From eb25bb05bb9b00215100488b573d61dacaa3a844 Mon Sep 17 00:00:00 2001
From: ThePhD <phdofthehouse@gmail.com>
Date: Sat, 28 Jun 2014 23:16:48 -0700
Subject: [PATCH] Overloaded functions now work properly when types are
 specified in signature this triggered overhaul of
 set_function/pusher<function_t>::push(...) both state and table reflect
 changes to userdata structure to make it easier to use tests updated to
 account for overload resolution some function-related traits added to make
 use easier -- cleaned up archaic typenames in function_types.hpp Account for
 std::reference_wrapper for objects -- sol now uses copy-by-default
 (value-semantics) for all functors updated tests to reflect this

---
 sol/function.hpp       | 139 +++++++++++++++++++-------------
 sol/function_types.hpp |  30 +++----
 sol/stack.hpp          |   9 ++-
 sol/state.hpp          |  53 ++++++++----
 sol/table.hpp          | 177 +++++++++++++----------------------------
 sol/traits.hpp         |  59 +++++++++++---
 sol/types.hpp          |   6 +-
 sol/userdata.hpp       | 144 +++++++++++++--------------------
 tests.cpp              |  68 +++++++++++++---
 9 files changed, 364 insertions(+), 321 deletions(-)

diff --git a/sol/function.hpp b/sol/function.hpp
index d81578c7..0edbf854 100644
--- a/sol/function.hpp
+++ b/sol/function.hpp
@@ -85,76 +85,112 @@ public:
 };
 
 namespace stack {
-template <>
-struct pusher<function_t> {
+template <typename... Sigs>
+struct pusher<function_sig_t<Sigs...>> {
 
-    template<typename TFx>
-    static void set_isfunction_fx(std::true_type, lua_State* L, TFx&& fx) {
-        set_fx(std::false_type(), L, std::forward<TFx>(fx));
+    template<typename R, typename... Args, typename Fx, typename = typename std::result_of<Fx(Args...)>::type>
+    static void set_memfx(types<R(Args...)> t, lua_State* L, Fx&& fx) {
+        typedef Decay<Unwrap<Fx>> raw_fx_t;
+        typedef R(* fx_ptr_t)(Args...);
+        typedef std::is_convertible<raw_fx_t, fx_ptr_t> is_convertible;
+        set_isconvertible_fx(is_convertible(), t, L, std::forward<Fx>(fx));
     }
 
-    template<typename TFx>
-    static void set_isfunction_fx(std::false_type, lua_State* L, TFx&& fx) {
-        typedef Decay<TFx> clean_lambda;
-        typedef typename function_traits<decltype(&clean_lambda::operator())>::free_function_pointer_type raw_func_t;
-        typedef std::is_convertible<clean_lambda, raw_func_t> is_convertible;
-        set_isconvertible_fx(is_convertible(), L, std::forward<TFx>(fx));
+    template<typename... Args, typename Fx, typename... Cx, typename R = typename std::result_of<Fx(Args...)>::type>
+    static void set_memfx(types<Args...>, lua_State* L, Fx&& fx){
+        set_memfx(types<R(Args...)>(), L, std::forward<Fx>(fx));
     }
 
-    template<typename TFx>
-    static void set_isconvertible_fx(std::true_type, lua_State* L, TFx&& fx) {
-        typedef Decay<TFx> clean_lambda;
-        typedef typename function_traits<decltype(&clean_lambda::operator())>::free_function_pointer_type raw_func_t;
-        set_isfunction_fx(std::true_type(), L, raw_func_t(std::forward<TFx>(fx)));
+    template<typename Fx>
+    static void set_memfx(types<>, lua_State* L, Fx&& fx) {
+        typedef Unqualified<Unwrap<Fx>> fx_t;
+        typedef decltype(&fx_t::operator()) Sig;
+        set_memfx(types<function_signature_t<Sig>>(), L, std::forward<Fx>(fx));
     }
 
-    template<typename TFx>
-    static void set_isconvertible_fx(std::false_type, lua_State* L, TFx&& fx) {
-        typedef typename std::remove_pointer<Decay<TFx>>::type clean_fx;
-        std::unique_ptr<base_function> sptr(new functor_function<clean_fx>(std::forward<TFx>(fx)));
-        set_fx<TFx>(L, std::move(sptr));
+    template<typename... Args, typename R>
+    static void set(lua_State* L, R fxptr(Args...)){
+        set_fx(std::false_type(), L, fxptr);
     }
 
-    template<typename TFx, typename TObj>
-    static void set_lvalue_fx(std::true_type, lua_State* L, TFx&& fx, TObj&& obj) {
-        set_fx(std::true_type(), L, std::forward<TFx>(fx), std::forward<TObj>(obj));
+    template<typename Sig>
+    static void set(lua_State* L, Sig* fxptr){
+       set_fx(std::false_type(), L, fxptr);
     }
 
-    template<typename TFx, typename TObj>
-    static void set_lvalue_fx(std::false_type, lua_State* L, TFx&& fx, TObj&& obj) {
-        typedef typename std::remove_pointer<Decay<TFx>>::type clean_fx;
-        std::unique_ptr<base_function> sptr(new member_function<clean_fx, TObj>(std::forward<TObj>(obj), std::forward<TFx>(fx)));
-        return set_fx<TFx>(L, std::move(sptr));
+    template<typename... Args, typename R, typename C, typename T>
+    static void set(lua_State* L, R (C::*memfxptr)(Args...), T&& obj) {
+        typedef Bool<is_specialization_of<T, std::reference_wrapper>::value || std::is_pointer<T>::value> is_reference;
+        set_reference_fx(is_reference(), L, memfxptr, std::forward<T>(obj));
     }
 
