//
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// execution/allocator.hpp
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// ~~~~~~~~~~~~~~~~~~~~~~~
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//
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// Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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#ifndef BOOST_ASIO_EXECUTION_ALLOCATOR_HPP
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#define BOOST_ASIO_EXECUTION_ALLOCATOR_HPP
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#if defined(_MSC_VER) && (_MSC_VER >= 1200)
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# pragma once
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#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
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#include <boost/asio/detail/config.hpp>
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#include <boost/asio/detail/type_traits.hpp>
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#include <boost/asio/execution/executor.hpp>
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#include <boost/asio/execution/scheduler.hpp>
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#include <boost/asio/execution/sender.hpp>
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#include <boost/asio/is_applicable_property.hpp>
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#include <boost/asio/traits/query_static_constexpr_member.hpp>
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#include <boost/asio/traits/static_query.hpp>
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#include <boost/asio/detail/push_options.hpp>
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namespace boost {
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namespace asio {
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#if defined(GENERATING_DOCUMENTATION)
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namespace execution {
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/// A property to describe which allocator an executor will use to allocate the
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/// memory required to store a submitted function object.
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template <typename ProtoAllocator>
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struct allocator_t
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{
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/// The allocator_t property applies to executors, senders, and schedulers.
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template <typename T>
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static constexpr bool is_applicable_property_v =
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is_executor_v<T> || is_sender_v<T> || is_scheduler_v<T>;
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/// The allocator_t property can be required.
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static constexpr bool is_requirable = true;
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/// The allocator_t property can be preferred.
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static constexpr bool is_preferable = true;
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/// Default constructor.
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constexpr allocator_t();
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/// Obtain the allocator stored in the allocator_t property object.
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/**
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* Present only if @c ProtoAllocator is non-void.
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*/
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constexpr ProtoAllocator value() const;
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/// Create an allocator_t object with a different allocator.
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/**
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* Present only if @c ProtoAllocator is void.
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*/
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template <typename OtherAllocator>
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allocator_t<OtherAllocator operator()(const OtherAllocator& a);
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};
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/// A special value used for accessing the allocator_t property.
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constexpr allocator_t<void> allocator;
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} // namespace execution
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#else // defined(GENERATING_DOCUMENTATION)
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namespace execution {
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template <typename ProtoAllocator>
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struct allocator_t
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{
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#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
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template <typename T>
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BOOST_ASIO_STATIC_CONSTEXPR(bool,
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is_applicable_property_v = is_executor<T>::value
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|| is_sender<T>::value || is_scheduler<T>::value);
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#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
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BOOST_ASIO_STATIC_CONSTEXPR(bool, is_requirable = true);
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BOOST_ASIO_STATIC_CONSTEXPR(bool, is_preferable = true);
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#if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \
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&& defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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template <typename T>
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static BOOST_ASIO_CONSTEXPR
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typename traits::query_static_constexpr_member<T, allocator_t>::result_type
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static_query()
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BOOST_ASIO_NOEXCEPT_IF((
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traits::query_static_constexpr_member<T, allocator_t>::is_noexcept))
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{
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return traits::query_static_constexpr_member<T, allocator_t>::value();
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}
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template <typename E, typename T = decltype(allocator_t::static_query<E>())>
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static BOOST_ASIO_CONSTEXPR const T static_query_v
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= allocator_t::static_query<E>();
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#endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
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// && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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BOOST_ASIO_CONSTEXPR ProtoAllocator value() const
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{
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return a_;
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}
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private:
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friend struct allocator_t<void>;
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explicit BOOST_ASIO_CONSTEXPR allocator_t(const ProtoAllocator& a)
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: a_(a)
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{
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}
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ProtoAllocator a_;
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};
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#if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \
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&& defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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template <typename ProtoAllocator> template <typename E, typename T>
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const T allocator_t<ProtoAllocator>::static_query_v;
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#endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
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// && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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template <>
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struct allocator_t<void>
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{
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#if defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
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template <typename T>
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BOOST_ASIO_STATIC_CONSTEXPR(bool,
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is_applicable_property_v = is_executor<T>::value
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|| is_sender<T>::value || is_scheduler<T>::value);
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#endif // defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
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BOOST_ASIO_STATIC_CONSTEXPR(bool, is_requirable = true);
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BOOST_ASIO_STATIC_CONSTEXPR(bool, is_preferable = true);
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BOOST_ASIO_CONSTEXPR allocator_t()
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{
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}
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#if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \
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&& defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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template <typename T>
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static BOOST_ASIO_CONSTEXPR
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typename traits::query_static_constexpr_member<T, allocator_t>::result_type
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static_query()
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BOOST_ASIO_NOEXCEPT_IF((
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traits::query_static_constexpr_member<T, allocator_t>::is_noexcept))
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{
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return traits::query_static_constexpr_member<T, allocator_t>::value();
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}
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template <typename E, typename T = decltype(allocator_t::static_query<E>())>
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static BOOST_ASIO_CONSTEXPR const T static_query_v
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= allocator_t::static_query<E>();
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#endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
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// && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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template <typename OtherProtoAllocator>
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BOOST_ASIO_CONSTEXPR allocator_t<OtherProtoAllocator> operator()(
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const OtherProtoAllocator& a) const
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{
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return allocator_t<OtherProtoAllocator>(a);
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}
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};
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#if defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \
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&& defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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template <typename E, typename T>
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const T allocator_t<void>::static_query_v;
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#endif // defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
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// && defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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#if defined(BOOST_ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION)
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constexpr allocator_t<void> allocator;
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#else // defined(BOOST_ASIO_HAS_CONSTEXPR) || defined(GENERATING_DOCUMENTATION)
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template <typename T>
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struct allocator_instance
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{
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static allocator_t<T> instance;
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};
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template <typename T>
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allocator_t<T> allocator_instance<T>::instance;
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namespace {
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static const allocator_t<void>& allocator = allocator_instance<void>::instance;
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} // namespace
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#endif
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} // namespace execution
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#if !defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
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template <typename T, typename ProtoAllocator>
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struct is_applicable_property<T, execution::allocator_t<ProtoAllocator> >
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: integral_constant<bool,
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execution::is_executor<T>::value
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|| execution::is_sender<T>::value
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|| execution::is_scheduler<T>::value>
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{
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};
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#endif // !defined(BOOST_ASIO_HAS_VARIABLE_TEMPLATES)
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namespace traits {
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#if !defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT) \
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|| !defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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template <typename T, typename ProtoAllocator>
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struct static_query<T, execution::allocator_t<ProtoAllocator>,
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typename enable_if<
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traits::query_static_constexpr_member<T,
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execution::allocator_t<ProtoAllocator> >::is_valid
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>::type>
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{
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BOOST_ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
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BOOST_ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
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typedef typename traits::query_static_constexpr_member<T,
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execution::allocator_t<ProtoAllocator> >::result_type result_type;
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static BOOST_ASIO_CONSTEXPR result_type value()
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{
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return traits::query_static_constexpr_member<T,
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execution::allocator_t<ProtoAllocator> >::value();
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}
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};
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#endif // !defined(BOOST_ASIO_HAS_DEDUCED_STATIC_QUERY_TRAIT)
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// || !defined(BOOST_ASIO_HAS_SFINAE_VARIABLE_TEMPLATES)
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} // namespace traits
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#endif // defined(GENERATING_DOCUMENTATION)
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} // namespace asio
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} // namespace boost
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#include <boost/asio/detail/pop_options.hpp>
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#endif // BOOST_ASIO_EXECUTION_ALLOCATOR_HPP
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