diff --git a/sol/function.hpp b/sol/function.hpp
index 49319308..264fc0e9 100644
--- a/sol/function.hpp
+++ b/sol/function.hpp
@@ -58,6 +58,8 @@ public:
     function(lua_State* L, int index = -1): reference(L, index) {
         type_assert(L, index, type::function);
     }
+    function(const function&) = default;
+    function& operator=(const function&) = default;
 
     template<typename... Ret, typename... Args>
     auto call(Args&&... args) -> decltype(invoke(types<Ret...>(), sizeof...(Args))) {
diff --git a/sol/functional.hpp b/sol/functional.hpp
deleted file mode 100644
index 0ede1e5a..00000000
--- a/sol/functional.hpp
+++ /dev/null
@@ -1,125 +0,0 @@
-// The MIT License (MIT)
-
-// Copyright (c) 2013 Danny Y., Rapptz
-
-// 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_FUNCTIONAL_HPP
-#define SOL_FUNCTIONAL_HPP
-
-#include "tuple.hpp"
-
-namespace sol {
-namespace detail {
-
-template<typename TFuncSignature>
-struct function_traits;
-
-template<typename T, typename R, typename... Args>
-struct function_traits<R(T::*)(Args...)> {
-    static const std::size_t arity = sizeof...(Args);
-    static const bool is_member_function = true;
-    typedef std::tuple<Args...> arg_tuple_type;
-    typedef types<Args...> args_type;
-    typedef R(T::* function_pointer_type)(Args...);
-    typedef typename std::remove_pointer<function_pointer_type>::type function_type;
-    typedef R(* free_function_pointer_type)(Args...);
-    typedef R return_type;
-    template<std::size_t i>
-    using arg = typename std::tuple_element<i, arg_tuple_type>::type;
-};
-
-template<typename T, typename R, typename... Args>
-struct function_traits<R(T::*)(Args...) const> {
-    static const std::size_t arity = sizeof...(Args);
-    static const bool is_member_function = true;
-    typedef std::tuple<Args...> arg_tuple_type;
-    typedef types<Args...> args_type;
-    typedef R(T::* function_pointer_type)(Args...);
-    typedef typename std::remove_pointer<function_pointer_type>::type function_type;
-    typedef R(* free_function_pointer_type)(Args...);
-    typedef R return_type;
-    template<std::size_t i>
-    using arg = typename std::tuple_element<i, arg_tuple_type>::type;
-};
-
-template<typename R, typename... Args>
-struct function_traits<R(Args...)> {
-    static const std::size_t arity = sizeof...(Args);
-    static const bool is_member_function = false;
-    typedef std::tuple<Args...> arg_tuple_type;
-    typedef types<Args...> args_type;
-    typedef R(function_type)(Args...);
-    typedef R(*function_pointer_type)(Args...);
-    typedef R(* free_function_pointer_type)(Args...);
-    typedef R return_type;
-    template<std::size_t i>
-    using arg = typename std::tuple_element<i, arg_tuple_type>::type;
-};
-
-template<typename R, typename... Args>
-struct function_traits<R(*)(Args...)> {
-    static const std::size_t arity = sizeof...(Args);
-    static const bool is_member_function = false;
-    typedef std::tuple<Args...> arg_tuple_type;
-    typedef types<Args...> args_type;
-    typedef R(function_type)(Args...);
-    typedef R(*function_pointer_type)(Args...);
-    typedef R(* free_function_pointer_type)(Args...);
-    typedef R return_type;
-    template<std::size_t i>
-    using arg = typename std::tuple_element<i, arg_tuple_type>::type;
-};
-
-using std::get;
-
-template<typename Function, typename Tuple, size_t... Indices>
-inline auto call(Function&& f, const Tuple& t, indices<Indices...>) -> decltype(f(get<Indices>(t)...)) {
-    return f(get<Indices>(t)...);
-}
-} // detail
-
-template<typename... Ret>
-struct lua_return_type {
-    typedef std::tuple<Ret...> type;
-};
-
-template<typename Ret>
-struct lua_return_type<Ret> {
-    typedef Ret type;
-};
-
-template<>
-struct lua_return_type<> {
-    typedef void type;
-};
-
-template<>
-struct lua_return_type<void> {
-    typedef void type;
-};
-
-template<typename Function, typename... Args>
-inline auto call(Function&& f, const std::tuple<Args...>& t) -> decltype(detail::call(std::forward<Function>(f), t, build_indices<sizeof...(Args)>{})) {
-    return call(std::forward<Function>(f), t, build_indices<sizeof...(Args)>{});
-}
-
-} // sol
-
-
-#endif // SOL_FUNCTIONAL_HPP
\ No newline at end of file
diff --git a/sol/lua_function.hpp b/sol/lua_function.hpp
index 5fc65538..89c56614 100644
--- a/sol/lua_function.hpp
+++ b/sol/lua_function.hpp
@@ -22,7 +22,6 @@
 #ifndef SOL_LUA_FUNC_HPP
 #define SOL_LUA_FUNC_HPP
 
