109 lines
2.8 KiB
C++
109 lines
2.8 KiB
C++
|
//
|
||
|
|
// traits/static_query.hpp
|
||
|
|
// ~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
|
//
|
||
|
|
// Copyright (c) 2003-2023 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
|