From 2d14cedc174880fcb2f4338fcf599d9483497e2e Mon Sep 17 00:00:00 2001
From: ThePhD <phdofthehouse@gmail.com>
Date: Thu, 31 Mar 2016 12:12:04 -0400
Subject: [PATCH] Eat shit, `std::tuple`

---
 sol/coroutine.hpp                |  2 +-
 sol/function.hpp                 |  2 +-
 sol/function_types.hpp           |  2 +-
 sol/function_types_allocator.hpp |  2 +-
 sol/function_types_overload.hpp  |  6 +++---
 sol/function_types_usertype.hpp  |  6 ------
 sol/protected_function.hpp       |  2 +-
 sol/proxy_base.hpp               | 10 ++++++++--
 sol/stack_check.hpp              |  2 +-
 sol/stack_field.hpp              |  4 ++--
 sol/stack_get.hpp                |  2 +-
 sol/table_core.hpp               |  2 +-
 sol/traits.hpp                   | 15 +++++++++++++--
 sol/tuple.hpp                    |  2 +-
 14 files changed, 35 insertions(+), 24 deletions(-)

diff --git a/sol/coroutine.hpp b/sol/coroutine.hpp
index af81c008..535194ac 100644
--- a/sol/coroutine.hpp
+++ b/sol/coroutine.hpp
@@ -104,7 +104,7 @@ public:
     decltype(auto) call( Args&&... args ) {
         push();
         int pushcount = stack::multi_push( lua_state(), std::forward<Args>( args )... );
-        return invoke( types<Ret...>( ), std::index_sequence_for<Ret...>(), pushcount );
+        return invoke( types<Ret...>( ), std::make_index_sequence<sizeof...(Ret)>(), pushcount );
     }
 };
 }
diff --git a/sol/function.hpp b/sol/function.hpp
index 7e131622..2e67fb8e 100644
--- a/sol/function.hpp
+++ b/sol/function.hpp
@@ -81,7 +81,7 @@ public:
     decltype(auto) call( Args&&... args ) const {
         push( );
         int pushcount = stack::multi_push( lua_state( ), std::forward<Args>( args )... );
-        return invoke( types<Ret...>( ), std::index_sequence_for<Ret...>(), pushcount );
+        return invoke( types<Ret...>( ), std::make_index_sequence<sizeof...(Ret)>(), pushcount );
     }
 };
 
diff --git a/sol/function_types.hpp b/sol/function_types.hpp
index ef2e13d0..4531381e 100644
--- a/sol/function_types.hpp
+++ b/sol/function_types.hpp
@@ -204,7 +204,7 @@ struct pusher<function_arguments<T, Args...>> {
 
     template <typename FP>
     static int push(lua_State* L, FP&& fp) {
-        return push_func(std::index_sequence_for<Args...>(), L, std::forward<FP>(fp));
+        return push_func(std::make_index_sequence<sizeof...(Args)>(), L, std::forward<FP>(fp));
     }
 };
 
diff --git a/sol/function_types_allocator.hpp b/sol/function_types_allocator.hpp
index c42de8bf..922197a0 100644
--- a/sol/function_types_allocator.hpp
+++ b/sol/function_types_allocator.hpp
@@ -94,7 +94,7 @@ inline int destruct(lua_State* L) {
 template <typename T, typename... Functions>
 struct usertype_constructor_function : base_function {
     typedef std::tuple<Functions...> overload_list;
-    typedef std::index_sequence_for<Functions...> indices;
+    typedef std::make_index_sequence<sizeof...(Functions)> indices;
     overload_list overloads;
 
     usertype_constructor_function(overload_list set) : overloads(std::move(set)) {}
diff --git a/sol/function_types_overload.hpp b/sol/function_types_overload.hpp
index 78c40e16..e3f73cc0 100644
--- a/sol/function_types_overload.hpp
+++ b/sol/function_types_overload.hpp
@@ -66,7 +66,7 @@ inline int overload_match_arity(types<Fx, Fxs...>, std::index_sequence<I, In...>
 
 template <typename... Functions, typename Match, typename... Args>
 inline int overload_match_arity(Match&& matchfx, lua_State* L, int fxarity, int start, Args&&... args) {
-    return internals::overload_match_arity(types<Functions...>(), std::index_sequence_for<Functions...>(), std::index_sequence<>(), std::forward<Match>(matchfx), L, fxarity,  start, std::forward<Args>(args)...);
+    return internals::overload_match_arity(types<Functions...>(), std::make_index_sequence<sizeof...(Functions)>(), std::index_sequence<>(), std::forward<Match>(matchfx), L, fxarity,  start, std::forward<Args>(args)...);
 }
 
 template <typename... Functions, typename Match, typename... Args>
@@ -78,7 +78,7 @@ inline int overload_match(Match&& matchfx, lua_State* L, int start, Args&&... ar
 template <typename... Functions>
 struct overloaded_function : base_function {
     typedef std::tuple<Functions...> overload_list;
-    typedef std::index_sequence_for<Functions...> indices;
+    typedef std::make_index_sequence<sizeof...(Functions)> indices;
     overload_list overloads;
 
