[ceph.git] / ceph / src / boost / boost / asio / query.hpp

//
// 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 BOOST_ASIO_QUERY_HPP
#define BOOST_ASIO_QUERY_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include <boost/asio/detail/config.hpp>
#include <boost/asio/detail/type_traits.hpp>
#include <boost/asio/is_applicable_property.hpp>
#include <boost/asio/traits/query_member.hpp>
#include <boost/asio/traits/query_free.hpp>
#include <boost/asio/traits/static_query.hpp>

#include <boost/asio/detail/push_options.hpp>

#if defined(GENERATING_DOCUMENTATION)

namespace boost {
namespace asio {

/// A customisation point that queries the value of a property.
/**
 * The name <tt>query</tt> denotes a customization point object. The
 * expression <tt>boost::asio::query(E, P)</tt> for some
 * subexpressions <tt>E</tt> and <tt>P</tt> (with types <tt>T =
 * decay_t<decltype(E)></tt> and <tt>Prop = decay_t<decltype(P)></tt>) is
 * expression-equivalent to:
 *
 * @li If <tt>is_applicable_property_v<T, Prop></tt> is not a well-formed
 *   constant expression with value <tt>true</tt>, <tt>boost::asio::query(E,
 *   P)</tt> is ill-formed.
 *
 * @li Otherwise, <tt>Prop::template static_query_v<T></tt> if the expression
 *   <tt>Prop::template static_query_v<T></tt> is a well-formed constant
 *   expression.
 *
 * @li Otherwise, <tt>(E).query(P)</tt> if the expression
 *   <tt>(E).query(P)</tt> is well-formed.
 *
 * @li Otherwise, <tt>query(E, P)</tt> if the expression
 *   <tt>query(E, P)</tt> is a valid expression with overload
 *   resolution performed in a context that does not include the declaration
 *   of the <tt>query</tt> customization point object.
 *
 * @li Otherwise, <tt>boost::asio::query(E, P)</tt> is ill-formed.
 */
inline constexpr unspecified query = unspecified;

/// A type trait that determines whether a @c query expression is well-formed.
/**
 * Class template @c can_query is a trait that is derived from
 * @c true_type if the expression <tt>boost::asio::query(std::declval<T>(),
 * std::declval<Property>())</tt> is well formed; otherwise @c false_type.
 */
template <typename T, typename Property>
struct can_query :
  integral_constant<bool, automatically_determined>
{
};

/// A type trait that determines whether a @c query expression will
/// not throw.
/**
 * Class template @c is_nothrow_query is a trait that is derived from
 * @c true_type if the expression <tt>boost::asio::query(std::declval<T>(),
 * std::declval<Property>())</tt> is @c noexcept; otherwise @c false_type.
 */
template <typename T, typename Property>
struct is_nothrow_query :
  integral_constant<bool, automatically_determined>
{
};

/// A type trait that determines the result type of a @c query expression.
/**
 * Class template @c query_result is a trait that determines the result
 * type of the expression <tt>boost::asio::query(std::declval<T>(),
 * std::declval<Property>())</tt>.
 */
template <typename T, typename Property>
struct query_result
{
  /// The result of the @c query expression.
  typedef automatically_determined type;
};

} // namespace asio
} // namespace boost

#else // defined(GENERATING_DOCUMENTATION)

namespace boost_asio_query_fn {

using boost::asio::conditional;
using boost::asio::decay;
using boost::asio::declval;
using boost::asio::enable_if;
using boost::asio::is_applicable_property;
using boost::asio::traits::query_free;
using boost::asio::traits::query_member;
using boost::asio::traits::static_query;

void query();

enum overload_type
{
  static_value,
  call_member,
  call_free,
  ill_formed
};

template <typename Impl, typename T, typename Properties,
    typename = void, typename = void, typename = void, typename = void>
struct call_traits
{
  BOOST_ASIO_STATIC_CONSTEXPR(overload_type, overload = ill_formed);
  BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = false);
  typedef void result_type;
};

template <typename Impl, typename T, typename Property>
struct call_traits<Impl, T, void(Property),
  typename enable_if<
    is_applicable_property<
      typename decay<T>::type,
      typename decay<Property>::type
    >::value
  >::type,
  typename enable_if<
    static_query<T, Property>::is_valid
  >::type> :
  static_query<T, Property>
{
  BOOST_ASIO_STATIC_CONSTEXPR(overload_type, overload = static_value);
};

