed_table_truth == mixed_table_value);
+		REQUIRE(mixed_nested_table_truth == mixed_nested_table_value);
+	}
+	SECTION("pushing/popping (object)") {
+		lua["obj_mixed_table"] = lv_mixed_table;
+		lua["obj_mixed_nested_table"] = lv_mixed_nested_table;
+
+		sol::object obj_mixed_table = lua["obj_mixed_table"];
+		sol::object obj_mixed_nested_table = lua["obj_mixed_nested_table"];
+
+		REQUIRE(obj_mixed_table.is<sol::table>());
+		REQUIRE(obj_mixed_nested_table.is<sol::table>());
+
+		std::vector<std::variant<int, int_entry>> mixed_table_value = obj_mixed_table.as<std::vector<std::variant<int, int_entry>>>();
+		std::vector<nested_entry> mixed_nested_table_value = obj_mixed_nested_table.as<std::vector<nested_entry>>();
+
+		REQUIRE(mixed_table_truth == mixed_table_value);
+		REQUIRE(mixed_nested_table_truth == mixed_nested_table_value);
+	}
+#else
+	REQUIRE(true);
+#endif // C++17
+}
+
+TEST_CASE("lua_value/basic types", "make sure we can stick values and nested values in a lua_value and retrieve them") {
+	sol::state lua;
+
+	const int_entry userdata_truth = int_entry(3);
+	const std::vector<int> int_table_truth = { 1, 2, 3, 4, 5 };
+
+	sol::lua_value lv_int(lua, 1);
+	sol::lua_value lv_double(lua, 2.0);
+	sol::lua_value lv_string(lua, "heyo");
+	sol::lua_value lv_lstring(lua, L"hiyo");
+	sol::lua_value lv_bool(lua, true);
+	sol::lua_value lv_nil(lua, sol::lua_nil);
+	sol::lua_value lv_userdata(lua, int_entry(3));
+	sol::lua_value lv_int_table(lua, { 1, 2, 3, 4, 5 });
+	REQUIRE(lv_int.is<int>());
+	REQUIRE(lv_double.is<double>());
+	REQUIRE(lv_string.is<std::string>());
+	REQUIRE(lv_lstring.is<std::string>());
+	REQUIRE(lv_bool.is<bool>());
+	REQUIRE(lv_nil.is<sol::lua_nil_t>());
+	REQUIRE(lv_userdata.is<sol::userdata>());
+	REQUIRE(lv_userdata.is<int_entry>());
+	REQUIRE(lv_int_table.is<sol::table>());
+
+	REQUIRE(lv_int.as<int>() == 1);
+	REQUIRE(lv_double.as<double>() == 2.0);
+	REQUIRE(lv_string.as<std::string>() == "heyo");
+	REQUIRE(lv_lstring.as<std::string>() == "hiyo");
+	REQUIRE(lv_lstring.as<std::wstring>() == L"hiyo");
+	REQUIRE(lv_bool.as<bool>());
+	REQUIRE(lv_nil.as<sol::lua_nil_t>() == sol::lua_nil);
+	REQUIRE(lv_userdata.as<int_entry>() == userdata_truth);
+
+	std::vector<int> int_table_value_lv = lv_int_table.as<std::vector<int>>();
+	REQUIRE(int_table_truth == int_table_value_lv);
+
+	SECTION("type check (object)") {
+		sol::object obj_int(lv_int.value());
+		sol::object obj_double(lv_double.value());
+		sol::object obj_string(lv_string.value());
+		sol::object obj_lstring(lv_lstring.value());
+		sol::object obj_bool(lv_bool.value());
+		sol::object obj_nil(lv_nil.value());
+		sol::object obj_userdata(lv_userdata.value());
+		sol::object obj_int_table(lv_int_table.value());
+
+		REQUIRE(obj_int.is<int>());
+		REQUIRE(obj_double.is<double>());
+		REQUIRE(obj_string.is<std::string>());
+		REQUIRE(obj_lstring.is<std::string>());
+		REQUIRE(obj_bool.is<bool>());
+		REQUIRE(obj_nil.is<sol::lua_nil_t>());
+		REQUIRE(obj_userdata.is<sol::userdata>());
+		REQUIRE(obj_userdata.is<int_entry>());
+		REQUIRE(obj_int_table.is<sol::table>());
+
+		REQUIRE(obj_int.as<int>() == 1);
+		REQUIRE(obj_double.as<double>() == 2.0);
+		REQUIRE(obj_string.as<std::string>() == "heyo");
+		REQUIRE(obj_lstring.as<std::string>() == "hiyo");
+		REQUIRE(obj_lstring.as<std::wstring>() == L"hiyo");
+		REQUIRE(obj_bool.as<bool>());
+		REQUIRE(obj_userdata.as<int_entry>() == userdata_truth);
+		REQUIRE(obj_nil.as<sol::lua_nil_t>() == sol::lua_nil);
+
+		std::vector<int> int_table_value = obj_int_table.as<std::vector<int>>();
+		REQUIRE(int_table_truth == int_table_value);
+	}
+	SECTION("push/popping") {
+		lua["obj_int"] = lv_int;
+		lua["obj_double"] = lv_double;
+		lua["obj_string"] = lv_string;
+		lua["obj_lstring"] = lv_lstring;
+		lua["obj_bool"] = lv_bool;
+		lua["obj_nil"] = lv_nil;
+		lua["obj_userdata"] = lv_userdata;
+		lua["obj_int_table"] = lv_int_table;
+
+		// these all actually invoke the constructor
+		// so do one .get<> explicitly to ensure it's
+		// working correctl for a few cases...
+		// but it's nice to make sure it's all there now
+		sol::lua_value obj_int = lua["obj_int"].get<sol::lua_value>();
+		sol::lua_value obj_double = lua["obj_double"].get<sol::lua_value>();
+		sol::lua_value obj_string = lua["obj_string"].get<sol::lua_value>();
+		sol::lua_value obj_lstring = lua["obj_lstring"].get<sol::lua_value>();
+		sol::lua_value obj_bool = lua["obj_bool"].get<sol::lua_value>();
+		sol::lua_value obj_nil = lua["obj_nil"];
+		sol::lua_value obj_userdata = lua["obj_userdata"];
+		sol::lua_value obj_int_table = lua["obj_int_table"];
+
+		REQUIRE(obj_int.is<int>());
+		REQUIRE(obj_double.is<double>());
+		REQUIRE(obj_string.is<std::string>());
+		REQUIRE(obj_lstring.is<std::string>());
+		REQUIRE(obj_bool.is<bool>());
+		REQUIRE(obj_nil.is<sol::lua_nil_t>());
+		REQUIRE(obj_int_table.is<sol::table>());
+
+		REQUIRE(obj_int.as<int>() == 1);
+		REQUIRE(obj_double.as<double>() == 2.0);
+		REQUIRE(obj_string.as<std::string>() == "heyo");
+		REQUIRE(obj_lstring.as<std::string>() == "hiyo");
+		REQUIRE(obj_lstring.as<std::wstring>() == L"hiyo");
+		REQUIRE(obj_bool.as<bool>());
+		REQUIRE(obj_nil.as<sol::lua_nil_t>() == sol::lua_nil);
+
+		std::vector<int> int_table_value = obj_int_table.as<std::vector<int>>();
+		REQUIRE(int_table_truth == int_table_value);
+	}
+	SECTION("push/popping (object)") {
+		lua["obj_int"] = lv_int;
+		lua["obj_double"] = lv_double;
+		lua["obj_string"] = lv_string;
+		lua["obj_lstring"] = lv_lstring;
+		lua["obj_bool"] = lv_bool;
+		lua["obj_nil"] = lv_nil;
+		lua["obj_userdata"] = lv_userdata;
+		lua["obj_int_table"] = lv_int_table;
+
+		sol::object obj_int = lua["obj_int"];
+		sol::object obj_double = lua["obj_double"];
+		sol::object obj_string = lua["obj_string"];
+		sol::object obj_lstring = lua["obj_lstring"];
+		sol::object obj_bool = lua["obj_bool"];
+		sol::object obj_nil = lua["obj_nil"];
+		sol::object obj_userdata = lua["obj_userdata"];
+		sol::object obj_int_table = lua["obj_int_table"];
+
+		REQUIRE(obj_int.is<int>());
+		REQUIRE(obj_double.is<double>());
+		REQUIRE(obj_string.is<std::string>());
+		REQUIRE(obj_lstring.is<std::string>());
+		REQUIRE(obj_bool.is<bool>());
+		REQUIRE(obj_nil.is<sol::lua_nil_t>());
+		REQUIRE(obj_userdata.is<sol::userdata>());
+		REQUIRE(obj_userdata.is<int_entry>());
+		REQUIRE(obj_int_table.is<sol::table>());
+
+		REQUIRE(obj_int.as<int>() == 1);
+		REQUIRE(obj_double.as<double>() == 2.0);
+		REQUIRE(obj_string.as<std::string>() == "heyo");
+		REQUIRE(obj_lstring.as<std::string>() == "hiyo");
+		REQUIRE(obj_lstring.as<std::wstring>() == L"hiyo");
+		REQUIRE(obj_bool.as<bool>());
+		REQUIRE(obj_nil.as<sol::lua_nil_t>() == sol::lua_nil);
+		REQUIRE(obj_userdata.as<int_entry>() == userdata_truth);
+
+		std::vector<int> int_table_value = obj_int_table.as<std::vector<int>>();
+		REQUIRE(int_table_truth == int_table_value);
+	}
+}
+
+TEST_CASE("lua_value/threading", "test that thread_local in lua_value constructors do not race or clobber") {
+	REQUIRE_NOTHROW([]() {
+		std::thread thrds[24];
+		for (int i = 0; i < 24; i++) {
+			thrds[i] = std::thread(&lua_value_construct_race);
+		}
+
+		for (int i = 0; i < 24; i++) {
+			thrds[i].join();
+		}
+	}());
+}

