luabind/out_value.hpp

   1
   2 template<int N>
   3 struct char_array
   4 {
   5         char storage[N];
   6 };
   7
   8 template<class T>
   9 struct indirect_sizeof
  10 {
  11         template<class U>
  12         char_array<sizeof(U)> test(reference_to<U>);
  13
  14         template<class U>
  15         char_array<sizeof(U)> test(const_reference_to<U>);
  16
  17         template<class U>
  18         char_array<sizeof(U)> test(pointer_to<U>);
  19
  20         template<class U>
  21         char_array<sizeof(U)> test(const_pointer_to<U>);
  22
  23         template<class U>
  24         char_array<sizeof(U)> test(value_to<U>);
  25
  26     BOOST_STATIC_CONSTANT(int, value = sizeof(test(LUABIND_DECORATE_TYPE(T))));
  27 };
  28
  29 template<int N>
  30 struct out_value_converter
  31 {
  32         template<class T>
  33         static T& apply(lua_State* L, reference_to<T>, int index)
  34         {
  35                 new (m_storage) T(primitive_param_converter::apply(L, value_to<T>(), index));
  36                 return *reinterpret_cast<T*>(m_storage);
  37         }
  38
  39         template<class T>
  40         static void postcall(lua_State* L, reference_to<T>, int)
  41         {
  42                 primitive_result_converter::apply(L, *reinterpret_cast<T*>(m_storage));
  43         }
  44
  45         template<class T>
  46         static int match(lua_State* L, reference_to<T>, int index)
  47         {
  48                 return primitive_param_converter::match(L, value_to<T>(), index);
  49         }
  50
  51         char m_storage[N];
  52 };
  53
  54 template<class T>
  55 struct out_value_policy
  56 {
  57         BOOST_STATIC_CONSTANT(int, size = indirect_sizeof<T>::value);
  58         typedef out_value_converter<size> type;
  59 };
  60
  61 template<int N>
  62 struct out_value_policy_gen
  63 {
  64         template<class T, class Direction>
  65         struct generate_policy
  66         {
  67                 typedef typename mpl::apply_if<is_same<Direction, lua_to_cpp>
  68                         , out_value_policy<T>
  69                         , error
  70                 >::type type;
  71         };
  72 };