-    template<typename TFx, typename TObj>
-    static void set_fx(std::true_type, lua_State* L, TFx&& fx, TObj&& obj) {
+    template<typename Sig, typename C, typename T>
+    static void set(lua_State* L, Sig C::* memfxptr, T&& obj) {
+        typedef Bool<is_specialization_of<T, std::reference_wrapper>::value || std::is_pointer<T>::value> is_reference;
+        set_reference_fx(is_reference(), L, memfxptr, std::forward<T>(obj));
+    }
+
+    template<typename... Sig, typename Fx>
+    static void set(lua_State* L, Fx&& fx) {
+        set_memfx(types<Sig...>(), L, std::forward<Fx>(fx));
+    }
+
+    template<typename Fx, typename R, typename... Args>
+    static void set_isconvertible_fx(std::true_type, types<R(Args...)>, lua_State* L, Fx&& fx) {
+        typedef R(* fx_ptr_t)(Args...);
+        fx_ptr_t fxptr = unwrapper(std::forward<Fx>(fx));
+        set(L, fxptr);
+    }
+
+    template<typename Fx, typename R, typename... Args>
+    static void set_isconvertible_fx(std::false_type, types<R(Args...)>, lua_State* L, Fx&& fx) {
+        typedef Decay<Unwrap<Fx>> fx_t;
+        std::unique_ptr<base_function> sptr(new functor_function<fx_t>(std::forward<Fx>(fx)));
+        set_fx<Fx>(L, std::move(sptr));
+    }
+
+    template<typename Fx, typename T>
+    static void set_reference_fx(std::true_type, lua_State* L, Fx&& fx, T&& obj) {
+        set_fx(std::true_type(), L, std::forward<Fx>(fx), std::forward<T>(obj));
+    }
+
+    template<typename Fx, typename T>
+    static void set_reference_fx(std::false_type, lua_State* L, Fx&& fx, T&& obj) {
+        typedef typename std::remove_pointer<Decay<Fx>>::type clean_fx;
+        std::unique_ptr<base_function> sptr(new member_function<clean_fx, T>(std::forward<T>(obj), std::forward<Fx>(fx)));
+        return set_fx<Fx>(L, std::move(sptr));
+    }
+
+    template<typename Fx, typename T>
+    static void set_fx(std::true_type, lua_State* L, Fx&& fx, T&& obj) {
         // Layout:
         // idx 1...n: verbatim data of member function pointer
         // idx n + 1: is the object's void pointer
         // We don't need to store the size, because the other side is templated
         // with the same member function pointer type
-        Decay<TFx> fxptr(std::forward<TFx>(fx));
-        void* userobjdata = static_cast<void*>(sol::detail::get_ptr(obj));
-        lua_CFunction freefunc = &static_member_function<Decay<TObj>, TFx>::call;
+        Decay<Fx> memfxptr(std::forward<Fx>(fx));
+        auto userptr = sol::detail::get_ptr(obj);
+        void* userobjdata = static_cast<void*>(userptr);
+        lua_CFunction freefunc = &static_member_function<Decay<decltype(*userptr)>, Fx>::call;
 
-        int upvalues = stack::detail::push_as_upvalues(L, fxptr);
+        int upvalues = stack::detail::push_as_upvalues(L, memfxptr);
         stack::push(L, userobjdata);
-        stack::pusher<lua_CFunction>{}.push(L, freefunc, upvalues);
+        ++upvalues;
+        stack::push(L, freefunc, upvalues);
     }
 
-    template<typename TFx>
-    static void set_fx(lua_State* L, std::false_type, TFx&& fx) {
-        Decay<TFx> target(std::forward<TFx>(fx));
-        lua_CFunction freefunc = &static_function<TFx>::call;
+    template<typename Fx>
+    static void set_fx(std::false_type, lua_State* L, Fx&& fx) {
+        Decay<Fx> target(std::forward<Fx>(fx));
+        lua_CFunction freefunc = &static_function<Fx>::call;
 
         int upvalues = stack::detail::push_as_upvalues(L, target);
-        stack::pusher<lua_CFunction>{}.push(L, freefunc, upvalues);
+        stack::push(L, freefunc, upvalues);
     }
 
-    template<typename TFx>
+    template<typename Fx>
     static void set_fx(lua_State* L, std::unique_ptr<base_function> luafunc) {
-        auto&& metakey = userdata_traits<Unqualified<TFx>>::metatable;
+        auto&& metakey = userdata_traits<Unqualified<Fx>>::metatable;
         const char* metatablename = std::addressof(metakey[0]);
         base_function* target = luafunc.release();
         void* userdata = reinterpret_cast<void*>(target);
@@ -164,27 +200,16 @@ struct pusher<function_t> {
             lua_pushstring(L, "__gc");
             stack::push(L, &base_function::gc);
             lua_settable(L, -3);
+            lua_pop(L, 1);
         }
 
         stack::detail::push_userdata<void*>(L, metatablename, userdata);
-        stack::pusher<lua_CFunction>{}.push(L, freefunc, 1);
-    }
-
-    template<typename TFx>
-    static void set_function(lua_State* L, TFx&& fx) {
-        typedef typename std::remove_pointer<Decay<TFx>>::type clean_fx;
-        set_isfunction_fx(std::is_function<clean_fx>(), L, std::forward<TFx>(fx));
-    }
-
-    template<typename TFx, typename TObj>
-    static void set_function(lua_State* L, TFx&& fx, TObj&& obj) {
-        set_lvalue_fx(Bool<std::is_lvalue_reference<TObj>::value || std::is_pointer<TObj>::value>(),
-            L, std::forward<TFx>(fx), std::forward<TObj>(obj));
+        stack::push(L, freefunc, 1);
     }
 
