From 8ef3ceb8a00c3c7d538414948867a362e4204dec Mon Sep 17 00:00:00 2001
From: ThePhD <phdofthehouse@gmail.com>
Date: Sun, 15 Dec 2013 16:27:20 -0500
Subject: [PATCH] New test cases for the order of returns. Apparently, its
 screwing up between both lua and C++. Have to test thoroughly. Changes
 currently are half-working.

---
 sol/function.hpp     |  2 +-
 sol/lua_function.hpp | 69 +++++++++++++++++++++++++++++---------------
 sol/stack.hpp        | 35 +++++++++++++++++++++-
 sol/tuple.hpp        | 11 ++++++-
 tests.cpp            | 15 ++++++++++
 5 files changed, 105 insertions(+), 27 deletions(-)

diff --git a/sol/function.hpp b/sol/function.hpp
index 1f60a257..aac52037 100644
--- a/sol/function.hpp
+++ b/sol/function.hpp
@@ -36,7 +36,7 @@ private:
     template<typename... Ret>
     std::tuple<Ret...> invoke(types<Ret...>, std::size_t n) {
         luacall(n, sizeof...(Ret));
-        return stack::pop_call(state(), std::make_tuple<Ret...>, types<Ret...>());
+        return stack::pop_reverse_call(state(), std::make_tuple<Ret...>, types<Ret...>());
     }
 
     template<typename Ret>
diff --git a/sol/lua_function.hpp b/sol/lua_function.hpp
index 89c56614..0d278f7b 100644
--- a/sol/lua_function.hpp
+++ b/sol/lua_function.hpp
@@ -62,6 +62,11 @@ template<typename TFx>
 struct static_lua_func {
     typedef typename std::remove_pointer<typename std::decay<TFx>::type>::type fx_t;
     typedef function_traits<fx_t> fx_traits;
+    
+    template<typename... Args>
+    static int typed_call(types<>, types<Args...> t, fx_t* fx, lua_State* L) {
+        return (*this)(types<void>(), t, fx, L);
+    }
 
     template<typename... Args>
     static int typed_call(types<void>, types<Args...> t, fx_t* fx, lua_State* L) {
@@ -69,11 +74,11 @@ struct static_lua_func {
         return 0;
     }
 
-    template<typename... TRn, typename... Args>
-    static int typed_call(types<TRn...>, types<Args...> t, fx_t* fx, lua_State* L) {
+    template<typename... Ret, typename... Args>
+    static int typed_call(types<Ret...>, types<Args...> t, fx_t* fx, lua_State* L) {
         auto r = stack::pop_call(L, fx, t);
-        stack::push(L, std::move(r));
-        return sizeof...(TRn);
+        stack::push_reverse(L, std::move(r));
+        return sizeof...(Ret);
     }
 
     static int call(lua_State* L) {
@@ -101,9 +106,9 @@ struct static_object_lua_func {
         return 0;
     }
 
-    template<typename TR, typename... Args>
-    static int typed_call(types<TR>, types<Args...>, T& item, fx_t& ifx, lua_State* L) {
-        auto fx = [&item, &ifx](Args&&... args) -> TR { 
+    template<typename Ret, typename... Args>
+    static int typed_call(types<Ret>, types<Args...>, T& item, fx_t& ifx, lua_State* L) {
+        auto fx = [&item, &ifx](Args&&... args) -> Ret { 
            return (item.*ifx)(std::forward<Args>(args)...); 
         };
         auto r = stack::pop_call(L, fx, types<Args...>());
@@ -111,12 +116,12 @@ struct static_object_lua_func {
         return 1;
     }
 
-    template<typename... TRn, typename... Args>
-    static int typed_call(types<TRn...>, types<Args...>, T& item, fx_t& ifx, lua_State* L) {
-        auto fx = [&item, &ifx](Args&&... args) -> std::tuple<TRn...> { return (item.*ifx)(std::forward<Args>(args)...); };
+    template<typename... Ret, typename... Args>
+    static int typed_call(types<Ret...>, types<Args...>, T& item, fx_t& ifx, lua_State* L) {
+        auto fx = [&item, &ifx](Args&&... args) -> std::tuple<Ret...> { return (item.*ifx)(std::forward<Args>(args)...); };
         auto r = stack::pop_call(L, fx, types<Args...>());
-        stack::push(L, std::move(r));
-        return sizeof...(TRn);
+        stack::push_reverse(L, std::move(r));
+        return sizeof...(Ret);
     }
 
     static int call(lua_State* L) {
@@ -182,17 +187,23 @@ struct lambda_lua_func : public lua_func {
         return (*this)(tuple_types<typename fx_traits::return_type>(), typename fx_traits::args_type(), L);
     }
 
