add single, add examples

CMakeLists.txt

@@ -61,7 +61,7 @@ if (EXAMPLES)
   source_group(examples FILES ${EXAMPLES_SRC})
   foreach(example_source_file ${EXAMPLES_SRC})
     get_filename_component(example_name ${example_source_file} NAME_WE)
-    set(example_name "example-${example_name}")
+    set(example_name "example_${example_name}")
     add_executable(${example_name} ${example_source_file} ${HEADER_SRCS})
     target_link_libraries(${example_name} ${LUA_LIBRARIES})
     target_compile_features(${example_name} PUBLIC ${CXX_FEATURES})
@@ -74,7 +74,7 @@ if (TESTS)
   source_group(tests FILES ${TEST_SRC})
 
   add_executable(tests ${TEST_SRC} ${HEADER_SRCS})
-  target_include_directories(tests PRIVATE ./Catch/include/)
+  target_include_directories(tests PRIVATE ${CMAKE_SOURCE_DIR}/Catch/include/)
 
   find_package(Threads)
   target_link_libraries(tests Threads::Threads ${LUA_LIBRARIES})
@@ -83,10 +83,10 @@ endif()
 
 find_package(PythonInterp 3)
 if (PYTHONINTERP_FOUND)
-  add_custom_command(OUTPUT single/sol/sol.hpp single/sol/sol_forward.hpp COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/single.py --output ${CMAKE_CURRENT_SOURCE_DIR}/single/sol/sol.hpp DEPENDS ${HEADER_SRCS})
+  add_custom_command(OUTPUT single/sol/sol.hpp single/sol/sol_forward.hpp COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_SOURCE_DIR}/single.py --output ${CMAKE_CURRENT_BINARY_DIR}/single/sol/sol.hpp DEPENDS ${HEADER_SRCS})
   add_custom_target(single_sol DEPENDS single/sol/sol.hpp single/sol/sol_forward.hpp)
-  install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/single/sol/sol.hpp" DESTINATION include/sol)
-  install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/single/sol/sol_forward.hpp" DESTINATION include/sol)
+  install(FILES "${CMAKE_SOURCE_DIR}/single/sol/sol.hpp" DESTINATION include/sol)
+  install(FILES "${CMAKE_SOURCE_DIR}/single/sol/sol_forward.hpp" DESTINATION include/sol)
   message(STATUS "single_sol can be generated as python 3 has been found.")
 else()
   message(STATUS "single_sol cannot be generated as python 3 has not been found.")

docs/source/api/stack.rst

@@ -88,6 +88,32 @@ You may also retrieve an :doc:`sol::optional\<T><optional>` from this as well, t
 
 Checks if the object at ``index`` is of type ``T``. If it is not, it will call the ``handler`` function with ``lua_State*``, ``int index``, ``type`` expected, and ``type`` actual as arguments. If you do not pass your own handler, a ``no_panic`` handler will be passed.
 
+.. code-block:: cpp
+	:caption: function: get_usertype
+	:name: stack-get-usertype
+
+	template <typename T>
+	auto get_usertype( lua_State* L, int index = -1 )
+	template <typename T>
+	auto get_usertype( lua_State* L, int index, record& tracking )
+
+Directly attempts to rertieve the type ``T`` using sol2's usertype mechanisms. Similar to a regular ``get`` for a user-defined type. Useful when you need to access sol2's usertype getter mechanism while at the same time `providing your own customization`_.
+
+.. code-block:: cpp
+	:caption: function: check_usertype
+	:name: stack-check
+
+	template <typename T>
+	bool check_usertype( lua_State* L, int index = -1 )
+
+	template <typename T, typename Handler>
+	bool check_usertype( lua_State* L, int index, Handler&& handler )
+
+	template <typename T, typename Handler>
+	bool check_usertype( lua_State* L, int index, Handler&& handler, record& tracking )
+
+Checks if the object at ``index`` is of type ``T`` and stored as a sol2 usertype. Useful when you need to access sol2's usertype checker mechanism while at the same time `providing your own customization`_.
+
 .. code-block:: cpp
 	:caption: function: check_get
 	:name: stack-check-get
@@ -305,3 +331,4 @@ This is an SFINAE-friendly struct that is meant to expose a function ``get`` tha
 .. _Lua stack works in general: https://www.lua.org/pil/24.2.html
 .. _calling C functions works: https://www.lua.org/pil/26.html
 .. _interop examples: https://github.com/ThePhD/sol2/blob/develop/examples/interop
+.. _providing your own customization: https://github.com/ThePhD/sol2/blob/develop/examples/customization_convert_on_get.cpp