     template <typename... Args>
     static void push(lua_State* L, Args&&... args) {
-        set_function(L, std::forward<Args>(args)...);
+        set(L, std::forward<Args>(args)...);
     }
 };
 
diff --git a/sol/function_types.hpp b/sol/function_types.hpp
index fb6b79b7..229e29ed 100644
--- a/sol/function_types.hpp
+++ b/sol/function_types.hpp
@@ -208,7 +208,8 @@ struct base_function {
 template<typename Function>
 struct functor_function : public base_function {
     typedef decltype(&Function::operator()) function_type;
-    typedef function_traits<function_type> traits_type;
+    typedef function_return_t<function_type> return_type;
+    typedef function_args_t<function_type> args_type;
     Function fx;
 
     template<typename... FxArgs>
@@ -229,7 +230,6 @@ struct functor_function : public base_function {
 
     template<typename... Ret, typename... Args>
     int operator()(types<Ret...>, types<Args...> t, lua_State* L) {
-        typedef typename return_type<Ret...>::type return_type;
         return_type r = stack::get_call(L, fx, t);
         std::ptrdiff_t nargs = sizeof...(Args);
         lua_pop(L, nargs);
@@ -238,29 +238,30 @@ struct functor_function : public base_function {
     }
 
     virtual int operator()(lua_State* L) override {
-        return (*this)(tuple_types<typename traits_type::return_type>(), typename traits_type::args_type(), L);
+        return (*this)(tuple_types<return_type>(), args_type(), L);
     }
 };
 
 template<typename Function, typename T>
 struct member_function : public base_function {
-    typedef typename std::remove_pointer<typename std::decay<Function>::type>::type function_type;
-    typedef function_traits<function_type> traits_type;
+    typedef typename std::remove_pointer<Decay<Function>>::type function_type;
+    typedef function_return_t<function_type> return_type;
+    typedef function_args_t<function_type> args_type;
     struct functor {
         T member;
         function_type invocation;
 
-        template<typename... FxArgs>
-        functor(T m, FxArgs&&... fxargs): member(std::move(m)), invocation(std::forward<FxArgs>(fxargs)...) {}
+        template<typename Tm, typename... FxArgs>
+        functor(Tm&& m, FxArgs&&... fxargs): member(std::forward<Tm>(m)), invocation(std::forward<FxArgs>(fxargs)...) {}
 
         template<typename... Args>
-        typename traits_type::return_type operator()(Args&&... args) {
+        return_type operator()(Args&&... args) {
            return (member.*invocation)(std::forward<Args>(args)...);
         }
     } fx;
 
-    template<typename... FxArgs>
-    member_function(T m, FxArgs&&... fxargs): fx(std::move(m), std::forward<FxArgs>(fxargs)...) {}
+    template<typename Tm, typename... FxArgs>
+    member_function(Tm&& m, FxArgs&&... fxargs): fx(std::forward<Tm>(m), std::forward<FxArgs>(fxargs)...) {}
 
     template<typename... Args>
     int operator()(types<void>, types<Args...> t, lua_State* L) {
@@ -275,7 +276,6 @@ struct member_function : public base_function {
 
     template<typename... Ret, typename... Args>
     int operator()(types<Ret...>, types<Args...> t, lua_State* L) {
-        typedef typename return_type<Ret...>::type return_type;
         return_type r = stack::get_call(L, fx, t);
         std::ptrdiff_t nargs = sizeof...(Args);
         lua_pop(L, nargs);
@@ -284,7 +284,7 @@ struct member_function : public base_function {
     }
 
     virtual int operator()(lua_State* L) override {
-        return (*this)(tuple_types<typename traits_type::return_type>(), typename traits_type::args_type(), L);
+        return (*this)(tuple_types<return_type>(), args_type(), L);
     }
 };
 
@@ -292,8 +292,8 @@ template<typename Function, typename Tp>
 struct userdata_function : public base_function {
     typedef typename std::remove_pointer<Tp>::type T;
     typedef typename std::remove_pointer<typename std::decay<Function>::type>::type function_type;
-    typedef function_traits<function_type> traits_type;
-    typedef typename traits_type::return_type return_type;
+    typedef function_args_t<function_type> args_type;
+    typedef function_return_t<function_type> return_type;
 
     detail::functor<T, function_type, return_type> fx;
 
@@ -347,7 +347,7 @@ struct userdata_function : public base_function {
         fx.item = detail::get_ptr(stack::get<Tp>(L, 1));
         if (fx.item == nullptr)
             throw error("userdata for function call is null: are you using wrong call syntax? (use item:function(...) synax)");
-        return (*this)(tuple_types<typename traits_type::return_type>(), typename traits_type::args_type(), L);
+        return (*this)(tuple_types<return_type>(), args_type(), L);
     }
 };
 
diff --git a/sol/stack.hpp b/sol/stack.hpp
index 884966b0..e1bcf429 100644
--- a/sol/stack.hpp
+++ b/sol/stack.hpp
@@ -39,6 +39,11 @@ inline T* get_ptr(T& val) {
     return std::addressof(val);
 }
 
+template<typename T>
+inline T* get_ptr(std::reference_wrapper<T> val) {
+    return std::addressof(val.get());
+}
+
 template<typename T>
 inline T* get_ptr(T* val) {
     return val;
@@ -310,8 +315,8 @@ inline void push(lua_State* L, T&& t, Args&&... args) {
 
