Restoring authorship annotation for Andrey Khalyavin <halyavin@gmail.com>. Commit 1 of 2.

1 files changed, 2695 insertions, 2695 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/include/atomic b/contrib/libs/cxxsupp/libcxx/include/atomic
index 992c745961..1a917368eb 100644
--- a/contrib/libs/cxxsupp/libcxx/include/atomic
+++ b/contrib/libs/cxxsupp/libcxx/include/atomic
@@ -1,2723 +1,2723 @@
-// -*- C++ -*-
-//===--------------------------- atomic -----------------------------------===//
-//
+// -*- C++ -*- 
+//===--------------------------- atomic -----------------------------------===// 
+// 
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_ATOMIC
-#define _LIBCPP_ATOMIC
-
-/*
-    atomic synopsis
-
-namespace std
-{
-
-// feature test macro [version.syn]
-
-#define __cpp_lib_atomic_is_always_lock_free
-#define __cpp_lib_atomic_flag_test
-#define __cpp_lib_atomic_lock_free_type_aliases
-#define __cpp_lib_atomic_wait
-
+// 
+//===----------------------------------------------------------------------===// 
+ 
+#ifndef _LIBCPP_ATOMIC 
+#define _LIBCPP_ATOMIC 
+ 
+/* 
+    atomic synopsis 
+ 
+namespace std 
+{ 
+ 
+// feature test macro [version.syn] 
+ 
+#define __cpp_lib_atomic_is_always_lock_free 
+#define __cpp_lib_atomic_flag_test 
+#define __cpp_lib_atomic_lock_free_type_aliases 
+#define __cpp_lib_atomic_wait 
+ 
  // order and consistency
-
- enum memory_order: unspecified // enum class in C++20
+ 
+ enum memory_order: unspecified // enum class in C++20 
  {
-    relaxed,
-    consume, // load-consume
-    acquire, // load-acquire
-    release, // store-release
-    acq_rel, // store-release load-acquire
-    seq_cst // store-release load-acquire
- };
-
- inline constexpr auto memory_order_relaxed = memory_order::relaxed;
- inline constexpr auto memory_order_consume = memory_order::consume;
- inline constexpr auto memory_order_acquire = memory_order::acquire;
- inline constexpr auto memory_order_release = memory_order::release;
- inline constexpr auto memory_order_acq_rel = memory_order::acq_rel;
- inline constexpr auto memory_order_seq_cst = memory_order::seq_cst;
-
-template <class T> T kill_dependency(T y) noexcept;
-
-// lock-free property
-
-#define ATOMIC_BOOL_LOCK_FREE unspecified
-#define ATOMIC_CHAR_LOCK_FREE unspecified
-#define ATOMIC_CHAR8_T_LOCK_FREE unspecified // C++20
-#define ATOMIC_CHAR16_T_LOCK_FREE unspecified
-#define ATOMIC_CHAR32_T_LOCK_FREE unspecified
-#define ATOMIC_WCHAR_T_LOCK_FREE unspecified
-#define ATOMIC_SHORT_LOCK_FREE unspecified
-#define ATOMIC_INT_LOCK_FREE unspecified
-#define ATOMIC_LONG_LOCK_FREE unspecified
-#define ATOMIC_LLONG_LOCK_FREE unspecified
-#define ATOMIC_POINTER_LOCK_FREE unspecified
-
-template <class T>
-struct atomic
-{
-    using value_type = T;
-
-    static constexpr bool is_always_lock_free;
-    bool is_lock_free() const volatile noexcept;
-    bool is_lock_free() const noexcept;
-
-    atomic() noexcept = default; // until C++20
-    constexpr atomic() noexcept(is_nothrow_default_constructible_v<T>); // since C++20
-    constexpr atomic(T desr) noexcept;
-    atomic(const atomic&) = delete;
-    atomic& operator=(const atomic&) = delete;
-    atomic& operator=(const atomic&) volatile = delete;
-
-    T load(memory_order m = memory_order_seq_cst) const volatile noexcept;
-    T load(memory_order m = memory_order_seq_cst) const noexcept;
-    operator T() const volatile noexcept;
-    operator T() const noexcept;
-    void store(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    void store(T desr, memory_order m = memory_order_seq_cst) noexcept;
-    T operator=(T) volatile noexcept;
-    T operator=(T) noexcept;
-
-    T exchange(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    T exchange(T desr, memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_weak(T& expc, T desr,
-                               memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_weak(T& expc, T desr, memory_order s, memory_order f) noexcept;
-    bool compare_exchange_strong(T& expc, T desr,
-                                 memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_strong(T& expc, T desr,
-                                 memory_order s, memory_order f) noexcept;
-    bool compare_exchange_weak(T& expc, T desr,
-                               memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_weak(T& expc, T desr,
-                               memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_strong(T& expc, T desr,
-                                memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_strong(T& expc, T desr,
-                                 memory_order m = memory_order_seq_cst) noexcept;
-
-    void wait(T, memory_order = memory_order::seq_cst) const volatile noexcept;
-    void wait(T, memory_order = memory_order::seq_cst) const noexcept;
-    void notify_one() volatile noexcept;
-    void notify_one() noexcept;
-    void notify_all() volatile noexcept;
-    void notify_all() noexcept;
-};
-
-template <>
-struct atomic<integral>
-{
-    using value_type = integral;
-    using difference_type = value_type;
-
-    static constexpr bool is_always_lock_free;
-    bool is_lock_free() const volatile noexcept;
-    bool is_lock_free() const noexcept;
-
-    atomic() noexcept = default;
-    constexpr atomic(integral desr) noexcept;
-    atomic(const atomic&) = delete;
-    atomic& operator=(const atomic&) = delete;
-    atomic& operator=(const atomic&) volatile = delete;
-
-    integral load(memory_order m = memory_order_seq_cst) const volatile noexcept;
-    integral load(memory_order m = memory_order_seq_cst) const noexcept;
-    operator integral() const volatile noexcept;
-    operator integral() const noexcept;
-    void store(integral desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    void store(integral desr, memory_order m = memory_order_seq_cst) noexcept;
-    integral operator=(integral desr) volatile noexcept;
-    integral operator=(integral desr) noexcept;
-
-    integral exchange(integral desr,
-                      memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral exchange(integral desr, memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_weak(integral& expc, integral desr,
-                               memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_weak(integral& expc, integral desr,
-                               memory_order s, memory_order f) noexcept;
-    bool compare_exchange_strong(integral& expc, integral desr,
-                                 memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_strong(integral& expc, integral desr,
-                                 memory_order s, memory_order f) noexcept;
-    bool compare_exchange_weak(integral& expc, integral desr,
-                               memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_weak(integral& expc, integral desr,
-                               memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_strong(integral& expc, integral desr,
-                                memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_strong(integral& expc, integral desr,
-                                 memory_order m = memory_order_seq_cst) noexcept;
-
-    integral fetch_add(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_add(integral op, memory_order m = memory_order_seq_cst) noexcept;
-    integral fetch_sub(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_sub(integral op, memory_order m = memory_order_seq_cst) noexcept;
-    integral fetch_and(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_and(integral op, memory_order m = memory_order_seq_cst) noexcept;
-    integral fetch_or(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_or(integral op, memory_order m = memory_order_seq_cst) noexcept;
-    integral fetch_xor(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_xor(integral op, memory_order m = memory_order_seq_cst) noexcept;
-
-    integral operator++(int) volatile noexcept;
-    integral operator++(int) noexcept;
-    integral operator--(int) volatile noexcept;
-    integral operator--(int) noexcept;
-    integral operator++() volatile noexcept;
-    integral operator++() noexcept;
-    integral operator--() volatile noexcept;
-    integral operator--() noexcept;
-    integral operator+=(integral op) volatile noexcept;
-    integral operator+=(integral op) noexcept;
-    integral operator-=(integral op) volatile noexcept;
-    integral operator-=(integral op) noexcept;
-    integral operator&=(integral op) volatile noexcept;
-    integral operator&=(integral op) noexcept;
-    integral operator|=(integral op) volatile noexcept;
-    integral operator|=(integral op) noexcept;
-    integral operator^=(integral op) volatile noexcept;
-    integral operator^=(integral op) noexcept;
-
-    void wait(integral, memory_order = memory_order::seq_cst) const volatile noexcept;
-    void wait(integral, memory_order = memory_order::seq_cst) const noexcept;
-    void notify_one() volatile noexcept;
-    void notify_one() noexcept;
-    void notify_all() volatile noexcept;
-    void notify_all() noexcept;
-};
-
-template <class T>
-struct atomic<T*>
-{
-    using value_type = T*;
-    using difference_type = ptrdiff_t;
-
-    static constexpr bool is_always_lock_free;
-    bool is_lock_free() const volatile noexcept;
-    bool is_lock_free() const noexcept;
-
-    atomic() noexcept = default; // until C++20
-    constexpr atomic() noexcept; // since C++20
-    constexpr atomic(T* desr) noexcept;
-    atomic(const atomic&) = delete;
-    atomic& operator=(const atomic&) = delete;
-    atomic& operator=(const atomic&) volatile = delete;
-
-    T* load(memory_order m = memory_order_seq_cst) const volatile noexcept;
-    T* load(memory_order m = memory_order_seq_cst) const noexcept;
-    operator T*() const volatile noexcept;
-    operator T*() const noexcept;
-    void store(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    void store(T* desr, memory_order m = memory_order_seq_cst) noexcept;
-    T* operator=(T*) volatile noexcept;
-    T* operator=(T*) noexcept;
-
-    T* exchange(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    T* exchange(T* desr, memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_weak(T*& expc, T* desr,
-                               memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_weak(T*& expc, T* desr,
-                               memory_order s, memory_order f) noexcept;
-    bool compare_exchange_strong(T*& expc, T* desr,
-                                 memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_strong(T*& expc, T* desr,
-                                 memory_order s, memory_order f) noexcept;
-    bool compare_exchange_weak(T*& expc, T* desr,
-                               memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_weak(T*& expc, T* desr,
-                               memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_strong(T*& expc, T* desr,
-                                memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_strong(T*& expc, T* desr,
-                                 memory_order m = memory_order_seq_cst) noexcept;
-    T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;
-    T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;
-
-    T* operator++(int) volatile noexcept;
-    T* operator++(int) noexcept;
-    T* operator--(int) volatile noexcept;
-    T* operator--(int) noexcept;
-    T* operator++() volatile noexcept;
-    T* operator++() noexcept;
-    T* operator--() volatile noexcept;
-    T* operator--() noexcept;
-    T* operator+=(ptrdiff_t op) volatile noexcept;
-    T* operator+=(ptrdiff_t op) noexcept;
-    T* operator-=(ptrdiff_t op) volatile noexcept;
-    T* operator-=(ptrdiff_t op) noexcept;
-
-    void wait(T*, memory_order = memory_order::seq_cst) const volatile noexcept;
-    void wait(T*, memory_order = memory_order::seq_cst) const noexcept;
-    void notify_one() volatile noexcept;
-    void notify_one() noexcept;
-    void notify_all() volatile noexcept;
-    void notify_all() noexcept;
-};
-
-
-// [atomics.nonmembers], non-member functions
-template<class T>
-  bool atomic_is_lock_free(const volatile atomic<T>*) noexcept;
-template<class T>
-  bool atomic_is_lock_free(const atomic<T>*) noexcept;
-template<class T>
-  void atomic_store(volatile atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  void atomic_store(atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  void atomic_store_explicit(volatile atomic<T>*, atomic<T>::value_type,
-                             memory_order) noexcept;
-template<class T>
-  void atomic_store_explicit(atomic<T>*, atomic<T>::value_type,
-                             memory_order) noexcept;
-template<class T>
-  T atomic_load(const volatile atomic<T>*) noexcept;
-template<class T>
-  T atomic_load(const atomic<T>*) noexcept;
-template<class T>
-  T atomic_load_explicit(const volatile atomic<T>*, memory_order) noexcept;
-template<class T>
-  T atomic_load_explicit(const atomic<T>*, memory_order) noexcept;
-template<class T>
-  T atomic_exchange(volatile atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  T atomic_exchange(atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  T atomic_exchange_explicit(volatile atomic<T>*, atomic<T>::value_type,
-                             memory_order) noexcept;
-template<class T>
-  T atomic_exchange_explicit(atomic<T>*, atomic<T>::value_type,
-                             memory_order) noexcept;
-template<class T>
-  bool atomic_compare_exchange_weak(volatile atomic<T>*, atomic<T>::value_type*,
-                                    atomic<T>::value_type) noexcept;
-template<class T>
-  bool atomic_compare_exchange_weak(atomic<T>*, atomic<T>::value_type*,
-                                    atomic<T>::value_type) noexcept;
-template<class T>
-  bool atomic_compare_exchange_strong(volatile atomic<T>*, atomic<T>::value_type*,
-                                      atomic<T>::value_type) noexcept;
-template<class T>
-  bool atomic_compare_exchange_strong(atomic<T>*, atomic<T>::value_type*,
-                                      atomic<T>::value_type) noexcept;
-template<class T>
-  bool atomic_compare_exchange_weak_explicit(volatile atomic<T>*, atomic<T>::value_type*,
-                                             atomic<T>::value_type,
-                                             memory_order, memory_order) noexcept;
-template<class T>
-  bool atomic_compare_exchange_weak_explicit(atomic<T>*, atomic<T>::value_type*,
-                                             atomic<T>::value_type,
-                                             memory_order, memory_order) noexcept;
-template<class T>
-  bool atomic_compare_exchange_strong_explicit(volatile atomic<T>*, atomic<T>::value_type*,
-                                               atomic<T>::value_type,
-                                               memory_order, memory_order) noexcept;
-template<class T>
-  bool atomic_compare_exchange_strong_explicit(atomic<T>*, atomic<T>::value_type*,
-                                               atomic<T>::value_type,
-                                               memory_order, memory_order) noexcept;
-
-template<class T>
-  T atomic_fetch_add(volatile atomic<T>*, atomic<T>::difference_type) noexcept;
-template<class T>
-  T atomic_fetch_add(atomic<T>*, atomic<T>::difference_type) noexcept;
-template<class T>
-  T atomic_fetch_add_explicit(volatile atomic<T>*, atomic<T>::difference_type,
-                              memory_order) noexcept;
-template<class T>
-  T atomic_fetch_add_explicit(atomic<T>*, atomic<T>::difference_type,
-                              memory_order) noexcept;
-template<class T>
-  T atomic_fetch_sub(volatile atomic<T>*, atomic<T>::difference_type) noexcept;
-template<class T>
-  T atomic_fetch_sub(atomic<T>*, atomic<T>::difference_type) noexcept;
-template<class T>
-  T atomic_fetch_sub_explicit(volatile atomic<T>*, atomic<T>::difference_type,
-                              memory_order) noexcept;
-template<class T>
-  T atomic_fetch_sub_explicit(atomic<T>*, atomic<T>::difference_type,
-                              memory_order) noexcept;
-template<class T>