docs/source/api/usertype.rst

@@ -238,6 +238,8 @@ If you don't specify a ``sol::meta_function`` name (or equivalent string metamet
 	- a ``sol::meta_function::pairs`` operator is generated for you
 	- Allows you to iterate using ``for k, v in pairs( obj ) do ... end`` in Lua
 	- **Lua 5.2 and better only: LuaJIT does not allow this, Lua 5.1 does NOT allow this**
+* for cases where ``.size()`` exists on the C++ type
+	- the length operator of Lua (``#my_obj``) operator is generated for you
 * for comparison operations where ``operator <`` and ``operator <=`` exist on the C++ type 
 	- These two ``sol::meta_function::less_than(_or_equal_to)`` are generated for you
 	- ``>`` and ``>=`` operators are generated in Lua based on ``<`` and ``<=`` operators
@@ -264,8 +266,9 @@ Otherwise, the following is used to specify functions to bind on the specific us
 	- Binds a typical variable to ``"{name}"``, but gets and sets using the specified setter and getter functions. Not that if you do not pass a setter function, the variable will be read-only. Also not that if you do not pass a getter function, it will be write-only
 * ``"{name}", sol::var( some_value )`` or ``"{name}", sol::var( std::ref( some_value ) )``
 	- Binds a typical variable to ``"{name}"``, optionally by reference (e.g., refers to the same memory in C++). This is useful for global variables / static class variables and the like
-* ``"{name}", sol::overloaded( Func1, Func2, ... )``
-	- Creates an oveloaded member function that discriminates on number of arguments and types.
+* ``"{name}", sol::overload( Func1, Func2, ... )``
+	- Creates an oveloaded member function that discriminates on number of arguments and types
+	- Dumping multiple functions out with the same name **does not make an overload**: you must use **this syntax** in order for it to work
 * ``sol::base_classes, sol::bases<Bases...>``
 	- Tells a usertype what its base classes are. You need this to have derived-to-base conversions work properly. See :ref:`inheritance<usertype-inheritance>`
 

examples/customization.cpp

@@ -2,7 +2,6 @@
 #include <sol.hpp>
 
 #include <iostream>
-#include <iomanip>
 #include <cassert>
 
 struct two_things {

examples/customization_convert_on_get.cpp

@@ -0,0 +1,68 @@
+#define SOL_CHECK_ARGUMENTS 1
+#include <sol.hpp>
+
+#include <iostream>
+#include <iomanip>
+#include <cassert>
+
+struct number_shim {
+	double num = 0;
+};
+
+namespace sol {
+
+	template <>
+	struct lua_type_of<number_shim> : std::integral_constant<sol::type, sol::type::poly> {};
+
+	namespace stack {
+		template <>
+		struct checker<number_shim> {
+			template <typename Handler>
+			static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
+				// check_usertype is a backdoor for directly checking sol2 usertypes
+				if (!check_usertype<number_shim>(L, index) && !stack::check<double>(L, index)) {
+					handler(L, index, type_of(L, index), type::userdata, "expected a number_shim or a number");
+					return false;
+				}
+				tracking.use(1);
+				return true;
+			}
+		};
+
+		template <>
+		struct getter<number_shim> {
+			static number_shim get(lua_State* L, int index, record& tracking) {
+				if (check_usertype<number_shim>(L, index)) {
+					number_shim& ns = get_usertype<number_shim>(L, index, tracking);
+					return ns;
+				}
+				number_shim ns{};
+				ns.num = stack::get<double>(L, index, tracking);
+				return ns;
+			}
+		};
+
+	} // namespace stack
+} // namespace sol
+
+int main() {
+	sol::state lua;
+
+	// Create a pass-through style of function
+	lua.safe_script("function f ( a ) return a end");
+	lua.set_function("g", [](double a) {
+		number_shim ns;
+		ns.num = a;
+		return ns;
+	});
+
+	lua.script("vf = f(25) vg = g(35)");
+	
+	number_shim thingsf = lua["vf"];
+	number_shim thingsg = lua["vg"];
+
+	assert(thingsf.num == 25);
+	assert(thingsg.num == 35);
+
+	return 0;
+}

single.py

@@ -191,7 +191,11 @@ if not args.quiet:
     print('finished creating single forward declaration header for sol\n')
 
 with open(single_file, 'w', encoding='utf-8') as f:
+    if not args.quiet:
+        print('writing {}...'.format(single_file))
     f.write(result)
 
 with open(forward_single_file, 'w', encoding='utf-8') as f:
+    if not args.quiet:
+        print('writing {}...'.format(single_file))
     f.write(forward_result)

single/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 2017-12-10 06:34:23.982786 UTC
-// This header was generated with sol v2.19.0 (revision 87b4dd6)
+// Generated 2017-12-10 20:56:35.224200 UTC
+// This header was generated with sol v2.19.0 (revision c3c7f42)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_HPP
@@ -72,7 +72,6 @@
 
 #if defined(__cpp_noexcept_function_type) || ((defined(_MSC_VER) && _MSC_VER > 1911) && ((defined(_HAS_CXX17) && _HAS_CXX17 == 1) || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)))
 #ifndef SOL_NOEXCEPT_FUNCTION_TYPE
-#define SOL_NOEXCEPT_FUNCTION_TYPE 1
 #endif // noexcept is part of a function's type
 #endif
 