 // overload allows to use a pusher of a specific type, but pass in any kind of args
 template<typename T, typename Arg, typename... Args>
-inline void push(lua_State* L, Arg&& t, Args&&... args) {
-    pusher<Unqualified<T>>{}.push(L, std::forward<T>(t), std::forward<Args>(args)...);
+inline void push(lua_State* L, Arg&& arg, Args&&... args) {
+    pusher<Unqualified<T>>{}.push(L, std::forward<Arg>(arg), std::forward<Args>(args)...);
 }
 
 inline void push_args(lua_State*) {
diff --git a/sol/state.hpp b/sol/state.hpp
index 2375d727..024f16ab 100644
--- a/sol/state.hpp
+++ b/sol/state.hpp
@@ -61,6 +61,10 @@ public:
         lua_atpanic(L.get(), detail::atpanic);
     }
 
+    lua_State* lua_state() const {
+        return L.get();
+    }
+
     template<typename... Args>
     void open_libraries(Args&&... args) {
         static_assert(are_same<lib, Args...>::value, "all types must be libraries");
@@ -133,21 +137,14 @@ public:
         return *this;
     }
 
-    template<typename T, typename TFx>
-    state& set_function(T&& key, TFx&& fx) {
-        global.set_function(std::forward<T>(key), std::forward<TFx>(fx));
-        return *this;
-    }
-
-    template<typename T, typename TFx, typename TObj>
-    state& set_function(T&& key, TFx&& fx, TObj&& obj) {
-        global.set_function(std::forward<T>(key), std::forward<TFx>(fx), std::forward<TObj>(obj));
-        return *this;
-    }
-
     template<typename T>
     state& set_userdata(userdata<T>& user) {
-        global.set_userdata(user);
+        return set_userdata(user.name(), user);
+    }
+
+    template<typename Key, typename T>
+    state& set_userdata(Key&& key, userdata<T>& user) {
+        global.set_userdata(std::forward<Key>(key), user);
         return *this;
     }
 
@@ -198,8 +195,34 @@ public:
         return global[std::forward<T>(key)];
     }
 
-    lua_State* lua_state() const {
-        return L.get();
+    template<typename... Args, typename R, typename Key>
+    state& set_function(Key&& key, R fun_ptr(Args...)){
+        global.set_function(std::forward<Key>(key), fun_ptr);
+        return *this;
+    }
+
+    template<typename Sig, typename Key>
+    state& set_function(Key&& key, Sig* fun_ptr){
+        global.set_function(std::forward<Key>(key), fun_ptr);
+        return *this;
+    }
+
+    template<typename... Args, typename R, typename C, typename T, typename Key>
+    state& set_function(Key&& key, R (C::*mem_ptr)(Args...), T&& obj) {
+        global.set_function(std::forward<Key>(key), mem_ptr, std::forward<T>(obj));
+        return *this;
+    }
+
+    template<typename Sig, typename C, typename T, typename Key>
+    state& set_function(Key&& key, Sig C::* mem_ptr, T&& obj) {
+        global.set_function(std::forward<Key>(key), mem_ptr, std::forward<T>(obj));
+        return *this;
+    }
+
+    template<typename... Sig, typename Fx, typename Key>
+    state& set_function(Key&& key, Fx&& fx) {
+        global.set_function<Sig...>(std::forward<Key>(key), std::forward<Fx>(fx));
+        return *this;
     }
 };
 } // sol
diff --git a/sol/table.hpp b/sol/table.hpp
index b739ed26..3506f3a2 100644
--- a/sol/table.hpp
+++ b/sol/table.hpp
@@ -83,23 +83,16 @@ public:
         return *this;
     }
 
-    template<typename T, typename TFx>
-    table& set_function(T&& key, TFx&& fx) {
-        typedef typename std::remove_pointer<Decay<TFx>>::type clean_fx;
-        return set_isfunction_fx(std::is_function<clean_fx>(), std::forward<T>(key), std::forward<TFx>(fx));
-    }
-
-    template<typename T, typename TFx, typename TObj>
-    table& set_function(T&& key, TFx&& fx, TObj&& obj) {
-        return set_lvalue_fx(Bool<std::is_lvalue_reference<TObj>::value || std::is_pointer<TObj>::value>(),
-            std::forward<T>(key), std::forward<TFx>(fx), std::forward<TObj>(obj));
-    }
-
     template<typename T>
-    table& set_userdata(userdata<T>& user) {     
-        stack::push(state(), user);
-        lua_setglobal(state(), user.name().c_str());
+    table& set_userdata(userdata<T>& user) {
+        return set_userdata(user.name(), user);
+    }
 
+    template<typename Key, typename T>
+    table& set_userdata(Key&& key, userdata<T>& user) {
+        std::string ukey(std::forward<Key>(key));
+        stack::push(state(), user);
+        lua_setglobal(state(), ukey.c_str());
         return *this;
     }
 
@@ -121,121 +114,63 @@ public:
     void pop(int n = 1) const noexcept {
         lua_pop(state(), n);
     }
+
+    template<typename... Args, typename R, typename Key>
+    table& set_function(Key&& key, R fun_ptr(Args...)){
+        set_resolved_function(std::forward<Key>(key), fun_ptr);
+        return *this;
+    }
+
+    template<typename Sig, typename Key>
+    table& set_function(Key&& key, Sig* fun_ptr){
+        set_resolved_function(std::forward<Key>(key), fun_ptr);
+        return *this;
+    }
+
+    template<typename... Args, typename R, typename C, typename T, typename Key>
+    table& set_function(Key&& key, R (C::*mem_ptr)(Args...), T&& obj) {
+        set_resolved_function(std::forward<Key>(key), mem_ptr, std::forward<T>(obj));
+        return *this;
+    }
+
+    template<typename Sig, typename C, typename T, typename Key>
+    table& set_function(Key&& key, Sig C::* mem_ptr, T&& obj) {
+        set_resolved_function(std::forward<Key>(key), mem_ptr, std::forward<T>(obj));
+        return *this;
+    }
+
+    template<typename... Sig, typename Fx, typename Key>
+    table& set_function(Key&& key, Fx&& fx) {
+        set_fx(types<Sig...>(), std::forward<Key>(key), std::forward<Fx>(fx));
+        return *this;
+    }
+
 private:
-    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));
+    template<typename R, typename... Args, typename Fx, typename Key, typename = typename std::result_of<Fx(Args...)>::type>
+    void set_fx(types<R(Args...)>, Key&& key, Fx&& fx) {
+        set_resolved_function<R(Args...)>(std::forward<Key>(key), std::forward<Fx>(fx));
     }
 