-  T atomic_fetch_and(volatile atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  T atomic_fetch_and(atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  T atomic_fetch_and_explicit(volatile atomic<T>*, atomic<T>::value_type,
-                              memory_order) noexcept;
-template<class T>
-  T atomic_fetch_and_explicit(atomic<T>*, atomic<T>::value_type,
-                              memory_order) noexcept;
-template<class T>
-  T atomic_fetch_or(volatile atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  T atomic_fetch_or(atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  T atomic_fetch_or_explicit(volatile atomic<T>*, atomic<T>::value_type,
-                             memory_order) noexcept;
-template<class T>
-  T atomic_fetch_or_explicit(atomic<T>*, atomic<T>::value_type,
-                             memory_order) noexcept;
-template<class T>
-  T atomic_fetch_xor(volatile atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  T atomic_fetch_xor(atomic<T>*, atomic<T>::value_type) noexcept;
-template<class T>
-  T atomic_fetch_xor_explicit(volatile atomic<T>*, atomic<T>::value_type,
-                              memory_order) noexcept;
-template<class T>
-  T atomic_fetch_xor_explicit(atomic<T>*, atomic<T>::value_type,
-                              memory_order) noexcept;
-
-template<class T>
-  void atomic_wait(const volatile atomic<T>*, atomic<T>::value_type);
-template<class T>
-  void atomic_wait(const atomic<T>*, atomic<T>::value_type);
-template<class T>
-  void atomic_wait_explicit(const volatile atomic<T>*, atomic<T>::value_type,
-                            memory_order);
-template<class T>
-  void atomic_wait_explicit(const atomic<T>*, atomic<T>::value_type,
-                            memory_order);
-template<class T>
-  void atomic_notify_one(volatile atomic<T>*);
-template<class T>
-  void atomic_notify_one(atomic<T>*);
-template<class T>
-  void atomic_notify_all(volatile atomic<T>*);
-template<class T>
-  void atomic_notify_all(atomic<T>*);
-
-// Atomics for standard typedef types
-
-typedef atomic<bool>               atomic_bool;
-typedef atomic<char>               atomic_char;
-typedef atomic<signed char>        atomic_schar;
-typedef atomic<unsigned char>      atomic_uchar;
-typedef atomic<short>              atomic_short;
-typedef atomic<unsigned short>     atomic_ushort;
-typedef atomic<int>                atomic_int;
-typedef atomic<unsigned int>       atomic_uint;
-typedef atomic<long>               atomic_long;
-typedef atomic<unsigned long>      atomic_ulong;
-typedef atomic<long long>          atomic_llong;
-typedef atomic<unsigned long long> atomic_ullong;
-typedef atomic<char8_t>            atomic_char8_t; // C++20
-typedef atomic<char16_t>           atomic_char16_t;
-typedef atomic<char32_t>           atomic_char32_t;
-typedef atomic<wchar_t>            atomic_wchar_t;
-
-typedef atomic<int_least8_t>   atomic_int_least8_t;
-typedef atomic<uint_least8_t>  atomic_uint_least8_t;
-typedef atomic<int_least16_t>  atomic_int_least16_t;
-typedef atomic<uint_least16_t> atomic_uint_least16_t;
-typedef atomic<int_least32_t>  atomic_int_least32_t;
-typedef atomic<uint_least32_t> atomic_uint_least32_t;
-typedef atomic<int_least64_t>  atomic_int_least64_t;
-typedef atomic<uint_least64_t> atomic_uint_least64_t;
-
-typedef atomic<int_fast8_t>   atomic_int_fast8_t;
-typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
-typedef atomic<int_fast16_t>  atomic_int_fast16_t;
-typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
-typedef atomic<int_fast32_t>  atomic_int_fast32_t;
-typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
-typedef atomic<int_fast64_t>  atomic_int_fast64_t;
-typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
-
-typedef atomic<int8_t>   atomic_int8_t;
-typedef atomic<uint8_t>  atomic_uint8_t;
-typedef atomic<int16_t>  atomic_int16_t;
-typedef atomic<uint16_t> atomic_uint16_t;
-typedef atomic<int32_t>  atomic_int32_t;
-typedef atomic<uint32_t> atomic_uint32_t;
-typedef atomic<int64_t>  atomic_int64_t;
-typedef atomic<uint64_t> atomic_uint64_t;
-
-typedef atomic<intptr_t>  atomic_intptr_t;
-typedef atomic<uintptr_t> atomic_uintptr_t;
-typedef atomic<size_t>    atomic_size_t;
-typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
-typedef atomic<intmax_t>  atomic_intmax_t;
-typedef atomic<uintmax_t> atomic_uintmax_t;
-
-// flag type and operations
-
-typedef struct atomic_flag
-{
-    atomic_flag() noexcept = default; // until C++20
-    constexpr atomic_flag() noexcept; // since C++20
-    atomic_flag(const atomic_flag&) = delete;
-    atomic_flag& operator=(const atomic_flag&) = delete;
-    atomic_flag& operator=(const atomic_flag&) volatile = delete;
-
-    bool test(memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool test(memory_order m = memory_order_seq_cst) noexcept;
-    bool test_and_set(memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool test_and_set(memory_order m = memory_order_seq_cst) noexcept;
-    void clear(memory_order m = memory_order_seq_cst) volatile noexcept;
-    void clear(memory_order m = memory_order_seq_cst) noexcept;
-
-    void wait(bool, memory_order = memory_order::seq_cst) const volatile noexcept;
-    void wait(bool, memory_order = memory_order::seq_cst) const noexcept;
-    void notify_one() volatile noexcept;
-    void notify_one() noexcept;
-    void notify_all() volatile noexcept;
-    void notify_all() noexcept;
-} atomic_flag;
-
-bool atomic_flag_test(volatile atomic_flag* obj) noexcept;
-bool atomic_flag_test(atomic_flag* obj) noexcept;
-bool atomic_flag_test_explicit(volatile atomic_flag* obj,
-                               memory_order m) noexcept;
-bool atomic_flag_test_explicit(atomic_flag* obj, memory_order m) noexcept;
-bool atomic_flag_test_and_set(volatile atomic_flag* obj) noexcept;
-bool atomic_flag_test_and_set(atomic_flag* obj) noexcept;
-bool atomic_flag_test_and_set_explicit(volatile atomic_flag* obj,
-                                       memory_order m) noexcept;
-bool atomic_flag_test_and_set_explicit(atomic_flag* obj, memory_order m) noexcept;
-void atomic_flag_clear(volatile atomic_flag* obj) noexcept;
-void atomic_flag_clear(atomic_flag* obj) noexcept;
-void atomic_flag_clear_explicit(volatile atomic_flag* obj, memory_order m) noexcept;
-void atomic_flag_clear_explicit(atomic_flag* obj, memory_order m) noexcept;
-
-void atomic_wait(const volatile atomic_flag* obj, T old) noexcept;
-void atomic_wait(const atomic_flag* obj, T old) noexcept;
-void atomic_wait_explicit(const volatile atomic_flag* obj, T old, memory_order m) noexcept;
-void atomic_wait_explicit(const atomic_flag* obj, T old, memory_order m) noexcept;
-void atomic_one(volatile atomic_flag* obj) noexcept;
-void atomic_one(atomic_flag* obj) noexcept;
-void atomic_all(volatile atomic_flag* obj) noexcept;
-void atomic_all(atomic_flag* obj) noexcept;
-
-// fences
-
-void atomic_thread_fence(memory_order m) noexcept;
-void atomic_signal_fence(memory_order m) noexcept;
-
-// deprecated
-
-template <class T>
-  void atomic_init(volatile atomic<T>* obj, atomic<T>::value_type desr) noexcept;
-
-template <class T>
-  void atomic_init(atomic<T>* obj, atomic<T>::value_type desr) noexcept;
-
-#define ATOMIC_VAR_INIT(value) see below
-
-#define ATOMIC_FLAG_INIT see below
-
-}  // std
-
-*/
-
-#include <__availability>
-#include <__config>
-#include <__threading_support>
-#include <cstddef>
-#include <cstdint>
-#include <cstring>
-#include <type_traits>
+    relaxed, 
+    consume, // load-consume 
+    acquire, // load-acquire 
+    release, // store-release 
+    acq_rel, // store-release load-acquire 
+    seq_cst // store-release load-acquire 
+ }; 
+ 
+ inline constexpr auto memory_order_relaxed = memory_order::relaxed; 
+ inline constexpr auto memory_order_consume = memory_order::consume; 
+ inline constexpr auto memory_order_acquire = memory_order::acquire; 
+ inline constexpr auto memory_order_release = memory_order::release; 
+ inline constexpr auto memory_order_acq_rel = memory_order::acq_rel; 
+ inline constexpr auto memory_order_seq_cst = memory_order::seq_cst; 
+ 
+template <class T> T kill_dependency(T y) noexcept; 
+ 
+// lock-free property 
+ 
+#define ATOMIC_BOOL_LOCK_FREE unspecified 
+#define ATOMIC_CHAR_LOCK_FREE unspecified 
+#define ATOMIC_CHAR8_T_LOCK_FREE unspecified // C++20 
+#define ATOMIC_CHAR16_T_LOCK_FREE unspecified 
+#define ATOMIC_CHAR32_T_LOCK_FREE unspecified 
+#define ATOMIC_WCHAR_T_LOCK_FREE unspecified 
+#define ATOMIC_SHORT_LOCK_FREE unspecified 
+#define ATOMIC_INT_LOCK_FREE unspecified 
+#define ATOMIC_LONG_LOCK_FREE unspecified 
+#define ATOMIC_LLONG_LOCK_FREE unspecified 
+#define ATOMIC_POINTER_LOCK_FREE unspecified 
+ 
+template <class T> 
+struct atomic 
+{ 
+    using value_type = T; 
+ 
+    static constexpr bool is_always_lock_free; 
+    bool is_lock_free() const volatile noexcept; 
+    bool is_lock_free() const noexcept; 
+ 
+    atomic() noexcept = default; // until C++20 
+    constexpr atomic() noexcept(is_nothrow_default_constructible_v<T>); // since C++20 
+    constexpr atomic(T desr) noexcept; 
+    atomic(const atomic&) = delete; 
+    atomic& operator=(const atomic&) = delete; 
+    atomic& operator=(const atomic&) volatile = delete; 
+ 
+    T load(memory_order m = memory_order_seq_cst) const volatile noexcept; 
+    T load(memory_order m = memory_order_seq_cst) const noexcept; 
+    operator T() const volatile noexcept; 
+    operator T() const noexcept; 
+    void store(T desr, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    void store(T desr, memory_order m = memory_order_seq_cst) noexcept; 
+    T operator=(T) volatile noexcept; 
+    T operator=(T) noexcept; 
+ 
+    T exchange(T desr, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    T exchange(T desr, memory_order m = memory_order_seq_cst) noexcept; 
+    bool compare_exchange_weak(T& expc, T desr, 
+                               memory_order s, memory_order f) volatile noexcept; 
+    bool compare_exchange_weak(T& expc, T desr, memory_order s, memory_order f) noexcept; 
+    bool compare_exchange_strong(T& expc, T desr, 
+                                 memory_order s, memory_order f) volatile noexcept; 
+    bool compare_exchange_strong(T& expc, T desr, 
+                                 memory_order s, memory_order f) noexcept; 
+    bool compare_exchange_weak(T& expc, T desr, 
+                               memory_order m = memory_order_seq_cst) volatile noexcept; 
+    bool compare_exchange_weak(T& expc, T desr, 
+                               memory_order m = memory_order_seq_cst) noexcept; 
+    bool compare_exchange_strong(T& expc, T desr, 
+                                memory_order m = memory_order_seq_cst) volatile noexcept; 
+    bool compare_exchange_strong(T& expc, T desr, 
+                                 memory_order m = memory_order_seq_cst) noexcept; 
+ 
+    void wait(T, memory_order = memory_order::seq_cst) const volatile noexcept; 
+    void wait(T, memory_order = memory_order::seq_cst) const noexcept; 
+    void notify_one() volatile noexcept; 
+    void notify_one() noexcept; 
+    void notify_all() volatile noexcept; 
+    void notify_all() noexcept; 
+}; 
+ 
+template <> 
+struct atomic<integral> 
+{ 
+    using value_type = integral; 
+    using difference_type = value_type; 
+ 
+    static constexpr bool is_always_lock_free; 
+    bool is_lock_free() const volatile noexcept; 
+    bool is_lock_free() const noexcept; 
+ 
+    atomic() noexcept = default; 
+    constexpr atomic(integral desr) noexcept; 
+    atomic(const atomic&) = delete; 
+    atomic& operator=(const atomic&) = delete; 
+    atomic& operator=(const atomic&) volatile = delete; 
+ 
+    integral load(memory_order m = memory_order_seq_cst) const volatile noexcept; 
+    integral load(memory_order m = memory_order_seq_cst) const noexcept; 
+    operator integral() const volatile noexcept; 
+    operator integral() const noexcept; 
+    void store(integral desr, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    void store(integral desr, memory_order m = memory_order_seq_cst) noexcept; 
+    integral operator=(integral desr) volatile noexcept; 
+    integral operator=(integral desr) noexcept; 
+ 
+    integral exchange(integral desr, 
+                      memory_order m = memory_order_seq_cst) volatile noexcept; 
+    integral exchange(integral desr, memory_order m = memory_order_seq_cst) noexcept; 
+    bool compare_exchange_weak(integral& expc, integral desr, 
+                               memory_order s, memory_order f) volatile noexcept; 
+    bool compare_exchange_weak(integral& expc, integral desr, 
+                               memory_order s, memory_order f) noexcept; 
+    bool compare_exchange_strong(integral& expc, integral desr, 
+                                 memory_order s, memory_order f) volatile noexcept; 
+    bool compare_exchange_strong(integral& expc, integral desr, 
+                                 memory_order s, memory_order f) noexcept; 
+    bool compare_exchange_weak(integral& expc, integral desr, 
+                               memory_order m = memory_order_seq_cst) volatile noexcept; 
+    bool compare_exchange_weak(integral& expc, integral desr, 
+                               memory_order m = memory_order_seq_cst) noexcept; 
+    bool compare_exchange_strong(integral& expc, integral desr, 
+                                memory_order m = memory_order_seq_cst) volatile noexcept; 
+    bool compare_exchange_strong(integral& expc, integral desr, 
+                                 memory_order m = memory_order_seq_cst) noexcept; 
+ 
+    integral fetch_add(integral op, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    integral fetch_add(integral op, memory_order m = memory_order_seq_cst) noexcept; 
+    integral fetch_sub(integral op, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    integral fetch_sub(integral op, memory_order m = memory_order_seq_cst) noexcept; 
+    integral fetch_and(integral op, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    integral fetch_and(integral op, memory_order m = memory_order_seq_cst) noexcept; 
+    integral fetch_or(integral op, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    integral fetch_or(integral op, memory_order m = memory_order_seq_cst) noexcept; 
+    integral fetch_xor(integral op, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    integral fetch_xor(integral op, memory_order m = memory_order_seq_cst) noexcept; 
+ 
+    integral operator++(int) volatile noexcept; 
+    integral operator++(int) noexcept; 
+    integral operator--(int) volatile noexcept; 
+    integral operator--(int) noexcept; 
+    integral operator++() volatile noexcept; 
+    integral operator++() noexcept; 
+    integral operator--() volatile noexcept; 
+    integral operator--() noexcept; 
+    integral operator+=(integral op) volatile noexcept; 
+    integral operator+=(integral op) noexcept; 
+    integral operator-=(integral op) volatile noexcept; 
+    integral operator-=(integral op) noexcept; 
+    integral operator&=(integral op) volatile noexcept; 
+    integral operator&=(integral op) noexcept; 
+    integral operator|=(integral op) volatile noexcept; 
+    integral operator|=(integral op) noexcept; 
+    integral operator^=(integral op) volatile noexcept; 
+    integral operator^=(integral op) noexcept; 
+ 
+    void wait(integral, memory_order = memory_order::seq_cst) const volatile noexcept; 
+    void wait(integral, memory_order = memory_order::seq_cst) const noexcept; 
+    void notify_one() volatile noexcept; 
+    void notify_one() noexcept; 
+    void notify_all() volatile noexcept; 
+    void notify_all() noexcept; 
+}; 
+ 
+template <class T> 
+struct atomic<T*> 
+{ 
+    using value_type = T*; 
+    using difference_type = ptrdiff_t; 
+ 
+    static constexpr bool is_always_lock_free; 
+    bool is_lock_free() const volatile noexcept; 
+    bool is_lock_free() const noexcept; 
+ 
+    atomic() noexcept = default; // until C++20 
+    constexpr atomic() noexcept; // since C++20 
+    constexpr atomic(T* desr) noexcept; 
+    atomic(const atomic&) = delete; 
+    atomic& operator=(const atomic&) = delete; 
+    atomic& operator=(const atomic&) volatile = delete; 
