106c3fb27SDimitry Andric //===----------------------------------------------------------------------===// 206c3fb27SDimitry Andric // 306c3fb27SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 406c3fb27SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 506c3fb27SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 606c3fb27SDimitry Andric // 706c3fb27SDimitry Andric //===----------------------------------------------------------------------===// 806c3fb27SDimitry Andric 906c3fb27SDimitry Andric #ifndef _LIBCPP___ATOMIC_MEMORY_ORDER_H 1006c3fb27SDimitry Andric #define _LIBCPP___ATOMIC_MEMORY_ORDER_H 1106c3fb27SDimitry Andric 1206c3fb27SDimitry Andric #include <__config> 1306c3fb27SDimitry Andric #include <__type_traits/is_same.h> 1406c3fb27SDimitry Andric #include <__type_traits/underlying_type.h> 1506c3fb27SDimitry Andric 1606c3fb27SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 1706c3fb27SDimitry Andric # pragma GCC system_header 1806c3fb27SDimitry Andric #endif 1906c3fb27SDimitry Andric 2006c3fb27SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 2106c3fb27SDimitry Andric 2206c3fb27SDimitry Andric // Figure out what the underlying type for `memory_order` would be if it were 2306c3fb27SDimitry Andric // declared as an unscoped enum (accounting for -fshort-enums). Use this result 2406c3fb27SDimitry Andric // to pin the underlying type in C++20. 25cb14a3feSDimitry Andric enum __legacy_memory_order { __mo_relaxed, __mo_consume, __mo_acquire, __mo_release, __mo_acq_rel, __mo_seq_cst }; 2606c3fb27SDimitry Andric 2706c3fb27SDimitry Andric using __memory_order_underlying_t = underlying_type<__legacy_memory_order>::type; 2806c3fb27SDimitry Andric 2906c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20 3006c3fb27SDimitry Andric 3106c3fb27SDimitry Andric enum class memory_order : __memory_order_underlying_t { 3206c3fb27SDimitry Andric relaxed = __mo_relaxed, 3306c3fb27SDimitry Andric consume = __mo_consume, 3406c3fb27SDimitry Andric acquire = __mo_acquire, 3506c3fb27SDimitry Andric release = __mo_release, 3606c3fb27SDimitry Andric acq_rel = __mo_acq_rel, 3706c3fb27SDimitry Andric seq_cst = __mo_seq_cst 3806c3fb27SDimitry Andric }; 3906c3fb27SDimitry Andric 40*0fca6ea1SDimitry Andric static_assert(is_same<underlying_type<memory_order>::type, __memory_order_underlying_t>::value, 4106c3fb27SDimitry Andric "unexpected underlying type for std::memory_order"); 4206c3fb27SDimitry Andric 4306c3fb27SDimitry Andric inline constexpr auto memory_order_relaxed = memory_order::relaxed; 4406c3fb27SDimitry Andric inline constexpr auto memory_order_consume = memory_order::consume; 4506c3fb27SDimitry Andric inline constexpr auto memory_order_acquire = memory_order::acquire; 4606c3fb27SDimitry Andric inline constexpr auto memory_order_release = memory_order::release; 4706c3fb27SDimitry Andric inline constexpr auto memory_order_acq_rel = memory_order::acq_rel; 4806c3fb27SDimitry Andric inline constexpr auto memory_order_seq_cst = memory_order::seq_cst; 4906c3fb27SDimitry Andric 5006c3fb27SDimitry Andric #else 5106c3fb27SDimitry Andric 5206c3fb27SDimitry Andric enum memory_order { 5306c3fb27SDimitry Andric memory_order_relaxed = __mo_relaxed, 5406c3fb27SDimitry Andric memory_order_consume = __mo_consume, 5506c3fb27SDimitry Andric memory_order_acquire = __mo_acquire, 5606c3fb27SDimitry Andric memory_order_release = __mo_release, 5706c3fb27SDimitry Andric memory_order_acq_rel = __mo_acq_rel, 5806c3fb27SDimitry Andric memory_order_seq_cst = __mo_seq_cst, 5906c3fb27SDimitry Andric }; 6006c3fb27SDimitry Andric 6106c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20 6206c3fb27SDimitry Andric 6306c3fb27SDimitry Andric _LIBCPP_END_NAMESPACE_STD 6406c3fb27SDimitry Andric 6506c3fb27SDimitry Andric #endif // _LIBCPP___ATOMIC_MEMORY_ORDER_H 66