boost/serialization/version.hpp

   1 #ifndef BOOST_SERIALIZATION_VERSION_HPP
   2 #define BOOST_SERIALIZATION_VERSION_HPP
   3
   4 // MS compatible compilers support #pragma once
   5 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
   6 # pragma once
   7 #endif
   8
   9 /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
  10 // version.hpp:
  11
  12 // (C) Copyright 2002 Robert Ramey - http://www.rrsd.com .
  13 // Use, modification and distribution is subject to the Boost Software
  14 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  15 // http://www.boost.org/LICENSE_1_0.txt)
  16
  17 //  See http://www.boost.org for updates, documentation, and revision history.
  18
  19 #include <boost/config.hpp>
  20 #include <boost/mpl/int.hpp>
  21 #include <boost/mpl/eval_if.hpp>
  22 #include <boost/mpl/identity.hpp>
  23 #include <boost/mpl/integral_c_tag.hpp>
  24
  25 #include <boost/type_traits/is_base_and_derived.hpp>
  26 //#include <boost/serialization/traits.hpp>
  27
  28 namespace boost {
  29 namespace serialization {
  30
  31 struct basic_traits;
  32
  33 // default version number is 0. Override with higher version
  34 // when class definition changes.
  35 template<class T>
  36 struct version
  37 {
  38     template<class U>
  39     struct traits_class_version {
  40         typedef BOOST_DEDUCED_TYPENAME U::version type;
  41     };
  42
  43     typedef mpl::integral_c_tag tag;
  44     // note: at least one compiler complained w/o the full qualification
  45     // on basic traits below
  46     typedef
  47         BOOST_DEDUCED_TYPENAME mpl::eval_if<
  48             is_base_and_derived<boost::serialization::basic_traits,T>,
  49             traits_class_version<T>,
  50             mpl::int_<0>
  51         >::type type;
  52     BOOST_STATIC_CONSTANT(unsigned int, value = version::type::value);
  53 };
  54
  55 } // namespace serialization
  56 } // namespace boost
  57
  58 // specify the current version number for the class
  59 #define BOOST_CLASS_VERSION(T, N)                                      \
  60 namespace boost {                                                      \
  61 namespace serialization {                                              \
  62 template<>                                                             \
  63 struct version<T >                                                     \
  64 {                                                                      \
  65     typedef mpl::int_<N> type;                                         \
  66     typedef mpl::integral_c_tag tag;                                   \
  67     BOOST_STATIC_CONSTANT(unsigned int, value = version::type::value); \
  68     /* require that class info saved when versioning is used */        \
  69     /*                                                                 \
  70     BOOST_STATIC_ASSERT((                                              \
  71         mpl::or_<                                                      \
  72             mpl::equal_to<                                             \
  73                 mpl::int_<0>,                                          \
  74                 mpl::int_<N>                                           \
  75             >,                                                         \
  76             mpl::equal_to<                                             \
  77                 implementation_level<T>,                               \
  78                 mpl::int_<object_class_info>                           \
  79             >                                                          \
  80         >::value                                                       \
  81     ));                                                                \
  82     */                                                                 \
  83 };                                                                     \
  84 }                                                                      \
  85 }
  86
  87 #endif // BOOST_SERIALIZATION_VERSION_HPP