ceph/src/boost/libs/container/include/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 container_detail {
  36
  37 template <class T, unsigned V>
  38 struct version_type
  39     : public container_detail::integral_constant<unsigned, V>
  40 {
  41     typedef T type;
  42
  43     version_type(const version_type<T, 0>&);
  44 };
  45
  46 namespace impl{
  47
  48 template <class T,
  49           bool = container_detail::is_convertible<version_type<T, 0>, typename T::version>::value>
  50 struct extract_version
  51 {
  52    static const unsigned value = 1;
  53 };
  54
  55 template <class T>
  56 struct extract_version<T, true>
  57 {
  58    static const unsigned value = T::version::value;
  59 };
  60
  61 template <class T>
  62 struct has_version
  63 {
  64    private:
  65    struct two {char _[2];};
  66    template <class U> static two test(...);
  67    template <class U> static char test(const typename U::version*);
  68    public:
  69    static const bool value = sizeof(test<T>(0)) == 1;
  70    void dummy(){}
  71 };
  72
  73 template <class T, bool = has_version<T>::value>
  74 struct version
  75 {
  76    static const unsigned value = 1;
  77 };
  78
  79 template <class T>
  80 struct version<T, true>
  81 {
  82    static const unsigned value = extract_version<T>::value;
  83 };
  84
  85 }  //namespace impl
  86
  87 template <class T>
  88 struct version
  89    : public container_detail::integral_constant<unsigned, impl::version<T>::value>
  90 {};
  91
  92 template<class T, unsigned N>
  93 struct is_version
  94 {
  95    static const bool value =
  96       is_same< typename version<T>::type, integral_constant<unsigned, N> >::value;
  97 };
  98
  99 }  //namespace container_detail {
 100
 101 typedef container_detail::integral_constant<unsigned, 0> version_0;
 102 typedef container_detail::integral_constant<unsigned, 1> version_1;
 103 typedef container_detail::integral_constant<unsigned, 2> version_2;
 104
 105 }  //namespace container {
 106 }  //namespace boost{
 107
 108 #include <boost/container/detail/config_end.hpp>
 109
 110 #endif   //#define BOOST_CONTAINER_DETAIL_VERSION_TYPE_HPP