tests/runtime_tests/source/state.cpp

@@ -152,7 +152,7 @@ TEST_CASE("state/require_script", "opening strings as 'requires' clauses") {
 	std::string code = "return { modfunc = function () return 221 end }";
 
 	sol::state lua;
-	sol::stack_guard sg(lua);
+	sol::stack_guard luasg(lua);
 	sol::table thingy1 = lua.require_script("thingy", code);
 	sol::table thingy2 = lua.require_script("thingy", code);
 
@@ -173,7 +173,7 @@ TEST_CASE("state/require", "require using a function") {
 	};
 
 	sol::state lua;
-	sol::stack_guard sg(lua);
+	sol::stack_guard luasg(lua);
 	sol::table thingy1 = lua.require("thingy", open::open_func);
 	sol::table thingy2 = lua.require("thingy", open::open_func);
 
@@ -344,7 +344,7 @@ return example;
 	};
 
 	sol::state lua;
-	sol::stack_guard sg(lua);
+	sol::stack_guard luasg(lua);
 	lua.open_libraries();
 
 	lua.set_function("foo", foo);
@@ -369,7 +369,7 @@ TEST_CASE("state/copy and move", "ensure state can be properly copied and moved"
 
 TEST_CASE("state/requires-reload", "ensure that reloading semantics do not cause a crash") {
 	sol::state lua;
-	sol::stack_guard sg(lua);
+	sol::stack_guard luasg(lua);
 	lua.open_libraries();
 	lua.safe_script("require 'io'\nreturn 'test1'");
 	lua.require_script("test2", "require 'io'\nreturn 'test2'");
@@ -400,7 +400,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 
 	SECTION("script") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		int ar = lua.safe_script(good);
 		int a = lua["a"];
 		REQUIRE(a == 21);
@@ -409,7 +409,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("unsafe_script") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		int ar = lua.unsafe_script(good);
 		int a = lua["a"];
 		REQUIRE(a == 21);
@@ -418,7 +418,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("script-handler") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		auto errbs = lua.safe_script(bad_syntax, sol::script_pass_on_error);
 		REQUIRE(!errbs.valid());
 
@@ -435,7 +435,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("do_string") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		auto errbs = lua.do_string(bad_syntax);
 		REQUIRE(!errbs.valid());
 
@@ -452,7 +452,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("load_string") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		auto errbsload = lua.load(bad_syntax);
 		REQUIRE(!errbsload.valid());
 
@@ -475,7 +475,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("load") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		string_reader_load bssrl(bad_syntax);
 		void* vpbssrl = static_cast<void*>(&bssrl);
 		auto errbsload = lua.load(&string_reader, vpbssrl, bad_syntax);
@@ -504,7 +504,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("load_string (text)") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		auto errbsload = lua.load(bad_syntax, bad_syntax, sol::load_mode::text);
 		REQUIRE(!errbsload.valid());
 
@@ -527,7 +527,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("load (text)") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		string_reader_load bssrl(bad_syntax);
 		void* vpbssrl = static_cast<void*>(&bssrl);
 		auto errbsload = lua.load(&string_reader, vpbssrl, bad_syntax, sol::load_mode::text);
@@ -556,7 +556,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("script_file") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		int ar = lua.safe_script_file(file_good);
 		int a = lua["a"];
 		REQUIRE(a == 21);
@@ -565,7 +565,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("unsafe_script_file") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		int ar = lua.unsafe_script_file(file_good);
 		int a = lua["a"];
 		REQUIRE(a == 21);
@@ -574,7 +574,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("script_file-handler") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		auto errbs = lua.safe_script_file(file_bad_syntax, sol::script_pass_on_error);
 		REQUIRE(!errbs.valid());
 
@@ -591,7 +591,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("safe_script_file-handler") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		auto errbs = lua.safe_script_file(file_bad_syntax, sol::script_pass_on_error);
 		REQUIRE(!errbs.valid());
 
@@ -608,7 +608,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("do_file") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		auto errbs = lua.do_file(file_bad_syntax);
 		REQUIRE(!errbs.valid());
 
@@ -625,7 +625,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("load_file") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		auto errbsload = lua.load_file(file_bad_syntax);
 		REQUIRE(!errbsload.valid());
 