-    template<typename T, typename TFx>
-    table& set_isfunction_fx(std::false_type, T&& key, TFx&& fx) {
-        typedef Decay<TFx> clean_lambda;
-        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));
+    template<typename... Args, typename Fx, typename Key, typename R = typename std::result_of<Fx(Args...)>::type>
+    void set_fx(types<Args...>, Key&& key, Fx&& fx){
+        set_fx(types<R(Args...)>(), std::forward<Key>(key), std::forward<Fx>(fx));
     }
 
-    template<typename T, typename TFx>
-    table& set_isconvertible_fx(std::true_type, T&& key, TFx&& fx) {
-        typedef Decay<TFx> clean_lambda;
-        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)));
+    template<typename Fx, typename Key>
+    void set_fx(types<>, Key&& key, Fx&& fx) {
+        typedef Unqualified<Unwrap<Fx>> fx_t;
+        typedef decltype(&fx_t::operator()) Sig;
+        set_fx(types<function_signature_t<Sig>>(), std::forward<Key>(key), std::forward<Fx>(fx));
     }
 
-    template<typename T, typename TFx>
-    table& set_isconvertible_fx(std::false_type, T&& key, TFx&& fx) {
-        typedef typename std::remove_pointer<Decay<TFx>>::type clean_fx;
-        std::unique_ptr<base_function> sptr(new functor_function<clean_fx>(std::forward<TFx>(fx)));
-        return set_fx(std::forward<T>(key), std::move(sptr));
-    }
-
-    template<typename T, typename TFx, typename TObj>
-    table& set_lvalue_fx(std::true_type, T&& key, TFx&& fx, TObj&& obj) {
-        return set_fx(std::true_type(), std::forward<T>(key), std::forward<TFx>(fx), std::forward<TObj>(obj));
-    }
-
-    template<typename T, typename TFx, typename TObj>
-    table& set_lvalue_fx(std::false_type, T&& key, TFx&& fx, TObj&& obj) {
-        typedef typename std::remove_pointer<Decay<TFx>>::type clean_fx;
-        std::unique_ptr<base_function> sptr(new member_function<clean_fx, TObj>(std::forward<TObj>(obj), std::forward<TFx>(fx)));
-        return set_fx(std::forward<T>(key), std::move(sptr));
-    }
-
-    template<typename T, typename TFx, typename TObj>
-    table& set_fx(std::true_type, T&& key, TFx&& fx, TObj&& obj) {
-        std::string fkey(key);
-
-        // Layout:
-        // idx 1...n: verbatim data of member function pointer
-        // idx n + 1: is the object's void pointer
-        // We don't need to store the size, because the other side is templated
-        // with the same member function pointer type
-        Decay<TFx> fxptr(std::forward<TFx>(fx));
-        void* userobjdata = static_cast<void*>(detail::get_ptr(obj));
-        lua_CFunction freefunc = &static_member_function<Decay<TObj>, TFx>::call;
-        const char* freefuncname = fkey.c_str();
-        const luaL_Reg funcreg[2] = {
-            { freefuncname, freefunc },
-            { nullptr, nullptr }
-        };
-
-
+    template<typename... Sig, typename... Args, typename Key>
+    void set_resolved_function(Key&& key, Args&&... args) {
+        std::string fkey(std::forward<Key>(key));
         push();
-
-        int upvalues = stack::detail::push_as_upvalues(state(), fxptr);
-        stack::push(state(), userobjdata);
-        luaL_setfuncs(state(), funcreg, upvalues + 1);
-
+        int tabletarget = lua_gettop(state());
+        stack::push<function_sig_t<Sig...>>(state(), std::forward<Args>(args)...);
+        lua_setfield(state(), tabletarget, fkey.c_str());
         pop();
-        return *this;
-    }
-
-    template<typename T, typename TFx>
-    table& set_fx(std::false_type, T&& key, TFx&& fx) {
-        std::string fkey(key);
-        Decay<TFx> target(std::forward<TFx>(fx));
-        lua_CFunction freefunc = &static_function<TFx>::call;
-        const char* freefuncname = fkey.c_str();
-        const luaL_Reg funcreg[2] = {
-            { freefuncname, freefunc },
-            { nullptr, nullptr }
-        };
-
-        push();
-        int upvalues = stack::detail::push_as_upvalues(state(), target);
-        luaL_setfuncs(state(), funcreg, upvalues);
-        pop();
-
-        return *this;
-    }
-
-    template<typename T>
-    table& set_fx(T&& key, std::unique_ptr<base_function> luafunc) {
-        std::string fkey(key);
-        std::string metakey("sol.stateful.");
-        metakey += fkey;
-        metakey += ".meta";
-        base_function* target = luafunc.release();
-        void* userdata = reinterpret_cast<void*>(target);
-        lua_CFunction freefunc = &base_function::call;
-        const char* freefuncname = fkey.c_str();
-        const char* metatablename = metakey.c_str();
-        const luaL_Reg funcreg[2] = {
-            { freefuncname, freefunc },
-            { nullptr, nullptr }
-        };
-
-        if (luaL_newmetatable(state(), metatablename) == 1) {
-            lua_pushstring(state(), "__gc");
-            lua_pushcclosure(state(), &base_function::gc, 0);
-            lua_settable(state(), -3);
-        }
-
-        push();
-        stack::detail::push_userdata<void*>(state(), metatablename, userdata);
-        luaL_setfuncs(state(), funcreg, 1);
-        pop();
-        return *this;
     }
 };
 } // sol
diff --git a/sol/traits.hpp b/sol/traits.hpp
index 3de0af90..059774bb 100644
--- a/sol/traits.hpp
+++ b/sol/traits.hpp
@@ -24,11 +24,33 @@
 