@@ -4439,6 +4438,11 @@ namespace sol {
 		int static_trampoline_noexcept(lua_State* L) noexcept {
 			return f(L);
 		}
+#else
+		template <lua_CFunction f>
+		int static_trampoline_noexcept(lua_State* L) noexcept {
+			return f(L);
+		}
 #endif
 
 		template <typename Fx, typename... Args>
@@ -7099,6 +7103,20 @@ namespace sol {
 					use_reference_tag;
 				return pusher<std::conditional_t<use_reference_tag::value, detail::as_reference_tag, meta::unqualified_t<T>>>{}.push(L, std::forward<Arg>(arg), std::forward<Args>(args)...);
 			}
+
+			template <typename T, typename Handler>
+			bool check_usertype(std::false_type, lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
+				typedef meta::unqualified_t<T> Tu;
+				typedef detail::as_value_tag<Tu> detail_t;
+				return checker<detail_t, type::userdata>{}.check(types<meta::unqualified_t<T>>(), L, index, indextype, std::forward<Handler>(handler), tracking);
+			}
+
+			template <typename T, typename Handler>
+			bool check_usertype(std::true_type, lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
+				typedef meta::unqualified_t<std::remove_pointer_t<meta::unqualified_t<T>>> Tu;
+				typedef detail::as_pointer_tag<Tu> detail_t;
+				return checker<detail_t, type::userdata>{}.check(L, index, indextype, std::forward<Handler>(handler), tracking);
+			}
 		} // namespace stack_detail
 
 		inline bool maybe_indexable(lua_State* L, int index = -1) {
@@ -7198,6 +7216,24 @@ namespace sol {
 			return check<T>(L, index, handler);
 		}
 
+		template <typename T, typename Handler>
+		bool check_usertype(lua_State* L, int index, Handler&& handler, record& tracking) {
+			type indextype = type_of(L, index);
+			return stack_detail::check_usertype<T>(std::is_pointer<T>(), L, index, indextype, std::forward<Handler>(handler), tracking);
+		}
+
+		template <typename T, typename Handler>
+		bool check_usertype(lua_State* L, int index, Handler&& handler) {
+			record tracking{};
+			return check_usertype<T>(L, index, std::forward<Handler>(handler), tracking);
+		}
+
+		template <typename T>
+		bool check_usertype(lua_State* L, int index = -lua_size<meta::unqualified_t<T>>::value) {
+			auto handler = no_panic;
+			return check_usertype<T>(L, index, handler);
+		}
+
 		template <typename T, typename Handler>
 		inline decltype(auto) check_get(lua_State* L, int index, Handler&& handler, record& tracking) {
 			typedef meta::unqualified_t<T> Tu;
@@ -7226,6 +7262,11 @@ namespace sol {
 				auto op = check_get<T>(L, index, type_panic_c_str, tracking);
 				return *std::move(op);
 			}
+
+			template <typename T>
+			inline decltype(auto) tagged_get(types<optional<T>>, lua_State* L, int index, record& tracking) {
+				return stack_detail::unchecked_get<optional<T>>(L, index, tracking);
+			}
 #else
 			template <typename T>
 			inline decltype(auto) tagged_get(types<T>, lua_State* L, int index, record& tracking) {
@@ -7233,11 +7274,6 @@ namespace sol {
 			}
 #endif
 
-			template <typename T>
-			inline decltype(auto) tagged_get(types<optional<T>>, lua_State* L, int index, record& tracking) {
-				return stack_detail::unchecked_get<optional<T>>(L, index, tracking);
-			}
-
 			template <bool b>
 			struct check_types {
 				template <typename T, typename... Args, typename Handler>
@@ -7295,6 +7331,21 @@ namespace sol {
 			return multi_check<true, Args...>(L, index);
 		}
 
+		template <typename T>
+		inline decltype(auto) get_usertype(lua_State* L, int index, record& tracking) {
+#ifdef SOL_SAFE_GETTER
+			return stack_detail::tagged_get(types<std::conditional_t<std::is_pointer<T>::value, detail::as_pointer_tag<std::remove_pointer_t<T>>, detail::as_value_tag<T>>>(), L, index, tracking);
+#else
+			return stack_detail::unchecked_get<std::conditional_t<std::is_pointer<T>::value, detail::as_pointer_tag<std::remove_pointer_t<T>>, detail::as_value_tag<T>>>(L, index, tracking);
+#endif
+		}
+
+		template <typename T>
+		inline decltype(auto) get_usertype(lua_State* L, int index = -lua_size<meta::unqualified_t<T>>::value) {
+			record tracking{};
+			return get_usertype<T>(L, index, tracking);
+		}
+
 		template <typename T>
 		inline decltype(auto) get(lua_State* L, int index, record& tracking) {
 			return stack_detail::tagged_get(types<T>(), L, index, tracking);
@@ -7578,17 +7629,21 @@ namespace stack {
 			int isnum = 0;
 			lua_tointegerx(L, index, &isnum);
 			const bool success = isnum != 0;
+			if (!success) {
+				// expected type, actual type
+				handler(L, index, type::number, type_of(L, index), "not a numeric type or numeric string");
+			}
 #else
 			// this check is precise, does not convert
 			if (lua_isinteger(L, index) == 1) {
 				return true;
 			}
 			const bool success = false;
-#endif // If numbers are enabled, use the imprecise check
 			if (!success) {
 				// expected type, actual type
 				handler(L, index, type::number, type_of(L, index), "not a numeric type");
 			}
+#endif // If numbers are enabled, use the imprecise check
 			return success;
 #else
 #ifndef SOL_STRINGS_ARE_NUMBERS
@@ -7887,6 +7942,12 @@ namespace stack {
 