template <typename Impl, typename T, typename Property>
struct call_traits<Impl, T, void(Property),
  typename enable_if<
    is_applicable_property<
      typename decay<T>::type,
      typename decay<Property>::type
    >::value
  >::type,
  typename enable_if<
    !static_query<T, Property>::is_valid
  >::type,
  typename enable_if<
    query_member<typename Impl::template proxy<T>::type, Property>::is_valid
  >::type> :
  query_member<typename Impl::template proxy<T>::type, Property>
{
  BOOST_ASIO_STATIC_CONSTEXPR(overload_type, overload = call_member);
};

template <typename Impl, typename T, typename Property>
struct call_traits<Impl, T, void(Property),
  typename enable_if<
    is_applicable_property<
      typename decay<T>::type,
      typename decay<Property>::type
    >::value
  >::type,
  typename enable_if<
    !static_query<T, Property>::is_valid
  >::type,
  typename enable_if<
    !query_member<typename Impl::template proxy<T>::type, Property>::is_valid
  >::type,
  typename enable_if<
    query_free<T, Property>::is_valid
  >::type> :
  query_free<T, Property>
{
  BOOST_ASIO_STATIC_CONSTEXPR(overload_type, overload = call_free);
};

struct impl
{
  template <typename T>
  struct proxy
  {
#if defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
    struct type
    {
      template <typename P>
      auto query(BOOST_ASIO_MOVE_ARG(P) p)
        noexcept(
          noexcept(
            declval<typename conditional<true, T, P>::type>().query(
              BOOST_ASIO_MOVE_CAST(P)(p))
          )
        )
        -> decltype(
          declval<typename conditional<true, T, P>::type>().query(
            BOOST_ASIO_MOVE_CAST(P)(p))
        );
    };
#else // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
    typedef T type;
#endif // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
  };

  template <typename T, typename Property>
  BOOST_ASIO_NODISCARD BOOST_ASIO_CONSTEXPR typename enable_if<
    call_traits<impl, T, void(Property)>::overload == static_value,
    typename call_traits<impl, T, void(Property)>::result_type
  >::type
  operator()(
      BOOST_ASIO_MOVE_ARG(T),
      BOOST_ASIO_MOVE_ARG(Property)) const
    BOOST_ASIO_NOEXCEPT_IF((
      call_traits<impl, T, void(Property)>::is_noexcept))
  {
    return static_query<
      typename decay<T>::type,
      typename decay<Property>::type
    >::value();
  }

  template <typename T, typename Property>
  BOOST_ASIO_NODISCARD BOOST_ASIO_CONSTEXPR typename enable_if<
    call_traits<impl, T, void(Property)>::overload == call_member,
    typename call_traits<impl, T, void(Property)>::result_type
  >::type
  operator()(
      BOOST_ASIO_MOVE_ARG(T) t,
      BOOST_ASIO_MOVE_ARG(Property) p) const
    BOOST_ASIO_NOEXCEPT_IF((
      call_traits<impl, T, void(Property)>::is_noexcept))
  {
    return BOOST_ASIO_MOVE_CAST(T)(t).query(BOOST_ASIO_MOVE_CAST(Property)(p));
  }

  template <typename T, typename Property>
  BOOST_ASIO_NODISCARD BOOST_ASIO_CONSTEXPR typename enable_if<
    call_traits<impl, T, void(Property)>::overload == call_free,
    typename call_traits<impl, T, void(Property)>::result_type
  >::type
  operator()(
      BOOST_ASIO_MOVE_ARG(T) t,
      BOOST_ASIO_MOVE_ARG(Property) p) const
    BOOST_ASIO_NOEXCEPT_IF((
      call_traits<impl, T, void(Property)>::is_noexcept))
  {
    return query(BOOST_ASIO_MOVE_CAST(T)(t), BOOST_ASIO_MOVE_CAST(Property)(p));
  }
};

template <typename T = impl>
struct static_instance
{
  static const T instance;
};

template <typename T>
const T static_instance<T>::instance = {};

} // namespace boost_asio_query_fn
namespace boost {
namespace asio {
namespace {

static BOOST_ASIO_CONSTEXPR const boost_asio_query_fn::impl&
  query = boost_asio_query_fn::static_instance<>::instance;

} // namespace

typedef boost_asio_query_fn::impl query_t;

template <typename T, typename Property>
struct can_query :
  integral_constant<bool,
    boost_asio_query_fn::call_traits<query_t, T, void(Property)>::overload !=
      boost_asio_query_fn::ill_formed>
{
};