 #include "tuple.hpp"
 #include <type_traits>
+#include <functional>
 
 namespace sol {
 template <typename T>
 struct identity { typedef T type; };
 
+template<typename... Args>
+struct is_tuple : std::false_type{ };
+
+template<typename... Args>
+struct is_tuple<std::tuple<Args...>> : std::true_type{ };
+
+template <typename T>
+struct unwrap {
+    typedef T type;
+};
+
+template <typename T>
+struct unwrap<std::reference_wrapper<T>> {
+    typedef typename std::add_lvalue_reference<T>::type type;
+};
+
+template <typename T, template <typename...> class Templ>
+struct is_specialization_of : std::false_type { };
+template <typename... T, template <typename...> class Templ>
+struct is_specialization_of<Templ<T...>, Templ> : std::true_type { };
+
 template<class T, class...>
 struct are_same : std::true_type { };
 
@@ -68,6 +90,9 @@ using Unqualified = typename std::remove_cv<typename std::remove_reference<T>::t
 template<typename T>
 using Decay = typename std::decay<T>::type;
 
+template <typename T>
+using Unwrap = typename unwrap<T>::type;
+
 template<typename... Args>
 struct return_type {
     typedef std::tuple<Args...> type;
@@ -83,17 +108,6 @@ struct return_type<> : types<>{
     typedef void type;
 };
 
-template<typename... Args>
-struct is_tuple : std::false_type{ };
-
-template<typename... Args>
-struct is_tuple<std::tuple<Args...>> : std::true_type{ };
-
-template <typename T, template <typename...> class Templ>
-struct is_specialization_of : std::false_type { };
-template <typename... T, template <typename...> class Templ>
-struct is_specialization_of<Templ<T...>, Templ> : std::true_type { };
-
 namespace detail {
 template<typename T, bool isclass = std::is_class<Unqualified<T>>::value>
 struct is_function_impl : std::is_function<typename std::remove_pointer<T>::type> {};
@@ -123,6 +137,15 @@ struct Function : Bool<detail::is_function_impl<T>::value> {};
 template<typename TFuncSignature>
 struct function_traits;
 
+template <typename TFuncSignature>
+using function_args_t = typename function_traits<TFuncSignature>::args_type;
+
+template <typename TFuncSignature>
+using function_signature_t = typename function_traits<TFuncSignature>::signature_type;
+
+template <typename TFuncSignature>
+using function_return_t = typename function_traits<TFuncSignature>::return_type;
+
 template<typename T, typename R, typename... Args>
 struct function_traits<R(T::*)(Args...)> {
     static const std::size_t arity = sizeof...(Args);
@@ -133,6 +156,7 @@ struct function_traits<R(T::*)(Args...)> {
     typedef typename std::remove_pointer<function_pointer_type>::type function_type;
     typedef R(*free_function_pointer_type)(Args...);
     typedef R return_type;
+    typedef typename std::remove_pointer<free_function_pointer_type>::type signature_type;
     template<std::size_t i>
     using arg = typename std::tuple_element<i, arg_tuple_type>::type;
 };
@@ -147,6 +171,7 @@ struct function_traits<R(T::*)(Args...) const> {
     typedef typename std::remove_pointer<function_pointer_type>::type function_type;
     typedef R(*free_function_pointer_type)(Args...);
     typedef R return_type;
+    typedef typename std::remove_pointer<free_function_pointer_type>::type signature_type;
     template<std::size_t i>
     using arg = typename std::tuple_element<i, arg_tuple_type>::type;
 };
@@ -161,6 +186,7 @@ struct function_traits<R(Args...)> {
     typedef R(*function_pointer_type)(Args...);
     typedef R(*free_function_pointer_type)(Args...);
     typedef R return_type;
+    typedef typename std::remove_pointer<free_function_pointer_type>::type signature_type;
     template<std::size_t i>
     using arg = typename std::tuple_element<i, arg_tuple_type>::type;
 };
@@ -175,6 +201,7 @@ struct function_traits<R(*)(Args...)> {
     typedef R(*function_pointer_type)(Args...);
     typedef R(*free_function_pointer_type)(Args...);
     typedef R return_type;
+    typedef typename std::remove_pointer<free_function_pointer_type>::type signature_type;
     template<std::size_t i>
     using arg = typename std::tuple_element<i, arg_tuple_type>::type;
 };
@@ -205,6 +232,16 @@ struct has_key_value_pair_impl {
 
 template<typename T>
 struct has_key_value_pair : decltype(has_key_value_pair_impl::test<T>(0)) {};
+
+template <typename T>
+auto unwrapper(T&& item) -> decltype(std::forward<T>(item)) {
+    return std::forward<T>(item);
+}
+
+template <typename Arg>
+Unwrap<Arg> unwrapper(std::reference_wrapper<Arg> arg) {
+    return arg.get();
+}
 } // sol
 
