1 // Copyright (c) 2003 Daniel Wallin and Arvid Norberg 2 3 // Permission is hereby granted, free of charge, to any person obtaining a 4 // copy of this software and associated documentation files (the "Software"), 5 // to deal in the Software without restriction, including without limitation 6 // the rights to use, copy, modify, merge, publish, distribute, sublicense, 7 // and/or sell copies of the Software, and to permit persons to whom the 8 // Software is furnished to do so, subject to the following conditions: 9 10 // The above copyright notice and this permission notice shall be included 11 // in all copies or substantial portions of the Software. 12 13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF 14 // ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 15 // TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 16 // PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT 17 // SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 18 // ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 19 // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE 21 // OR OTHER DEALINGS IN THE SOFTWARE. 22 23 #ifndef LUABIND_RETURN_REFERENCE_TO_POLICY_HPP_INCLUDED 24 #define LUABIND_RETURN_REFERENCE_TO_POLICY_HPP_INCLUDED 25 26 namespace luabind { namespace detail 27 { 28 template<class T> 29 struct return_reference_to_converter; 30 31 template<> 32 struct return_reference_to_converter<cpp_to_lua> 33 { 34 template<class T> applyluabind::detail::return_reference_to_converter35 void apply(lua_State* L, const T&) 36 { 37 lua_pushnil(L); 38 } 39 }; 40 41 template<int N> 42 struct return_reference_to_policy : conversion_policy<0> 43 { precallluabind::detail::return_reference_to_policy44 static void precall(lua_State*, const index_map&) {} postcallluabind::detail::return_reference_to_policy45 static void postcall(lua_State* L, const index_map& indices) 46 { 47 int result_index = indices[0]; 48 int ref_to_index = indices[N]; 49 50 lua_pushvalue(L, ref_to_index); 51 lua_replace(L, result_index); 52 } 53 54 template<class T, class Direction> 55 struct apply 56 { 57 typedef return_reference_to_converter<Direction> type; 58 }; 59 }; 60 }} 61 62 namespace luabind 63 { 64 template<int N> 65 detail::policy_cons<detail::return_reference_to_policy<N>, detail::null_type> return_reference_to(LUABIND_PLACEHOLDER_ARG (N))66 return_reference_to(LUABIND_PLACEHOLDER_ARG(N)) 67 { 68 return detail::policy_cons<detail::return_reference_to_policy<N>, detail::null_type>(); 69 } 70 } 71 72 #endif // LUABIND_RETURN_REFERENCE_TO_POLICY_HPP_INCLUDED 73 74