 	template <typename T, typename C>
 	struct checker<detail::as_value_tag<T>, type::userdata, C> {
+		template <typename Handler>
+		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
+			const type indextype = type_of(L, index);
+			return check(types<T>(), L, index, indextype, handler, tracking);
+		}
+
 		template <typename U, typename Handler>
 		static bool check(types<U>, lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
 #ifdef SOL_ENABLE_INTEROP
@@ -7937,11 +7998,28 @@ namespace stack {
 	};
 
 	template <typename T, typename C>
-	struct checker<T, type::userdata, C> {
+	struct checker<detail::as_pointer_tag<T>, type::userdata, C> {
+		template <typename Handler>
+		static bool check(lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
+			if (indextype == type::lua_nil) {
+				tracking.use(1);
+				return true;
+			}
+			return stack_detail::check_usertype<T>(std::false_type(), L, index, indextype, std::forward<Handler>(handler), tracking);
+		}
+
 		template <typename Handler>
 		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
 			const type indextype = type_of(L, index);
-			return checker<detail::as_value_tag<T>, type::userdata, C>{}.check(types<T>(), L, index, indextype, std::forward<Handler>(handler), tracking);
+			return check(L, index, handler, indextype, tracking);
+		}
+	};
+
+	template <typename T, typename C>
+	struct checker<T, type::userdata, C> {
+		template <typename Handler>
+		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
+			return check_usertype<T>(L, index, std::forward<Handler>(handler), tracking);
 		}
 	};
 
@@ -7949,13 +8027,7 @@ namespace stack {
 	struct checker<T*, type::userdata, C> {
 		template <typename Handler>
 		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
-			const type indextype = type_of(L, index);
-			// Allow lua_nil to be transformed to nullptr
-			if (indextype == type::lua_nil) {
-				tracking.use(1);
-				return true;
-			}
-			return checker<meta::unqualified_t<T>, type::userdata, C>{}.check(L, index, std::forward<Handler>(handler), tracking);
+			return check_usertype<T*>(L, index, std::forward<Handler>(handler), tracking);
 		}
 	};
 
@@ -15148,9 +15220,8 @@ namespace sol {
 			};
 
 			static auto& get_src(lua_State* L) {
-				typedef std::remove_pointer_t<meta::unwrap_unqualified_t<X>> Tu;
 #ifdef SOL_SAFE_USERTYPE
-				auto p = stack::check_get<Tu*>(L, 1);
+				auto p = stack::check_get<T*>(L, 1);
 				if (!p) {
 					luaL_error(L, "sol: 'self' is not of type '%s' (pass 'self' as first argument with ':' or call on proper type)", detail::demangle<T>().c_str());
 				}
@@ -17050,14 +17121,21 @@ namespace sol {
 			if (toplevel && stack::get<type>(L, keyidx) != type::string) {
 				return is_index ? f.indexfunc(L) : f.newindexfunc(L);
 			}
-			std::string name = stack::get<std::string>(L, keyidx);
-			auto memberit = f.mapping.find(name);
-			if (memberit != f.mapping.cend()) {
-				const usertype_detail::call_information& ci = memberit->second;
-				const usertype_detail::member_search& member = is_index ? ci.index : ci.new_index;
-				return (member)(L, static_cast<void*>(&f), ci.runtime_target);
+			int runtime_target = 0;
+			usertype_detail::member_search member = nullptr;
+			{
+				std::string name = stack::get<std::string>(L, keyidx);
+				auto memberit = f.mapping.find(name);
+				if (memberit != f.mapping.cend()) {
+					const usertype_detail::call_information& ci = memberit->second;
+					member = is_index ? ci.index : ci.new_index;
+					runtime_target = ci.runtime_target;
+				}
 			}
-			string_view accessor = name;
+			if (member != nullptr) {
+				return (member)(L, static_cast<void*>(&f), runtime_target);
+			}
+			string_view accessor = stack::get<string_view>(L, keyidx);
 			int ret = 0;
 			bool found = false;
 			// Otherwise, we need to do propagating calls through the bases
@@ -17311,7 +17389,7 @@ namespace sol {
 			function_map& functions = sm.functions;
 			static const int keyidx = -2 + static_cast<int>(is_index);
 			if (toplevel) {
-				if (stack::get<type>(L, keyidx) != type::string) {
+				if (type_of(L, keyidx) != type::string) {
 					if (has_indexing) {
 						object& indexingfunc = is_index
 							? sm.index
@@ -17326,35 +17404,44 @@ namespace sol {
 				}
 			}
 			string_view accessor = stack::get<string_view>(L, keyidx);
-			std::string accessorkey = accessor.data();
-			auto vit = variables.find(accessorkey);
-			if (vit != variables.cend()) {
-				auto& varwrap = *(vit->second);
-				if (is_index) {
-					return varwrap.index(L);
+			variable_wrapper* varwrap = nullptr;
+			{
+				std::string accessorkey(accessor.data(), accessor.size());
+				auto vit = variables.find(accessorkey);
+				if (vit != variables.cend()) {
+					varwrap = vit->second.get();
 				}
-				return varwrap.new_index(L);
 			}
-			auto fit = functions.find(accessorkey);
-			if (fit != functions.cend()) {
-				object& func = fit->second;
-				if (is_index) {
-					return stack::push(L, func);
-				}
-				else {
-					if (has_indexing && !is_toplevel(L)) {
-						object& indexingfunc = is_index
-							? sm.index
-							: sm.newindex;
-						return call_indexing_object(L, indexingfunc);
+			if (varwrap != nullptr) {
+				return is_index ? varwrap->index(L) : varwrap->new_index(L);
+			}
+			bool function_failed = false;
+			{
+				std::string accessorkey(accessor.data(), accessor.size());
+				auto fit = functions.find(accessorkey);
+				if (fit != functions.cend()) {
+					object& func = fit->second;
+					if (is_index) {
+						return stack::push(L, func);
 					}
 					else {
-						return is_index
-							? indexing_fail<T, is_index>(L)
-							: metatable_newindex<T, true>(L);
+						function_failed = true;
 					}
 				}
 			}
+			if (function_failed) {
+				if (has_indexing && !is_toplevel(L)) {
+					object& indexingfunc = is_index
+						? sm.index
+						: sm.newindex;
+					return call_indexing_object(L, indexingfunc);
+				}
+				else {
+					return is_index
+						? indexing_fail<T, is_index>(L)
+						: metatable_newindex<T, true>(L);
+				}
+			}
 			/* Check table storage first for a method that works
 			luaL_getmetatable(L, sm.metakey);
 			if (type_of(L, -1) != type::lua_nil) {

