luabind/back_reference.hpp

   1 // Copyright (c) 2004 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_BACK_REFERENCE_040510_HPP
  24 #define LUABIND_BACK_REFERENCE_040510_HPP
  25
  26 #include <luabind/lua_include.hpp>
  27 #include <luabind/wrapper_base.hpp>
  28 #include <luabind/detail/has_get_pointer.hpp>
  29 #include <luabind/get_pointer.hpp>
  30 #include <boost/type_traits/is_polymorphic.hpp>
  31 #include <boost/type_traits/is_const.hpp>
  32 #include <boost/mpl/if.hpp>
  33
  34 namespace luabind {
  35
  36 namespace detail
  37 {
  38   namespace mpl = boost::mpl;
  39
  40   template<class T>
  41   wrap_base const* get_back_reference_aux0(T const* p, mpl::true_)
  42   {
  43       return dynamic_cast<wrap_base const*>(p);
  44   }
  45
  46   template<class T>
  47   wrap_base const* get_back_reference_aux0(T const* p, mpl::false_)
  48   {
  49       return 0;
  50   }
  51
  52   template<class T>
  53   wrap_base const* get_back_reference_aux1(T const* p)
  54   {
  55       return get_back_reference_aux0(p, boost::is_polymorphic<T>());
  56   }
  57
  58   template<class T>
  59   wrap_base const* get_back_reference_aux2(T const& x, mpl::true_)
  60   {
  61       return get_back_reference_aux1(get_pointer(x));
  62   }
  63
  64   template<class T>
  65   wrap_base const* get_back_reference_aux2(T const& x, mpl::false_)
  66   {
  67       return get_back_reference_aux1(&x);
  68   }
  69
  70   template<class T>
  71   wrap_base const* get_back_reference(T const& x)
  72   {
  73       return detail::get_back_reference_aux2(
  74           x
  75         , has_get_pointer<T>()
  76       );
  77   }
  78
  79 } // namespace detail
  80
  81 template<class T>
  82 bool get_back_reference(lua_State* L, T const& x)
  83 {
  84 #ifndef LUABIND_NO_RTTI
  85     if (wrap_base const* w = detail::get_back_reference(x))
  86     {
  87         detail::wrap_access::ref(*w).get(L);
  88         return true;
  89     }
  90 #endif
  91     return false;
  92 }
  93
  94 template<class T>
  95 bool move_back_reference(lua_State* L, T const& x)
  96 {
  97 #ifndef LUABIND_NO_RTTI
  98     if (wrap_base* w = const_cast<wrap_base*>(detail::get_back_reference(x)))
  99     {
 100         assert(detail::wrap_access::ref(*w).m_strong_ref.is_valid());
 101         detail::wrap_access::ref(*w).get(L);
 102         detail::wrap_access::ref(*w).m_strong_ref.reset();
 103         return true;
 104     }
 105 #endif
 106     return false;
 107 }
 108
 109 } // namespace luabind
 110
 111 #endif // LUABIND_BACK_REFERENCE_040510_HPP
 112