luabind/detail/has_get_pointer.hpp

   1 // Copyright (c) 2005 Daniel Wallin
   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_HAS_GET_POINTER_051022_HPP
  24 # define LUABIND_HAS_GET_POINTER_051022_HPP
  25
  26 # include <boost/type_traits/add_reference.hpp>
  27
  28 # ifndef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
  29 #  include <memory>
  30 # endif
  31
  32 namespace luabind { namespace detail {
  33
  34 namespace has_get_pointer_
  35 {
  36
  37   struct any
  38   {
  39       template<class T> any(T const&);
  40   };
  41
  42   struct no_overload_tag
  43   {};
  44
  45   typedef char (&yes)[1];
  46   typedef char (&no)[2];
  47
  48   no_overload_tag operator,(no_overload_tag, int);
  49
  50 //
  51 // On compilers with ADL, we need these generic overloads in this
  52 // namespace as well as in luabind::. Otherwise get_pointer(any)
  53 // will be found before them.
  54 //
  55 # ifndef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
  56
  57   template<class T>
  58   T* get_pointer(T const volatile*);
  59
  60   template<class T>
  61   T* get_pointer(std::auto_ptr<T> const&);
  62
  63 # endif
  64
  65 //
  66 // On compilers that doesn't support ADL, the overload below has to
  67 // live in luabind::.
  68 //
  69 # ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
  70 }} // namespace detail::has_get_pointer_
  71 # endif
  72
  73 detail::has_get_pointer_::no_overload_tag
  74   get_pointer(detail::has_get_pointer_::any);
  75
  76 # ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
  77 namespace detail { namespace has_get_pointer_
  78 {
  79 # endif
  80
  81   template<class T>
  82   yes check(T const&);
  83   no check(no_overload_tag);
  84
  85   template<class T>
  86   struct impl
  87   {
  88       static typename boost::add_reference<T>::type x;
  89
  90       BOOST_STATIC_CONSTANT(bool,
  91           value = sizeof(has_get_pointer_::check( (get_pointer(x),0) )) == 1
  92       );
  93
  94       typedef boost::mpl::bool_<value> type;
  95   };
  96
  97 } // namespace has_get_pointer_
  98
  99 template<class T>
 100 struct has_get_pointer
 101   : has_get_pointer_::impl<T>::type
 102 {};
 103
 104 }} // namespace luabind::detail
 105
 106 #endif // LUABIND_HAS_GET_POINTER_051022_HPP
 107