#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)

template <typename T, typename Property>
constexpr bool can_query_v
  = can_query<T, Property>::value;

#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)

template <typename T, typename Property>
struct is_nothrow_query :
  integral_constant<bool,
    boost_asio_query_fn::call_traits<query_t, T, void(Property)>::is_noexcept>
{
};

#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)

template <typename T, typename Property>
constexpr bool is_nothrow_query_v
  = is_nothrow_query<T, Property>::value;

#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)

template <typename T, typename Property>
struct query_result
{
  typedef typename boost_asio_query_fn::call_traits<
      query_t, T, void(Property)>::result_type type;
};

} // namespace asio
} // namespace boost

#endif // defined(GENERATING_DOCUMENTATION)

#include <boost/asio/detail/pop_options.hpp>

#endif // BOOST_ASIO_QUERY_HPP
Commit	Line	Data
20effc67 TL	1	//
	2	// query.hpp
	3	// ~~~~~~~~~
	4	//
1e59de90	5	// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
20effc67 TL	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_QUERY_HPP
	12	#define BOOST_ASIO_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	#include <boost/asio/is_applicable_property.hpp>
	21	#include <boost/asio/traits/query_member.hpp>
	22	#include <boost/asio/traits/query_free.hpp>
	23	#include <boost/asio/traits/static_query.hpp>
	24
	25	#include <boost/asio/detail/push_options.hpp>
	26
	27	#if defined(GENERATING_DOCUMENTATION)
	28
	29	namespace boost {
	30	namespace asio {
	31
	32	/// A customisation point that queries the value of a property.
	33	/**
	34	* The name <tt>query</tt> denotes a customization point object. The
	35	* expression <tt>boost::asio::query(E, P)</tt> for some
	36	* subexpressions <tt>E</tt> and <tt>P</tt> (with types <tt>T =
	37	* decay_t<decltype(E)></tt> and <tt>Prop = decay_t<decltype(P)></tt>) is
	38	* expression-equivalent to:
	39	*
	40	* @li If <tt>is_applicable_property_v<T, Prop></tt> is not a well-formed
	41	* constant expression with value <tt>true</tt>, <tt>boost::asio::query(E,
	42	* P)</tt> is ill-formed.
	43	*
	44	* @li Otherwise, <tt>Prop::template static_query_v<T></tt> if the expression
	45	* <tt>Prop::template static_query_v<T></tt> is a well-formed constant
	46	* expression.
	47	*
	48	* @li Otherwise, <tt>(E).query(P)</tt> if the expression
	49	* <tt>(E).query(P)</tt> is well-formed.
	50	*
	51	* @li Otherwise, <tt>query(E, P)</tt> if the expression
	52	* <tt>query(E, P)</tt> is a valid expression with overload
	53	* resolution performed in a context that does not include the declaration
	54	* of the <tt>query</tt> customization point object.
	55	*
	56	* @li Otherwise, <tt>boost::asio::query(E, P)</tt> is ill-formed.
	57	*/
	58	inline constexpr unspecified query = unspecified;
	59
	60	/// A type trait that determines whether a @c query expression is well-formed.
	61	/**
	62	* Class template @c can_query is a trait that is derived from
	63	* @c true_type if the expression <tt>boost::asio::query(std::declval<T>(),
	64	* std::declval<Property>())</tt> is well formed; otherwise @c false_type.
	65	*/
	66	template <typename T, typename Property>
	67	struct can_query :
	68	integral_constant<bool, automatically_determined>
	69	{
70	};
71
72	/// A type trait that determines whether a @c query expression will
73	/// not throw.
74	/**
75	* Class template @c is_nothrow_query is a trait that is derived from
76	* @c true_type if the expression <tt>boost::asio::query(std::declval<T>(),
77	* std::declval<Property>())</tt> is @c noexcept; otherwise @c false_type.
78	*/
79	template <typename T, typename Property>
80	struct is_nothrow_query :
81	integral_constant<bool, automatically_determined>
82	{
83	};
84
85	/// A type trait that determines the result type of a @c query expression.
86	/**