-#include "functional.hpp"
 #include "stack.hpp"
 #include <memory>
 
@@ -62,7 +61,7 @@ void get_upvalue(lua_State* L, T& data, int& upvalue) {
 template<typename TFx>
 struct static_lua_func {
     typedef typename std::remove_pointer<typename std::decay<TFx>::type>::type fx_t;
-    typedef detail::function_traits<fx_t> fx_traits;
+    typedef function_traits<fx_t> fx_traits;
 
     template<typename... Args>
     static int typed_call(types<void>, types<Args...> t, fx_t* fx, lua_State* L) {
@@ -93,7 +92,7 @@ struct static_lua_func {
 template<typename T, typename TFx>
 struct static_object_lua_func {
     typedef typename std::decay<TFx>::type fx_t;
-    typedef detail::function_traits<fx_t> fx_traits;
+    typedef function_traits<fx_t> fx_traits;
 
     template<typename... Args>
     static int typed_call(types<void>, types<Args...>, T& item, fx_t& ifx, lua_State* L) {
@@ -173,7 +172,7 @@ struct lua_func {
 template<typename TFx>
 struct lambda_lua_func : public lua_func {
     typedef decltype(&TFx::operator()) fx_t;
-    typedef detail::function_traits<fx_t> fx_traits;
+    typedef function_traits<fx_t> fx_traits;
     TFx fx;
 
     template<typename... FxArgs>
@@ -200,7 +199,7 @@ struct lambda_lua_func : public lua_func {
 template<typename TFx, typename T = TFx, bool is_member_pointer = std::is_member_function_pointer<TFx>::value>
 struct explicit_lua_func : public lua_func {
     typedef typename std::remove_pointer<typename std::decay<TFx>::type>::type fx_t;
-    typedef detail::function_traits<fx_t> fx_traits;
+    typedef function_traits<fx_t> fx_traits;
     TFx fx;
 
     template<typename... FxArgs>
@@ -227,7 +226,7 @@ struct explicit_lua_func : public lua_func {
 template<typename TFx, typename T>
 struct explicit_lua_func<TFx, T, true> : public lua_func {
     typedef typename std::remove_pointer<typename std::decay<TFx>::type>::type fx_t;
-    typedef detail::function_traits<fx_t> fx_traits;
+    typedef function_traits<fx_t> fx_traits;
     struct lambda {
         T member;
         TFx invocation;
diff --git a/sol/table.hpp b/sol/table.hpp
index 3ea92e20..462bb34e 100644
--- a/sol/table.hpp
+++ b/sol/table.hpp
@@ -91,6 +91,30 @@ public:
         return lua_rawlen(state(), -1);
     }
 private:
+    template<typename T>
+    struct proxy {
+    private:
+        table& t;
+        T& key;
+    public:
+        proxy(table& t, T& key) : t(t), key(key) {}
+
+        template<typename U>
+        EnableIf<Function<Unqualified<U>>> operator=(U&& other) {
+            t.set_function(key, std::forward<U>(other));
+        }
+    
+        template<typename U>
+        DisableIf<Function<Unqualified<U>>> operator=(U&& other) {
+            t.set(key, std::forward<U>(other));
+        }
+
+        template<typename U>
+        operator U() const {
+            return t.get<U>(key);
+        }
+    };
+
     template<typename T, typename TFx>
     table& set_isfunction_fx(std::true_type, T&& key, TFx&& fx) {
         return set_fx(std::false_type(), std::forward<T>(key), std::forward<TFx>(fx));
@@ -99,7 +123,7 @@ private:
     template<typename T, typename TFx>
     table& set_isfunction_fx(std::false_type, T&& key, TFx&& fx) {
         typedef Decay<TFx> clean_lambda;
-        typedef typename detail::function_traits<decltype(&clean_lambda::operator())>::free_function_pointer_type raw_func_t;
+        typedef typename function_traits<decltype(&clean_lambda::operator())>::free_function_pointer_type raw_func_t;
         typedef std::is_convertible<clean_lambda, raw_func_t> isconvertible;
         return set_isconvertible_fx(isconvertible(), std::forward<T>(key), std::forward<TFx>(fx));
     }
@@ -107,7 +131,7 @@ private:
     template<typename T, typename TFx>
     table& set_isconvertible_fx(std::true_type, T&& key, TFx&& fx) {
         typedef Decay<TFx> clean_lambda;
-        typedef typename detail::function_traits<decltype(&clean_lambda::operator())>::free_function_pointer_type raw_func_t;
+        typedef typename function_traits<decltype(&clean_lambda::operator())>::free_function_pointer_type raw_func_t;
         return set_isfunction_fx(std::true_type(), std::forward<T>(key), raw_func_t(std::forward<TFx>(fx)));
     }
 
