diff --git a/single/sol/sol.hpp b/single/sol/sol.hpp
index cf0f4138..9640bd3e 100644
--- a/single/sol/sol.hpp
+++ b/single/sol/sol.hpp
@@ -20,8 +20,8 @@
 // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 // This file was generated with a script.
-// Generated 2016-12-10 04:29:58.120585 UTC
-// This header was generated with sol v2.15.5 (revision c6110e5)
+// Generated 2016-12-10 10:55:55.463053 UTC
+// This header was generated with sol v2.15.5 (revision f4f3bff)
 // https://github.com/ThePhD/sol2
 
 #ifndef SOL_SINGLE_INCLUDE_HPP
@@ -4003,6 +4003,8 @@ namespace sol {
 		basic_userdata& operator=(basic_userdata&&) = default;
 		basic_userdata(const stack_reference& r) : basic_userdata(r.lua_state(), r.stack_index()) {}
 		basic_userdata(stack_reference&& r) : basic_userdata(r.lua_state(), r.stack_index()) {}
+		template <typename T, meta::enable<meta::neg<std::is_integral<meta::unqualified_t<T>>>, meta::neg<std::is_same<T, ref_index>>> = meta::enabler>
+		basic_userdata(lua_State* L, T&& r) : basic_userdata(L, sol::ref_index(r.registry_index())) {}
 		basic_userdata(lua_State* L, int index = -1) : base_t(L, index) {
 #ifdef SOL_CHECK_ARGUMENTS
 			type_assert(L, index, type::userdata);
@@ -4035,6 +4037,8 @@ namespace sol {
 		basic_lightuserdata& operator=(basic_lightuserdata&&) = default;
 		basic_lightuserdata(const stack_reference& r) : basic_lightuserdata(r.lua_state(), r.stack_index()) {}
 		basic_lightuserdata(stack_reference&& r) : basic_lightuserdata(r.lua_state(), r.stack_index()) {}
+		template <typename T, meta::enable<meta::neg<std::is_integral<meta::unqualified_t<T>>>, meta::neg<std::is_same<T, ref_index>>> = meta::enabler>
+		basic_lightuserdata(lua_State* L, T&& r) : basic_lightuserdata(L, sol::ref_index(r.registry_index())) {}
 		basic_lightuserdata(lua_State* L, int index = -1) : base_t(L, index) {
 #ifdef SOL_CHECK_ARGUMENTS
 			type_assert(L, index, type::lightuserdata);
@@ -9008,6 +9012,8 @@ namespace sol {
 		basic_function& operator=(basic_function&&) = default;
 		basic_function(const stack_reference& r) : basic_function(r.lua_state(), r.stack_index()) {}
 		basic_function(stack_reference&& r) : basic_function(r.lua_state(), r.stack_index()) {}
+		template <typename T, meta::enable<meta::neg<std::is_integral<meta::unqualified_t<T>>>, meta::neg<std::is_same<T, ref_index>>> = meta::enabler>
+		basic_function(lua_State* L, T&& r) : basic_function(L, sol::ref_index(r.registry_index())) {}
 		basic_function(lua_State* L, int index = -1) : base_t(L, index) {
 #ifdef SOL_CHECK_ARGUMENTS
 			stack::check<basic_function>(L, index, type_panic);
@@ -9323,6 +9329,8 @@ namespace sol {
 		basic_protected_function(proxy_base<Super>&& p, reference eh = get_default_handler()) : basic_protected_function(p.operator basic_function<base_t>(), std::move(eh)) {}
 		template <typename Super>
 		basic_protected_function(const proxy_base<Super>& p, reference eh = get_default_handler()) : basic_protected_function(static_cast<basic_function<base_t>>(p), std::move(eh)) {}
+		template <typename T, meta::enable<meta::neg<std::is_integral<meta::unqualified_t<T>>>, meta::neg<std::is_same<T, ref_index>>> = meta::enabler>
+		basic_protected_function(lua_State* L, T&& r, reference eh) : basic_protected_function(L, sol::ref_index(r.registry_index()), std::move(eh)) {}
 		basic_protected_function(lua_State* L, int index = -1, reference eh = get_default_handler()) : base_t(L, index), error_handler(std::move(eh)) {
 #ifdef SOL_CHECK_ARGUMENTS
 			stack::check<basic_protected_function>(L, index, type_panic);
@@ -11869,6 +11877,8 @@ namespace sol {
 		basic_table_core& operator=(basic_table_core&&) = default;
 		basic_table_core(const stack_reference& r) : basic_table_core(r.lua_state(), r.stack_index()) {}
 		basic_table_core(stack_reference&& r) : basic_table_core(r.lua_state(), r.stack_index()) {}
+		template <typename T, meta::enable<meta::neg<std::is_integral<meta::unqualified_t<T>>>, meta::neg<std::is_same<T, ref_index>>> = meta::enabler>
+		basic_table_core(lua_State* L, T&& r) : basic_table_core(L, sol::ref_index(r.registry_index())) {}
 		basic_table_core(lua_State* L, int index = -1) : base_t(L, index) {
 #ifdef SOL_CHECK_ARGUMENTS
 			stack::check<basic_table_core>(L, index, type_panic);
@@ -12856,7 +12866,7 @@ namespace sol {
 	}
 
