ceph/src/boost/boost/asio/traits/static_require.hpp

   1 //
   2 // traits/static_require.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10
  11 #ifndef BOOST_ASIO_TRAITS_STATIC_REQUIRE_HPP
  12 #define BOOST_ASIO_TRAITS_STATIC_REQUIRE_HPP
  13
  14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  15 # pragma once
  16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  17
  18 #include <boost/asio/detail/config.hpp>
  19 #include <boost/asio/detail/type_traits.hpp>
  20 #include <boost/asio/traits/static_query.hpp>
  21
  22 #if defined(BOOST_ASIO_HAS_DECLTYPE) \
  23   && defined(BOOST_ASIO_HAS_NOEXCEPT)
  24 # define BOOST_ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT 1
  25 #endif // defined(BOOST_ASIO_HAS_DECLTYPE)
  26        //   && defined(BOOST_ASIO_HAS_NOEXCEPT)
  27
  28 #include <boost/asio/detail/push_options.hpp>
  29
  30 namespace boost {
  31 namespace asio {
  32 namespace traits {
  33
  34 template <typename T, typename Property, typename = void>
  35 struct static_require_default;
  36
  37 template <typename T, typename Property, typename = void>
  38 struct static_require;
  39
  40 } // namespace traits
  41 namespace detail {
  42
  43 struct no_static_require
  44 {
  45   BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = false);
  46 };
  47
  48 template <typename T, typename Property, typename = void>
  49 struct static_require_trait :
  50   conditional<
  51     is_same<T, typename decay<T>::type>::value
  52       && is_same<Property, typename decay<Property>::type>::value,
  53     no_static_require,
  54     traits::static_require<
  55       typename decay<T>::type,
  56       typename decay<Property>::type>
  57   >::type
  58 {
  59 };
  60
  61 #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT)
  62
  63 #if defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE)
  64
  65 template <typename T, typename Property>
  66 struct static_require_trait<T, Property,
  67   typename enable_if<
  68     decay<Property>::type::value() == traits::static_query<T, Property>::value()
  69   >::type>
  70 {
  71   BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
  72 };
  73
  74 #else // defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE)
  75
  76 false_type static_require_test(...);
  77
  78 template <typename T, typename Property>
  79 true_type static_require_test(T*, Property*,
  80     typename enable_if<
  81       Property::value() == traits::static_query<T, Property>::value()
  82     >::type* = 0);
  83
  84 template <typename T, typename Property>
  85 struct has_static_require
  86 {
  87   BOOST_ASIO_STATIC_CONSTEXPR(bool, value =
  88     decltype((static_require_test)(
  89       static_cast<T*>(0), static_cast<Property*>(0)))::value);
  90 };
  91
  92 template <typename T, typename Property>
  93 struct static_require_trait<T, Property,
  94   typename enable_if<
  95     has_static_require<typename decay<T>::type,
  96       typename decay<Property>::type>::value
  97   >::type>
  98 {
  99   BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
 100 };
 101
 102 #endif // defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE)
 103
 104 #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT)
 105
 106 } // namespace detail
 107 namespace traits {
 108
 109 template <typename T, typename Property, typename>
 110 struct static_require_default : detail::static_require_trait<T, Property>
 111 {
 112 };
 113
 114 template <typename T, typename Property, typename>
 115 struct static_require : static_require_default<T, Property>
 116 {
 117 };
 118
 119 } // namespace traits
 120 } // namespace asio
 121 } // namespace boost
 122
 123 #include <boost/asio/detail/pop_options.hpp>
 124
 125 #endif // BOOST_ASIO_TRAITS_STATIC_REQUIRE_HPP