+ 
+    T* load(memory_order m = memory_order_seq_cst) const volatile noexcept; 
+    T* load(memory_order m = memory_order_seq_cst) const noexcept; 
+    operator T*() const volatile noexcept; 
+    operator T*() const noexcept; 
+    void store(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    void store(T* desr, memory_order m = memory_order_seq_cst) noexcept; 
+    T* operator=(T*) volatile noexcept; 
+    T* operator=(T*) noexcept; 
+ 
+    T* exchange(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    T* exchange(T* desr, memory_order m = memory_order_seq_cst) noexcept; 
+    bool compare_exchange_weak(T*& expc, T* desr, 
+                               memory_order s, memory_order f) volatile noexcept; 
+    bool compare_exchange_weak(T*& expc, T* desr, 
+                               memory_order s, memory_order f) noexcept; 
+    bool compare_exchange_strong(T*& expc, T* desr, 
+                                 memory_order s, memory_order f) volatile noexcept; 
+    bool compare_exchange_strong(T*& expc, T* desr, 
+                                 memory_order s, memory_order f) noexcept; 
+    bool compare_exchange_weak(T*& expc, T* desr, 
+                               memory_order m = memory_order_seq_cst) volatile noexcept; 
+    bool compare_exchange_weak(T*& expc, T* desr, 
+                               memory_order m = memory_order_seq_cst) noexcept; 
+    bool compare_exchange_strong(T*& expc, T* desr, 
+                                memory_order m = memory_order_seq_cst) volatile noexcept; 
+    bool compare_exchange_strong(T*& expc, T* desr, 
+                                 memory_order m = memory_order_seq_cst) noexcept; 
+    T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept; 
+    T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept; 
+    T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept; 
+ 
+    T* operator++(int) volatile noexcept; 
+    T* operator++(int) noexcept; 
+    T* operator--(int) volatile noexcept; 
+    T* operator--(int) noexcept; 
+    T* operator++() volatile noexcept; 
+    T* operator++() noexcept; 
+    T* operator--() volatile noexcept; 
+    T* operator--() noexcept; 
+    T* operator+=(ptrdiff_t op) volatile noexcept; 
+    T* operator+=(ptrdiff_t op) noexcept; 
+    T* operator-=(ptrdiff_t op) volatile noexcept; 
+    T* operator-=(ptrdiff_t op) noexcept; 
+ 
+    void wait(T*, memory_order = memory_order::seq_cst) const volatile noexcept; 
+    void wait(T*, memory_order = memory_order::seq_cst) const noexcept; 
+    void notify_one() volatile noexcept; 
+    void notify_one() noexcept; 
+    void notify_all() volatile noexcept; 
+    void notify_all() noexcept; 
+}; 
+ 
+ 
+// [atomics.nonmembers], non-member functions 
+template<class T> 
+  bool atomic_is_lock_free(const volatile atomic<T>*) noexcept; 
+template<class T> 
+  bool atomic_is_lock_free(const atomic<T>*) noexcept; 
+template<class T> 
+  void atomic_store(volatile atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  void atomic_store(atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  void atomic_store_explicit(volatile atomic<T>*, atomic<T>::value_type, 
+                             memory_order) noexcept; 
+template<class T> 
+  void atomic_store_explicit(atomic<T>*, atomic<T>::value_type, 
+                             memory_order) noexcept; 
+template<class T> 
+  T atomic_load(const volatile atomic<T>*) noexcept; 
+template<class T> 
+  T atomic_load(const atomic<T>*) noexcept; 
+template<class T> 
+  T atomic_load_explicit(const volatile atomic<T>*, memory_order) noexcept; 
+template<class T> 
+  T atomic_load_explicit(const atomic<T>*, memory_order) noexcept; 
+template<class T> 
+  T atomic_exchange(volatile atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  T atomic_exchange(atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  T atomic_exchange_explicit(volatile atomic<T>*, atomic<T>::value_type, 
+                             memory_order) noexcept; 
+template<class T> 
+  T atomic_exchange_explicit(atomic<T>*, atomic<T>::value_type, 
+                             memory_order) noexcept; 
+template<class T> 
+  bool atomic_compare_exchange_weak(volatile atomic<T>*, atomic<T>::value_type*, 
+                                    atomic<T>::value_type) noexcept; 
+template<class T> 
+  bool atomic_compare_exchange_weak(atomic<T>*, atomic<T>::value_type*, 
+                                    atomic<T>::value_type) noexcept; 
+template<class T> 
+  bool atomic_compare_exchange_strong(volatile atomic<T>*, atomic<T>::value_type*, 
+                                      atomic<T>::value_type) noexcept; 
+template<class T> 
+  bool atomic_compare_exchange_strong(atomic<T>*, atomic<T>::value_type*, 
+                                      atomic<T>::value_type) noexcept; 
+template<class T> 
+  bool atomic_compare_exchange_weak_explicit(volatile atomic<T>*, atomic<T>::value_type*, 
+                                             atomic<T>::value_type, 
+                                             memory_order, memory_order) noexcept; 
+template<class T> 
+  bool atomic_compare_exchange_weak_explicit(atomic<T>*, atomic<T>::value_type*, 
+                                             atomic<T>::value_type, 
+                                             memory_order, memory_order) noexcept; 
+template<class T> 
+  bool atomic_compare_exchange_strong_explicit(volatile atomic<T>*, atomic<T>::value_type*, 
+                                               atomic<T>::value_type, 
+                                               memory_order, memory_order) noexcept; 
+template<class T> 
+  bool atomic_compare_exchange_strong_explicit(atomic<T>*, atomic<T>::value_type*, 
+                                               atomic<T>::value_type, 
+                                               memory_order, memory_order) noexcept; 
+ 
+template<class T> 
+  T atomic_fetch_add(volatile atomic<T>*, atomic<T>::difference_type) noexcept; 
+template<class T> 
+  T atomic_fetch_add(atomic<T>*, atomic<T>::difference_type) noexcept; 
+template<class T> 
+  T atomic_fetch_add_explicit(volatile atomic<T>*, atomic<T>::difference_type, 
+                              memory_order) noexcept; 
+template<class T> 
+  T atomic_fetch_add_explicit(atomic<T>*, atomic<T>::difference_type, 
+                              memory_order) noexcept; 
+template<class T> 
+  T atomic_fetch_sub(volatile atomic<T>*, atomic<T>::difference_type) noexcept; 
+template<class T> 
+  T atomic_fetch_sub(atomic<T>*, atomic<T>::difference_type) noexcept; 
+template<class T> 
+  T atomic_fetch_sub_explicit(volatile atomic<T>*, atomic<T>::difference_type, 
+                              memory_order) noexcept; 
+template<class T> 
+  T atomic_fetch_sub_explicit(atomic<T>*, atomic<T>::difference_type, 
+                              memory_order) noexcept; 
+template<class T> 
+  T atomic_fetch_and(volatile atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  T atomic_fetch_and(atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  T atomic_fetch_and_explicit(volatile atomic<T>*, atomic<T>::value_type, 
+                              memory_order) noexcept; 
+template<class T> 
+  T atomic_fetch_and_explicit(atomic<T>*, atomic<T>::value_type, 
+                              memory_order) noexcept; 
+template<class T> 
+  T atomic_fetch_or(volatile atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  T atomic_fetch_or(atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  T atomic_fetch_or_explicit(volatile atomic<T>*, atomic<T>::value_type, 
+                             memory_order) noexcept; 
+template<class T> 
+  T atomic_fetch_or_explicit(atomic<T>*, atomic<T>::value_type, 
+                             memory_order) noexcept; 
+template<class T> 
+  T atomic_fetch_xor(volatile atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  T atomic_fetch_xor(atomic<T>*, atomic<T>::value_type) noexcept; 
+template<class T> 
+  T atomic_fetch_xor_explicit(volatile atomic<T>*, atomic<T>::value_type, 
+                              memory_order) noexcept; 
+template<class T> 
+  T atomic_fetch_xor_explicit(atomic<T>*, atomic<T>::value_type, 
+                              memory_order) noexcept; 
+ 
+template<class T> 
+  void atomic_wait(const volatile atomic<T>*, atomic<T>::value_type); 
+template<class T> 
+  void atomic_wait(const atomic<T>*, atomic<T>::value_type); 
+template<class T> 
+  void atomic_wait_explicit(const volatile atomic<T>*, atomic<T>::value_type, 
+                            memory_order); 
+template<class T> 
+  void atomic_wait_explicit(const atomic<T>*, atomic<T>::value_type, 
+                            memory_order); 
+template<class T> 
+  void atomic_notify_one(volatile atomic<T>*); 
+template<class T> 
+  void atomic_notify_one(atomic<T>*); 
+template<class T> 
+  void atomic_notify_all(volatile atomic<T>*); 
+template<class T> 
+  void atomic_notify_all(atomic<T>*); 
+ 
+// Atomics for standard typedef types 
+ 
+typedef atomic<bool>               atomic_bool; 
+typedef atomic<char>               atomic_char; 
+typedef atomic<signed char>        atomic_schar; 
+typedef atomic<unsigned char>      atomic_uchar; 
+typedef atomic<short>              atomic_short; 
+typedef atomic<unsigned short>     atomic_ushort; 
+typedef atomic<int>                atomic_int; 
+typedef atomic<unsigned int>       atomic_uint; 
+typedef atomic<long>               atomic_long; 
+typedef atomic<unsigned long>      atomic_ulong; 
+typedef atomic<long long>          atomic_llong; 
+typedef atomic<unsigned long long> atomic_ullong; 
+typedef atomic<char8_t>            atomic_char8_t; // C++20 
+typedef atomic<char16_t>           atomic_char16_t; 
+typedef atomic<char32_t>           atomic_char32_t; 
+typedef atomic<wchar_t>            atomic_wchar_t; 
+ 
+typedef atomic<int_least8_t>   atomic_int_least8_t; 
+typedef atomic<uint_least8_t>  atomic_uint_least8_t; 
+typedef atomic<int_least16_t>  atomic_int_least16_t; 
+typedef atomic<uint_least16_t> atomic_uint_least16_t; 
+typedef atomic<int_least32_t>  atomic_int_least32_t; 
+typedef atomic<uint_least32_t> atomic_uint_least32_t; 
+typedef atomic<int_least64_t>  atomic_int_least64_t; 
+typedef atomic<uint_least64_t> atomic_uint_least64_t; 
+ 
+typedef atomic<int_fast8_t>   atomic_int_fast8_t; 
+typedef atomic<uint_fast8_t>  atomic_uint_fast8_t; 
+typedef atomic<int_fast16_t>  atomic_int_fast16_t; 
+typedef atomic<uint_fast16_t> atomic_uint_fast16_t; 
+typedef atomic<int_fast32_t>  atomic_int_fast32_t; 
+typedef atomic<uint_fast32_t> atomic_uint_fast32_t; 
+typedef atomic<int_fast64_t>  atomic_int_fast64_t; 
+typedef atomic<uint_fast64_t> atomic_uint_fast64_t; 
+ 
+typedef atomic<int8_t>   atomic_int8_t; 
+typedef atomic<uint8_t>  atomic_uint8_t; 
+typedef atomic<int16_t>  atomic_int16_t; 
+typedef atomic<uint16_t> atomic_uint16_t; 
+typedef atomic<int32_t>  atomic_int32_t; 
+typedef atomic<uint32_t> atomic_uint32_t; 
+typedef atomic<int64_t>  atomic_int64_t; 
+typedef atomic<uint64_t> atomic_uint64_t; 
+ 
+typedef atomic<intptr_t>  atomic_intptr_t; 
+typedef atomic<uintptr_t> atomic_uintptr_t; 
+typedef atomic<size_t>    atomic_size_t; 
+typedef atomic<ptrdiff_t> atomic_ptrdiff_t; 
+typedef atomic<intmax_t>  atomic_intmax_t; 
+typedef atomic<uintmax_t> atomic_uintmax_t; 
+ 
+// flag type and operations 
+ 
+typedef struct atomic_flag 
+{ 
+    atomic_flag() noexcept = default; // until C++20 
+    constexpr atomic_flag() noexcept; // since C++20 
+    atomic_flag(const atomic_flag&) = delete; 
+    atomic_flag& operator=(const atomic_flag&) = delete; 
+    atomic_flag& operator=(const atomic_flag&) volatile = delete; 
+ 
+    bool test(memory_order m = memory_order_seq_cst) volatile noexcept; 
+    bool test(memory_order m = memory_order_seq_cst) noexcept; 
+    bool test_and_set(memory_order m = memory_order_seq_cst) volatile noexcept; 
+    bool test_and_set(memory_order m = memory_order_seq_cst) noexcept; 
+    void clear(memory_order m = memory_order_seq_cst) volatile noexcept; 
+    void clear(memory_order m = memory_order_seq_cst) noexcept; 
+ 
+    void wait(bool, memory_order = memory_order::seq_cst) const volatile noexcept; 
+    void wait(bool, memory_order = memory_order::seq_cst) const noexcept; 
+    void notify_one() volatile noexcept; 
+    void notify_one() noexcept; 
+    void notify_all() volatile noexcept; 
+    void notify_all() noexcept; 
+} atomic_flag; 
+ 
+bool atomic_flag_test(volatile atomic_flag* obj) noexcept; 
+bool atomic_flag_test(atomic_flag* obj) noexcept; 
+bool atomic_flag_test_explicit(volatile atomic_flag* obj, 
+                               memory_order m) noexcept; 
+bool atomic_flag_test_explicit(atomic_flag* obj, memory_order m) noexcept; 
+bool atomic_flag_test_and_set(volatile atomic_flag* obj) noexcept; 
+bool atomic_flag_test_and_set(atomic_flag* obj) noexcept; 
+bool atomic_flag_test_and_set_explicit(volatile atomic_flag* obj, 
+                                       memory_order m) noexcept; 
+bool atomic_flag_test_and_set_explicit(atomic_flag* obj, memory_order m) noexcept; 
+void atomic_flag_clear(volatile atomic_flag* obj) noexcept; 
+void atomic_flag_clear(atomic_flag* obj) noexcept; 
+void atomic_flag_clear_explicit(volatile atomic_flag* obj, memory_order m) noexcept; 
+void atomic_flag_clear_explicit(atomic_flag* obj, memory_order m) noexcept; 
+ 
+void atomic_wait(const volatile atomic_flag* obj, T old) noexcept; 
+void atomic_wait(const atomic_flag* obj, T old) noexcept; 
+void atomic_wait_explicit(const volatile atomic_flag* obj, T old, memory_order m) noexcept; 
+void atomic_wait_explicit(const atomic_flag* obj, T old, memory_order m) noexcept; 
+void atomic_one(volatile atomic_flag* obj) noexcept; 
+void atomic_one(atomic_flag* obj) noexcept; 
+void atomic_all(volatile atomic_flag* obj) noexcept; 
+void atomic_all(atomic_flag* obj) noexcept; 
+ 
+// fences 
+ 
+void atomic_thread_fence(memory_order m) noexcept; 
+void atomic_signal_fence(memory_order m) noexcept; 
+ 
+// deprecated 
+ 
+template <class T> 
+  void atomic_init(volatile atomic<T>* obj, atomic<T>::value_type desr) noexcept; 
+ 
+template <class T> 
+  void atomic_init(atomic<T>* obj, atomic<T>::value_type desr) noexcept; 
+ 
+#define ATOMIC_VAR_INIT(value) see below 
+ 
+#define ATOMIC_FLAG_INIT see below 
+ 
+}  // std 
+ 
+*/ 
+ 
+#include <__availability> 
+#include <__config> 
+#include <__threading_support> 
+#include <cstddef> 
+#include <cstdint> 
+#include <cstring> 
+#include <type_traits> 
 #include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef _LIBCPP_HAS_NO_THREADS
+ 
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 
+#pragma GCC system_header 
+#endif 
+ 
+#ifdef _LIBCPP_HAS_NO_THREADS 
 # error <atomic> is not supported on this single threaded system
-#endif
-#ifdef _LIBCPP_HAS_NO_ATOMIC_HEADER
+#endif 
+#ifdef _LIBCPP_HAS_NO_ATOMIC_HEADER 
 # error <atomic> is not implemented
-#endif
-#ifdef kill_dependency
+#endif 
+#ifdef kill_dependency 
 # error C++ standard library is incompatible with <stdatomic.h>
-#endif
-
-#define _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) \
-  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_consume || \
-                           __m == memory_order_acquire || \
-                           __m == memory_order_acq_rel,   \
-                        "memory order argument to atomic operation is invalid")
-
-#define _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) \
-  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_release || \
-                           __m == memory_order_acq_rel,   \
-                        "memory order argument to atomic operation is invalid")
-
-#define _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__m, __f) \
-  _LIBCPP_DIAGNOSE_WARNING(__f == memory_order_release || \
-                           __f == memory_order_acq_rel,   \
-                        "memory order argument to atomic operation is invalid")
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// Figure out what the underlying type for `memory_order` would be if it were
-// declared as an unscoped enum (accounting for -fshort-enums). Use this result
-// to pin the underlying type in C++20.