     overloaded_function(overload_list set)
@@ -104,7 +104,7 @@ struct overloaded_function : base_function {
 template <typename T, typename... Functions>
 struct usertype_overloaded_function : base_function {
     typedef std::tuple<functor<T, std::remove_pointer_t<std::decay_t<Functions>>>...> overload_list;
-    typedef std::index_sequence_for<Functions...> indices;
+    typedef std::make_index_sequence<sizeof...(Functions)> indices;
     overload_list overloads;
     
     usertype_overloaded_function(std::tuple<Functions...> set) : overloads(std::move(set)) {}
diff --git a/sol/function_types_usertype.hpp b/sol/function_types_usertype.hpp
index 2a2d3baf..67c84508 100644
--- a/sol/function_types_usertype.hpp
+++ b/sol/function_types_usertype.hpp
@@ -94,9 +94,6 @@ struct usertype_function : public usertype_function_core<Function, Tp> {
 
     int prelude(lua_State* L) {
         this->fx.item = detail::ptr(stack::get<T>(L, 1));
-        if(this->fx.item == nullptr) {
-            return luaL_error(L, "sol: userdata for function call is null: are you using the wrong syntax? (use item:function/variable(...) syntax)");
-        }
         return static_cast<base_t&>(*this)(meta::tuple_types<return_type>(), args_type(), Index<2>(), L);
     }
 
@@ -119,9 +116,6 @@ struct usertype_variable_function : public usertype_function_core<Function, Tp>
     int prelude(lua_State* L) {
         int argcount = lua_gettop(L);
         this->fx.item = stack::get<T*>(L, 1);
-        if(this->fx.item == nullptr) {
-            return luaL_error(L, "sol: userdata for member variable is null");
-        }
         switch(argcount) {
         case 2:
             return static_cast<base_t&>(*this)(meta::tuple_types<return_type>(), types<>(), Index<2>(), L);
diff --git a/sol/protected_function.hpp b/sol/protected_function.hpp
index aeb8d940..eb3a1a15 100644
--- a/sol/protected_function.hpp
+++ b/sol/protected_function.hpp
@@ -154,7 +154,7 @@ public:
         handler h(error_handler);
         push();
         int pushcount = stack::multi_push(lua_state(), std::forward<Args>(args)...);
-        return invoke(types<Ret...>(), std::index_sequence_for<Ret...>(), pushcount, h);
+        return invoke(types<Ret...>(), std::make_index_sequence<sizeof...(Ret)>(), pushcount, h);
     }
 };
 } // sol
diff --git a/sol/proxy_base.hpp b/sol/proxy_base.hpp
index 037a27fc..8e274f5a 100644
--- a/sol/proxy_base.hpp
+++ b/sol/proxy_base.hpp
@@ -34,13 +34,19 @@ struct proxy_base {
         return super.template get<std::string>();
     }
 
-    template<typename T, meta::EnableIf<meta::Not<meta::is_string_constructible<T>>, is_proxy_primitive<meta::Unqualified<T>>> = 0>
+    template <typename... Args>
+    operator std::tuple<Args...>() const {
+        const Super& super = *static_cast<const Super*>(static_cast<const void*>(this));
+	   return detail::forward_tuple(super.template get<std::tuple<Args...>>());
+    }
+
+    template<typename T, meta::EnableIf<meta::Not<meta::is_specialization_of<meta::Unqualified<T>, std::tuple>>, meta::Not<meta::is_string_constructible<T>>, is_proxy_primitive<meta::Unqualified<T>>> = 0>
     operator T ( ) const {
         const Super& super = *static_cast<const Super*>(static_cast<const void*>(this));
         return super.template get<T>( );
     }
 
-    template<typename T, meta::EnableIf<meta::Not<meta::is_string_constructible<T>>, meta::Not<is_proxy_primitive<meta::Unqualified<T>>>> = 0>
+    template<typename T, meta::EnableIf<meta::Not<meta::is_specialization_of<meta::Unqualified<T>, std::tuple>>, meta::Not<meta::is_string_constructible<T>>, meta::Not<is_proxy_primitive<meta::Unqualified<T>>>> = 0>
     operator T& ( ) const {
         const Super& super = *static_cast<const Super*>(static_cast<const void*>(this));
         return super.template get<T&>( );
diff --git a/sol/stack_check.hpp b/sol/stack_check.hpp
index eac0630a..8be8885a 100644
--- a/sol/stack_check.hpp
+++ b/sol/stack_check.hpp
@@ -273,7 +273,7 @@ struct checker<std::tuple<Args...>, type::poly, C> {
 
     template <typename Handler>
     static bool check(lua_State* L, int index, Handler&& handler) {
-        return apply(std::index_sequence_for<Args...>(), L, index, std::forward<Handler>(handler));
+        return apply(std::make_index_sequence<sizeof...(Args)>(), L, index, std::forward<Handler>(handler));
     }
 };
 