87	* Class template @c query_result is a trait that determines the result
88	* type of the expression <tt>boost::asio::query(std::declval<T>(),
89	* std::declval<Property>())</tt>.
90	*/
91	template <typename T, typename Property>
92	struct query_result
93	{
94	/// The result of the @c query expression.
95	typedef automatically_determined type;
96	};
97
98	} // namespace asio
99	} // namespace boost
100
101	#else // defined(GENERATING_DOCUMENTATION)
102
1e59de90	103	namespace boost_asio_query_fn {
20effc67	104
1e59de90	105	using boost::asio::conditional;
20effc67 TL	106	using boost::asio::decay;
	107	using boost::asio::declval;
	108	using boost::asio::enable_if;
	109	using boost::asio::is_applicable_property;
	110	using boost::asio::traits::query_free;
	111	using boost::asio::traits::query_member;
	112	using boost::asio::traits::static_query;
	113
	114	void query();
	115
	116	enum overload_type
	117	{
	118	static_value,
	119	call_member,
	120	call_free,
	121	ill_formed
	122	};
	123
1e59de90 TL	124	template <typename Impl, typename T, typename Properties,
1e59de90 TL	125	typename = void, typename = void, typename = void, typename = void>
20effc67 TL	126	struct call_traits
	127	{
	128	BOOST_ASIO_STATIC_CONSTEXPR(overload_type, overload = ill_formed);
	129	BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = false);
	130	typedef void result_type;
	131	};
	132
1e59de90 TL	133	template <typename Impl, typename T, typename Property>
1e59de90 TL	134	struct call_traits<Impl, T, void(Property),
20effc67	135	typename enable_if<
1e59de90 TL	136	is_applicable_property<
	137	typename decay<T>::type,
	138	typename decay<Property>::type
	139	>::value
	140	>::type,
	141	typename enable_if<
	142	static_query<T, Property>::is_valid
20effc67 TL	143	>::type> :
	144	static_query<T, Property>
	145	{
	146	BOOST_ASIO_STATIC_CONSTEXPR(overload_type, overload = static_value);
	147	};
	148
1e59de90 TL	149	template <typename Impl, typename T, typename Property>
	150	struct call_traits<Impl, T, void(Property),
	151	typename enable_if<
	152	is_applicable_property<
	153	typename decay<T>::type,
	154	typename decay<Property>::type
	155	>::value
	156	>::type,
	157	typename enable_if<
	158	!static_query<T, Property>::is_valid
	159	>::type,
20effc67	160	typename enable_if<
1e59de90	161	query_member<typename Impl::template proxy<T>::type, Property>::is_valid
20effc67	162	>::type> :
1e59de90	163	query_member<typename Impl::template proxy<T>::type, Property>
20effc67 TL	164	{
	165	BOOST_ASIO_STATIC_CONSTEXPR(overload_type, overload = call_member);
	166	};
	167
1e59de90 TL	168	template <typename Impl, typename T, typename Property>
	169	struct call_traits<Impl, T, void(Property),
	170	typename enable_if<
	171	is_applicable_property<
	172	typename decay<T>::type,
	173	typename decay<Property>::type
	174	>::value
	175	>::type,
	176	typename enable_if<
	177	!static_query<T, Property>::is_valid
	178	>::type,
20effc67	179	typename enable_if<
1e59de90 TL	180	!query_member<typename Impl::template proxy<T>::type, Property>::is_valid
	181	>::type,
	182	typename enable_if<
	183	query_free<T, Property>::is_valid
20effc67 TL	184	>::type> :
	185	query_free<T, Property>
	186	{
	187	BOOST_ASIO_STATIC_CONSTEXPR(overload_type, overload = call_free);
	188	};
	189
	190	struct impl
	191	{
1e59de90 TL	192	template <typename T>
	193	struct proxy
	194	{
	195	#if defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
	196	struct type
	197	{
	198	template <typename P>
	199	auto query(BOOST_ASIO_MOVE_ARG(P) p)
	200	noexcept(
	201	noexcept(
	202	declval<typename conditional<true, T, P>::type>().query(
	203	BOOST_ASIO_MOVE_CAST(P)(p))
	204	)
	205	)
	206	-> decltype(
	207	declval<typename conditional<true, T, P>::type>().query(
	208	BOOST_ASIO_MOVE_CAST(P)(p))
	209	);
	210	};
	211	#else // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
	212	typedef T type;
	213	#endif // defined(BOOST_ASIO_HAS_DEDUCED_QUERY_MEMBER_TRAIT)