+    template<typename... Args>
+    int operator()(types<>, types<Args...> t, lua_State* L) {
+        stack::pop_call(L, fx, t);
+        return 0;
+    }
+
     template<typename... Args>
     int operator()(types<void>, types<Args...> t, lua_State* L) {
         stack::pop_call(L, fx, t);
         return 0;
     }
 
-    template<typename... TRn, typename... Args>
-    int operator()(types<TRn...>, types<Args...> t, lua_State* L) {
+    template<typename... Ret, typename... Args>
+    int operator()(types<Ret...>, types<Args...> t, lua_State* L) {
         auto r = stack::pop_call(L, fx, t);
-        stack::push(L, r);
-        return sizeof...(TRn);
+        stack::push_reverse(L, r);
+        return sizeof...(Ret);
     }
 };
 
@@ -209,17 +220,22 @@ struct explicit_lua_func : public lua_func {
         return (*this)(tuple_types<typename fx_traits::return_type>(), typename fx_traits::args_type(), L);
     }
 
+    template<typename... Args>
+    int operator()(types<>, types<Args...> t, lua_State* L) {
+        return (*this)(types<void>(), t, L);
+    }
+
     template<typename... Args>
     int operator()(types<void>, types<Args...> t, lua_State* L) {
         stack::pop_call(L, fx, t);
         return 0;
     }
 
-    template<typename... TRn, typename... Args>
-    int operator()(types<TRn...>, types<Args...> t, lua_State* L) {
+    template<typename... Ret, typename... Args>
+    int operator()(types<Ret...>, types<Args...> t, lua_State* L) {
         auto r = stack::pop_call(L, fx, t);
-        stack::push(L, std::move(r));
-        return sizeof...(TRn);
+        stack::push_reverse(L, std::move(r));
+        return sizeof...(Ret);
     }
 };
 
@@ -247,17 +263,22 @@ struct explicit_lua_func<TFx, T, true> : public lua_func {
         return (*this)(tuple_types<typename fx_traits::return_type>(), typename fx_traits::args_type(), L);
     }
 
+    template<typename... Args>
+    int operator()(types<>, types<Args...> t, lua_State* L) {
+        return (*this)(types<void>(), t, L);
+    }
+
     template<typename... Args>
     int operator()(types<void>, types<Args...> t, lua_State* L) {
         stack::pop_call(L, fx, t);
         return 0;
     }
 
-    template<typename... TRn, typename... Args>
-    int operator()(types<TRn...>, types<Args...> t, lua_State* L) {
+    template<typename... Ret, typename... Args>
+    int operator()(types<Ret...>, types<Args...> t, lua_State* L) {
         auto r = stack::pop_call(L, fx, t);
-        stack::push(L, r);
-        return sizeof...(TRn);
+        stack::push_reverse(L, r);
+        return sizeof...(Ret);
     }
 };
 
diff --git a/sol/stack.hpp b/sol/stack.hpp
index 782bd98d..a0c5c230 100644
--- a/sol/stack.hpp
+++ b/sol/stack.hpp
@@ -224,15 +224,43 @@ template<typename F, typename Head, typename... Tail, typename... Vs>
 auto ltr_pop(lua_State* L, F&& f, types<Head, Tail...>, Vs&&... vs) -> decltype(f(std::forward<Vs>(vs)..., std::declval<Head>(), std::declval<Tail>()...)) {
     return ltr_pop(L, std::forward<F>(f), types<Tail...>(), std::forward<Vs>(vs)..., pop<Head>(L));
 }
+
+template<typename F, typename... Vs>
+auto rtl_pop(lua_State*, F&& f, types<>, Vs&&... vs) -> decltype(f(std::forward<Vs>(vs)...)) {
+    return f(std::forward<Vs>(vs)...);
+}
+template<typename F, typename Head, typename... Vs>
+auto rtl_pop(lua_State* L, F&& f, types<Head>, Vs&&... vs) -> decltype(rtl_pop(L, std::forward<F>(f), types<>(), pop<Head>(L), std::forward<Vs>(vs)...)) {
+    return rtl_pop(L, std::forward<F>(f), types<>(), pop<Head>(L), std::forward<Vs>(vs)...);
+}
+template<typename F, typename Head, typename... Tail, typename... Vs>
+auto rtl_pop(lua_State* L, F&& f, types<Head, Tail...>, Vs&&... vs) -> decltype(rtl_pop(L, std::forward<F>(f), types<Tail...>(), pop<Head>(L), std::forward<Vs>(vs)...)) {
+	return rtl_pop(L, std::forward<F>(f), types<Tail...>(), pop<Head>(L), std::forward<Vs>(vs)...);
+}
 } // detail
 
