blah2/lib/asio-1.26.0/asio/traits/static_query.hpp
2023-05-04 20:55:37 +09:30

108 lines
2.8 KiB
C++

//
// traits/static_query.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef ASIO_TRAITS_STATIC_QUERY_HPP
#define ASIO_TRAITS_STATIC_QUERY_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include "asio/detail/config.hpp"
#include "asio/detail/type_traits.hpp"
#if defined(ASIO_HAS_DECLTYPE) \
&& defined(ASIO_HAS_NOEXCEPT) \
&& defined(ASIO_HAS_CONSTEXPR) \
&& defined(ASIO_HAS_VARIABLE_TEMPLATES) \
&& defined(ASIO_HAS_WORKING_EXPRESSION_SFINAE)
# define ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT 1
#endif // defined(ASIO_HAS_DECLTYPE)
// && defined(ASIO_HAS_NOEXCEPT)
// && defined(ASIO_HAS_CONSTEXPR)
// && defined(ASIO_HAS_VARIABLE_TEMPLATES)
// && defined(ASIO_HAS_WORKING_EXPRESSION_SFINAE)
#include "asio/detail/push_options.hpp"
namespace asio {
namespace traits {
template <typename T, typename Property, typename = void>
struct static_query_default;
template <typename T, typename Property, typename = void>
struct static_query;
} // namespace traits
namespace detail {
struct no_static_query
{
ASIO_STATIC_CONSTEXPR(bool, is_valid = false);
ASIO_STATIC_CONSTEXPR(bool, is_noexcept = false);
};
template <typename T, typename Property, typename = void>
struct static_query_trait :
conditional<
is_same<T, typename decay<T>::type>::value
&& is_same<Property, typename decay<Property>::type>::value,
no_static_query,
traits::static_query<
typename decay<T>::type,
typename decay<Property>::type>
>::type
{
};
#if defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
template <typename T, typename Property>
struct static_query_trait<T, Property,
typename void_type<
decltype(decay<Property>::type::template static_query_v<T>)
>::type>
{
ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
using result_type = decltype(
decay<Property>::type::template static_query_v<T>);
ASIO_STATIC_CONSTEXPR(bool, is_noexcept =
noexcept(decay<Property>::type::template static_query_v<T>));
static ASIO_CONSTEXPR result_type value() noexcept(is_noexcept)
{
return decay<Property>::type::template static_query_v<T>;
}
};
#endif // defined(ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
} // namespace detail
namespace traits {
template <typename T, typename Property, typename>
struct static_query_default : detail::static_query_trait<T, Property>
{
};
template <typename T, typename Property, typename>
struct static_query : static_query_default<T, Property>
{
};
} // namespace traits
} // namespace asio
#include "asio/detail/pop_options.hpp"
#endif // ASIO_TRAITS_STATIC_QUERY_HPP