@@ -648,7 +648,7 @@ TEST_CASE("state/script, do, and load", "test success and failure cases for load
 	}
 	SECTION("load_file (text)") {
 		sol::state lua;
-		sol::stack_guard sg(lua);
+		sol::stack_guard luasg(lua);
 		auto errbsload = lua.load_file(file_bad_syntax, sol::load_mode::text);
 		REQUIRE(!errbsload.valid());
 

tests/runtime_tests/source/storage.cpp

@@ -36,6 +36,8 @@ end
 )";
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	{
 		auto r = lua.safe_script(code, sol::script_pass_on_error);
 		REQUIRE(r.valid());

tests/runtime_tests/source/strings.cpp

@@ -41,6 +41,7 @@ namespace muh_namespace {
 
 TEST_CASE("stack/strings", "test that strings can be roundtripped") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 
 	static const char utf8str[] = "\xF0\x9F\x8D\x8C\x20\xE6\x99\xA5\x20\x46\x6F\x6F\x20\xC2\xA9\x20\x62\x61\x72\x20\xF0\x9D\x8C\x86\x20\x62\x61\x7A\x20\xE2\x98\x83\x20\x71\x75\x78";
 	static const char16_t utf16str[] = { 0xD83C, 0xDF4C, 0x20, 0x6665, 0x20, 0x46, 0x6F, 0x6F, 0x20, 0xA9, 0x20, 0x62, 0x61, 0x72, 0x20, 0xD834, 0xDF06, 0x20, 0x62, 0x61, 0x7A, 0x20, 0x2603, 0x20, 0x71, 0x75, 0x78, 0x00 };

tests/runtime_tests/source/tables.checks.cpp

@@ -0,0 +1,51 @@
+// sol3
+
+// The MIT License (MIT)
+
+// Copyright (c) 2013-2019 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#include "sol_test.hpp"
+
+#include <catch.hpp>
+
+struct not_a_table_at_all {};
+
+TEST_CASE("tables/lua_table", "check that lua_table accepts only lua-style tables, and not other types") {
+	sol::state lua;
+	lua["f"] = [](sol::lua_table lt) {
+		int x = lt["a"];
+		REQUIRE(x == 3);
+	};
+	lua["ud"] = not_a_table_at_all{};
+
+	auto result0 = lua.safe_script("t = { a = 3 }", sol::script_pass_on_error);
+	REQUIRE(result0.valid());
+	auto result1 = lua.safe_script("f(t)", sol::script_pass_on_error);
+	REQUIRE(result1.valid());
+	
+	auto result2 = lua.safe_script("f(ud)", sol::script_pass_on_error);
+	REQUIRE_FALSE(result2.valid());
+	auto result3 = lua.safe_script("f(24)", sol::script_pass_on_error);
+	REQUIRE_FALSE(result3.valid());
+	auto result4 = lua.safe_script("f(nil)", sol::script_pass_on_error);
+	REQUIRE_FALSE(result4.valid());
+	auto result5 = lua.safe_script("f('bark')", sol::script_pass_on_error);
+	REQUIRE_FALSE(result5.valid());
+}

tests/runtime_tests/source/tables.cpp

@@ -42,61 +42,9 @@ struct object {
 	}
 };
 
-int plop_xyz(int x, int y, std::string z) {
-	INFO(x << " " << y << " " << z);
-	return 11;
-}
-
-TEST_CASE("tables/as enums", "Making sure enums can be put in and gotten out as values") {
-	enum direction {
-		up,
-		down,
-		left,
-		right
-	};
-
-	sol::state lua;
-	lua.open_libraries(sol::lib::base);
-
-	lua["direction"] = lua.create_table_with(
-		"up", direction::up,
-		"down", direction::down,
-		"left", direction::left,
-		"right", direction::right);
-
-	sol::object obj = lua["direction"]["up"];
-	bool isdir = obj.is<direction>();
-	REQUIRE(isdir);
-	auto dir = obj.as<direction>();
-	REQUIRE(dir == direction::up);
-}
-
-TEST_CASE("tables/as enum classes", "Making sure enums can be put in and gotten out as values") {
-	enum class direction {
-		up,
-		down,
-		left,
-		right
-	};
-
-	sol::state lua;
-	lua.open_libraries(sol::lib::base);
-
-	lua["direction"] = lua.create_table_with(
-		"up", direction::up,
-		"down", direction::down,
-		"left", direction::left,
-		"right", direction::right);
-
-	sol::object obj = lua["direction"]["up"];
-	bool isdir = obj.is<direction>();
-	REQUIRE(isdir);
-	auto dir = obj.as<direction>();
-	REQUIRE(dir == direction::up);
-}
-
 TEST_CASE("tables/cleanup", "make sure tables leave the stack balanced") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries();
 
 	auto f = [] { return 5; };
@@ -131,222 +79,6 @@ TEST_CASE("tables/nested cleanup", "make sure tables leave the stack balanced")
 	}
 }
 
-TEST_CASE("tables/new_enum", "Making sure enums can be put in and gotten out as values") {
-	enum class direction {
-		up,
-		down,
-		left,
-		right
-	};
-
-	SECTION("variadics") {
-		sol::state lua;
-		lua.open_libraries(sol::lib::base);
-
-		lua.new_enum("direction",
-			"up", direction::up,
-			"down", direction::down,
-			"left", direction::left,
-			"right", direction::right);
-
-		direction d = lua["direction"]["left"];
-		REQUIRE(d == direction::left);
-		auto result = lua.safe_script("direction.left = 50", sol::script_pass_on_error);
-		REQUIRE_FALSE(result.valid());
-		d = lua["direction"]["left"];
-		REQUIRE(d == direction::left);
-	}
-	SECTION("initializer_list") {
-		sol::state lua;
-		lua.open_libraries(sol::lib::base);
-
-		lua.new_enum<direction>("direction", { { "up", direction::up }, { "down", direction::down }, { "left", direction::left }, { "right", direction::right } });
-
-		direction d = lua["direction"]["left"];
-		REQUIRE(d == direction::left);
-		auto result = lua.safe_script("direction.left = 50", sol::script_pass_on_error);
-		REQUIRE_FALSE(result.valid());
-		d = lua["direction"]["left"];
-		REQUIRE(d == direction::left);
-	}
-}
-
-TEST_CASE("tables/for_each", "Testing the use of for_each to get values from a lua table") {
-	sol::state lua;
-	lua.open_libraries(sol::lib::base);
-
-	lua.safe_script(
-		"arr = {\n"
-		"[0] = \"Hi\",\n"
-		"[1] = 123.45,\n"
-		"[2] = \"String value\",\n"
-		// Does nothing
-		//"[3] = nil,\n"
-		//"[nil] = 3,\n"
-		"[\"WOOF\"] = 123,\n"
-		"}");
-	sol::table tbl = lua["arr"];
-	std::size_t tablesize = 4;
-	std::size_t iterations = 0;
-	auto fx = [&iterations](sol::object key, sol::object value) {
-		++iterations;
-		sol::type keytype = key.get_type();
-		switch (keytype) {
-		case sol::type::number:
-			switch (key.as<int>()) {
-			case 0:
-				REQUIRE((value.as<std::string>() == "Hi"));
-				break;
-			case 1:
-				REQUIRE((value.as<double>() == 123.45));
-				break;
-			case 2:
-				REQUIRE((value.as<std::string>() == "String value"));
-				break;
-			case 3:
-				REQUIRE((value.is<sol::lua_nil_t>()));
-				break;
-			}
-			break;
-		case sol::type::string:
-			if (key.as<std::string>() == "WOOF") {
-				REQUIRE((value.as<double>() == 123));
-			}
-			break;
-		case sol::type::lua_nil:
-			REQUIRE((value.as<double>() == 3));
-			break;
-		default:
-			break;
-		}
-	};
-	auto fxpair = [&fx](std::pair<sol::object, sol::object> kvp) { fx(kvp.first, kvp.second); };
-	tbl.for_each(fx);
-	REQUIRE(iterations == tablesize);
-
-	iterations = 0;
-	tbl.for_each(fxpair);
-	REQUIRE(iterations == tablesize);
-}
-
-TEST_CASE("tables/for_each empty", "empty tables should not crash") {
-	sol::state lua;
-	lua.open_libraries(sol::lib::base);
-
-	lua.safe_script("arr = {}");
-	sol::table tbl = lua["arr"];
-	REQUIRE(tbl.empty());
-	std::size_t tablesize = 0;
-	std::size_t iterations = 0;
-	auto fx = [&iterations](sol::object key, sol::object value) {
-		++iterations;
-		sol::type keytype = key.get_type();
-		switch (keytype) {
-		case sol::type::number:
-			switch (key.as<int>()) {
-			case 0:
-				REQUIRE((value.as<std::string>() == "Hi"));
-				break;
-			case 1:
-				REQUIRE((value.as<double>() == 123.45));
-				break;
-			case 2:
-				REQUIRE((value.as<std::string>() == "String value"));
-				break;
-			case 3:
-				REQUIRE((value.is<sol::lua_nil_t>()));
-				break;
-			}
-			break;
-		case sol::type::string:
-			if (key.as<std::string>() == "WOOF") {
-				REQUIRE((value.as<double>() == 123));
-			}
-			break;
-		case sol::type::lua_nil:
-			REQUIRE((value.as<double>() == 3));
-			break;
-		default:
-			break;
-		}
-	};
-	auto fxpair = [&fx](std::pair<sol::object, sol::object> kvp) { fx(kvp.first, kvp.second); };
-	tbl.for_each(fx);
-	REQUIRE(iterations == tablesize);
-
-	iterations = 0;
-	tbl.for_each(fxpair);
-	REQUIRE(iterations == tablesize);
-
-	iterations = 0;
-	for (const auto& kvp : tbl) {
-		fxpair(kvp);
-		++iterations;
-	}
-	REQUIRE(iterations == tablesize);
-}
-
-TEST_CASE("tables/iterators", "Testing the use of iteratrs to get values from a lua table") {
-	sol::state lua;
-	lua.open_libraries(sol::lib::base);
-
-	lua.safe_script(
-		"arr = {\n"
-		"[0] = \"Hi\",\n"
-		"[1] = 123.45,\n"
-		"[2] = \"String value\",\n"
-		// Does nothing
-		//"[3] = nil,\n"
-		//"[nil] = 3,\n"
-		"[\"WOOF\"] = 123,\n"
-		"}");
-	sol::table tbl = lua["arr"];
-	std::size_t tablesize = 4;
-	std::size_t iterations = 0;
-
-	int begintop = 0;
-	int endtop = 0;
-	{
-		test_stack_guard s(lua.lua_state(), begintop, endtop);
-		for (auto& kvp : tbl) {
-			[&iterations](sol::object key, sol::object value) {
-				++iterations;
-				sol::type keytype = key.get_type();
-				switch (keytype) {
-				case sol::type::number:
-					switch (key.as<int>()) {
-					case 0:
-						REQUIRE((value.as<std::string>() == "Hi"));
-						break;
-					case 1:
-						REQUIRE((value.as<double>() == 123.45));
-						break;
-					case 2:
-						REQUIRE((value.as<std::string>() == "String value"));
-						break;
-					case 3:
-						REQUIRE((value.is<sol::lua_nil_t>()));
-						break;
-					}
-					break;
-				case sol::type::string:
-					if (key.as<std::string>() == "WOOF") {
-						REQUIRE((value.as<double>() == 123));
-					}
-					break;
-				case sol::type::lua_nil:
-					REQUIRE((value.as<double>() == 3));
-					break;
-				default:
-					break;
-				}
-			}(kvp.first, kvp.second);
-		}
-	}
-	REQUIRE(begintop == endtop);
-	REQUIRE(iterations == tablesize);
-}
-
 TEST_CASE("tables/variables", "Check if tables and variables work as intended") {
 	sol::state lua;
 	lua.open_libraries(sol::lib::base, sol::lib::os);
@@ -450,127 +182,6 @@ TEST_CASE("tables/function variables", "Check if tables and function calls work
 	REQUIRE_NOTHROW(run_script(lua));
 }
 