-enum __legacy_memory_order {
-    __mo_relaxed,
-    __mo_consume,
-    __mo_acquire,
-    __mo_release,
-    __mo_acq_rel,
-    __mo_seq_cst
-};
-
-typedef underlying_type<__legacy_memory_order>::type __memory_order_underlying_t;
-
-#if _LIBCPP_STD_VER > 17
-
-enum class memory_order : __memory_order_underlying_t {
-  relaxed = __mo_relaxed,
-  consume = __mo_consume,
-  acquire = __mo_acquire,
-  release = __mo_release,
-  acq_rel = __mo_acq_rel,
-  seq_cst = __mo_seq_cst
-};
-
-inline constexpr auto memory_order_relaxed = memory_order::relaxed;
-inline constexpr auto memory_order_consume = memory_order::consume;
-inline constexpr auto memory_order_acquire = memory_order::acquire;
-inline constexpr auto memory_order_release = memory_order::release;
-inline constexpr auto memory_order_acq_rel = memory_order::acq_rel;
-inline constexpr auto memory_order_seq_cst = memory_order::seq_cst;
-
-#else
-
-typedef enum memory_order {
-  memory_order_relaxed = __mo_relaxed,
-  memory_order_consume = __mo_consume,
-  memory_order_acquire = __mo_acquire,
-  memory_order_release = __mo_release,
-  memory_order_acq_rel = __mo_acq_rel,
-  memory_order_seq_cst = __mo_seq_cst,
-} memory_order;
-
-#endif // _LIBCPP_STD_VER > 17
-
-template <typename _Tp> _LIBCPP_INLINE_VISIBILITY
-bool __cxx_nonatomic_compare_equal(_Tp const& __lhs, _Tp const& __rhs) {
-    return _VSTD::memcmp(&__lhs, &__rhs, sizeof(_Tp)) == 0;
-}
-
-static_assert((is_same<underlying_type<memory_order>::type, __memory_order_underlying_t>::value),
-  "unexpected underlying type for std::memory_order");
-
-#if defined(_LIBCPP_HAS_GCC_ATOMIC_IMP) || \
+#endif 
+ 
+#define _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) \ 
+  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_consume || \ 
+                           __m == memory_order_acquire || \ 
+                           __m == memory_order_acq_rel,   \ 
+                        "memory order argument to atomic operation is invalid") 
+ 
+#define _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) \ 
+  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_release || \ 
+                           __m == memory_order_acq_rel,   \ 
+                        "memory order argument to atomic operation is invalid") 
+ 
+#define _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__m, __f) \ 
+  _LIBCPP_DIAGNOSE_WARNING(__f == memory_order_release || \ 
+                           __f == memory_order_acq_rel,   \ 
+                        "memory order argument to atomic operation is invalid") 
+ 
+_LIBCPP_BEGIN_NAMESPACE_STD 
+ 
+// Figure out what the underlying type for `memory_order` would be if it were 
+// declared as an unscoped enum (accounting for -fshort-enums). Use this result 
+// to pin the underlying type in C++20. 
+enum __legacy_memory_order { 
+    __mo_relaxed, 
+    __mo_consume, 
+    __mo_acquire, 
+    __mo_release, 
+    __mo_acq_rel, 
+    __mo_seq_cst 
+}; 
+ 
+typedef underlying_type<__legacy_memory_order>::type __memory_order_underlying_t; 
+ 
+#if _LIBCPP_STD_VER > 17 
+ 
+enum class memory_order : __memory_order_underlying_t { 
+  relaxed = __mo_relaxed, 
+  consume = __mo_consume, 
+  acquire = __mo_acquire, 
+  release = __mo_release, 
+  acq_rel = __mo_acq_rel, 
+  seq_cst = __mo_seq_cst 
+}; 
+ 
+inline constexpr auto memory_order_relaxed = memory_order::relaxed; 
+inline constexpr auto memory_order_consume = memory_order::consume; 
+inline constexpr auto memory_order_acquire = memory_order::acquire; 
+inline constexpr auto memory_order_release = memory_order::release; 
+inline constexpr auto memory_order_acq_rel = memory_order::acq_rel; 
+inline constexpr auto memory_order_seq_cst = memory_order::seq_cst; 
+ 
+#else 
+ 
+typedef enum memory_order { 
+  memory_order_relaxed = __mo_relaxed, 
+  memory_order_consume = __mo_consume, 
+  memory_order_acquire = __mo_acquire, 
+  memory_order_release = __mo_release, 
+  memory_order_acq_rel = __mo_acq_rel, 
+  memory_order_seq_cst = __mo_seq_cst, 
+} memory_order; 
+ 
+#endif // _LIBCPP_STD_VER > 17 
+ 
+template <typename _Tp> _LIBCPP_INLINE_VISIBILITY 
+bool __cxx_nonatomic_compare_equal(_Tp const& __lhs, _Tp const& __rhs) { 
+    return _VSTD::memcmp(&__lhs, &__rhs, sizeof(_Tp)) == 0; 
+} 
+ 
+static_assert((is_same<underlying_type<memory_order>::type, __memory_order_underlying_t>::value), 
+  "unexpected underlying type for std::memory_order"); 
+ 
+#if defined(_LIBCPP_HAS_GCC_ATOMIC_IMP) || \ 
 	defined(_LIBCPP_ATOMIC_ONLY_USE_BUILTINS)
-
-// [atomics.types.generic]p1 guarantees _Tp is trivially copyable. Because
-// the default operator= in an object is not volatile, a byte-by-byte copy
-// is required.
-template <typename _Tp, typename _Tv> _LIBCPP_INLINE_VISIBILITY
-typename enable_if<is_assignable<_Tp&, _Tv>::value>::type
-__cxx_atomic_assign_volatile(_Tp& __a_value, _Tv const& __val) {
-  __a_value = __val;
-}
-template <typename _Tp, typename _Tv> _LIBCPP_INLINE_VISIBILITY
-typename enable_if<is_assignable<_Tp&, _Tv>::value>::type
-__cxx_atomic_assign_volatile(_Tp volatile& __a_value, _Tv volatile const& __val) {
-  volatile char* __to = reinterpret_cast<volatile char*>(&__a_value);
-  volatile char* __end = __to + sizeof(_Tp);
-  volatile const char* __from = reinterpret_cast<volatile const char*>(&__val);
-  while (__to != __end)
-    *__to++ = *__from++;
-}
-
-#endif
-
-#if defined(_LIBCPP_HAS_GCC_ATOMIC_IMP)
-
-template <typename _Tp>
-struct __cxx_atomic_base_impl {
-
-  _LIBCPP_INLINE_VISIBILITY
+ 
+// [atomics.types.generic]p1 guarantees _Tp is trivially copyable. Because 
+// the default operator= in an object is not volatile, a byte-by-byte copy 
+// is required. 
+template <typename _Tp, typename _Tv> _LIBCPP_INLINE_VISIBILITY 
+typename enable_if<is_assignable<_Tp&, _Tv>::value>::type 
+__cxx_atomic_assign_volatile(_Tp& __a_value, _Tv const& __val) { 
+  __a_value = __val; 
+} 
+template <typename _Tp, typename _Tv> _LIBCPP_INLINE_VISIBILITY 
+typename enable_if<is_assignable<_Tp&, _Tv>::value>::type 
+__cxx_atomic_assign_volatile(_Tp volatile& __a_value, _Tv volatile const& __val) { 
+  volatile char* __to = reinterpret_cast<volatile char*>(&__a_value); 
+  volatile char* __end = __to + sizeof(_Tp); 
+  volatile const char* __from = reinterpret_cast<volatile const char*>(&__val); 
+  while (__to != __end) 
+    *__to++ = *__from++; 
+} 
+ 
+#endif 
+ 
+#if defined(_LIBCPP_HAS_GCC_ATOMIC_IMP) 
+ 
+template <typename _Tp> 
+struct __cxx_atomic_base_impl { 
+
+  _LIBCPP_INLINE_VISIBILITY 
 #ifndef _LIBCPP_CXX03_LANG
-    __cxx_atomic_base_impl() _NOEXCEPT = default;
-#else
-    __cxx_atomic_base_impl() _NOEXCEPT : __a_value() {}
+    __cxx_atomic_base_impl() _NOEXCEPT = default; 
+#else 
+    __cxx_atomic_base_impl() _NOEXCEPT : __a_value() {} 
 #endif // _LIBCPP_CXX03_LANG
-  _LIBCPP_CONSTEXPR explicit __cxx_atomic_base_impl(_Tp value) _NOEXCEPT
-    : __a_value(value) {}
-  _Tp __a_value;
-};
-
-_LIBCPP_INLINE_VISIBILITY inline _LIBCPP_CONSTEXPR int __to_gcc_order(memory_order __order) {
-  // Avoid switch statement to make this a constexpr.
-  return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
-         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
-          (__order == memory_order_release ? __ATOMIC_RELEASE:
-           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
-            (__order == memory_order_acq_rel ? __ATOMIC_ACQ_REL:
-              __ATOMIC_CONSUME))));
-}
-
-_LIBCPP_INLINE_VISIBILITY inline _LIBCPP_CONSTEXPR int __to_gcc_failure_order(memory_order __order) {
-  // Avoid switch statement to make this a constexpr.
-  return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
-         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
-          (__order == memory_order_release ? __ATOMIC_RELAXED:
-           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
-            (__order == memory_order_acq_rel ? __ATOMIC_ACQUIRE:
-              __ATOMIC_CONSUME))));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_init(volatile __cxx_atomic_base_impl<_Tp>* __a,  _Tp __val) {
-  __cxx_atomic_assign_volatile(__a->__a_value, __val);
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_init(__cxx_atomic_base_impl<_Tp>* __a,  _Tp __val) {
-  __a->__a_value = __val;
-}
-
-_LIBCPP_INLINE_VISIBILITY inline
-void __cxx_atomic_thread_fence(memory_order __order) {
-  __atomic_thread_fence(__to_gcc_order(__order));
-}
-
-_LIBCPP_INLINE_VISIBILITY inline
-void __cxx_atomic_signal_fence(memory_order __order) {
-  __atomic_signal_fence(__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_store(volatile __cxx_atomic_base_impl<_Tp>* __a,  _Tp __val,
+  _LIBCPP_CONSTEXPR explicit __cxx_atomic_base_impl(_Tp value) _NOEXCEPT 
+    : __a_value(value) {} 
+  _Tp __a_value; 
+}; 
+ 
+_LIBCPP_INLINE_VISIBILITY inline _LIBCPP_CONSTEXPR int __to_gcc_order(memory_order __order) { 
+  // Avoid switch statement to make this a constexpr. 
+  return __order == memory_order_relaxed ? __ATOMIC_RELAXED: 
+         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE: 
+          (__order == memory_order_release ? __ATOMIC_RELEASE: 
+           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST: 
+            (__order == memory_order_acq_rel ? __ATOMIC_ACQ_REL: 
+              __ATOMIC_CONSUME)))); 
+} 
+ 
+_LIBCPP_INLINE_VISIBILITY inline _LIBCPP_CONSTEXPR int __to_gcc_failure_order(memory_order __order) { 
+  // Avoid switch statement to make this a constexpr. 
+  return __order == memory_order_relaxed ? __ATOMIC_RELAXED: 
+         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE: 
+          (__order == memory_order_release ? __ATOMIC_RELAXED: 
+           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST: 
+            (__order == memory_order_acq_rel ? __ATOMIC_ACQUIRE: 
+              __ATOMIC_CONSUME)))); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_init(volatile __cxx_atomic_base_impl<_Tp>* __a,  _Tp __val) { 
+  __cxx_atomic_assign_volatile(__a->__a_value, __val); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_init(__cxx_atomic_base_impl<_Tp>* __a,  _Tp __val) { 
+  __a->__a_value = __val; 
+} 
+ 
+_LIBCPP_INLINE_VISIBILITY inline 
+void __cxx_atomic_thread_fence(memory_order __order) { 
+  __atomic_thread_fence(__to_gcc_order(__order)); 
+} 
+ 
+_LIBCPP_INLINE_VISIBILITY inline 
+void __cxx_atomic_signal_fence(memory_order __order) { 
+  __atomic_signal_fence(__to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_store(volatile __cxx_atomic_base_impl<_Tp>* __a,  _Tp __val, 
                         memory_order __order) {
-  __atomic_store(&__a->__a_value, &__val,
-                 __to_gcc_order(__order));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_store(__cxx_atomic_base_impl<_Tp>* __a,  _Tp __val,
+  __atomic_store(&__a->__a_value, &__val, 
+                 __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_store(__cxx_atomic_base_impl<_Tp>* __a,  _Tp __val, 
                         memory_order __order) {
-  __atomic_store(&__a->__a_value, &__val,
-                 __to_gcc_order(__order));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_load(const volatile __cxx_atomic_base_impl<_Tp>* __a,
+  __atomic_store(&__a->__a_value, &__val, 
+                 __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_load(const volatile __cxx_atomic_base_impl<_Tp>* __a, 
                       memory_order __order) {
-  _Tp __ret;
-  __atomic_load(&__a->__a_value, &__ret,
-                __to_gcc_order(__order));
-  return __ret;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_load(const __cxx_atomic_base_impl<_Tp>* __a, memory_order __order) {
-  _Tp __ret;
-  __atomic_load(&__a->__a_value, &__ret,
-                __to_gcc_order(__order));
-  return __ret;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_exchange(volatile __cxx_atomic_base_impl<_Tp>* __a,
+  _Tp __ret; 
+  __atomic_load(&__a->__a_value, &__ret, 
+                __to_gcc_order(__order)); 
+  return __ret; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_load(const __cxx_atomic_base_impl<_Tp>* __a, memory_order __order) { 
+  _Tp __ret; 
+  __atomic_load(&__a->__a_value, &__ret, 
+                __to_gcc_order(__order)); 
+  return __ret; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_exchange(volatile __cxx_atomic_base_impl<_Tp>* __a, 
                           _Tp __value, memory_order __order) {
-  _Tp __ret;
-  __atomic_exchange(&__a->__a_value, &__value, &__ret,
-                    __to_gcc_order(__order));
-  return __ret;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_exchange(__cxx_atomic_base_impl<_Tp>* __a, _Tp __value,
+  _Tp __ret; 
+  __atomic_exchange(&__a->__a_value, &__value, &__ret, 
+                    __to_gcc_order(__order)); 
+  return __ret; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_exchange(__cxx_atomic_base_impl<_Tp>* __a, _Tp __value, 
                           memory_order __order) {
-  _Tp __ret;
-  __atomic_exchange(&__a->__a_value, &__value, &__ret,
-                    __to_gcc_order(__order));
-  return __ret;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_strong(
-    volatile __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value,
-    memory_order __success, memory_order __failure) {
-  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
-                                   false,
-                                   __to_gcc_order(__success),
-                                   __to_gcc_failure_order(__failure));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_strong(
-    __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value, memory_order __success,
-    memory_order __failure) {
-  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
-                                   false,
-                                   __to_gcc_order(__success),
-                                   __to_gcc_failure_order(__failure));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_weak(
-    volatile __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value,
-    memory_order __success, memory_order __failure) {
-  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
-                                   true,
-                                   __to_gcc_order(__success),
-                                   __to_gcc_failure_order(__failure));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_weak(
-    __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value, memory_order __success,
-    memory_order __failure) {
-  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
-                                   true,
-                                   __to_gcc_order(__success),
-                                   __to_gcc_failure_order(__failure));
-}
-
-template <typename _Tp>
-struct __skip_amt { enum {value = 1}; };
-
-template <typename _Tp>
-struct __skip_amt<_Tp*> { enum {value = sizeof(_Tp)}; };
-
-// FIXME: Haven't figured out what the spec says about using arrays with
-// atomic_fetch_add. Force a failure rather than creating bad behavior.