 #endif // SOL_TRAITS_HPP
diff --git a/sol/types.hpp b/sol/types.hpp
index dd644db9..45c21467 100644
--- a/sol/types.hpp
+++ b/sol/types.hpp
@@ -31,7 +31,11 @@ struct nil_t {};
 const nil_t nil {};
 struct void_type {};
 const void_type Void {};
-struct function_t {};
+
+template <typename... T>
+struct function_sig_t {};
+using function_t = function_sig_t<>;
+
 struct upvalue_t {
     void* value;
     upvalue_t(void* data) : value(data) {}
diff --git a/sol/userdata.hpp b/sol/userdata.hpp
index 42cd9b7b..6d18a7e4 100644
--- a/sol/userdata.hpp
+++ b/sol/userdata.hpp
@@ -108,6 +108,36 @@ private:
         }
     };
 
+    template <bool release = false, typename TCont>
+    static int push_upvalues (lua_State* L, TCont&& cont) {
+        int n = 0;
+        for (auto& c : cont) {
+            if (release)
+               stack::push<upvalue_t>(L, c.release());
+            else
+                stack::push<upvalue_t>(L, c.get());
+            ++n;
+        }
+        return n;
+    }
+
+    template <typename Meta, typename Funcs, typename FuncTable, typename MetaFuncs, typename MetaFuncTable>
+    static void push_metatable(lua_State* L, Meta&& meta, Funcs&& funcs, FuncTable&& functable, MetaFuncs&& metafuncs, MetaFuncTable&& metafunctable) {
+        luaL_newmetatable(L, std::addressof(meta[0]));
+        if (functable.size() > 1) {
+            // regular functions accessed through __index semantics
+            int up = push_upvalues(L, funcs);
+            luaL_setfuncs(L, functable.data(), up);
+        }
+        if (metafunctable.size() > 1) {
+            // meta functions
+            int up = push_upvalues(L, metafuncs);
+            luaL_setfuncs(L, metafunctable.data(), up);
+        }
+        lua_pushvalue(L, -1);
+        lua_setfield(L, -1, "__index");
+    }
+
     template<std::size_t N, std::size_t M>
     void build_function_tables() {}
 
@@ -177,49 +207,33 @@ public:
     userdata(const char* name, constructors<CArgs...> c, Args&&... args) :
         userdata(std::string(name), std::move(c), std::forward<Args>(args)...) {}
 
-    std::vector<std::string>& function_names () {
-        return functionnames;
-    }
-
-    std::vector<std::unique_ptr<base_function>>& functions () {
-        return funcs;
-    }
-
-    std::vector<std::unique_ptr<base_function>>& reference_functions () {
-        return ptrfuncs;
-    }
-
-    std::vector<std::unique_ptr<base_function>>& meta_functions () {
-        return metafuncs;
-    }
-
-    std::vector<std::unique_ptr<base_function>>& meta_reference_functions () {
-        return ptrmetafuncs;
-    }
-
-    std::vector<luaL_Reg>& function_table () {
-        return functiontable;
-    }
-
-    std::vector<luaL_Reg>& reference_function_table () {
-        return ptrfunctiontable;
-    }
-
-    std::vector<luaL_Reg>& meta_function_table () {
-        return metafunctiontable;
-    }
-
-    std::vector<luaL_Reg>& meta_reference_function_table () {
-        return ptrmetafunctiontable;
-    }
-
-    lua_CFunction cleanup_function () {
-        return cleanup;
-    }
-
     const std::string& name () const {
         return luaname;
     }
+
+    void push (lua_State* L) {
+        // push pointer tables first,
+        // but leave the regular T table on last so it can be linked to a type for usage with `.new(...)`
+        push_metatable(L, userdata_traits<T*>::metatable,
+                       ptrfuncs, ptrfunctiontable,
+                       ptrmetafuncs, ptrmetafunctiontable);
+        push_metatable(L, userdata_traits<T>::metatable,
+                       funcs, functiontable,
+                       metafuncs, metafunctiontable);
+        // Automatic deleter table -- stays alive until lua VM dies
+        // even if the user calls collectgarbage()
+        lua_createtable(L, 0, 0);
+        lua_createtable(L, 0, 1);
+        int up = push_upvalues<true>(L, funcs);
+        up += push_upvalues<true>(L, ptrfuncs);
+        up += push_upvalues<true>(L, metafuncs);
+        up += push_upvalues<true>(L, ptrmetafuncs);
+        lua_pushcclosure(L, cleanup, up);
+        lua_setfield(L, -2, "__gc");
+        lua_setmetatable(L, -2);
+        // gctable name by default has ♻ part of it
+        lua_setglobal(L, std::addressof(userdata_traits<T>::gctable[0]));
+    }
 };
 