-TEST_CASE("tables/operator[]", "Check if operator[] retrieval and setting works properly") {
-	sol::state lua;
-	lua.open_libraries(sol::lib::base);
-
-	lua.safe_script("foo = 20\nbar = \"hello world\"");
-	// basic retrieval
-	std::string bar = lua["bar"];
-	int foo = lua["foo"];
-	REQUIRE(bar == "hello world");
-	REQUIRE(foo == 20);
-	// test operator= for stringification
-	// errors due to ambiguous operators
-	bar = lua["bar"];
-
-	// basic setting
-	lua["bar"] = 20.4;
-	lua["foo"] = "goodbye";
-
-	// doesn't modify the actual values obviously.
-	REQUIRE(bar == "hello world");
-	REQUIRE(foo == 20);
-
-	// function setting
-	lua["test"] = plop_xyz;
-	{
-		auto result = lua.safe_script("assert(test(10, 11, \"hello\") == 11)", sol::script_pass_on_error);
-		REQUIRE(result.valid());
-	}
-
-	// function retrieval
-	sol::function test = lua["test"];
-	REQUIRE(test.call<int>(10, 11, "hello") == 11);
-
-	// setting a lambda
-	lua["lamb"] = [](int x) {
-		return x * 2;
-	};
-
-	{
-		auto result = lua.safe_script("assert(lamb(220) == 440)", sol::script_pass_on_error);
-		REQUIRE(result.valid());
-	}
-
-	// function retrieval of a lambda
-	sol::function lamb = lua["lamb"];
-	REQUIRE(lamb.call<int>(220) == 440);
-
-	// test const table retrieval
-	auto assert1 = [](const sol::table& t) {
-		std::string a = t["foo"];
-		double b = t["bar"];
-		REQUIRE(a == "goodbye");
-		REQUIRE(b == 20.4);
-	};
-
-	REQUIRE_NOTHROW(assert1(lua.globals()));
-}
-
-TEST_CASE("tables/operator[] valid", "Test if proxies on tables can lazily evaluate validity") {
-	sol::state lua;
-	bool isFullScreen = false;
-	auto fullscreennopers = lua["fullscreen"]["nopers"];
-	auto fullscreen = lua["fullscreen"];
-	REQUIRE_FALSE(fullscreennopers.valid());
-	REQUIRE_FALSE(fullscreen.valid());
-
-	lua["fullscreen"] = true;
-
-	REQUIRE_FALSE(fullscreennopers.valid());
-	REQUIRE(fullscreen.valid());
-	isFullScreen = lua["fullscreen"];
-	REQUIRE(isFullScreen);
-
-	lua["fullscreen"] = false;
-	REQUIRE_FALSE(fullscreennopers.valid());
-	REQUIRE(fullscreen.valid());
-	isFullScreen = lua["fullscreen"];
-	REQUIRE_FALSE(isFullScreen);
-}
-
-TEST_CASE("tables/operator[] optional", "Test if proxies on tables can lazily evaluate validity") {
-	sol::state lua;
-
-	sol::optional<int> test1 = lua["no_exist_yet"];
-	bool present = (bool)test1;
-	REQUIRE_FALSE(present);
-
-	lua["no_exist_yet"] = 262;
-	sol::optional<int> test2 = lua["no_exist_yet"];
-	present = (bool)test2;
-	REQUIRE(present);
-	REQUIRE(test2.value() == 262);
-
-	sol::optional<int> nope = lua["nope"]["kek"]["hah"];
-	auto nope2 = lua.get<sol::optional<int>>(std::make_tuple("nope", "kek", "hah"));
-	present = (bool)nope;
-	REQUIRE_FALSE(present);
-	present = (bool)nope2;
-	REQUIRE_FALSE(present);
-	lua.create_named_table("nope", "kek", lua.create_table_with("hah", 1));
-	sol::optional<int> non_nope = lua["nope"]["kek"]["hah"].get<sol::optional<int>>();
-	sol::optional<int> non_nope2 = lua.get<sol::optional<int>>(std::make_tuple("nope", "kek", "hah"));
-	present = (bool)non_nope;
-	REQUIRE(present);
-	present = (bool)non_nope2;
-	REQUIRE(present);
-	REQUIRE(non_nope.value() == 1);
-	REQUIRE(non_nope2.value() == 1);
-
-	INFO("Keys: nope, kek, hah");
-	lua.set(std::make_tuple("nope", "kek", "hah"), 35);
-	sol::optional<int> non_nope3 = lua["nope"]["kek"]["hah"].get<sol::optional<int>>();
-	sol::optional<int> non_nope4 = lua.get<sol::optional<int>>(std::make_tuple("nope", "kek", "hah"));
-	present = (bool)non_nope3;
-	REQUIRE(present);
-	present = (bool)non_nope4;
-	REQUIRE(present);
-	REQUIRE(non_nope3.value() == 35);
-	REQUIRE(non_nope4.value() == 35);
-}
-
 TEST_CASE("tables/add", "Basic test to make sure the 'add' feature works") {
 	static const int sz = 120;
 