single/sol/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 2017-12-10 06:34:24.172779 UTC
-// This header was generated with sol v2.19.0 (revision 87b4dd6)
+// Generated 2017-12-10 20:56:35.410742 UTC
+// This header was generated with sol v2.19.0 (revision c3c7f42)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_FORWARD_HPP
@@ -39,7 +39,6 @@
 
 #if defined(__cpp_noexcept_function_type) || ((defined(_MSC_VER) && _MSC_VER > 1911) && ((defined(_HAS_CXX17) && _HAS_CXX17 == 1) || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)))
 #ifndef SOL_NOEXCEPT_FUNCTION_TYPE
-#define SOL_NOEXCEPT_FUNCTION_TYPE 1
 #endif // noexcept is part of a function's type
 #endif
 

sol/container_traits.hpp

@@ -538,9 +538,8 @@ namespace sol {
 			};
 
 			static auto& get_src(lua_State* L) {
-				typedef std::remove_pointer_t<meta::unwrap_unqualified_t<X>> Tu;
 #ifdef SOL_SAFE_USERTYPE
-				auto p = stack::check_get<Tu*>(L, 1);
+				auto p = stack::check_get<T*>(L, 1);
 				if (!p) {
 					luaL_error(L, "sol: 'self' is not of type '%s' (pass 'self' as first argument with ':' or call on proper type)", detail::demangle<T>().c_str());
 				}

sol/feature_test.hpp

@@ -30,7 +30,7 @@
 
 #if defined(__cpp_noexcept_function_type) || ((defined(_MSC_VER) && _MSC_VER > 1911) && ((defined(_HAS_CXX17) && _HAS_CXX17 == 1) || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)))
 #ifndef SOL_NOEXCEPT_FUNCTION_TYPE
-#define SOL_NOEXCEPT_FUNCTION_TYPE 1
+//#define SOL_NOEXCEPT_FUNCTION_TYPE 1
 #endif // noexcept is part of a function's type
 #endif
 

