From 0faacb5d2ca5735f5272c2e3429a3f4b8af972f4 Mon Sep 17 00:00:00 2001
From: ThePhD <phdofthehouse@gmail.com>
Date: Mon, 20 Jun 2016 07:03:44 -0400
Subject: [PATCH] Slight refactoring of implementation. Also, stray #endif due
 to not being recognized by include guard regex -- the formula must be
 kept...! (TODO: transition sol2 to include guards...?)

---
 sol/bind_traits.hpp |  2 +-
 sol/function.hpp    | 10 ++++------
 sol/stack_check.hpp |  3 ++-
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/sol/bind_traits.hpp b/sol/bind_traits.hpp
index 5b18b403..1549d4f0 100644
--- a/sol/bind_traits.hpp
+++ b/sol/bind_traits.hpp
@@ -239,4 +239,4 @@ namespace sol {
 	} // meta
 } // sol
 
-#endif // SOL_BIND_TRAITS
+#endif // SOL_BIND_TRAITS_HPP
diff --git a/sol/function.hpp b/sol/function.hpp
index 38baeefb..6e26d455 100644
--- a/sol/function.hpp
+++ b/sol/function.hpp
@@ -105,9 +105,6 @@ namespace sol {
 
 			template<typename... Args, typename... Ret>
 			static std::function<Signature> get_std_func(types<Ret...>, types<Args...>, lua_State* L, int index = -1) {
-				if (lua_isnil(L, index) || lua_isnone(L, index)) {
-					return nullptr;
-				}
 				sol::function f(L, index);
 				auto fx = [f, L, index](Args&&... args) -> meta::return_type_t<Ret...> {
 					return f.call<Ret...>(std::forward<Args>(args)...);
@@ -117,9 +114,6 @@ namespace sol {
 
 			template<typename... FxArgs>
 			static std::function<Signature> get_std_func(types<void>, types<FxArgs...>, lua_State* L, int index = -1) {
-				if (lua_isnil(L, index) || lua_isnone(L, index)) {
-					return nullptr;
-				}
 				sol::function f(L, index);
 				auto fx = [f, L, index](FxArgs&&... args) -> void {
 					f(std::forward<FxArgs>(args)...);
@@ -133,6 +127,10 @@ namespace sol {
 			}
 
 			static std::function<Signature> get(lua_State* L, int index) {
+				type t = type_of(L, index);
+				if (t == type::none || t == type::nil) {
+					return nullptr;
+				}
 				return get_std_func(return_types(), args_lists(), L, index);
 			}
 		};
diff --git a/sol/stack_check.hpp b/sol/stack_check.hpp
index 05c373bf..fd920fc4 100644
--- a/sol/stack_check.hpp
+++ b/sol/stack_check.hpp
@@ -196,7 +196,8 @@ namespace sol {
 			template <typename Handler>
 			static bool check(lua_State* L, int index, Handler&& handler) {
 				type t = type_of(L, index);
-				if (t == type::function) {
+				if (t == type::nil || t == type::none || t == type::function) {
+					// allow for nil to be returned
 					return true;
 				}
 				if (t != type::userdata && t != type::table) {