tests/runtime_tests/source/tables.enums.cpp

@@ -0,0 +1,90 @@
+// sol3
+
+// The MIT License (MIT)
+
+// Copyright (c) 2013-2019 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#include "sol_test.hpp"
+
+#include <catch.hpp>
+
+enum weak_direction { up, down, left, right };
+enum class strong_direction { up, down, left, right };
+
+TEST_CASE("tables/as enums", "Making sure enums can be put in and gotten out as values") {
+
+	sol::state lua;
+	lua.open_libraries(sol::lib::base);
+
+	lua["strong_direction"]
+	     = lua.create_table_with("up", weak_direction::up, "down", weak_direction::down, "left", weak_direction::left, "right", weak_direction::right);
+
+	sol::object obj = lua["strong_direction"]["up"];
+	bool isdir = obj.is<weak_direction>();
+	REQUIRE(isdir);
+	auto dir = obj.as<weak_direction>();
+	REQUIRE(dir == weak_direction::up);
+}
+
+TEST_CASE("tables/as enum classes", "Making sure enums can be put in and gotten out as values") {
+	sol::state lua;
+	lua.open_libraries(sol::lib::base);
+
+	lua["strong_direction"]
+	     = lua.create_table_with("up", strong_direction::up, "down", strong_direction::down, "left", strong_direction::left, "right", strong_direction::right);
+
+	sol::object obj = lua["strong_direction"]["up"];
+	bool isdir = obj.is<strong_direction>();
+	REQUIRE(isdir);
+	auto dir = obj.as<strong_direction>();
+	REQUIRE(dir == strong_direction::up);
+}
+
+TEST_CASE("tables/new_enum", "Making sure enums can be put in and gotten out as values") {
+	enum class strong_direction { up, down, left, right };
+
+	SECTION("variadics") {
+		sol::state lua;
+		lua.open_libraries(sol::lib::base);
+
+		lua.new_enum("strong_direction", "up", strong_direction::up, "down", strong_direction::down, "left", strong_direction::left, "right", strong_direction::right);
+
+		strong_direction d = lua["strong_direction"]["left"];
+		REQUIRE(d == strong_direction::left);
+		auto result = lua.safe_script("strong_direction.left = 50", sol::script_pass_on_error);
+		REQUIRE_FALSE(result.valid());
+		d = lua["strong_direction"]["left"];
+		REQUIRE(d == strong_direction::left);
+	}
+	SECTION("initializer_list") {
+		sol::state lua;
+		lua.open_libraries(sol::lib::base);
+
+		lua.new_enum<strong_direction>(
+		     "strong_direction", { { "up", strong_direction::up }, { "down", strong_direction::down }, { "left", strong_direction::left }, { "right", strong_direction::right } });
+
+		strong_direction d = lua["strong_direction"]["left"];
+		REQUIRE(d == strong_direction::left);
+		auto result = lua.safe_script("strong_direction.left = 50", sol::script_pass_on_error);
+		REQUIRE_FALSE(result.valid());
+		d = lua["strong_direction"]["left"];
+		REQUIRE(d == strong_direction::left);
+	}
+}

tests/runtime_tests/source/tables.indexing.cpp

@@ -0,0 +1,151 @@
+// sol3
+
+// The MIT License (MIT)
+
+// Copyright (c) 2013-2019 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#include "sol_test.hpp"
+
+#include <catch.hpp>
+
+int plop_xyz(int x, int y, std::string z) {
+	INFO(x << " " << y << " " << z);
+	return 11;
+}
+
+TEST_CASE("tables/operator[]", "Check if operator[] retrieval and setting works properly") {
+	sol::state lua;
+	lua.open_libraries(sol::lib::base);
+
+	lua.safe_script("foo = 20\nbar = \"hello world\"");
+	// basic retrieval
+	std::string bar = lua["bar"];
+	int foo = lua["foo"];
+	REQUIRE(bar == "hello world");
+	REQUIRE(foo == 20);
+	// test operator= for stringification
+	// errors due to ambiguous operators
+	bar = lua["bar"];
+
+	// basic setting
+	lua["bar"] = 20.4;
+	lua["foo"] = "goodbye";
+
+	// doesn't modify the actual values obviously.
+	REQUIRE(bar == "hello world");
+	REQUIRE(foo == 20);
+
+	// function setting
+	lua["test"] = plop_xyz;
+	{
+		auto result = lua.safe_script("assert(test(10, 11, \"hello\") == 11)", sol::script_pass_on_error);
+		REQUIRE(result.valid());
+	}
+
+	// function retrieval
+	sol::function test = lua["test"];
+	REQUIRE(test.call<int>(10, 11, "hello") == 11);
+
+	// setting a lambda
+	lua["lamb"] = [](int x) { return x * 2; };
+
+	{
+		auto result = lua.safe_script("assert(lamb(220) == 440)", sol::script_pass_on_error);
+		REQUIRE(result.valid());
+	}
+
+	// function retrieval of a lambda
+	sol::function lamb = lua["lamb"];
+	REQUIRE(lamb.call<int>(220) == 440);
+
+	// test const table retrieval
+	auto assert1 = [](const sol::table& t) {
+		std::string a = t["foo"];
+		double b = t["bar"];
+		REQUIRE(a == "goodbye");
+		REQUIRE(b == 20.4);
+	};
+
+	REQUIRE_NOTHROW(assert1(lua.globals()));
+}
+
+TEST_CASE("tables/operator[] valid", "Test if proxies on tables can lazily evaluate validity") {
+	sol::state lua;
+	bool isFullScreen = false;
+	auto fullscreennopers = lua["fullscreen"]["nopers"];
+	auto fullscreen = lua["fullscreen"];
+	REQUIRE_FALSE(fullscreennopers.valid());
+	REQUIRE_FALSE(fullscreen.valid());
+
+	lua["fullscreen"] = true;
+
+	REQUIRE_FALSE(fullscreennopers.valid());
+	REQUIRE(fullscreen.valid());
+	isFullScreen = lua["fullscreen"];
+	REQUIRE(isFullScreen);
+
+	lua["fullscreen"] = false;
+	REQUIRE_FALSE(fullscreennopers.valid());
+	REQUIRE(fullscreen.valid());
+	isFullScreen = lua["fullscreen"];
+	REQUIRE_FALSE(isFullScreen);
+}
+
+TEST_CASE("tables/operator[] optional", "Test if proxies on tables can lazily evaluate validity") {
+	sol::state lua;
+
+	sol::optional<int> test1 = lua["no_exist_yet"];
+	bool present = (bool)test1;
+	REQUIRE_FALSE(present);
+
+	lua["no_exist_yet"] = 262;
+	sol::optional<int> test2 = lua["no_exist_yet"];
+	present = (bool)test2;
+	REQUIRE(present);
+	REQUIRE(test2.value() == 262);
+
+	sol::optional<int> nope = lua["nope"]["kek"]["hah"];
+	auto nope2 = lua.get<sol::optional<int>>(std::make_tuple("nope", "kek", "hah"));
+	present = (bool)nope;
+	REQUIRE_FALSE(present);
+	present = (bool)nope2;
+	REQUIRE_FALSE(present);
+	lua.create_named_table("nope", "kek", lua.create_table_with("hah", 1));
+	sol::optional<int> non_nope = lua["nope"]["kek"]["hah"].get<sol::optional<int>>();
+	sol::optional<int> non_nope2 = lua.get<sol::optional<int>>(std::make_tuple("nope", "kek", "hah"));
+	present = (bool)non_nope;
+	REQUIRE(present);
+	present = (bool)non_nope2;
+	REQUIRE(present);
+	REQUIRE(non_nope.value() == 1);
+	REQUIRE(non_nope2.value() == 1);
+
+	INFO("Keys: nope, kek, hah");
+	lua.set(std::make_tuple("nope", "kek", "hah"), 35);
+	sol::optional<int> non_nope3 = lua["nope"]["kek"]["hah"].get<sol::optional<int>>();
+	sol::optional<int> non_nope4 = lua.get<sol::optional<int>>(std::make_tuple("nope", "kek", "hah"));
+	present = (bool)non_nope3;
+	REQUIRE(present);
+	present = (bool)non_nope4;
+	REQUIRE(present);
+	REQUIRE(non_nope3.value() == 35);
+	REQUIRE(non_nope4.value() == 35);
+}
+