sol/simple_usertype_metatable.hpp

@@ -51,7 +51,7 @@ namespace sol {
 			function_map& functions = sm.functions;
 			static const int keyidx = -2 + static_cast<int>(is_index);
 			if (toplevel) {
-				if (stack::get<type>(L, keyidx) != type::string) {
+				if (type_of(L, keyidx) != type::string) {
 					if (has_indexing) {
 						object& indexingfunc = is_index
 							? sm.index
@@ -66,35 +66,44 @@ namespace sol {
 				}
 			}
 			string_view accessor = stack::get<string_view>(L, keyidx);
-			std::string accessorkey = accessor.data();
-			auto vit = variables.find(accessorkey);
-			if (vit != variables.cend()) {
-				auto& varwrap = *(vit->second);
-				if (is_index) {
-					return varwrap.index(L);
+			variable_wrapper* varwrap = nullptr;
+			{
+				std::string accessorkey(accessor.data(), accessor.size());
+				auto vit = variables.find(accessorkey);
+				if (vit != variables.cend()) {
+					varwrap = vit->second.get();
 				}
-				return varwrap.new_index(L);
 			}
-			auto fit = functions.find(accessorkey);
-			if (fit != functions.cend()) {
-				object& func = fit->second;
-				if (is_index) {
-					return stack::push(L, func);
-				}
-				else {
-					if (has_indexing && !is_toplevel(L)) {
-						object& indexingfunc = is_index
-							? sm.index
-							: sm.newindex;
-						return call_indexing_object(L, indexingfunc);
+			if (varwrap != nullptr) {
+				return is_index ? varwrap->index(L) : varwrap->new_index(L);
+			}
+			bool function_failed = false;
+			{
+				std::string accessorkey(accessor.data(), accessor.size());
+				auto fit = functions.find(accessorkey);
+				if (fit != functions.cend()) {
+					object& func = fit->second;
+					if (is_index) {
+						return stack::push(L, func);
 					}
 					else {
-						return is_index
-							? indexing_fail<T, is_index>(L)
-							: metatable_newindex<T, true>(L);
+						function_failed = true;
 					}
 				}
 			}
+			if (function_failed) {
+				if (has_indexing && !is_toplevel(L)) {
+					object& indexingfunc = is_index
+						? sm.index
+						: sm.newindex;
+					return call_indexing_object(L, indexingfunc);
+				}
+				else {
+					return is_index
+						? indexing_fail<T, is_index>(L)
+						: metatable_newindex<T, true>(L);
+				}
+			}
 			/* Check table storage first for a method that works
 			luaL_getmetatable(L, sm.metakey);
 			if (type_of(L, -1) != type::lua_nil) {

sol/stack_check.hpp

@@ -99,17 +99,21 @@ namespace stack {
 			int isnum = 0;
 			lua_tointegerx(L, index, &isnum);
 			const bool success = isnum != 0;
+			if (!success) {
+				// expected type, actual type
+				handler(L, index, type::number, type_of(L, index), "not a numeric type or numeric string");
+			}
 #else
 			// this check is precise, does not convert
 			if (lua_isinteger(L, index) == 1) {
 				return true;
 			}
 			const bool success = false;
-#endif // If numbers are enabled, use the imprecise check
 			if (!success) {
 				// expected type, actual type
 				handler(L, index, type::number, type_of(L, index), "not a numeric type");
 			}
+#endif // If numbers are enabled, use the imprecise check
 			return success;
 #else
 #ifndef SOL_STRINGS_ARE_NUMBERS
@@ -408,6 +412,12 @@ namespace stack {
 
 	template <typename T, typename C>
 	struct checker<detail::as_value_tag<T>, type::userdata, C> {
+		template <typename Handler>
+		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
+			const type indextype = type_of(L, index);
+			return check(types<T>(), L, index, indextype, handler, tracking);
+		}
+
 		template <typename U, typename Handler>
 		static bool check(types<U>, lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
 #ifdef SOL_ENABLE_INTEROP
@@ -458,11 +468,28 @@ namespace stack {
 	};
 
 	template <typename T, typename C>
-	struct checker<T, type::userdata, C> {
+	struct checker<detail::as_pointer_tag<T>, type::userdata, C> {
+		template <typename Handler>
+		static bool check(lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
+			if (indextype == type::lua_nil) {
+				tracking.use(1);
+				return true;
+			}
+			return stack_detail::check_usertype<T>(std::false_type(), L, index, indextype, std::forward<Handler>(handler), tracking);
+		}
+
 		template <typename Handler>
 		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
 			const type indextype = type_of(L, index);
-			return checker<detail::as_value_tag<T>, type::userdata, C>{}.check(types<T>(), L, index, indextype, std::forward<Handler>(handler), tracking);
+			return check(L, index, handler, indextype, tracking);
+		}
+	};
+
+	template <typename T, typename C>
+	struct checker<T, type::userdata, C> {
+		template <typename Handler>
+		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
+			return check_usertype<T>(L, index, std::forward<Handler>(handler), tracking);
 		}
 	};
 
@@ -470,13 +497,7 @@ namespace stack {
 	struct checker<T*, type::userdata, C> {
 		template <typename Handler>
 		static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
-			const type indextype = type_of(L, index);
-			// Allow lua_nil to be transformed to nullptr
-			if (indextype == type::lua_nil) {
-				tracking.use(1);
-				return true;
-			}
-			return checker<meta::unqualified_t<T>, type::userdata, C>{}.check(L, index, std::forward<Handler>(handler), tracking);
+			return check_usertype<T*>(L, index, std::forward<Handler>(handler), tracking);
 		}
 	};
 

sol/stack_core.hpp

@@ -550,6 +550,20 @@ namespace sol {
 					use_reference_tag;
 				return pusher<std::conditional_t<use_reference_tag::value, detail::as_reference_tag, meta::unqualified_t<T>>>{}.push(L, std::forward<Arg>(arg), std::forward<Args>(args)...);
 			}
+
+			template <typename T, typename Handler>
+			bool check_usertype(std::false_type, lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
+				typedef meta::unqualified_t<T> Tu;
+				typedef detail::as_value_tag<Tu> detail_t;
+				return checker<detail_t, type::userdata>{}.check(types<meta::unqualified_t<T>>(), L, index, indextype, std::forward<Handler>(handler), tracking);
+			}
+
+			template <typename T, typename Handler>
+			bool check_usertype(std::true_type, lua_State* L, int index, type indextype, Handler&& handler, record& tracking) {
+				typedef meta::unqualified_t<std::remove_pointer_t<meta::unqualified_t<T>>> Tu;
+				typedef detail::as_pointer_tag<Tu> detail_t;
+				return checker<detail_t, type::userdata>{}.check(L, index, indextype, std::forward<Handler>(handler), tracking);
+			}
 		} // namespace stack_detail
 
 		inline bool maybe_indexable(lua_State* L, int index = -1) {
@@ -649,6 +663,24 @@ namespace sol {
 			return check<T>(L, index, handler);
 		}
 