-template <typename _Tp>
-struct __skip_amt<_Tp[]> { };
-template <typename _Tp, int n>
-struct __skip_amt<_Tp[n]> { };
-
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_add(volatile __cxx_atomic_base_impl<_Tp>* __a,
+  _Tp __ret; 
+  __atomic_exchange(&__a->__a_value, &__value, &__ret, 
+                    __to_gcc_order(__order)); 
+  return __ret; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_strong( 
+    volatile __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value, 
+    memory_order __success, memory_order __failure) { 
+  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value, 
+                                   false, 
+                                   __to_gcc_order(__success), 
+                                   __to_gcc_failure_order(__failure)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_strong( 
+    __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value, memory_order __success, 
+    memory_order __failure) { 
+  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value, 
+                                   false, 
+                                   __to_gcc_order(__success), 
+                                   __to_gcc_failure_order(__failure)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_weak( 
+    volatile __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value, 
+    memory_order __success, memory_order __failure) { 
+  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value, 
+                                   true, 
+                                   __to_gcc_order(__success), 
+                                   __to_gcc_failure_order(__failure)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_weak( 
+    __cxx_atomic_base_impl<_Tp>* __a, _Tp* __expected, _Tp __value, memory_order __success, 
+    memory_order __failure) { 
+  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value, 
+                                   true, 
+                                   __to_gcc_order(__success), 
+                                   __to_gcc_failure_order(__failure)); 
+} 
+ 
+template <typename _Tp> 
+struct __skip_amt { enum {value = 1}; }; 
+ 
+template <typename _Tp> 
+struct __skip_amt<_Tp*> { enum {value = sizeof(_Tp)}; }; 
+ 
+// FIXME: Haven't figured out what the spec says about using arrays with 
+// atomic_fetch_add. Force a failure rather than creating bad behavior. 
+template <typename _Tp> 
+struct __skip_amt<_Tp[]> { }; 
+template <typename _Tp, int n> 
+struct __skip_amt<_Tp[n]> { }; 
+ 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_add(volatile __cxx_atomic_base_impl<_Tp>* __a, 
                            _Td __delta, memory_order __order) {
-  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
-                            __to_gcc_order(__order));
-}
-
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp>* __a, _Td __delta,
+  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value, 
+                            __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp>* __a, _Td __delta, 
                            memory_order __order) {
-  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
-                            __to_gcc_order(__order));
-}
-
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_sub(volatile __cxx_atomic_base_impl<_Tp>* __a,
+  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value, 
+                            __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_sub(volatile __cxx_atomic_base_impl<_Tp>* __a, 
                            _Td __delta, memory_order __order) {
-  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
-                            __to_gcc_order(__order));
-}
-
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp>* __a, _Td __delta,
+  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value, 
+                            __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp>* __a, _Td __delta, 
                            memory_order __order) {
-  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
-                            __to_gcc_order(__order));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_and(volatile __cxx_atomic_base_impl<_Tp>* __a,
+  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value, 
+                            __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_and(volatile __cxx_atomic_base_impl<_Tp>* __a, 
                            _Tp __pattern, memory_order __order) {
-  return __atomic_fetch_and(&__a->__a_value, __pattern,
-                            __to_gcc_order(__order));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_and(__cxx_atomic_base_impl<_Tp>* __a,
+  return __atomic_fetch_and(&__a->__a_value, __pattern, 
+                            __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_and(__cxx_atomic_base_impl<_Tp>* __a, 
                            _Tp __pattern, memory_order __order) {
-  return __atomic_fetch_and(&__a->__a_value, __pattern,
-                            __to_gcc_order(__order));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_or(volatile __cxx_atomic_base_impl<_Tp>* __a,
+  return __atomic_fetch_and(&__a->__a_value, __pattern, 
+                            __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_or(volatile __cxx_atomic_base_impl<_Tp>* __a, 
                           _Tp __pattern, memory_order __order) {
-  return __atomic_fetch_or(&__a->__a_value, __pattern,
-                           __to_gcc_order(__order));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_or(__cxx_atomic_base_impl<_Tp>* __a, _Tp __pattern,
+  return __atomic_fetch_or(&__a->__a_value, __pattern, 
+                           __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_or(__cxx_atomic_base_impl<_Tp>* __a, _Tp __pattern, 
                           memory_order __order) {
-  return __atomic_fetch_or(&__a->__a_value, __pattern,
-                           __to_gcc_order(__order));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_xor(volatile __cxx_atomic_base_impl<_Tp>* __a,
+  return __atomic_fetch_or(&__a->__a_value, __pattern, 
+                           __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_xor(volatile __cxx_atomic_base_impl<_Tp>* __a, 
                            _Tp __pattern, memory_order __order) {
-  return __atomic_fetch_xor(&__a->__a_value, __pattern,
-                            __to_gcc_order(__order));
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_xor(__cxx_atomic_base_impl<_Tp>* __a, _Tp __pattern,
+  return __atomic_fetch_xor(&__a->__a_value, __pattern, 
+                            __to_gcc_order(__order)); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_xor(__cxx_atomic_base_impl<_Tp>* __a, _Tp __pattern, 
                            memory_order __order) {
-  return __atomic_fetch_xor(&__a->__a_value, __pattern,
-                            __to_gcc_order(__order));
-}
-
-#define __cxx_atomic_is_lock_free(__s) __atomic_is_lock_free(__s, 0)
-
-#elif defined(_LIBCPP_HAS_C_ATOMIC_IMP) || defined(_LIBCPP_COMPILER_MSVC)
-
-#if defined(_LIBCPP_COMPILER_MSVC)
-_LIBCPP_END_NAMESPACE_STD
-#include <__support/win32/atomic_win32.h>
-_LIBCPP_BEGIN_NAMESPACE_STD
-#endif
-
-template <typename _Tp>
-struct __cxx_atomic_base_impl {
-
-  _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_CXX03_LANG
-    __cxx_atomic_base_impl() _NOEXCEPT = default;
-#else
-    __cxx_atomic_base_impl() _NOEXCEPT : __a_value() {}
-#endif // _LIBCPP_CXX03_LANG
-  _LIBCPP_CONSTEXPR explicit __cxx_atomic_base_impl(_Tp value) _NOEXCEPT
-    : __a_value(value) {}
-  _LIBCPP_DISABLE_EXTENSION_WARNING _Atomic(_Tp) __a_value;
-};
-
-#define __cxx_atomic_is_lock_free(__s) __c11_atomic_is_lock_free(__s)
-
-#ifdef _LIBCPP_COMPILER_MSVC
-#pragma warning ( push )
-#pragma warning ( disable : 4141 )
-#endif
-_LIBCPP_INLINE_VISIBILITY inline
-void __cxx_atomic_thread_fence(memory_order __order) _NOEXCEPT {
-    __c11_atomic_thread_fence(static_cast<__memory_order_underlying_t>(__order));
-}
-
-_LIBCPP_INLINE_VISIBILITY inline
-void __cxx_atomic_signal_fence(memory_order __order) _NOEXCEPT {
-    __c11_atomic_signal_fence(static_cast<__memory_order_underlying_t>(__order));
-}
-#ifdef _LIBCPP_COMPILER_MSVC
-#pragma warning ( pop )
-#endif
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_init(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __val) _NOEXCEPT {
-    __c11_atomic_init(&__a->__a_value, __val);
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_init(__cxx_atomic_base_impl<_Tp> * __a, _Tp __val) _NOEXCEPT {
-    __c11_atomic_init(&__a->__a_value, __val);
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_store(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __val, memory_order __order) _NOEXCEPT {
-    __c11_atomic_store(&__a->__a_value, __val, static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_store(__cxx_atomic_base_impl<_Tp> * __a, _Tp __val, memory_order __order) _NOEXCEPT {
-    __c11_atomic_store(&__a->__a_value, __val, static_cast<__memory_order_underlying_t>(__order));
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_load(__cxx_atomic_base_impl<_Tp> const volatile* __a, memory_order __order) _NOEXCEPT {
-    using __ptr_type = typename remove_const<decltype(__a->__a_value)>::type*;
-    return __c11_atomic_load(const_cast<__ptr_type>(&__a->__a_value), static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_load(__cxx_atomic_base_impl<_Tp> const* __a, memory_order __order) _NOEXCEPT {
-    using __ptr_type = typename remove_const<decltype(__a->__a_value)>::type*;
-    return __c11_atomic_load(const_cast<__ptr_type>(&__a->__a_value), static_cast<__memory_order_underlying_t>(__order));
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_exchange(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __value, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_exchange(&__a->__a_value, __value, static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_exchange(__cxx_atomic_base_impl<_Tp> * __a, _Tp __value, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_exchange(&__a->__a_value, __value, static_cast<__memory_order_underlying_t>(__order));
-}
-
-// Disable double inline warning
-#ifdef _LIBCPP_COMPILER_MSVC
-#pragma warning ( push )
-#pragma warning ( disable : 4141 )
-#endif
-_LIBCPP_INLINE_VISIBILITY inline _LIBCPP_CONSTEXPR memory_order __to_failure_order(memory_order __order) {
-  // Avoid switch statement to make this a constexpr.
-  return __order == memory_order_release ? memory_order_relaxed:
-         (__order == memory_order_acq_rel ? memory_order_acquire:
-             __order);
-}
-#ifdef _LIBCPP_COMPILER_MSVC
-#pragma warning ( pop )
-#endif
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_strong(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT {
-    return __c11_atomic_compare_exchange_strong(&__a->__a_value, __expected, __value, static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure)));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_strong(__cxx_atomic_base_impl<_Tp> * __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT {
-    return __c11_atomic_compare_exchange_strong(&__a->__a_value, __expected, __value, static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure)));
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_weak(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT {
-    return __c11_atomic_compare_exchange_weak(&__a->__a_value, __expected, __value, static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure)));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_weak(__cxx_atomic_base_impl<_Tp> * __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT {
-    return __c11_atomic_compare_exchange_weak(&__a->__a_value, __expected, __value,  static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure)));
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __delta, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp> * __a, _Tp __delta, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp* __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp*> volatile* __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp* __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp*> * __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __delta, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp> * __a, _Tp __delta, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp* __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp*> volatile* __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp* __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp*> * __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order));
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_and(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_and(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_and(__cxx_atomic_base_impl<_Tp> * __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_and(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_or(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_or(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
-}
+  return __atomic_fetch_xor(&__a->__a_value, __pattern, 
+                            __to_gcc_order(__order)); 
+} 
+ 
+#define __cxx_atomic_is_lock_free(__s) __atomic_is_lock_free(__s, 0) 
+ 
+#elif defined(_LIBCPP_HAS_C_ATOMIC_IMP) || defined(_LIBCPP_COMPILER_MSVC) 
+ 
+#if defined(_LIBCPP_COMPILER_MSVC) 
+_LIBCPP_END_NAMESPACE_STD 
+#include <__support/win32/atomic_win32.h> 
+_LIBCPP_BEGIN_NAMESPACE_STD 
+#endif 
+ 
+template <typename _Tp> 
+struct __cxx_atomic_base_impl { 
+ 
+  _LIBCPP_INLINE_VISIBILITY 
+#ifndef _LIBCPP_CXX03_LANG 
+    __cxx_atomic_base_impl() _NOEXCEPT = default; 
+#else 
+    __cxx_atomic_base_impl() _NOEXCEPT : __a_value() {} 
+#endif // _LIBCPP_CXX03_LANG 
+  _LIBCPP_CONSTEXPR explicit __cxx_atomic_base_impl(_Tp value) _NOEXCEPT 
+    : __a_value(value) {} 
+  _LIBCPP_DISABLE_EXTENSION_WARNING _Atomic(_Tp) __a_value; 
+}; 
+ 
+#define __cxx_atomic_is_lock_free(__s) __c11_atomic_is_lock_free(__s) 
+ 
+#ifdef _LIBCPP_COMPILER_MSVC 
+#pragma warning ( push ) 
+#pragma warning ( disable : 4141 ) 
+#endif 
+_LIBCPP_INLINE_VISIBILITY inline 
+void __cxx_atomic_thread_fence(memory_order __order) _NOEXCEPT { 
+    __c11_atomic_thread_fence(static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+_LIBCPP_INLINE_VISIBILITY inline 
+void __cxx_atomic_signal_fence(memory_order __order) _NOEXCEPT { 
+    __c11_atomic_signal_fence(static_cast<__memory_order_underlying_t>(__order)); 
+} 
+#ifdef _LIBCPP_COMPILER_MSVC 
+#pragma warning ( pop ) 
+#endif 
+ 
 template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_or(__cxx_atomic_base_impl<_Tp> * __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_or(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
-}
-
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_xor(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_xor(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
-}
-template<class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_xor(__cxx_atomic_base_impl<_Tp> * __a, _Tp __pattern, memory_order __order) _NOEXCEPT {
-    return __c11_atomic_fetch_xor(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order));
-}
-
-#endif // _LIBCPP_HAS_GCC_ATOMIC_IMP, _LIBCPP_HAS_C_ATOMIC_IMP
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp kill_dependency(_Tp __y) _NOEXCEPT
-{
-    return __y;
-}
-
-#if defined(__CLANG_ATOMIC_BOOL_LOCK_FREE)
-# define ATOMIC_BOOL_LOCK_FREE      __CLANG_ATOMIC_BOOL_LOCK_FREE
-# define ATOMIC_CHAR_LOCK_FREE      __CLANG_ATOMIC_CHAR_LOCK_FREE
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
-# define ATOMIC_CHAR8_T_LOCK_FREE   __CLANG_ATOMIC_CHAR8_T_LOCK_FREE
-#endif
-# define ATOMIC_CHAR16_T_LOCK_FREE  __CLANG_ATOMIC_CHAR16_T_LOCK_FREE
-# define ATOMIC_CHAR32_T_LOCK_FREE  __CLANG_ATOMIC_CHAR32_T_LOCK_FREE
-# define ATOMIC_WCHAR_T_LOCK_FREE   __CLANG_ATOMIC_WCHAR_T_LOCK_FREE
-# define ATOMIC_SHORT_LOCK_FREE     __CLANG_ATOMIC_SHORT_LOCK_FREE
-# define ATOMIC_INT_LOCK_FREE       __CLANG_ATOMIC_INT_LOCK_FREE
-# define ATOMIC_LONG_LOCK_FREE      __CLANG_ATOMIC_LONG_LOCK_FREE
-# define ATOMIC_LLONG_LOCK_FREE     __CLANG_ATOMIC_LLONG_LOCK_FREE
-# define ATOMIC_POINTER_LOCK_FREE   __CLANG_ATOMIC_POINTER_LOCK_FREE
-#elif defined(__GCC_ATOMIC_BOOL_LOCK_FREE)
-# define ATOMIC_BOOL_LOCK_FREE      __GCC_ATOMIC_BOOL_LOCK_FREE
-# define ATOMIC_CHAR_LOCK_FREE      __GCC_ATOMIC_CHAR_LOCK_FREE
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
-# define ATOMIC_CHAR8_T_LOCK_FREE   __GCC_ATOMIC_CHAR8_T_LOCK_FREE
-#endif
-# define ATOMIC_CHAR16_T_LOCK_FREE  __GCC_ATOMIC_CHAR16_T_LOCK_FREE
-# define ATOMIC_CHAR32_T_LOCK_FREE  __GCC_ATOMIC_CHAR32_T_LOCK_FREE
-# define ATOMIC_WCHAR_T_LOCK_FREE   __GCC_ATOMIC_WCHAR_T_LOCK_FREE
-# define ATOMIC_SHORT_LOCK_FREE     __GCC_ATOMIC_SHORT_LOCK_FREE
-# define ATOMIC_INT_LOCK_FREE       __GCC_ATOMIC_INT_LOCK_FREE
-# define ATOMIC_LONG_LOCK_FREE      __GCC_ATOMIC_LONG_LOCK_FREE
-# define ATOMIC_LLONG_LOCK_FREE     __GCC_ATOMIC_LLONG_LOCK_FREE
-# define ATOMIC_POINTER_LOCK_FREE   __GCC_ATOMIC_POINTER_LOCK_FREE
-#endif
-
-#ifdef _LIBCPP_ATOMIC_ONLY_USE_BUILTINS
-
-template<typename _Tp>
-struct __cxx_atomic_lock_impl {
-
-  _LIBCPP_INLINE_VISIBILITY
-  __cxx_atomic_lock_impl() _NOEXCEPT
-    : __a_value(), __a_lock(0) {}
-  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR explicit
-  __cxx_atomic_lock_impl(_Tp value) _NOEXCEPT
-    : __a_value(value), __a_lock(0) {}
-
-  _Tp __a_value;
-  mutable __cxx_atomic_base_impl<_LIBCPP_ATOMIC_FLAG_TYPE> __a_lock;
-
-  _LIBCPP_INLINE_VISIBILITY void __lock() const volatile {
-    while(1 == __cxx_atomic_exchange(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(true), memory_order_acquire))
-        /*spin*/;
-  }
-  _LIBCPP_INLINE_VISIBILITY void __lock() const {
-    while(1 == __cxx_atomic_exchange(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(true), memory_order_acquire))