tests/runtime_tests/source/tables.insertion.cpp

@@ -29,6 +29,7 @@
 
 TEST_CASE("tables/proxy override_value", "allow override_value by way of key") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base, sol::lib::io);
 
 	sol::optional<int> not_there = lua["a"]["b"]["c"];
@@ -42,6 +43,7 @@ TEST_CASE("tables/proxy override_value", "allow override_value by way of key") {
 TEST_CASE("tables/insertion override", "allow override all non-table values plus final value") {
 	SECTION("traverse") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		sol::optional<int> not_there = lua["a"]["b"]["c"];
 		REQUIRE_FALSE(static_cast<bool>(not_there));
@@ -59,6 +61,7 @@ TEST_CASE("tables/insertion override", "allow override all non-table values plus
 	}
 	SECTION("proxy") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		sol::optional<int> not_there = lua["a"]["b"]["c"];
 		REQUIRE_FALSE(static_cast<bool>(not_there));
@@ -76,6 +79,7 @@ TEST_CASE("tables/insertion override", "allow override all non-table values plus
 	}
 	SECTION("complex proxy") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		sol::optional<int> not_there = lua["a"]["b"]["c"];
 		REQUIRE_FALSE(static_cast<bool>(not_there));
@@ -91,6 +95,7 @@ TEST_CASE("tables/insertion override", "allow override all non-table values plus
 TEST_CASE("tables/insertion update_if_empty", "allow updating a value only if it's missing") {
 	SECTION("traverse") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		sol::optional<int> not_there = lua["a"]["b"]["c"];
 		REQUIRE_FALSE(static_cast<bool>(not_there));
@@ -101,6 +106,7 @@ TEST_CASE("tables/insertion update_if_empty", "allow updating a value only if it
 	}
 	SECTION("proxy") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		sol::optional<int> not_there = lua["a"]["b"]["c"];
 		REQUIRE_FALSE(static_cast<bool>(not_there));
@@ -116,6 +122,7 @@ TEST_CASE("tables/insertion update_if_empty", "allow updating a value only if it
 	}
 	SECTION("proxy invoker") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		sol::optional<int> not_there = lua["a"]["b"]["c"];
 		REQUIRE_FALSE(static_cast<bool>(not_there));

tests/runtime_tests/source/tables.traversal.cpp

@@ -0,0 +1,202 @@
+// sol3
+
+// The MIT License (MIT)
+
+// Copyright (c) 2013-2019 Rapptz, ThePhD and contributors
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so,
+// subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+#include "sol_test.hpp"
+
+#include <catch.hpp>
+
+TEST_CASE("tables/for_each", "Testing the use of for_each to get values from a lua table") {
+	sol::state lua;
+	lua.open_libraries(sol::lib::base);
+
+	lua.safe_script(
+	     "arr = {\n"
+	     "[0] = \"Hi\",\n"
+	     "[1] = 123.45,\n"
+	     "[2] = \"String value\",\n"
+	     // Does nothing
+	     //"[3] = nil,\n"
+	     //"[nil] = 3,\n"
+	     "[\"WOOF\"] = 123,\n"
+	     "}");
+	sol::table tbl = lua["arr"];
+	std::size_t tablesize = 4;
+	std::size_t iterations = 0;
+	auto fx = [&iterations](sol::object key, sol::object value) {
+		++iterations;
+		sol::type keytype = key.get_type();
+		switch (keytype) {
+		case sol::type::number:
+			switch (key.as<int>()) {
+			case 0:
+				REQUIRE((value.as<std::string>() == "Hi"));
+				break;
+			case 1:
+				REQUIRE((value.as<double>() == 123.45));
+				break;
+			case 2:
+				REQUIRE((value.as<std::string>() == "String value"));
+				break;
+			case 3:
+				REQUIRE((value.is<sol::lua_nil_t>()));
+				break;
+			}
+			break;
+		case sol::type::string:
+			if (key.as<std::string>() == "WOOF") {
+				REQUIRE((value.as<double>() == 123));
+			}
+			break;
+		case sol::type::lua_nil:
+			REQUIRE((value.as<double>() == 3));
+			break;
+		default:
+			break;
+		}
+	};
+	auto fxpair = [&fx](std::pair<sol::object, sol::object> kvp) { fx(kvp.first, kvp.second); };
+	tbl.for_each(fx);
+	REQUIRE(iterations == tablesize);
+
+	iterations = 0;
+	tbl.for_each(fxpair);
+	REQUIRE(iterations == tablesize);
+}
+
+TEST_CASE("tables/for_each empty", "empty tables should not crash") {
+	sol::state lua;
+	lua.open_libraries(sol::lib::base);
+
+	lua.safe_script("arr = {}");
+	sol::table tbl = lua["arr"];
+	REQUIRE(tbl.empty());
+	std::size_t tablesize = 0;
+	std::size_t iterations = 0;
+	auto fx = [&iterations](sol::object key, sol::object value) {
+		++iterations;
+		sol::type keytype = key.get_type();
+		switch (keytype) {
+		case sol::type::number:
+			switch (key.as<int>()) {
+			case 0:
+				REQUIRE((value.as<std::string>() == "Hi"));
+				break;
+			case 1:
+				REQUIRE((value.as<double>() == 123.45));
+				break;
+			case 2:
+				REQUIRE((value.as<std::string>() == "String value"));
+				break;
+			case 3:
+				REQUIRE((value.is<sol::lua_nil_t>()));
+				break;
+			}
+			break;
+		case sol::type::string:
+			if (key.as<std::string>() == "WOOF") {
+				REQUIRE((value.as<double>() == 123));
+			}
+			break;
+		case sol::type::lua_nil:
+			REQUIRE((value.as<double>() == 3));
+			break;
+		default:
+			break;
+		}
+	};
+	auto fxpair = [&fx](std::pair<sol::object, sol::object> kvp) { fx(kvp.first, kvp.second); };
+	tbl.for_each(fx);
+	REQUIRE(iterations == tablesize);
+
+	iterations = 0;
+	tbl.for_each(fxpair);
+	REQUIRE(iterations == tablesize);
+
+	iterations = 0;
+	for (const auto& kvp : tbl) {
+		fxpair(kvp);
+		++iterations;
+	}
+	REQUIRE(iterations == tablesize);
+}
+
+TEST_CASE("tables/iterators", "Testing the use of iteratrs to get values from a lua table") {
+	sol::state lua;
+	lua.open_libraries(sol::lib::base);
+
+	lua.safe_script(
+	     "arr = {\n"
+	     "[0] = \"Hi\",\n"
+	     "[1] = 123.45,\n"
+	     "[2] = \"String value\",\n"
+	     // Does nothing
+	     //"[3] = nil,\n"
+	     //"[nil] = 3,\n"
+	     "[\"WOOF\"] = 123,\n"
+	     "}");
+	sol::table tbl = lua["arr"];
+	std::size_t tablesize = 4;
+	std::size_t iterations = 0;
+
+	int begintop = 0;
+	int endtop = 0;
+	{
+		test_stack_guard s(lua.lua_state(), begintop, endtop);
+		for (auto& kvp : tbl) {
+			[&iterations](sol::object key, sol::object value) {
+				++iterations;
+				sol::type keytype = key.get_type();
+				switch (keytype) {
+				case sol::type::number:
+					switch (key.as<int>()) {
+					case 0:
+						REQUIRE((value.as<std::string>() == "Hi"));
+						break;
+					case 1:
+						REQUIRE((value.as<double>() == 123.45));
+						break;
+					case 2:
+						REQUIRE((value.as<std::string>() == "String value"));
+						break;
+					case 3:
+						REQUIRE((value.is<sol::lua_nil_t>()));
+						break;
+					}
+					break;
+				case sol::type::string:
+					if (key.as<std::string>() == "WOOF") {
+						REQUIRE((value.as<double>() == 123));
+					}
+					break;
+				case sol::type::lua_nil:
+					REQUIRE((value.as<double>() == 3));
+					break;
+				default:
+					break;
+				}
+			}(kvp.first, kvp.second);
+		}
+	}
+	REQUIRE(begintop == endtop);
+	REQUIRE(iterations == tablesize);
+}