+		template <typename T, typename Handler>
+		bool check_usertype(lua_State* L, int index, Handler&& handler, record& tracking) {
+			type indextype = type_of(L, index);
+			return stack_detail::check_usertype<T>(std::is_pointer<T>(), L, index, indextype, std::forward<Handler>(handler), tracking);
+		}
+
+		template <typename T, typename Handler>
+		bool check_usertype(lua_State* L, int index, Handler&& handler) {
+			record tracking{};
+			return check_usertype<T>(L, index, std::forward<Handler>(handler), tracking);
+		}
+
+		template <typename T>
+		bool check_usertype(lua_State* L, int index = -lua_size<meta::unqualified_t<T>>::value) {
+			auto handler = no_panic;
+			return check_usertype<T>(L, index, handler);
+		}
+
 		template <typename T, typename Handler>
 		inline decltype(auto) check_get(lua_State* L, int index, Handler&& handler, record& tracking) {
 			typedef meta::unqualified_t<T> Tu;
@@ -677,6 +709,11 @@ namespace sol {
 				auto op = check_get<T>(L, index, type_panic_c_str, tracking);
 				return *std::move(op);
 			}
+
+			template <typename T>
+			inline decltype(auto) tagged_get(types<optional<T>>, lua_State* L, int index, record& tracking) {
+				return stack_detail::unchecked_get<optional<T>>(L, index, tracking);
+			}
 #else
 			template <typename T>
 			inline decltype(auto) tagged_get(types<T>, lua_State* L, int index, record& tracking) {
@@ -684,11 +721,6 @@ namespace sol {
 			}
 #endif
 
-			template <typename T>
-			inline decltype(auto) tagged_get(types<optional<T>>, lua_State* L, int index, record& tracking) {
-				return stack_detail::unchecked_get<optional<T>>(L, index, tracking);
-			}
-
 			template <bool b>
 			struct check_types {
 				template <typename T, typename... Args, typename Handler>
@@ -746,6 +778,21 @@ namespace sol {
 			return multi_check<true, Args...>(L, index);
 		}
 
+		template <typename T>
+		inline decltype(auto) get_usertype(lua_State* L, int index, record& tracking) {
+#ifdef SOL_SAFE_GETTER
+			return stack_detail::tagged_get(types<std::conditional_t<std::is_pointer<T>::value, detail::as_pointer_tag<std::remove_pointer_t<T>>, detail::as_value_tag<T>>>(), L, index, tracking);
+#else
+			return stack_detail::unchecked_get<std::conditional_t<std::is_pointer<T>::value, detail::as_pointer_tag<std::remove_pointer_t<T>>, detail::as_value_tag<T>>>(L, index, tracking);
+#endif
+		}
+
+		template <typename T>
+		inline decltype(auto) get_usertype(lua_State* L, int index = -lua_size<meta::unqualified_t<T>>::value) {
+			record tracking{};
+			return get_usertype<T>(L, index, tracking);
+		}
+
 		template <typename T>
 		inline decltype(auto) get(lua_State* L, int index, record& tracking) {
 			return stack_detail::tagged_get(types<T>(), L, index, tracking);

sol/types.hpp

@@ -57,6 +57,11 @@ namespace sol {
 		int static_trampoline_noexcept(lua_State* L) noexcept {
 			return f(L);
 		}
+#else
+		template <lua_CFunction f>
+		int static_trampoline_noexcept(lua_State* L) noexcept {
+			return f(L);
+		}
 #endif
 
 		template <typename Fx, typename... Args>

sol/usertype_metatable.hpp

@@ -555,14 +555,21 @@ namespace sol {
 			if (toplevel && stack::get<type>(L, keyidx) != type::string) {
 				return is_index ? f.indexfunc(L) : f.newindexfunc(L);
 			}
-			std::string name = stack::get<std::string>(L, keyidx);
-			auto memberit = f.mapping.find(name);
-			if (memberit != f.mapping.cend()) {
-				const usertype_detail::call_information& ci = memberit->second;
-				const usertype_detail::member_search& member = is_index ? ci.index : ci.new_index;
-				return (member)(L, static_cast<void*>(&f), ci.runtime_target);
+			int runtime_target = 0;
+			usertype_detail::member_search member = nullptr;
+			{
+				std::string name = stack::get<std::string>(L, keyidx);
+				auto memberit = f.mapping.find(name);
+				if (memberit != f.mapping.cend()) {
+					const usertype_detail::call_information& ci = memberit->second;
+					member = is_index ? ci.index : ci.new_index;
+					runtime_target = ci.runtime_target;
+				}
 			}
-			string_view accessor = name;
+			if (member != nullptr) {
+				return (member)(L, static_cast<void*>(&f), runtime_target);
+			}
+			string_view accessor = stack::get<string_view>(L, keyidx);
 			int ret = 0;
 			bool found = false;
 			// Otherwise, we need to do propagating calls through the bases