 #if SOL_LUA_VERSION < 502
-	inline lua_State* main_thread(lua_State* L, lua_State* backup_if_unsupported = nullptr) {
+	inline lua_State* main_thread(lua_State*, lua_State* backup_if_unsupported = nullptr) {
 		return backup_if_unsupported;
 	}
 #else
@@ -12878,6 +12888,8 @@ namespace sol {
 		thread(stack_reference&& r) : thread(r.lua_state(), r.stack_index()) {};
 		thread& operator=(const thread&) = default;
 		thread& operator=(thread&&) = default;
+		template <typename T, meta::enable<meta::neg<std::is_integral<meta::unqualified_t<T>>>, meta::neg<std::is_same<T, ref_index>>> = meta::enabler>
+		thread(lua_State* L, T&& r) : thread(L, sol::ref_index(r.registry_index())) {}
 		thread(lua_State* L, int index = -1) : reference(L, index) {
 #ifdef SOL_CHECK_ARGUMENTS
 			type_assert(L, index, type::thread);
@@ -12992,6 +13004,8 @@ namespace sol {
 		coroutine(lua_nil_t r) : reference(r) {}
 		coroutine(const stack_reference& r) noexcept : coroutine(r.lua_state(), r.stack_index()) {}
 		coroutine(stack_reference&& r) noexcept : coroutine(r.lua_state(), r.stack_index()) {}
+		template <typename T, meta::enable<meta::neg<std::is_integral<meta::unqualified_t<T>>>, meta::neg<std::is_same<T, ref_index>>> = meta::enabler>
+		coroutine(lua_State* L, T&& r) : coroutine(L, sol::ref_index(r.registry_index())) {}
 		coroutine(lua_State* L, int index = -1) : reference(L, index) {
 #ifdef SOL_CHECK_ARGUMENTS
 			stack::check<coroutine>(L, index, type_panic);
diff --git a/sol/thread.hpp b/sol/thread.hpp
index 92ef110d..5e57ad1d 100644
--- a/sol/thread.hpp
+++ b/sol/thread.hpp
@@ -72,7 +72,7 @@ namespace sol {
 	}
 
 #if SOL_LUA_VERSION < 502
-	inline lua_State* main_thread(lua_State* L, lua_State* backup_if_unsupported = nullptr) {
+	inline lua_State* main_thread(lua_State*, lua_State* backup_if_unsupported = nullptr) {
 		return backup_if_unsupported;
 	}
 #else