tests/runtime_tests/source/usertypes.basic.cpp

@@ -30,6 +30,7 @@
 
 TEST_CASE("usertype/usertype", "Show that we can create classes from usertype and use them") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 
 	sol::usertype<fuser> lc = lua.new_usertype<fuser>("fuser", "add", &fuser::add, "add2", &fuser::add2);
 
@@ -56,6 +57,7 @@ TEST_CASE("usertype/usertype", "Show that we can create classes from usertype an
 
 TEST_CASE("usertype/usertype fundamentals", "Verify new_usertype registers basic member functions and a constructor") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 
 	lua.new_usertype<fuser>("fuser", "add", &fuser::add, "add2", &fuser::add2);
 

tests/runtime_tests/source/usertypes.cpp

@@ -54,6 +54,7 @@ struct self_test {
 
 TEST_CASE("usertype/self-referential usertype", "usertype classes must play nice when C++ object types are requested for C++ code") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
 
 	lua.new_usertype<self_test>("test", "g", &self_test::g, "f", &self_test::f);
@@ -68,6 +69,7 @@ TEST_CASE("usertype/self-referential usertype", "usertype classes must play nice
 
 TEST_CASE("usertype/nonmember-functions", "let users set non-member functions that take unqualified T as first parameter to usertype") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
 
 	lua.new_usertype<giver>("giver",
@@ -97,6 +99,8 @@ TEST_CASE("usertype/nonmember-functions", "let users set non-member functions th
 
 TEST_CASE("usertype/abstract-base-class", "Ensure that abstract base classes and such can be registered") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	lua.new_usertype<abstract_A>("A", "a", &abstract_A::a);
 	lua.new_usertype<abstract_B>("B", sol::base_classes, sol::bases<abstract_A>());
 	REQUIRE_NOTHROW([&]() {
@@ -114,7 +118,9 @@ TEST_CASE("usertype/as_function", "Ensure that variables can be turned into func
 	};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries();
+
 	lua.new_usertype<B>("B", "b", &B::bvar, "f", sol::as_function(&B::bvar));
 
 	B b;
@@ -137,6 +143,7 @@ TEST_CASE("usertype/call-initializers", "Ensure call constructors with initializ
 	};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries();
 
 	lua.new_usertype<A>("A",
@@ -153,6 +160,7 @@ TEST_CASE("usertype/missing-key", "make sure a missing key returns nil") {
 	struct thing {};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
 
 	lua.new_usertype<thing>("thing");
@@ -169,6 +177,7 @@ TEST_CASE("usertype/basic type information", "check that we can query some basic
 	struct my_thing {};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
 
 	lua.new_usertype<my_thing>("my_thing");
@@ -210,9 +219,8 @@ TEST_CASE("usertype/noexcept-methods", "make sure noexcept functions and methods
 	};
 
 	sol::state lua;
-	lua.new_usertype<T>("T",
+	sol::stack_guard luasg(lua);
-		"nf", &T::noexcept_function,
+	lua.new_usertype<T>("T", "nf", &T::noexcept_function, "nm", &T::noexcept_method);
-		"nm", &T::noexcept_method);
 
 	lua.safe_script("t = T.new()");
 	lua.safe_script("v1 = t.nf()");

tests/runtime_tests/source/usertypes.member_variables.cpp

@@ -30,6 +30,7 @@
 
 TEST_CASE("usertype/member-variables", "allow table-like accessors to behave as member variables for usertype") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
 	sol::constructors<sol::types<float, float, float>> ctor;
 	sol::usertype<Vec> udata
@@ -57,7 +58,6 @@ TEST_CASE("usertype/member-variables", "allow table-like accessors to behave as
 		sol::function f;
 	};
 
-	lua.open_libraries(sol::lib::base);
 	lua.set("b", breaks());
 	lua.new_usertype<breaks>("breaks", "f", &breaks::f);
 
@@ -90,6 +90,8 @@ TEST_CASE("usertype/reference-and-constness", "Make sure constness compiles prop
 	};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	lua.new_usertype<woof>("woof", "b", &woof::b);
 	lua.new_usertype<bark>("bark", "var", &bark::var);
 	lua.new_usertype<outer>("outer", "n", &outer::n);

tests/runtime_tests/source/usertypes.overload.cpp

@@ -40,6 +40,7 @@ struct overloading_test {
 
 TEST_CASE("usertype/overloading", "Check if overloading works properly for usertypes") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
 
 	lua.new_usertype<woof>("woof", "var", &woof::var, "func", sol::overload(&woof::func, &woof::func2, &woof::func2s));
@@ -61,6 +62,7 @@ TEST_CASE("usertype/overloading", "Check if overloading works properly for usert
 
 TEST_CASE("usertype/overloading_values", "ensure overloads handle properly") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.new_usertype<overloading_test>("overloading_test",
 	     sol::constructors<>(),
 	     "print",

tests/runtime_tests/source/usertypes.properties.cpp

@@ -105,7 +105,9 @@ TEST_CASE("usertype/properties", "Check if member properties/variables work") {
 	};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
+
 	lua.new_usertype<bark>("bark",
 	     "var",
 	     &bark::var,
@@ -172,6 +174,8 @@ TEST_CASE("usertype/copyability", "make sure user can write to a class variable
 	};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	lua.new_usertype<NoCopy>("NoCopy", "val", sol::property(&NoCopy::get, &NoCopy::set));
 