-        /*spin*/;
-  }
-  _LIBCPP_INLINE_VISIBILITY void __unlock() const volatile {
-    __cxx_atomic_store(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(false), memory_order_release);
-  }
-  _LIBCPP_INLINE_VISIBILITY void __unlock() const {
-    __cxx_atomic_store(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(false), memory_order_release);
-  }
-  _LIBCPP_INLINE_VISIBILITY _Tp __read() const volatile {
-    __lock();
-    _Tp __old;
-    __cxx_atomic_assign_volatile(__old, __a_value);
-    __unlock();
-    return __old;
-  }
-  _LIBCPP_INLINE_VISIBILITY _Tp __read() const {
-    __lock();
-    _Tp __old = __a_value;
-    __unlock();
-    return __old;
-  }
-};
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_init(volatile __cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val) {
-  __cxx_atomic_assign_volatile(__a->__a_value, __val);
-}
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_init(__cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val) {
-  __a->__a_value = __val;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_store(volatile __cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val, memory_order) {
-  __a->__lock();
-  __cxx_atomic_assign_volatile(__a->__a_value, __val);
-  __a->__unlock();
-}
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __cxx_atomic_store(__cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val, memory_order) {
-  __a->__lock();
-  __a->__a_value = __val;
-  __a->__unlock();
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_load(const volatile __cxx_atomic_lock_impl<_Tp>* __a, memory_order) {
-  return __a->__read();
-}
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_load(const __cxx_atomic_lock_impl<_Tp>* __a, memory_order) {
-  return __a->__read();
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_exchange(volatile __cxx_atomic_lock_impl<_Tp>* __a, _Tp __value, memory_order) {
-  __a->__lock();
-  _Tp __old;
-  __cxx_atomic_assign_volatile(__old, __a->__a_value);
-  __cxx_atomic_assign_volatile(__a->__a_value, __value);
-  __a->__unlock();
-  return __old;
-}
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_exchange(__cxx_atomic_lock_impl<_Tp>* __a, _Tp __value, memory_order) {
-  __a->__lock();
-  _Tp __old = __a->__a_value;
-  __a->__a_value = __value;
-  __a->__unlock();
-  return __old;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_strong(volatile __cxx_atomic_lock_impl<_Tp>* __a,
-                                          _Tp* __expected, _Tp __value, memory_order, memory_order) {
-  _Tp __temp;
-  __a->__lock();
-  __cxx_atomic_assign_volatile(__temp, __a->__a_value);
-  bool __ret = (_VSTD::memcmp(&__temp, __expected, sizeof(_Tp)) == 0);
-  if(__ret)
-    __cxx_atomic_assign_volatile(__a->__a_value, __value);
-  else
-    __cxx_atomic_assign_volatile(*__expected, __a->__a_value);
-  __a->__unlock();
-  return __ret;
-}
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_strong(__cxx_atomic_lock_impl<_Tp>* __a,
-                                          _Tp* __expected, _Tp __value, memory_order, memory_order) {
-  __a->__lock();
-  bool __ret = (_VSTD::memcmp(&__a->__a_value, __expected, sizeof(_Tp)) == 0);
-  if(__ret)
-    _VSTD::memcpy(&__a->__a_value, &__value, sizeof(_Tp));
-  else
-    _VSTD::memcpy(__expected, &__a->__a_value, sizeof(_Tp));
-  __a->__unlock();
-  return __ret;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_weak(volatile __cxx_atomic_lock_impl<_Tp>* __a,
-                                        _Tp* __expected, _Tp __value, memory_order, memory_order) {
-  _Tp __temp;
-  __a->__lock();
-  __cxx_atomic_assign_volatile(__temp, __a->__a_value);
-  bool __ret = (_VSTD::memcmp(&__temp, __expected, sizeof(_Tp)) == 0);
-  if(__ret)
-    __cxx_atomic_assign_volatile(__a->__a_value, __value);
-  else
-    __cxx_atomic_assign_volatile(*__expected, __a->__a_value);
-  __a->__unlock();
-  return __ret;
-}
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool __cxx_atomic_compare_exchange_weak(__cxx_atomic_lock_impl<_Tp>* __a,
-                                        _Tp* __expected, _Tp __value, memory_order, memory_order) {
-  __a->__lock();
-  bool __ret = (_VSTD::memcmp(&__a->__a_value, __expected, sizeof(_Tp)) == 0);
-  if(__ret)
-    _VSTD::memcpy(&__a->__a_value, &__value, sizeof(_Tp));
-  else
-    _VSTD::memcpy(__expected, &__a->__a_value, sizeof(_Tp));
-  __a->__unlock();
-  return __ret;
-}
-
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_add(volatile __cxx_atomic_lock_impl<_Tp>* __a,
-                           _Td __delta, memory_order) {
-  __a->__lock();
-  _Tp __old;
-  __cxx_atomic_assign_volatile(__old, __a->__a_value);
-  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old + __delta));
-  __a->__unlock();
-  return __old;
-}
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_add(__cxx_atomic_lock_impl<_Tp>* __a,
-                           _Td __delta, memory_order) {
-  __a->__lock();
-  _Tp __old = __a->__a_value;
-  __a->__a_value += __delta;
-  __a->__unlock();
-  return __old;
-}
-
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp* __cxx_atomic_fetch_add(volatile __cxx_atomic_lock_impl<_Tp*>* __a,
-                           ptrdiff_t __delta, memory_order) {
-  __a->__lock();
-  _Tp* __old;
-  __cxx_atomic_assign_volatile(__old, __a->__a_value);
-  __cxx_atomic_assign_volatile(__a->__a_value, __old + __delta);
-  __a->__unlock();
-  return __old;
-}
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp* __cxx_atomic_fetch_add(__cxx_atomic_lock_impl<_Tp*>* __a,
-                           ptrdiff_t __delta, memory_order) {
-  __a->__lock();
-  _Tp* __old = __a->__a_value;
-  __a->__a_value += __delta;
-  __a->__unlock();
-  return __old;
-}
-
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_sub(volatile __cxx_atomic_lock_impl<_Tp>* __a,
-                           _Td __delta, memory_order) {
-  __a->__lock();
-  _Tp __old;
-  __cxx_atomic_assign_volatile(__old, __a->__a_value);
-  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old - __delta));
-  __a->__unlock();
-  return __old;
-}
-template <typename _Tp, typename _Td>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_sub(__cxx_atomic_lock_impl<_Tp>* __a,
-                           _Td __delta, memory_order) {
-  __a->__lock();
-  _Tp __old = __a->__a_value;
-  __a->__a_value -= __delta;
-  __a->__unlock();
-  return __old;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_and(volatile __cxx_atomic_lock_impl<_Tp>* __a,
-                           _Tp __pattern, memory_order) {
-  __a->__lock();
-  _Tp __old;
-  __cxx_atomic_assign_volatile(__old, __a->__a_value);
-  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old & __pattern));
-  __a->__unlock();
-  return __old;
-}
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_and(__cxx_atomic_lock_impl<_Tp>* __a,
-                           _Tp __pattern, memory_order) {
-  __a->__lock();
-  _Tp __old = __a->__a_value;
-  __a->__a_value &= __pattern;
-  __a->__unlock();
-  return __old;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_or(volatile __cxx_atomic_lock_impl<_Tp>* __a,
-                          _Tp __pattern, memory_order) {
-  __a->__lock();
-  _Tp __old;
-  __cxx_atomic_assign_volatile(__old, __a->__a_value);
-  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old | __pattern));
-  __a->__unlock();
-  return __old;
-}
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_or(__cxx_atomic_lock_impl<_Tp>* __a,
-                          _Tp __pattern, memory_order) {
-  __a->__lock();
-  _Tp __old = __a->__a_value;
-  __a->__a_value |= __pattern;
-  __a->__unlock();
-  return __old;
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_xor(volatile __cxx_atomic_lock_impl<_Tp>* __a,
-                           _Tp __pattern, memory_order) {
-  __a->__lock();
-  _Tp __old;
-  __cxx_atomic_assign_volatile(__old, __a->__a_value);
-  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old ^ __pattern));
-  __a->__unlock();
-  return __old;
-}
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __cxx_atomic_fetch_xor(__cxx_atomic_lock_impl<_Tp>* __a,
-                           _Tp __pattern, memory_order) {
-  __a->__lock();
-  _Tp __old = __a->__a_value;
-  __a->__a_value ^= __pattern;
-  __a->__unlock();
-  return __old;
-}
-
-#ifdef __cpp_lib_atomic_is_always_lock_free
-
-template<typename _Tp> struct __cxx_is_always_lock_free {
-    enum { __value = __atomic_always_lock_free(sizeof(_Tp), 0) }; };
-
-#else
-
-template<typename _Tp> struct __cxx_is_always_lock_free { enum { __value = false }; };
-// Implementations must match the C ATOMIC_*_LOCK_FREE macro values.
-template<> struct __cxx_is_always_lock_free<bool> { enum { __value = 2 == ATOMIC_BOOL_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<signed char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<unsigned char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; };
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
-template<> struct __cxx_is_always_lock_free<char8_t> { enum { __value = 2 == ATOMIC_CHAR8_T_LOCK_FREE }; };
-#endif
-template<> struct __cxx_is_always_lock_free<char16_t> { enum { __value = 2 == ATOMIC_CHAR16_T_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<char32_t> { enum { __value = 2 == ATOMIC_CHAR32_T_LOCK_FREE }; };
-#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-template<> struct __cxx_is_always_lock_free<wchar_t> { enum { __value = 2 == ATOMIC_WCHAR_T_LOCK_FREE }; };
-#endif
-template<> struct __cxx_is_always_lock_free<short> { enum { __value = 2 == ATOMIC_SHORT_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<unsigned short> { enum { __value = 2 == ATOMIC_SHORT_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<int> { enum { __value = 2 == ATOMIC_INT_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<unsigned int> { enum { __value = 2 == ATOMIC_INT_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<long> { enum { __value = 2 == ATOMIC_LONG_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<unsigned long> { enum { __value = 2 == ATOMIC_LONG_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<long long> { enum { __value = 2 == ATOMIC_LLONG_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<unsigned long long> { enum { __value = 2 == ATOMIC_LLONG_LOCK_FREE }; };
-template<typename _Tp> struct __cxx_is_always_lock_free<_Tp*> { enum { __value = 2 == ATOMIC_POINTER_LOCK_FREE }; };
-template<> struct __cxx_is_always_lock_free<std::nullptr_t> { enum { __value = 2 == ATOMIC_POINTER_LOCK_FREE }; };
-
-#endif //__cpp_lib_atomic_is_always_lock_free
-
-template <typename _Tp,
-          typename _Base = typename conditional<__cxx_is_always_lock_free<_Tp>::__value,
-                                                __cxx_atomic_base_impl<_Tp>,
-                                                __cxx_atomic_lock_impl<_Tp> >::type>
-#else
-template <typename _Tp,
-          typename _Base = __cxx_atomic_base_impl<_Tp> >
-#endif //_LIBCPP_ATOMIC_ONLY_USE_BUILTINS
-struct __cxx_atomic_impl : public _Base {
-    static_assert(is_trivially_copyable<_Tp>::value,
-      "std::atomic<Tp> requires that 'Tp' be a trivially copyable type");
-
-  _LIBCPP_INLINE_VISIBILITY __cxx_atomic_impl() _NOEXCEPT _LIBCPP_DEFAULT
-  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR explicit __cxx_atomic_impl(_Tp value) _NOEXCEPT
-    : _Base(value) {}
-};
-
-#ifdef __linux__
-    using __cxx_contention_t = int32_t;
-#else
-    using __cxx_contention_t = int64_t;
-#endif //__linux__
-
-using __cxx_atomic_contention_t = __cxx_atomic_impl<__cxx_contention_t>;
-
-#ifndef _LIBCPP_HAS_NO_PLATFORM_WAIT
-
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_one(void const volatile*);
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_all(void const volatile*);
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI __cxx_contention_t __libcpp_atomic_monitor(void const volatile*);
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __libcpp_atomic_wait(void const volatile*, __cxx_contention_t);
-
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_one(__cxx_atomic_contention_t const volatile*);
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_all(__cxx_atomic_contention_t const volatile*);
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI __cxx_contention_t __libcpp_atomic_monitor(__cxx_atomic_contention_t const volatile*);
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __libcpp_atomic_wait(__cxx_atomic_contention_t const volatile*, __cxx_contention_t);
-
-template <class _Atp, class _Fn>
-struct __libcpp_atomic_wait_backoff_impl {
-    _Atp* __a;
-    _Fn __test_fn;
-    _LIBCPP_AVAILABILITY_SYNC
-    _LIBCPP_INLINE_VISIBILITY bool operator()(chrono::nanoseconds __elapsed) const
-    {
-        if(__elapsed > chrono::microseconds(64))
-        {
-            auto const __monitor = __libcpp_atomic_monitor(__a);
-            if(__test_fn())
-                return true;
-            __libcpp_atomic_wait(__a, __monitor);
-        }
-        else if(__elapsed > chrono::microseconds(4))
-            __libcpp_thread_yield();
-        else
-            {} // poll
-        return false;
-    }
-};
-
-template <class _Atp, class _Fn>
-_LIBCPP_AVAILABILITY_SYNC
-_LIBCPP_INLINE_VISIBILITY bool __cxx_atomic_wait(_Atp* __a, _Fn && __test_fn)
-{
-    __libcpp_atomic_wait_backoff_impl<_Atp, typename decay<_Fn>::type> __backoff_fn = {__a, __test_fn};
-    return __libcpp_thread_poll_with_backoff(__test_fn, __backoff_fn);
-}
-
-#else // _LIBCPP_HAS_NO_PLATFORM_WAIT
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY void __cxx_atomic_notify_all(__cxx_atomic_impl<_Tp> const volatile*) { }
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY void __cxx_atomic_notify_one(__cxx_atomic_impl<_Tp> const volatile*) { }
-template <class _Atp, class _Fn>
-_LIBCPP_INLINE_VISIBILITY bool __cxx_atomic_wait(_Atp*, _Fn && __test_fn)
-{
-    return __libcpp_thread_poll_with_backoff(__test_fn, __libcpp_timed_backoff_policy());
-}
-
-#endif // _LIBCPP_HAS_NO_PLATFORM_WAIT
-
-template <class _Atp, class _Tp>
-struct __cxx_atomic_wait_test_fn_impl {
-    _Atp* __a;
-    _Tp __val;
-    memory_order __order;
-    _LIBCPP_INLINE_VISIBILITY bool operator()() const
-    {
-        return !__cxx_nonatomic_compare_equal(__cxx_atomic_load(__a, __order), __val);
-    }
-};
-
-template <class _Atp, class _Tp>
-_LIBCPP_AVAILABILITY_SYNC
-_LIBCPP_INLINE_VISIBILITY bool __cxx_atomic_wait(_Atp* __a, _Tp const __val, memory_order __order)
-{
-    __cxx_atomic_wait_test_fn_impl<_Atp, _Tp> __test_fn = {__a, __val, __order};
-    return __cxx_atomic_wait(__a, __test_fn);
-}
-
-// general atomic<T>
-
-template <class _Tp, bool = is_integral<_Tp>::value && !is_same<_Tp, bool>::value>
-struct __atomic_base  // false
-{
-    mutable __cxx_atomic_impl<_Tp> __a_;
-
-#if defined(__cpp_lib_atomic_is_always_lock_free)
-  static _LIBCPP_CONSTEXPR bool is_always_lock_free = __atomic_always_lock_free(sizeof(__a_), 0);
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool is_lock_free() const volatile _NOEXCEPT
-        {return __cxx_atomic_is_lock_free(sizeof(_Tp));}
-    _LIBCPP_INLINE_VISIBILITY
-    bool is_lock_free() const _NOEXCEPT
-        {return static_cast<__atomic_base const volatile*>(this)->is_lock_free();}
-    _LIBCPP_INLINE_VISIBILITY
-    void store(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
-        {__cxx_atomic_store(&__a_, __d, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    void store(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
-        {__cxx_atomic_store(&__a_, __d, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp load(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
-      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-        {return __cxx_atomic_load(&__a_, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp load(memory_order __m = memory_order_seq_cst) const _NOEXCEPT
-      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-        {return __cxx_atomic_load(&__a_, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    operator _Tp() const volatile _NOEXCEPT {return load();}
-    _LIBCPP_INLINE_VISIBILITY
-    operator _Tp() const _NOEXCEPT          {return load();}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __cxx_atomic_exchange(&__a_, __d, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __cxx_atomic_exchange(&__a_, __d, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_weak(_Tp& __e, _Tp __d,
-                               memory_order __s, memory_order __f) volatile _NOEXCEPT
-      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_weak(_Tp& __e, _Tp __d,
-                               memory_order __s, memory_order __f) _NOEXCEPT
-      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_strong(_Tp& __e, _Tp __d,
-                                 memory_order __s, memory_order __f) volatile _NOEXCEPT
-      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_strong(_Tp& __e, _Tp __d,
-                                 memory_order __s, memory_order __f) _NOEXCEPT
-      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_weak(_Tp& __e, _Tp __d,
-                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_weak(_Tp& __e, _Tp __d,
-                               memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_strong(_Tp& __e, _Tp __d,
-                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_strong(_Tp& __e, _Tp __d,
-                                 memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
-
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void wait(_Tp __v, memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
-        {__cxx_atomic_wait(&__a_, __v, __m);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void wait(_Tp __v, memory_order __m = memory_order_seq_cst) const _NOEXCEPT