diff --git a/sol/stack_field.hpp b/sol/stack_field.hpp
index add7df2b..f31ae354 100644
--- a/sol/stack_field.hpp
+++ b/sol/stack_field.hpp
@@ -51,12 +51,12 @@ struct field_getter<std::tuple<Args...>, b, C> {
 
     template <typename Keys>
     void get(lua_State* L, Keys&& keys) {
-        apply(std::index_sequence_for<Args...>(), L, std::forward<Keys>(keys), lua_absindex(L, -1));
+        apply(std::make_index_sequence<sizeof...(Args)>(), L, std::forward<Keys>(keys), lua_absindex(L, -1));
     }
 
     template <typename Keys>
     void get(lua_State* L, Keys&& keys, int tableindex) {
-        apply(std::index_sequence_for<Args...>(), L, std::forward<Keys>(keys), tableindex);
+        apply(std::make_index_sequence<sizeof...(Args)>(), L, std::forward<Keys>(keys), tableindex);
     }
 };
 
diff --git a/sol/stack_get.hpp b/sol/stack_get.hpp
index 5143f025..e2a0c95b 100644
--- a/sol/stack_get.hpp
+++ b/sol/stack_get.hpp
@@ -249,7 +249,7 @@ struct getter<std::tuple<Args...>> {
     }
 
     static decltype(auto) get(lua_State* L, int index = -1) {
-        return apply(std::index_sequence_for<Args...>(), L, index);
+        return apply(std::make_index_sequence<sizeof...(Args)>(), L, index);
     }
 };
 
diff --git a/sol/table_core.hpp b/sol/table_core.hpp
index bc95cacb..f5c11ec3 100644
--- a/sol/table_core.hpp
+++ b/sol/table_core.hpp
@@ -175,7 +175,7 @@ public:
     decltype(auto) get( Keys&&... keys ) const {
         static_assert(sizeof...(Keys) == sizeof...(Ret), "number of keys and number of return types do not match");
 	   auto pp = stack::push_pop<is_global<Keys...>::value>(*this);
-	   return tuple_get( types<Ret...>( ), std::index_sequence_for<Ret...>( ), std::forward_as_tuple(std::forward<Keys>(keys)...));
+	   return tuple_get( types<Ret...>( ), std::make_index_sequence<sizeof...(Ret)>( ), std::forward_as_tuple(std::forward<Keys>(keys)...));
     }
 
     template<typename T, typename Key>
diff --git a/sol/traits.hpp b/sol/traits.hpp
index 55a79ecb..4124df3a 100644
--- a/sol/traits.hpp
+++ b/sol/traits.hpp
@@ -382,7 +382,7 @@ using is_c_str = Or<
 namespace meta_detail {
 template <typename T, meta::DisableIf<meta::is_specialization_of<meta::Unqualified<T>, std::tuple>> = 0>
 decltype(auto) force_tuple(T&& x) {
-    return std::forward_as_tuple(x);
+    return std::forward_as_tuple(std::forward<T>(x));
 }
 
 template <typename T, meta::EnableIf<meta::is_specialization_of<meta::Unqualified<T>, std::tuple>> = 0>
@@ -393,7 +393,7 @@ decltype(auto) force_tuple(T&& x) {
 
 template <typename... X>
 decltype(auto) tuplefy(X&&... x ) {
-    return std::tuple_cat(meta_detail::force_tuple(x)...);
+    return std::tuple_cat(meta_detail::force_tuple(std::forward<X>(x))...);
 }
 } // meta
 namespace detail {
@@ -402,6 +402,17 @@ decltype(auto) forward_get( Tuple&& tuple ) {
     return std::forward<meta::tuple_element_t<I, Tuple>>(std::get<I>(tuple));
 }
 
+template <std::size_t... I, typename Tuple>
+auto forward_tuple_impl( std::index_sequence<I...>, Tuple&& tuple ) -> decltype(std::tuple<decltype(forward_get<I>(tuple))...>(forward_get<I>(tuple)...)) {
+    return std::tuple<decltype(forward_get<I>(tuple))...>(std::move(std::get<I>(tuple))...);
+}
+
+template <typename Tuple>
+auto forward_tuple( Tuple&& tuple ) {
+    auto x = forward_tuple_impl(std::make_index_sequence<std::tuple_size<meta::Unqualified<Tuple>>::value>(), std::forward<Tuple>(tuple));
+    return x;
+}
+
 template<typename T>
 auto unwrap(T&& item) -> decltype(std::forward<T>(item)) {
     return std::forward<T>(item);
diff --git a/sol/tuple.hpp b/sol/tuple.hpp
index 5f2db93e..e91c2599 100644
--- a/sol/tuple.hpp
+++ b/sol/tuple.hpp
@@ -31,7 +31,7 @@ using swallow = std::initializer_list<int>;
 } // detail
 
 template<typename... Args>
-struct types { typedef std::index_sequence_for<Args...> indices; static constexpr std::size_t size() { return sizeof...(Args); } }; 
+struct types { typedef std::make_index_sequence<sizeof...(Args)> indices; static constexpr std::size_t size() { return sizeof...(Args); } }; 
 namespace meta {
 namespace detail {
 template<typename... Args>