 	REQUIRE_NOTHROW(lua.safe_script(R"__(
@@ -217,6 +221,7 @@ TEST_CASE("usertype/static-properties", "allow for static functions to get and s
 	test_t manager;
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 
 	lua.new_usertype<test_t>(
 	     "test", "f", std::function<std::size_t()>(std::bind(std::mem_fn(&test_t::func), &manager)), "g", sol::property(&test_t::s_func, &test_t::g_func));
@@ -241,6 +246,7 @@ TEST_CASE("usertype/var-and-property", "make sure const vars are readonly and pr
 	};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries();
 
 	lua.new_usertype<test>(
@@ -394,6 +400,8 @@ TEST_CASE("usertype/alignment", "ensure that alignment does not trigger weird al
 	struct aligned_derived : aligned_base {};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	auto f = [](aligned_base&, float d) { REQUIRE(d == 5.0f); };
 	lua.new_usertype<aligned_base>("Base", "x", sol::writeonly_property(weird_aligned_wrapper<aligned_base>(std::ref(f))));
 	lua.new_usertype<aligned_derived>("Derived", sol::base_classes, sol::bases<aligned_base>());

tests/runtime_tests/source/utility.cpp

@@ -29,10 +29,10 @@
 #include <mutex>
 #include <thread>
 
-#ifdef SOL_CXX17_FEATURES
+#if defined(SOL_CXX17_FEATURES) && SOL_CXX17_FEATURES
 #include <string_view>
 #include <variant>
-#endif
+#endif // C++17
 
 std::mutex basic_init_require_mutex;
 
@@ -109,6 +109,7 @@ TEST_CASE("utility/variant", "test that variant can be round-tripped") {
 
 TEST_CASE("utility/optional-conversion", "test that regular optional will properly catch certain types") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
 
 	lua.new_usertype<vars>("vars");
@@ -129,6 +130,7 @@ TEST_CASE("utility/std optional", "test that shit optional can be round-tripped"
 #ifdef SOL_CXX17_FEATURES
 	SECTION("okay") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		lua.set_function("f", [](int v) {
@@ -149,6 +151,7 @@ TEST_CASE("utility/std optional", "test that shit optional can be round-tripped"
 	}
 	SECTION("throws") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 		lua.open_libraries(sol::lib::base);
 
 		lua.set_function("f", [](int v) {
@@ -169,6 +172,8 @@ TEST_CASE("utility/std optional", "test that shit optional can be round-tripped"
 	}
 	SECTION("in classes") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
+
 		lua.open_libraries(sol::lib::base);
 
 		struct opt_c {
@@ -194,6 +199,7 @@ TEST_CASE("utility/std optional", "test that shit optional can be round-tripped"
 TEST_CASE("utility/string_view", "test that string_view can be taken as an argument") {
 #ifdef SOL_CXX17_FEATURES
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
 
 	lua.set_function("f", [](std::string_view v) {
@@ -224,6 +230,8 @@ TEST_CASE("utility/thread", "fire up lots of threads at the same time to make su
 
 TEST_CASE("utility/pointer", "check we can get pointer value from references") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	lua.set_function("f", [](bool aorb, sol::reference a, sol::stack_reference b) {
 		if (aorb) {
 			return a.pointer();
@@ -259,6 +267,8 @@ TEST_CASE("utility/this_state", "Ensure this_state argument can be gotten anywhe
 	};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
+
 	INFO("created lua state");
 	lua.open_libraries(sol::lib::base);
 	lua.new_usertype<bark>("bark",
@@ -290,6 +300,7 @@ TEST_CASE("utility/this_state", "Ensure this_state argument can be gotten anywhe
 
 TEST_CASE("safety/check_stack", "check to make sure that if we overflow the stack in safety mode, we get the appropriate error thrown") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
 
 	lua["okay"] = []() {

tests/runtime_tests/source/variadics.cpp

@@ -37,7 +37,9 @@ TEST_CASE("variadics/variadic_args", "Check to see we can receive multiple argum
 	};
 
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 	lua.open_libraries(sol::lib::base);
+
 	lua.set_function("v", [](sol::this_state, sol::variadic_args va) -> structure {
 		int r = 0;
 		for (auto v : va) {
@@ -83,6 +85,7 @@ TEST_CASE("variadics/required with variadic_args", "Check if a certain number of
 
 TEST_CASE("variadics/variadic_args get type", "Make sure we can inspect types proper from variadic_args") {
 	sol::state lua;
+	sol::stack_guard luasg(lua);
 
 	lua.set_function("f", [](sol::variadic_args va) {
 		sol::type types[] = {
@@ -108,6 +111,7 @@ TEST_CASE("variadics/variadic_args get type", "Make sure we can inspect types pr
 TEST_CASE("variadics/variadic_results", "returning a variable amount of arguments from C++") {
 	SECTION("as_returns - containers") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		lua.set_function("f", []() {
 			std::set<std::string> results{ "arf", "bark", "woof" };
@@ -139,17 +143,17 @@ TEST_CASE("variadics/variadic_results", "returning a variable amount of argument
 	}
 	SECTION("variadic_results - variadic_args") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		lua.set_function("f", [](sol::variadic_args args) {
 			return sol::variadic_results(args.cbegin(), args.cend());
 		});
 
-		REQUIRE_NOTHROW([&]() {
+		auto result1 = lua.safe_script(R"(
-			lua.safe_script(R"(
+			v1, v2, v3 = f(1, 'bark', true)
-	v1, v2, v3 = f(1, 'bark', true)
+			v4, v5 = f(25, 82)
-	v4, v5 = f(25, 82)
+		)", sol::script_pass_on_error);
-)");
+		REQUIRE(result1.valid());
-		}());
 
 		int v1 = lua["v1"];
 		std::string v2 = lua["v2"];
@@ -165,6 +169,7 @@ TEST_CASE("variadics/variadic_results", "returning a variable amount of argument
 	}
 	SECTION("variadic_results") {
 		sol::state lua;
+		sol::stack_guard luasg(lua);
 
 		lua.set_function("f", [](sol::this_state ts, bool maybe) {
 			if (maybe) {
@@ -184,12 +189,11 @@ TEST_CASE("variadics/variadic_results", "returning a variable amount of argument
 			}
 		});
 
-		REQUIRE_NOTHROW([&]() {
+		auto result1 = lua.safe_script(R"(
-			lua.safe_script(R"(
+			v1, v2, v3 = f(true)
-	v1, v2, v3 = f(true)
+			v4, v5, v6, v7 = f(false)
-	v4, v5, v6, v7 = f(false)
+		)", sol::script_pass_on_error);
-)");
+		REQUIRE(result1.valid());
-		}());
 
 		int v1 = lua["v1"];
 		int v2 = lua["v2"];
@@ -232,13 +236,15 @@ TEST_CASE("variadics/fallback_constructor", "ensure constructor matching behaves
 		}
 		return res; }));
 
-	REQUIRE_NOTHROW([&]() {
+	auto result1 = lua.safe_script("v0 = vec2x();", sol::script_pass_on_error);
-		lua.safe_script("v0 = vec2x();");
+	auto result2 = lua.safe_script("v1 = vec2x(1);", sol::script_pass_on_error);
-		lua.safe_script("v1 = vec2x(1);");
+	auto result3 = lua.safe_script("v2 = vec2x(1, 2);", sol::script_pass_on_error);
-		lua.safe_script("v2 = vec2x(1, 2);");
+	auto result4 = lua.safe_script("v3 = vec2x(v2)", sol::script_pass_on_error);
-		lua.safe_script("v3 = vec2x(v2)");
+	REQUIRE(result1.valid());
-	}());
+	REQUIRE(result2.valid());
-
+	REQUIRE(result3.valid());
+	REQUIRE(result4.valid());
+	
 	vec2x& v0 = lua["v0"];
 	vec2x& v1 = lua["v1"];
 	vec2x& v2 = lua["v2"];