-        {__cxx_atomic_wait(&__a_, __v, __m);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_one() volatile _NOEXCEPT
-        {__cxx_atomic_notify_one(&__a_);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_one() _NOEXCEPT
-        {__cxx_atomic_notify_one(&__a_);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_all() volatile _NOEXCEPT
-        {__cxx_atomic_notify_all(&__a_);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_all() _NOEXCEPT
-        {__cxx_atomic_notify_all(&__a_);}
-
-#if _LIBCPP_STD_VER > 17
-    _LIBCPP_INLINE_VISIBILITY constexpr
-    __atomic_base() noexcept(is_nothrow_default_constructible_v<_Tp>) : __a_(_Tp()) {}
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    __atomic_base() _NOEXCEPT _LIBCPP_DEFAULT
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    __atomic_base(_Tp __d) _NOEXCEPT : __a_(__d) {}
-
-#ifdef _LIBCPP_COMPILER_MSVC
-#pragma warning ( push )
-#pragma warning ( disable : 4522 )
-#endif
-#ifndef _LIBCPP_CXX03_LANG
-    __atomic_base(const __atomic_base&) = delete;
-#else
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    __atomic_base(const __atomic_base&);
-#endif
-#ifdef _LIBCPP_COMPILER_MSVC
-#pragma warning ( pop )
-#endif
-};
-
-#if defined(__cpp_lib_atomic_is_always_lock_free)
-template <class _Tp, bool __b>
-_LIBCPP_CONSTEXPR bool __atomic_base<_Tp, __b>::is_always_lock_free;
-#endif
-
-// atomic<Integral>
-
-template <class _Tp>
-struct __atomic_base<_Tp, true>
-    : public __atomic_base<_Tp, false>
-{
-    typedef __atomic_base<_Tp, false> __base;
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-    __atomic_base() _NOEXCEPT _LIBCPP_DEFAULT
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __base(__d) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __cxx_atomic_fetch_add(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __cxx_atomic_fetch_add(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __cxx_atomic_fetch_and(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __cxx_atomic_fetch_and(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __cxx_atomic_fetch_or(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __cxx_atomic_fetch_or(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __cxx_atomic_fetch_xor(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __cxx_atomic_fetch_xor(&this->__a_, __op, __m);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator++(int) volatile _NOEXCEPT      {return fetch_add(_Tp(1));}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator++(int) _NOEXCEPT               {return fetch_add(_Tp(1));}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator--(int) volatile _NOEXCEPT      {return fetch_sub(_Tp(1));}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator--(int) _NOEXCEPT               {return fetch_sub(_Tp(1));}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator++() volatile _NOEXCEPT         {return fetch_add(_Tp(1)) + _Tp(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator++() _NOEXCEPT                  {return fetch_add(_Tp(1)) + _Tp(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator--() volatile _NOEXCEPT         {return fetch_sub(_Tp(1)) - _Tp(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator--() _NOEXCEPT                  {return fetch_sub(_Tp(1)) - _Tp(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator+=(_Tp __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator+=(_Tp __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator-=(_Tp __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator-=(_Tp __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator&=(_Tp __op) volatile _NOEXCEPT {return fetch_and(__op) & __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator&=(_Tp __op) _NOEXCEPT          {return fetch_and(__op) & __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator|=(_Tp __op) volatile _NOEXCEPT {return fetch_or(__op) | __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator|=(_Tp __op) _NOEXCEPT          {return fetch_or(__op) | __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator^=(_Tp __op) volatile _NOEXCEPT {return fetch_xor(__op) ^ __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator^=(_Tp __op) _NOEXCEPT          {return fetch_xor(__op) ^ __op;}
-};
-
-// atomic<T>
-
-template <class _Tp>
-struct atomic
-    : public __atomic_base<_Tp>
-{
-    typedef __atomic_base<_Tp> __base;
-    typedef _Tp value_type;
-    typedef value_type difference_type;
-
-#if _LIBCPP_STD_VER > 17
-    _LIBCPP_INLINE_VISIBILITY
-    atomic() = default;
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    atomic() _NOEXCEPT _LIBCPP_DEFAULT
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR atomic(_Tp __d) _NOEXCEPT : __base(__d) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator=(_Tp __d) volatile _NOEXCEPT
-        {__base::store(__d); return __d;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator=(_Tp __d) _NOEXCEPT
-        {__base::store(__d); return __d;}
-
-    atomic& operator=(const atomic&) = delete;
-    atomic& operator=(const atomic&) volatile = delete;
-};
-
-// atomic<T*>
-
-template <class _Tp>
-struct atomic<_Tp*>
-    : public __atomic_base<_Tp*>
-{
-    typedef __atomic_base<_Tp*> __base;
-    typedef _Tp* value_type;
-    typedef ptrdiff_t difference_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    atomic() _NOEXCEPT _LIBCPP_DEFAULT
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR atomic(_Tp* __d) _NOEXCEPT : __base(__d) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator=(_Tp* __d) volatile _NOEXCEPT
-        {__base::store(__d); return __d;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator=(_Tp* __d) _NOEXCEPT
-        {__base::store(__d); return __d;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
-        // __atomic_fetch_add accepts function pointers, guard against them.
-        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed");
-        return __cxx_atomic_fetch_add(&this->__a_, __op, __m);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
-        // __atomic_fetch_add accepts function pointers, guard against them.
-        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed");
-        return __cxx_atomic_fetch_add(&this->__a_, __op, __m);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT {
-        // __atomic_fetch_add accepts function pointers, guard against them.
-        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed");
-        return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT {
-        // __atomic_fetch_add accepts function pointers, guard against them.
-        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed");
-        return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator++(int) volatile _NOEXCEPT            {return fetch_add(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator++(int) _NOEXCEPT                     {return fetch_add(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator--(int) volatile _NOEXCEPT            {return fetch_sub(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator--(int) _NOEXCEPT                     {return fetch_sub(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator++() volatile _NOEXCEPT               {return fetch_add(1) + 1;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator++() _NOEXCEPT                        {return fetch_add(1) + 1;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator--() volatile _NOEXCEPT               {return fetch_sub(1) - 1;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator--() _NOEXCEPT                        {return fetch_sub(1) - 1;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator+=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator+=(ptrdiff_t __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator-=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator-=(ptrdiff_t __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
-
-    atomic& operator=(const atomic&) = delete;
-    atomic& operator=(const atomic&) volatile = delete;
-};
-
-// atomic_is_lock_free
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_is_lock_free(const volatile atomic<_Tp>* __o) _NOEXCEPT
-{
-    return __o->is_lock_free();
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_is_lock_free(const atomic<_Tp>* __o) _NOEXCEPT
-{
-    return __o->is_lock_free();
-}
-
-// atomic_init
-
-template <class _Tp>
-_LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_INLINE_VISIBILITY
-void
-atomic_init(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    __cxx_atomic_init(&__o->__a_, __d);
-}
-
-template <class _Tp>
-_LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_INLINE_VISIBILITY
-void
-atomic_init(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    __cxx_atomic_init(&__o->__a_, __d);
-}
-
-// atomic_store
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void
-atomic_store(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    __o->store(__d);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void
-atomic_store(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    __o->store(__d);
-}
-
-// atomic_store_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void
-atomic_store_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
-{
-    __o->store(__d, __m);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-void
-atomic_store_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
-{
-    __o->store(__d, __m);
-}
-
-// atomic_load
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_load(const volatile atomic<_Tp>* __o) _NOEXCEPT
-{
-    return __o->load();
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_load(const atomic<_Tp>* __o) _NOEXCEPT
-{
-    return __o->load();
-}
-
-// atomic_load_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_load_explicit(const volatile atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-{
-    return __o->load(__m);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_load_explicit(const atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-{
-    return __o->load(__m);
-}
-
-// atomic_exchange
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_exchange(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    return __o->exchange(__d);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_exchange(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    return __o->exchange(__d);
-}
-
-// atomic_exchange_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_exchange_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT
-{
-    return __o->exchange(__d, __m);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_exchange_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT
-{
-    return __o->exchange(__d, __m);
-}
-
-// atomic_compare_exchange_weak
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_weak(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    return __o->compare_exchange_weak(*__e, __d);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_weak(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    return __o->compare_exchange_weak(*__e, __d);
-}
-
-// atomic_compare_exchange_strong
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_strong(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    return __o->compare_exchange_strong(*__e, __d);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_strong(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT
-{
-    return __o->compare_exchange_strong(*__e, __d);
-}
-
-// atomic_compare_exchange_weak_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_weak_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e,
-                                      typename atomic<_Tp>::value_type __d,
-                                      memory_order __s, memory_order __f) _NOEXCEPT
-  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-{
-    return __o->compare_exchange_weak(*__e, __d, __s, __f);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_weak_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d,
-                                      memory_order __s, memory_order __f) _NOEXCEPT
-  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-{
-    return __o->compare_exchange_weak(*__e, __d, __s, __f);
-}
-
-// atomic_compare_exchange_strong_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_strong_explicit(volatile atomic<_Tp>* __o,
-                                        typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d,
-                                        memory_order __s, memory_order __f) _NOEXCEPT
-  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-{
-    return __o->compare_exchange_strong(*__e, __d, __s, __f);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_strong_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e,
-                                        typename atomic<_Tp>::value_type __d,
-                                        memory_order __s, memory_order __f) _NOEXCEPT
-  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-{
-    return __o->compare_exchange_strong(*__e, __d, __s, __f);
-}
-
-// atomic_wait
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-void atomic_wait(const volatile atomic<_Tp>* __o,
-                 typename atomic<_Tp>::value_type __v) _NOEXCEPT
-{
-    return __o->wait(__v);
-}
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-void atomic_wait(const atomic<_Tp>* __o,
-                 typename atomic<_Tp>::value_type __v) _NOEXCEPT
-{
-    return __o->wait(__v);
-}
-
-// atomic_wait_explicit
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-void atomic_wait_explicit(const volatile atomic<_Tp>* __o,
-                          typename atomic<_Tp>::value_type __v,
-                          memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-{
-    return __o->wait(__v, __m);
-}
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-void atomic_wait_explicit(const atomic<_Tp>* __o,
-                          typename atomic<_Tp>::value_type __v,
-                          memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-{
-    return __o->wait(__v, __m);
-}
-
-// atomic_notify_one
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-void atomic_notify_one(volatile atomic<_Tp>* __o) _NOEXCEPT
-{
-    __o->notify_one();
-}
-template <class _Tp>
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-void atomic_notify_one(atomic<_Tp>* __o) _NOEXCEPT
-{
-    __o->notify_one();
-}
-
-// atomic_notify_one
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-void atomic_notify_all(volatile atomic<_Tp>* __o) _NOEXCEPT
-{
-    __o->notify_all();
-}
-template <class _Tp>
-_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-void atomic_notify_all(atomic<_Tp>* __o) _NOEXCEPT
-{
-    __o->notify_all();
-}
-
-// atomic_fetch_add
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_fetch_add(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT
-{
-    return __o->fetch_add(__op);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_fetch_add(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT
-{
-    return __o->fetch_add(__op);
-}
-
-// atomic_fetch_add_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp atomic_fetch_add_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_add(__op, __m);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp atomic_fetch_add_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_add(__op, __m);
-}
-
-// atomic_fetch_sub
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp atomic_fetch_sub(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT
-{
-    return __o->fetch_sub(__op);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp atomic_fetch_sub(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT
-{
-    return __o->fetch_sub(__op);
-}
-
-// atomic_fetch_sub_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp atomic_fetch_sub_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_sub(__op, __m);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp atomic_fetch_sub_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_sub(__op, __m);
-}
-
-// atomic_fetch_and
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_and(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
-{
-    return __o->fetch_and(__op);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_and(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
-{
-    return __o->fetch_and(__op);
-}
-
-// atomic_fetch_and_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_and_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_and(__op, __m);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_and_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_and(__op, __m);
-}
-
-// atomic_fetch_or
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_or(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
-{
-    return __o->fetch_or(__op);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_or(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
-{
-    return __o->fetch_or(__op);
-}
-
-// atomic_fetch_or_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_or_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_or(__op, __m);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_or_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_or(__op, __m);
-}
-
-// atomic_fetch_xor
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_xor(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
-{
-    return __o->fetch_xor(__op);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_xor(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT
-{
-    return __o->fetch_xor(__op);
-}
-
-// atomic_fetch_xor_explicit
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_xor_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_xor(__op, __m);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_xor_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_xor(__op, __m);
-}
-
-// flag type and operations
-
-typedef struct atomic_flag
-{