tests/test_containers.cpp

@@ -772,9 +772,7 @@ y = a.readonly_seq
 	std::list<bar>& seqrefy = lua["y"];
 	REQUIRE(&seqrefx == &seqrefy);
 	REQUIRE(seqrefx.size() == 3);
-	auto result = lua.do_string(R"(
-a.readonly_seq = value;
-)");
+	auto result = lua.safe_script("a.readonly_seq = value", sol::script_pass_on_error);
 	REQUIRE_FALSE(result.valid());
 }
 
@@ -903,7 +901,7 @@ TEST_CASE("containers/non_copyable", "make sure non-copyable types in containers
 
 		lua["v"] = std::vector<non_copyable>{};
 
-		auto pfr = lua.safe_script("t = test.new()\nt.b = v", sol::script_pass_on_error);
+		auto pfr = lua.safe_script("t = test.new() t.b = v", sol::script_pass_on_error);
 		REQUIRE_FALSE(pfr.valid());
 	}
 	SECTION("simple") {
@@ -913,7 +911,7 @@ TEST_CASE("containers/non_copyable", "make sure non-copyable types in containers
 
 		lua["v"] = std::vector<non_copyable>{};
 
-		auto pfr = lua.safe_script("t = test.new()\nt.b = v", sol::script_pass_on_error);
+		auto pfr = lua.safe_script("t = test.new() t.b = v", sol::script_pass_on_error);
 		REQUIRE_FALSE(pfr.valid());
 	}
 }

tests/test_customizations.cpp

@@ -12,6 +12,10 @@ struct two_things {
 	bool b;
 };
 
+struct number_shim {
+	double num = 0;
+};
+
 namespace sol {
 
 	// First, the expected size
@@ -23,6 +27,10 @@ namespace sol {
 	template <>
 	struct lua_type_of<two_things> : std::integral_constant<sol::type, sol::type::poly> {};
 
+	// do note specialize size for this because it is our type
+	template <>
+	struct lua_type_of<number_shim> : std::integral_constant<sol::type, sol::type::poly> {};
+
 	// Now, specialize various stack structures
 	namespace stack {
 
@@ -62,6 +70,33 @@ namespace sol {
 			}
 		};
 
+		template <>
+		struct checker<number_shim> {
+			template <typename Handler>
+			static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
+				// check_usertype is a backdoor for directly checking sol2 usertypes
+				if (!check_usertype<number_shim>(L, index) && !stack::check<double>(L, index)) {
+					handler(L, index, type_of(L, index), type::userdata, "expected a number_shim or a number");
+					return false;
+				}
+				tracking.use(1);
+				return true;
+			}
+		};
+
+		template <>
+		struct getter<number_shim> {
+			static number_shim get(lua_State* L, int index, record& tracking) {
+				if (check_usertype<number_shim>(L, index)) {
+					number_shim& ns = get_usertype<number_shim>(L, index, tracking);
+					return ns;
+				}
+				number_shim ns{};
+				ns.num = stack::get<double>(L, index, tracking);
+				return ns;
+			}
+		};
+
 	} // namespace stack
 } // namespace sol
 
@@ -89,3 +124,24 @@ TEST_CASE("customization/split struct", "using the newly documented customizatio
 	REQUIRE_FALSE(thingsg.b);
 	REQUIRE(d == 36.5);
 }
+
+TEST_CASE("customization/get_ check_usertype", "using the newly documented customization points to handle different kinds of classes") {
+	sol::state lua;
+
+	// Create a pass-through style of function
+	lua.safe_script("function f ( a ) return a end");
+	lua.set_function("g", [](double a) {
+		number_shim ns;
+		ns.num = a;
+		return ns;
+	});
+
+	auto result = lua.safe_script("vf = f(25) vg = g(35)", sol::script_pass_on_error);
+	REQUIRE(result.valid());
+
+	number_shim thingsf = lua["vf"];
+	number_shim thingsg = lua["vg"];
+	
+	REQUIRE(thingsf.num == 25);
+	REQUIRE(thingsg.num == 35);
+}

tests/test_simple_usertypes.cpp

@@ -635,15 +635,14 @@ end
 			REQUIRE_FALSE(result.valid());
 		}
 
-		REQUIRE_NOTHROW([&lua]() {
+		{
 			auto result = lua.safe_script(R"(
 function t:runtime_func(a)
 	return a + 52
 end
-		)",
-				sol::script_pass_on_error);
+		)", sol::script_pass_on_error);
 			REQUIRE_FALSE(result.valid());
-		}());
+		}
 
 		lua.safe_script("val = t:func(2)");
 		val = lua["val"];