ceph/src/boost/boost/container/detail/version_type.hpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2005-2013. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/container for documentation.
   8 //
   9 //////////////////////////////////////////////////////////////////////////////
  10 //
  11 //       This code comes from N1953 document by Howard E. Hinnant
  12 //
  13 //////////////////////////////////////////////////////////////////////////////
  14
  15
  16 #ifndef BOOST_CONTAINER_DETAIL_VERSION_TYPE_HPP
  17 #define BOOST_CONTAINER_DETAIL_VERSION_TYPE_HPP
  18
  19 #ifndef BOOST_CONFIG_HPP
  20 #  include <boost/config.hpp>
  21 #endif
  22
  23 #if defined(BOOST_HAS_PRAGMA_ONCE)
  24 #  pragma once
  25 #endif
  26
  27 #include <boost/container/detail/config_begin.hpp>
  28 #include <boost/container/detail/workaround.hpp>
  29
  30 #include <boost/container/detail/mpl.hpp>
  31 #include <boost/container/detail/type_traits.hpp>
  32
  33 namespace boost{
  34 namespace container {
  35 namespace dtl {
  36
  37 template <class T, unsigned V>
  38 struct version_type
  39     : public dtl::integral_constant<unsigned, V>
  40 {
  41     typedef T type;
  42 };
  43
  44 namespace impl{
  45
  46 template <class T>
  47 struct extract_version
  48 {
  49    typedef typename T::version type;
  50 };
  51
  52 template <class T>
  53 struct has_version
  54 {
  55    private:
  56    struct two {char _[2];};
  57    template <class U> static two test(...);
  58    template <class U> static char test(const typename U::version*);
  59    public:
  60    static const bool value = sizeof(test<T>(0)) == 1;
  61    void dummy(){}
  62 };
  63
  64 template <class T, bool = has_version<T>::value>
  65 struct version
  66 {
  67    static const unsigned value = 1;
  68 };
  69
  70 template <class T>
  71 struct version<T, true>
  72 {
  73    static const unsigned value = extract_version<T>::type::value;
  74 };
  75
  76 }  //namespace impl
  77
  78 template <class T>
  79 struct version
  80    : public dtl::integral_constant<unsigned, impl::version<T>::value>
  81 {};
  82
  83 template<class T, unsigned N>
  84 struct is_version
  85 {
  86    static const bool value =
  87       is_same< typename version<T>::type, integral_constant<unsigned, N> >::value;
  88 };
  89
  90 }  //namespace dtl {
  91
  92 typedef dtl::integral_constant<unsigned, 0> version_0;
  93 typedef dtl::integral_constant<unsigned, 1> version_1;
  94 typedef dtl::integral_constant<unsigned, 2> version_2;
  95
  96 }  //namespace container {
  97 }  //namespace boost{
  98
  99 #include <boost/container/detail/config_end.hpp>
 100
 101 #endif   //#define BOOST_CONTAINER_DETAIL_VERSION_TYPE_HPP