luabind/detail/pointee_sizeof.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 POINTEE_SIZEOF_040211_HPP
  24 #define POINTEE_SIZEOF_040211_HPP
  25
  26 #include <boost/mpl/int.hpp>
  27
  28 namespace luabind {
  29
  30     namespace detail {
  31
  32     template<class T> T& deref_type(T(*)(), int);
  33     template<class T> T& deref_type(T*(*)(), long);
  34
  35     } // namespace detail
  36
  37     // returns the indirect sizeof U, as in
  38     //    sizeof(T*) = sizeof(T)
  39     //    sizeof(T&) = sizeof(T)
  40     //    sizeof(T)  = sizeof(T)
  41     template<class T>
  42     struct pointee_sizeof
  43     {
  44         BOOST_STATIC_CONSTANT(int, value = (
  45             sizeof(detail::deref_type((T(*)())0), 0L)
  46         ));
  47
  48         typedef boost::mpl::int_<value> type;
  49     };
  50
  51 } // namespace luabind
  52
  53 #endif // POINTEE_SIZEOF_040211_HPP
  54