 template<typename... Args>
 inline void push(lua_State* L, const std::tuple<Args...>& tuplen) {
-    detail::push_tuple(L, build_reverse_indices<sizeof...(Args)>(), tuplen);
+    detail::push_tuple(L, build_indices<sizeof...(Args)>(), tuplen);
 }
 
 template<typename... Args>
 inline void push(lua_State* L, std::tuple<Args...>&& tuplen) {
+    detail::push_tuple(L, build_indices<sizeof...(Args)>(), std::move(tuplen));
+}
+
+template<typename T>
+inline void push_reverse(lua_State* L, T&& item) {
+    push(L, std::forward<T>(item));
+}
+
+template<typename... Args>
+inline void push_reverse(lua_State* L, const std::tuple<Args...>& tuplen) {
+    detail::push_tuple(L, build_reverse_indices<sizeof...(Args)>(), tuplen);
+}
+
+template<typename... Args>
+inline void push_reverse(lua_State* L, std::tuple<Args...>&& tuplen) {
     detail::push_tuple(L, build_reverse_indices<sizeof...(Args)>(), std::move(tuplen));
 }
 
@@ -241,6 +269,11 @@ inline auto pop_call(lua_State* L, TFx&& fx, types<Args...>) -> decltype(detail:
     return detail::ltr_pop(L, std::forward<TFx>(fx), types<Args...>());
 }
 
+template<typename... Args, typename TFx>
+inline auto pop_reverse_call(lua_State* L, TFx&& fx, types<Args...>) -> decltype(detail::rtl_pop(L, std::forward<TFx>(fx), types<Args...>())) {
+    return detail::rtl_pop(L, std::forward<TFx>(fx), reversed<Args...>());
+}
+
 void push_args(lua_State*) {
 
 }
diff --git a/sol/tuple.hpp b/sol/tuple.hpp
index 31285b04..cecaa3e8 100644
--- a/sol/tuple.hpp
+++ b/sol/tuple.hpp
@@ -57,7 +57,16 @@ template<size_t... Ns>
 struct build_reverse_indices<0, Ns...> : indices<Ns...> {};
 
 template<typename... Args>
-struct types : build_indices<sizeof...(Args)> {};
+struct types : build_indices<sizeof...(Args)> { typedef types type; };
+
+template<class Acc, class... Args>
+struct reversed_ : Acc{};
+ 
+template<typename... RArgs, typename Arg, typename... Args>
+struct reversed_<types<RArgs...>, Arg, Args...> : reversed_<types<Arg, RArgs...>, Args...>{};
+ 
+template<typename... Args>
+struct reversed : reversed_<types<>, Args...>{};
 
 template<typename... Args>
 struct tuple_types : types<Args...>, std::false_type {};
diff --git a/tests.cpp b/tests.cpp
index 5b020278..d9749f9b 100644
--- a/tests.cpp
+++ b/tests.cpp
@@ -220,6 +220,21 @@ TEST_CASE("tables/functions_variables", "Check if tables and function calls work
     REQUIRE_NOTHROW(run_script(lua));
 }
 
+TEST_CASE("functions/return _order", "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;
+    lua.set_function( "f", [ ] { 
+	    return std::make_tuple( 10, 11, 12 ); 
+    } );
+    lua.script( "function g() return 10, 11, 12 end" );
+    auto tcpp = lua.get<sol::function>( "f" ).call<int, int, int>( );
+    auto tlua = lua.get<sol::function>( "g" ).call<int, int, int>( );
+    std::cout << std::get<0>( tcpp ) << ',' << std::get<1>( tcpp ) << ',' << std::get<2>( tcpp ) << std::endl;
+    std::cout << std::get<0>( tlua ) << ',' << std::get<1>( tlua ) << ',' << std::get<2>( tlua ) << std::endl;
+    REQUIRE( tcpp == triple );
+    REQUIRE( tlua == triple );
+}
+
 TEST_CASE("tables/operator[]", "Check if operator[] retrieval and setting works properly") {
     sol::state lua;
     lua.open_libraries(sol::lib::base);