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

   1 //
   2 // traits/static_query.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_QUERY_HPP
  12 #define BOOST_ASIO_TRAITS_STATIC_QUERY_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
  21 #if defined(BOOST_ASIO_HAS_DECLTYPE) \
  22   && defined(BOOST_ASIO_HAS_NOEXCEPT) \
  23   && defined(BOOST_ASIO_HAS_CONSTEXPR) \
  24   && defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES) \
  25   && defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE)
  26 # define BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT 1
  27 #endif // defined(BOOST_ASIO_HAS_DECLTYPE)
  28        //   && defined(BOOST_ASIO_HAS_NOEXCEPT)
  29        //   && defined(BOOST_ASIO_HAS_CONSTEXPR)
  30        //   && defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
  31        //   && defined(BOOST_ASIO_HAS_WORKING_EXPRESSION_SFINAE)
  32
  33 #include <boost/asio/detail/push_options.hpp>
  34
  35 namespace boost {
  36 namespace asio {
  37 namespace traits {
  38
  39 template <typename T, typename Property, typename = void>
  40 struct static_query_default;
  41
  42 template <typename T, typename Property, typename = void>
  43 struct static_query;
  44
  45 } // namespace traits
  46 namespace detail {
  47
  48 struct no_static_query
  49 {
  50   BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = false);
  51   BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = false);
  52 };
  53
  54 template <typename T, typename Property, typename = void>
  55 struct static_query_trait :
  56   conditional<
  57     is_same<T, typename decay<T>::type>::value
  58       && is_same<Property, typename decay<Property>::type>::value,
  59     no_static_query,
  60     traits::static_query<
  61       typename decay<T>::type,
  62       typename decay<Property>::type>
  63   >::type
  64 {
  65 };
  66
  67 #if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
  68
  69 template <typename T, typename Property>
  70 struct static_query_trait<T, Property,
  71   typename void_type<
  72     decltype(decay<Property>::type::template static_query_v<T>)
  73   >::type>
  74 {
  75   BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
  76
  77   using result_type = decltype(
  78       decay<Property>::type::template static_query_v<T>);
  79
  80   BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
  81     noexcept(decay<Property>::type::template static_query_v<T>));
  82
  83   static BOOST_ASIO_CONSTEXPR result_type value() noexcept(is_noexcept)
  84   {
  85     return decay<Property>::type::template static_query_v<T>;
  86   }
  87 };
  88
  89 #endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
  90
  91 } // namespace detail
  92 namespace traits {
  93
  94 template <typename T, typename Property, typename>
  95 struct static_query_default : detail::static_query_trait<T, Property>
  96 {
  97 };
  98
  99 template <typename T, typename Property, typename>
 100 struct static_query : static_query_default<T, Property>
 101 {
 102 };
 103
 104 } // namespace traits
 105 } // namespace asio
 106 } // namespace boost
 107
 108 #include <boost/asio/detail/pop_options.hpp>
 109
 110 #endif // BOOST_ASIO_TRAITS_STATIC_QUERY_HPP