 template <typename T>
@@ -248,56 +262,8 @@ const std::array<std::string, 19> userdata<T>::metafunctionnames = {
 namespace stack {
 template <typename T>
 struct pusher<userdata<T>> {
-    template <bool release = false, typename TCont>
-    static int push_upvalues (lua_State* L, TCont&& cont) {
-        int n = 0;
-        for (auto& c : cont) {
-            if (release)
-               stack::push<upvalue_t>(L, c.release());
-            else
-                stack::push<upvalue_t>(L, c.get());
-            ++n;
-        }
-        return n;
-    }
-
-    template <typename Meta, typename Funcs, typename FuncTable, typename MetaFuncs, typename MetaFuncTable>
-    static void push_metatable(lua_State* L, Meta&& meta, Funcs&& funcs, FuncTable&& functable, MetaFuncs&& metafuncs, MetaFuncTable&& metafunctable) {
-        luaL_newmetatable(L, std::addressof(meta[0]));
-        if (functable.size() > 1) {
-            // regular functions accessed through __index semantics
-            int up = push_upvalues(L, funcs);
-            luaL_setfuncs(L, functable.data(), up);
-        }
-        if (metafunctable.size() > 1) {
-            // meta functions
-            int up = push_upvalues(L, metafuncs);
-            luaL_setfuncs(L, metafunctable.data(), up);
-        }
-        lua_pushvalue(L, -1);
-        lua_setfield(L, -1, "__index");
-    }
-
     static void push (lua_State* L, userdata<T>& user) {
-        // push pointer tables first,
-        // but leave the regular T table on last so it can be linked to a type for usage with `.new(...)`
-        push_metatable(L, userdata_traits<T*>::metatable, user.reference_functions(), user.reference_function_table(), user.meta_reference_functions(), user.meta_reference_function_table());
-        push_metatable(L, userdata_traits<T>::metatable, user.functions(), user.function_table(), user.meta_functions(), user.meta_function_table());
-
-        // Automatic deleter table -- stays alive until lua VM dies
-        // even if the user calls collectgarbage()
-        auto cleanup = user.cleanup_function();
-        lua_createtable(L, 0, 0);
-        lua_createtable(L, 0, 1);
-        int up = push_upvalues<true>(L, user.functions());
-        up += push_upvalues<true>(L, user.reference_functions());
-        up += push_upvalues<true>(L, user.meta_functions());
-        up += push_upvalues<true>(L, user.meta_reference_functions());
-        lua_pushcclosure(L, cleanup, up);
-        lua_setfield(L, -2, "__gc");
-        lua_setmetatable(L, -2);
-        // gctable name by default has ♻ part of it
-        lua_setglobal(L, std::addressof(userdata_traits<T>::gctable[0]));
+        user.push(L);
     }
 };
 } // stack
diff --git a/tests.cpp b/tests.cpp
index 3b13444b..7df28912 100644
--- a/tests.cpp
+++ b/tests.cpp
@@ -31,6 +31,26 @@ std::string free_function() {
     return "test";
 }
 
+int overloaded(int x) {
+    std::cout << x << std::endl;
+    return 3;
+}
+
+int overloaded(int x, int y) {
+    std::cout << x << " " << y << std::endl;
+    return 7;
+}
+
+int overloaded(int x, int y, int z) {
+    std::cout << x << " " << y << " " << z << std::endl;
+    return 11;
+}
+
+int non_overloaded(int x, int y, int z) {
+    std::cout << x << " " << y << " " << z << std::endl;
+    return 13;
+}
+
 std::vector<int> test_table_return_one() {
     return { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
 }
@@ -332,25 +352,33 @@ 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);
     REQUIRE_NOTHROW(run_script(lua));
 
-    // l-value, can optimise
+    // l-value, canNOT optimise
+    // prefer value semantics unless wrapped with std::reference_wrapper
+    {
     auto lval = object();
     lua.get<sol::table>("os").set_function("fun", &object::operator(), lval);
+    }
     REQUIRE_NOTHROW(run_script(lua));
 
+    auto reflval = object();
+    lua.get<sol::table>("os").set_function("fun", &object::operator(), std::ref(reflval));
+    REQUIRE_NOTHROW(run_script(lua));
+
+
     // stateful lambda: non-convertible, cannot be optimised
     int breakit = 50;
     lua.get<sol::table>("os").set_function("fun",
         [&breakit] () {
-        std::cout << "stateless lambda()" << std::endl;
-        return "test";
-    }
-);
+            std::cout << "stateful lambda()" << std::endl;
+            return "test";
+        }
+    );
     REQUIRE_NOTHROW(run_script(lua));
 
     // r-value, cannot optimise
@@ -363,6 +391,26 @@ TEST_CASE("tables/functions_variables", "Check if tables and function calls work
     REQUIRE_NOTHROW(run_script(lua));
 }
 
+TEST_CASE("functions/overloaded", "Check if overloaded function resolution templates compile/work") {
+    sol::state lua;
+	lua.open_libraries(sol::lib::base);
+
+    lua.set_function("non_overloaded", non_overloaded);
+    REQUIRE_NOTHROW(lua.script("x = non_overloaded(1)\nprint(x)"));
+
+    lua.set_function<int>("overloaded", overloaded);
+    REQUIRE_NOTHROW(lua.script("print(overloaded(1))"));
+
+    lua.set_function<int, int>("overloaded", overloaded);
+    REQUIRE_NOTHROW(lua.script("print(overloaded(1, 2))"));
+
+    lua.set_function<int(int, int)>("overloaded", overloaded);
+    REQUIRE_NOTHROW(lua.script("print(overloaded(1, 2))"));
+
+    lua.set_function<int, int, int>("overloaded", overloaded);
+    REQUIRE_NOTHROW(lua.script("print(overloaded(1, 2, 3))"));
+}
+
 TEST_CASE("functions/return_order_and_multi_get", "Check if return order is in the same reading order specified in Lua") {
     const static std::tuple<int, int, int> triple = std::make_tuple(10, 11, 12);
     sol::state lua;
@@ -730,10 +778,10 @@ TEST_CASE("userdata/lua-stored-userdata", "ensure userdata values can be stored
         // userdata dies, but still usable in lua!
     }
 
-	lua.script("collectgarbage()\n"
+	REQUIRE_NOTHROW(lua.script("collectgarbage()\n"
                 "v = Vec.new(1, 2, 3)\n"
-                "print(v:length())");
+                "print(v:length())"));
 
-	lua.script("v = Vec.new(1, 2, 3)\n"
-                "print(v:normalized():length())" );
+	REQUIRE_NOTHROW(lua.script("v = Vec.new(1, 2, 3)\n"
+                "print(v:normalized():length())" ));
 }