	214	};
	215
20effc67 TL	216	template <typename T, typename Property>
20effc67 TL	217	BOOST_ASIO_NODISCARD BOOST_ASIO_CONSTEXPR typename enable_if<
1e59de90 TL	218	call_traits<impl, T, void(Property)>::overload == static_value,
1e59de90 TL	219	typename call_traits<impl, T, void(Property)>::result_type
20effc67 TL	220	>::type
	221	operator()(
	222	BOOST_ASIO_MOVE_ARG(T),
	223	BOOST_ASIO_MOVE_ARG(Property)) const
	224	BOOST_ASIO_NOEXCEPT_IF((
1e59de90	225	call_traits<impl, T, void(Property)>::is_noexcept))
20effc67 TL	226	{
	227	return static_query<
	228	typename decay<T>::type,
	229	typename decay<Property>::type
	230	>::value();
	231	}
	232
	233	template <typename T, typename Property>
	234	BOOST_ASIO_NODISCARD BOOST_ASIO_CONSTEXPR typename enable_if<
1e59de90 TL	235	call_traits<impl, T, void(Property)>::overload == call_member,
1e59de90 TL	236	typename call_traits<impl, T, void(Property)>::result_type
20effc67 TL	237	>::type
	238	operator()(
	239	BOOST_ASIO_MOVE_ARG(T) t,
	240	BOOST_ASIO_MOVE_ARG(Property) p) const
	241	BOOST_ASIO_NOEXCEPT_IF((
1e59de90	242	call_traits<impl, T, void(Property)>::is_noexcept))
20effc67 TL	243	{
	244	return BOOST_ASIO_MOVE_CAST(T)(t).query(BOOST_ASIO_MOVE_CAST(Property)(p));
	245	}
	246
	247	template <typename T, typename Property>
	248	BOOST_ASIO_NODISCARD BOOST_ASIO_CONSTEXPR typename enable_if<
1e59de90 TL	249	call_traits<impl, T, void(Property)>::overload == call_free,
1e59de90 TL	250	typename call_traits<impl, T, void(Property)>::result_type
20effc67 TL	251	>::type
	252	operator()(
	253	BOOST_ASIO_MOVE_ARG(T) t,
	254	BOOST_ASIO_MOVE_ARG(Property) p) const
	255	BOOST_ASIO_NOEXCEPT_IF((
1e59de90	256	call_traits<impl, T, void(Property)>::is_noexcept))
20effc67 TL	257	{
	258	return query(BOOST_ASIO_MOVE_CAST(T)(t), BOOST_ASIO_MOVE_CAST(Property)(p));
	259	}
	260	};
	261
	262	template <typename T = impl>
	263	struct static_instance
	264	{
	265	static const T instance;
	266	};
	267
	268	template <typename T>
	269	const T static_instance<T>::instance = {};
	270
1e59de90	271	} // namespace boost_asio_query_fn
20effc67 TL	272	namespace boost {
	273	namespace asio {
	274	namespace {
	275
1e59de90 TL	276	static BOOST_ASIO_CONSTEXPR const boost_asio_query_fn::impl&
1e59de90 TL	277	query = boost_asio_query_fn::static_instance<>::instance;
20effc67 TL	278
	279	} // namespace
	280
1e59de90 TL	281	typedef boost_asio_query_fn::impl query_t;
1e59de90 TL	282
20effc67 TL	283	template <typename T, typename Property>
	284	struct can_query :
	285	integral_constant<bool,
1e59de90 TL	286	boost_asio_query_fn::call_traits<query_t, T, void(Property)>::overload !=
1e59de90 TL	287	boost_asio_query_fn::ill_formed>
20effc67 TL	288	{
	289	};
	290
	291	#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
	292
	293	template <typename T, typename Property>
	294	constexpr bool can_query_v
	295	= can_query<T, Property>::value;
	296
	297	#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
	298
	299	template <typename T, typename Property>
	300	struct is_nothrow_query :
	301	integral_constant<bool,
1e59de90	302	boost_asio_query_fn::call_traits<query_t, T, void(Property)>::is_noexcept>
20effc67 TL	303	{
	304	};
	305
	306	#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
	307
	308	template <typename T, typename Property>
	309	constexpr bool is_nothrow_query_v
	310	= is_nothrow_query<T, Property>::value;
	311
	312	#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
	313
	314	template <typename T, typename Property>
	315	struct query_result
	316	{
1e59de90 TL	317	typedef typename boost_asio_query_fn::call_traits<
1e59de90 TL	318	query_t, T, void(Property)>::result_type type;
20effc67 TL	319	};
	320
	321	} // namespace asio
	322	} // namespace boost
	323
	324	#endif // defined(GENERATING_DOCUMENTATION)
	325
	326	#include <boost/asio/detail/pop_options.hpp>
	327
	328	#endif // BOOST_ASIO_QUERY_HPP