@@ -207,30 +231,6 @@ private:
         lua_pop(state(), 1);
         return *this;
     }
-
-    template<typename T>
-    struct proxy {
-    private:
-        table& t;
-        T& key;
-    public:
-        proxy(table& t, T& key): t(t), key(key) {}
-
-        template<typename U>
-        DisableIf<Function<Unqualified<U>>> operator=(U&& other) {
-            t.set(key, std::forward<U>(other));
-        }
-
-        template<typename U>
-        EnableIf<Function<Unqualified<U>>> operator=(U&& other) {
-            t.set_function(key, std::forward<U>(other));
-        }
-
-        template<typename U>
-        operator U() const {
-            return t.get<U>(key);
-        }
-    };
 };
 } // sol
 
diff --git a/sol/traits.hpp b/sol/traits.hpp
index 63f5b9be..9b998305 100644
--- a/sol/traits.hpp
+++ b/sol/traits.hpp
@@ -40,11 +40,11 @@ using Decay = typename std::decay<T>::type;
 namespace detail {
 // code borrowed from Gears 
 // https://github.com/Rapptz/Gears/
-template<typename T, typename = void>
+template<typename T, bool isclass = std::is_class<Unqualified<T>>::value>
 struct is_function_impl : std::is_function<typename std::remove_pointer<T>::type> {};
 
 template<typename T>
-struct is_function_impl<T, EnableIf<std::is_class<Unqualified<T>>>> {
+struct is_function_impl<T, true> {
     using yes = char;
     using no = struct { char s[2]; };
 
@@ -67,6 +67,65 @@ using Bool = std::integral_constant<bool, B>;
 
 template<typename T>
 struct Function : Bool<detail::is_function_impl<T>::value> {};
+
+template<typename TFuncSignature>
+struct function_traits;
+
+template<typename T, typename R, typename... Args>
+struct function_traits<R( T::* )( Args... )> {
+	static const std::size_t arity = sizeof...( Args );
+	static const bool is_member_function = true;
+	typedef std::tuple<Args...> arg_tuple_type;
+	typedef types<Args...> args_type;
+	typedef R( T::* function_pointer_type )( Args... );
+	typedef typename std::remove_pointer<function_pointer_type>::type function_type;
+	typedef R( *free_function_pointer_type )( Args... );
+	typedef R return_type;
+	template<std::size_t i>
+	using arg = typename std::tuple_element<i, arg_tuple_type>::type;
+};
+
+template<typename T, typename R, typename... Args>
+struct function_traits<R( T::* )( Args... ) const> {
+	static const std::size_t arity = sizeof...( Args );
+	static const bool is_member_function = true;
+	typedef std::tuple<Args...> arg_tuple_type;
+	typedef types<Args...> args_type;
+	typedef R( T::* function_pointer_type )( Args... );
+	typedef typename std::remove_pointer<function_pointer_type>::type function_type;
+	typedef R( *free_function_pointer_type )( Args... );
+	typedef R return_type;
+	template<std::size_t i>
+	using arg = typename std::tuple_element<i, arg_tuple_type>::type;
+};
+
+template<typename R, typename... Args>
+struct function_traits<R( Args... )> {
+	static const std::size_t arity = sizeof...( Args );
+	static const bool is_member_function = false;
+	typedef std::tuple<Args...> arg_tuple_type;
+	typedef types<Args...> args_type;
+	typedef R( function_type )( Args... );
+	typedef R( *function_pointer_type )( Args... );
+	typedef R( *free_function_pointer_type )( Args... );
+	typedef R return_type;
+	template<std::size_t i>
+	using arg = typename std::tuple_element<i, arg_tuple_type>::type;
+};
+
+template<typename R, typename... Args>
+struct function_traits<R( *)( Args... )> {
+	static const std::size_t arity = sizeof...( Args );
+	static const bool is_member_function = false;
+	typedef std::tuple<Args...> arg_tuple_type;
+	typedef types<Args...> args_type;
+	typedef R( function_type )( Args... );
+	typedef R( *function_pointer_type )( Args... );
+	typedef R( *free_function_pointer_type )( Args... );
+	typedef R return_type;
+	template<std::size_t i>
+	using arg = typename std::tuple_element<i, arg_tuple_type>::type;
+};
 } // sol
 
 #endif // SOL_TRAITS_HPP
\ No newline at end of file
diff --git a/tests.cpp b/tests.cpp
index 0ed2659a..10a57b80 100644
--- a/tests.cpp
+++ b/tests.cpp
@@ -165,7 +165,7 @@ TEST_CASE("tables/functions_variables", "Check if tables and function calls work
             std::cout << "stateless lambda()" << std::endl;
             return "test";
         }
-    );
+   );
     REQUIRE_NOTHROW(run_script(lua));
 
     lua.get<sol::table>("os").set_function("fun", &free_function);
@@ -183,7 +183,7 @@ TEST_CASE("tables/functions_variables", "Check if tables and function calls work
         std::cout << "stateless lambda()" << std::endl;
         return "test";
     }
-    );
+   );
     REQUIRE_NOTHROW(run_script(lua));
 
     // r-value, cannot optomize