luabind/detail/is_indirect_const.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 IS_INDIRECT_CONST_040211_HPP
  24 #define IS_INDIRECT_CONST_040211_HPP
  25
  26 #include <luabind/detail/yes_no.hpp>
  27 #include <boost/type_traits/is_const.hpp>
  28 #include <boost/mpl/bool.hpp>
  29
  30 namespace luabind {
  31
  32     namespace detail {
  33
  34     template<class T>
  35     typename boost::is_const<T>::type
  36     is_indirect_const_check(T(*)(), int);
  37
  38     template<class T>
  39     typename boost::is_const<T>::type
  40     is_indirect_const_check(T*(*)(), long);
  41
  42     template<class T>
  43     typename boost::is_const<T>::type
  44     is_indirect_const_check(T&(*)(), long);
  45
  46     yes_t to_yes_no(boost::mpl::true_);
  47     no_t to_yes_no(boost::mpl::false_);
  48
  49     } // namespace detail
  50
  51     // returns true for:
  52     //    T = U*  is_const<U>
  53     //    T = U&  is_const<U>
  54     //    T = U   is_const<U>
  55     template<class T>
  56     struct is_indirect_const
  57     {
  58         BOOST_STATIC_CONSTANT(int, value = (
  59             sizeof(
  60                 detail::to_yes_no(
  61                     detail::is_indirect_const_check((T(*)())0, 0L)
  62             ))
  63          == sizeof(detail::yes_t)
  64         ));
  65     };
  66
  67 } // namespace luabind
  68
  69 #endif // IS_INDIRECT_CONST_040211_HPP
  70