-    __cxx_atomic_impl<_LIBCPP_ATOMIC_FLAG_TYPE> __a_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool test(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
-        {return _LIBCPP_ATOMIC_FLAG_TYPE(true) == __cxx_atomic_load(&__a_, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool test(memory_order __m = memory_order_seq_cst) const _NOEXCEPT
-        {return _LIBCPP_ATOMIC_FLAG_TYPE(true) == __cxx_atomic_load(&__a_, __m);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool test_and_set(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __cxx_atomic_exchange(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(true), __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool test_and_set(memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __cxx_atomic_exchange(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(true), __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {__cxx_atomic_store(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(false), __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear(memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {__cxx_atomic_store(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(false), __m);}
-
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-    void wait(bool __v, memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
-        {__cxx_atomic_wait(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(__v), __m);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-    void wait(bool __v, memory_order __m = memory_order_seq_cst) const _NOEXCEPT
-        {__cxx_atomic_wait(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(__v), __m);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-    void notify_one() volatile _NOEXCEPT
-        {__cxx_atomic_notify_one(&__a_);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-    void notify_one() _NOEXCEPT
-        {__cxx_atomic_notify_one(&__a_);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-    void notify_all() volatile _NOEXCEPT
-        {__cxx_atomic_notify_all(&__a_);}
-    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
-    void notify_all() _NOEXCEPT
-        {__cxx_atomic_notify_all(&__a_);}
-
-#if _LIBCPP_STD_VER > 17
-    _LIBCPP_INLINE_VISIBILITY constexpr
-    atomic_flag() _NOEXCEPT : __a_(false) {}
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    atomic_flag() _NOEXCEPT _LIBCPP_DEFAULT
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    atomic_flag(bool __b) _NOEXCEPT : __a_(__b) {} // EXTENSION
-
-#ifdef _LIBCPP_COMPILER_MSVC
-#pragma warning ( push )
-#pragma warning ( disable : 4522 )
-#endif
-#ifndef _LIBCPP_CXX03_LANG
-    atomic_flag(const atomic_flag&) = delete;
-    atomic_flag& operator=(const atomic_flag&) = delete;
-    atomic_flag& operator=(const atomic_flag&) volatile = delete;
-#else
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    atomic_flag(const atomic_flag&);
-    _LIBCPP_INLINE_VISIBILITY
-    atomic_flag& operator=(const atomic_flag&);
-    _LIBCPP_INLINE_VISIBILITY
-    atomic_flag& operator=(const atomic_flag&) volatile;
-#endif
-#ifdef _LIBCPP_COMPILER_MSVC
-#pragma warning ( pop )
-#endif
-} atomic_flag;
-
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test(const volatile atomic_flag* __o) _NOEXCEPT
-{
-    return __o->test();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test(const atomic_flag* __o) _NOEXCEPT
-{
-    return __o->test();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_explicit(const volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    return __o->test(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_explicit(const atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    return __o->test(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_and_set(volatile atomic_flag* __o) _NOEXCEPT
-{
-    return __o->test_and_set();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_and_set(atomic_flag* __o) _NOEXCEPT
-{
-    return __o->test_and_set();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_and_set_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    return __o->test_and_set(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_and_set_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    return __o->test_and_set(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_flag_clear(volatile atomic_flag* __o) _NOEXCEPT
-{
-    __o->clear();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_flag_clear(atomic_flag* __o) _NOEXCEPT
-{
-    __o->clear();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_flag_clear_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    __o->clear(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_flag_clear_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    __o->clear(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
-void
-atomic_flag_wait(const volatile atomic_flag* __o, bool __v) _NOEXCEPT
-{
-    __o->wait(__v);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
-void
-atomic_flag_wait(const atomic_flag* __o, bool __v) _NOEXCEPT
-{
-    __o->wait(__v);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
-void
-atomic_flag_wait_explicit(const volatile atomic_flag* __o,
-                          bool __v, memory_order __m) _NOEXCEPT
-{
-    __o->wait(__v, __m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
-void
-atomic_flag_wait_explicit(const atomic_flag* __o,
-                          bool __v, memory_order __m) _NOEXCEPT
-{
-    __o->wait(__v, __m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
-void
-atomic_flag_notify_one(volatile atomic_flag* __o) _NOEXCEPT
-{
-    __o->notify_one();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
-void
-atomic_flag_notify_one(atomic_flag* __o) _NOEXCEPT
-{
-    __o->notify_one();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
-void
-atomic_flag_notify_all(volatile atomic_flag* __o) _NOEXCEPT
-{
-    __o->notify_all();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC
-void
-atomic_flag_notify_all(atomic_flag* __o) _NOEXCEPT
-{
-    __o->notify_all();
-}
-
-// fences
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_thread_fence(memory_order __m) _NOEXCEPT
-{
-    __cxx_atomic_thread_fence(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_signal_fence(memory_order __m) _NOEXCEPT
-{
-    __cxx_atomic_signal_fence(__m);
-}
-
-// Atomics for standard typedef types
-
-typedef atomic<bool>               atomic_bool;
-typedef atomic<char>               atomic_char;
-typedef atomic<signed char>        atomic_schar;
-typedef atomic<unsigned char>      atomic_uchar;
-typedef atomic<short>              atomic_short;
-typedef atomic<unsigned short>     atomic_ushort;
-typedef atomic<int>                atomic_int;
-typedef atomic<unsigned int>       atomic_uint;
-typedef atomic<long>               atomic_long;
-typedef atomic<unsigned long>      atomic_ulong;
-typedef atomic<long long>          atomic_llong;
-typedef atomic<unsigned long long> atomic_ullong;
-#ifndef _LIBCPP_HAS_NO_CHAR8_T
-typedef atomic<char8_t>            atomic_char8_t;
-#endif
-typedef atomic<char16_t>           atomic_char16_t;
-typedef atomic<char32_t>           atomic_char32_t;
-#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-typedef atomic<wchar_t>            atomic_wchar_t;
-#endif
-
-typedef atomic<int_least8_t>   atomic_int_least8_t;
-typedef atomic<uint_least8_t>  atomic_uint_least8_t;
-typedef atomic<int_least16_t>  atomic_int_least16_t;
-typedef atomic<uint_least16_t> atomic_uint_least16_t;
-typedef atomic<int_least32_t>  atomic_int_least32_t;
-typedef atomic<uint_least32_t> atomic_uint_least32_t;
-typedef atomic<int_least64_t>  atomic_int_least64_t;
-typedef atomic<uint_least64_t> atomic_uint_least64_t;
-
-typedef atomic<int_fast8_t>   atomic_int_fast8_t;
-typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
-typedef atomic<int_fast16_t>  atomic_int_fast16_t;
-typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
-typedef atomic<int_fast32_t>  atomic_int_fast32_t;
-typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
-typedef atomic<int_fast64_t>  atomic_int_fast64_t;
-typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
-
-typedef atomic< int8_t>  atomic_int8_t;
-typedef atomic<uint8_t>  atomic_uint8_t;
-typedef atomic< int16_t> atomic_int16_t;
-typedef atomic<uint16_t> atomic_uint16_t;
-typedef atomic< int32_t> atomic_int32_t;
-typedef atomic<uint32_t> atomic_uint32_t;
-typedef atomic< int64_t> atomic_int64_t;
-typedef atomic<uint64_t> atomic_uint64_t;
-
-typedef atomic<intptr_t>  atomic_intptr_t;
-typedef atomic<uintptr_t> atomic_uintptr_t;
-typedef atomic<size_t>    atomic_size_t;
-typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
-typedef atomic<intmax_t>  atomic_intmax_t;
-typedef atomic<uintmax_t> atomic_uintmax_t;
-
-// atomic_*_lock_free : prefer the contention type most highly, then the largest lock-free type
-
-#ifdef __cpp_lib_atomic_is_always_lock_free
-# define _LIBCPP_CONTENTION_LOCK_FREE __atomic_always_lock_free(sizeof(__cxx_contention_t), 0)
-#else
-# define _LIBCPP_CONTENTION_LOCK_FREE false
-#endif
-
-#if ATOMIC_LLONG_LOCK_FREE == 2
-typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, long long>::type          __libcpp_signed_lock_free;
-typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned long long>::type __libcpp_unsigned_lock_free;
-#elif ATOMIC_INT_LOCK_FREE == 2
-typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, int>::type                __libcpp_signed_lock_free;
-typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned int>::type       __libcpp_unsigned_lock_free;
-#elif ATOMIC_SHORT_LOCK_FREE == 2
-typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, short>::type              __libcpp_signed_lock_free;
-typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned short>::type     __libcpp_unsigned_lock_free;
-#elif ATOMIC_CHAR_LOCK_FREE == 2
-typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, char>::type               __libcpp_signed_lock_free;
-typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned char>::type      __libcpp_unsigned_lock_free;
-#else
-    // No signed/unsigned lock-free types
-#endif
-
-typedef atomic<__libcpp_signed_lock_free> atomic_signed_lock_free;
-typedef atomic<__libcpp_unsigned_lock_free> atomic_unsigned_lock_free;
-
-#define ATOMIC_FLAG_INIT {false}
-#define ATOMIC_VAR_INIT(__v) {__v}
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP_ATOMIC
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_init(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __val) _NOEXCEPT { 
+    __c11_atomic_init(&__a->__a_value, __val); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_init(__cxx_atomic_base_impl<_Tp> * __a, _Tp __val) _NOEXCEPT { 
+    __c11_atomic_init(&__a->__a_value, __val); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_store(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __val, memory_order __order) _NOEXCEPT { 
+    __c11_atomic_store(&__a->__a_value, __val, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_store(__cxx_atomic_base_impl<_Tp> * __a, _Tp __val, memory_order __order) _NOEXCEPT { 
+    __c11_atomic_store(&__a->__a_value, __val, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_load(__cxx_atomic_base_impl<_Tp> const volatile* __a, memory_order __order) _NOEXCEPT { 
+    using __ptr_type = typename remove_const<decltype(__a->__a_value)>::type*; 
+    return __c11_atomic_load(const_cast<__ptr_type>(&__a->__a_value), static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_load(__cxx_atomic_base_impl<_Tp> const* __a, memory_order __order) _NOEXCEPT { 
+    using __ptr_type = typename remove_const<decltype(__a->__a_value)>::type*; 
+    return __c11_atomic_load(const_cast<__ptr_type>(&__a->__a_value), static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_exchange(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __value, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_exchange(&__a->__a_value, __value, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_exchange(__cxx_atomic_base_impl<_Tp> * __a, _Tp __value, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_exchange(&__a->__a_value, __value, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+// Disable double inline warning 
+#ifdef _LIBCPP_COMPILER_MSVC 
+#pragma warning ( push ) 
+#pragma warning ( disable : 4141 ) 
+#endif 
+_LIBCPP_INLINE_VISIBILITY inline _LIBCPP_CONSTEXPR memory_order __to_failure_order(memory_order __order) { 
+  // Avoid switch statement to make this a constexpr. 
+  return __order == memory_order_release ? memory_order_relaxed: 
+         (__order == memory_order_acq_rel ? memory_order_acquire: 
+             __order); 
+} 
+#ifdef _LIBCPP_COMPILER_MSVC 
+#pragma warning ( pop ) 
+#endif 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_strong(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT { 
+    return __c11_atomic_compare_exchange_strong(&__a->__a_value, __expected, __value, static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure))); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_strong(__cxx_atomic_base_impl<_Tp> * __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT { 
+    return __c11_atomic_compare_exchange_strong(&__a->__a_value, __expected, __value, static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure))); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_weak(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT { 
+    return __c11_atomic_compare_exchange_weak(&__a->__a_value, __expected, __value, static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure))); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_weak(__cxx_atomic_base_impl<_Tp> * __a, _Tp* __expected, _Tp __value, memory_order __success, memory_order __failure) _NOEXCEPT { 
+    return __c11_atomic_compare_exchange_weak(&__a->__a_value, __expected, __value,  static_cast<__memory_order_underlying_t>(__success), static_cast<__memory_order_underlying_t>(__to_failure_order(__failure))); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __delta, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp> * __a, _Tp __delta, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp* __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp*> volatile* __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp* __cxx_atomic_fetch_add(__cxx_atomic_base_impl<_Tp*> * __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_add(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __delta, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp> * __a, _Tp __delta, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp* __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp*> volatile* __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp* __cxx_atomic_fetch_sub(__cxx_atomic_base_impl<_Tp*> * __a, ptrdiff_t __delta, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_sub(&__a->__a_value, __delta, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_and(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __pattern, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_and(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_and(__cxx_atomic_base_impl<_Tp> * __a, _Tp __pattern, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_and(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_or(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __pattern, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_or(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_or(__cxx_atomic_base_impl<_Tp> * __a, _Tp __pattern, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_or(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_xor(__cxx_atomic_base_impl<_Tp> volatile* __a, _Tp __pattern, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_xor(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+template<class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_xor(__cxx_atomic_base_impl<_Tp> * __a, _Tp __pattern, memory_order __order) _NOEXCEPT { 
+    return __c11_atomic_fetch_xor(&__a->__a_value, __pattern, static_cast<__memory_order_underlying_t>(__order)); 
+} 
+ 
+#endif // _LIBCPP_HAS_GCC_ATOMIC_IMP, _LIBCPP_HAS_C_ATOMIC_IMP 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp kill_dependency(_Tp __y) _NOEXCEPT 
+{ 
+    return __y; 
+} 
+ 
+#if defined(__CLANG_ATOMIC_BOOL_LOCK_FREE) 
+# define ATOMIC_BOOL_LOCK_FREE      __CLANG_ATOMIC_BOOL_LOCK_FREE 
+# define ATOMIC_CHAR_LOCK_FREE      __CLANG_ATOMIC_CHAR_LOCK_FREE 
+#ifndef _LIBCPP_HAS_NO_CHAR8_T 
+# define ATOMIC_CHAR8_T_LOCK_FREE   __CLANG_ATOMIC_CHAR8_T_LOCK_FREE 
+#endif 
+# define ATOMIC_CHAR16_T_LOCK_FREE  __CLANG_ATOMIC_CHAR16_T_LOCK_FREE 
+# define ATOMIC_CHAR32_T_LOCK_FREE  __CLANG_ATOMIC_CHAR32_T_LOCK_FREE 
+# define ATOMIC_WCHAR_T_LOCK_FREE   __CLANG_ATOMIC_WCHAR_T_LOCK_FREE 
+# define ATOMIC_SHORT_LOCK_FREE     __CLANG_ATOMIC_SHORT_LOCK_FREE 
+# define ATOMIC_INT_LOCK_FREE       __CLANG_ATOMIC_INT_LOCK_FREE 
+# define ATOMIC_LONG_LOCK_FREE      __CLANG_ATOMIC_LONG_LOCK_FREE 
+# define ATOMIC_LLONG_LOCK_FREE     __CLANG_ATOMIC_LLONG_LOCK_FREE 
+# define ATOMIC_POINTER_LOCK_FREE   __CLANG_ATOMIC_POINTER_LOCK_FREE 
+#elif defined(__GCC_ATOMIC_BOOL_LOCK_FREE) 
+# define ATOMIC_BOOL_LOCK_FREE      __GCC_ATOMIC_BOOL_LOCK_FREE 
+# define ATOMIC_CHAR_LOCK_FREE      __GCC_ATOMIC_CHAR_LOCK_FREE 
+#ifndef _LIBCPP_HAS_NO_CHAR8_T 
+# define ATOMIC_CHAR8_T_LOCK_FREE   __GCC_ATOMIC_CHAR8_T_LOCK_FREE 
+#endif 
+# define ATOMIC_CHAR16_T_LOCK_FREE  __GCC_ATOMIC_CHAR16_T_LOCK_FREE 
+# define ATOMIC_CHAR32_T_LOCK_FREE  __GCC_ATOMIC_CHAR32_T_LOCK_FREE 
+# define ATOMIC_WCHAR_T_LOCK_FREE   __GCC_ATOMIC_WCHAR_T_LOCK_FREE 
+# define ATOMIC_SHORT_LOCK_FREE     __GCC_ATOMIC_SHORT_LOCK_FREE 
+# define ATOMIC_INT_LOCK_FREE       __GCC_ATOMIC_INT_LOCK_FREE 
+# define ATOMIC_LONG_LOCK_FREE      __GCC_ATOMIC_LONG_LOCK_FREE 
+# define ATOMIC_LLONG_LOCK_FREE     __GCC_ATOMIC_LLONG_LOCK_FREE 
+# define ATOMIC_POINTER_LOCK_FREE   __GCC_ATOMIC_POINTER_LOCK_FREE 
+#endif 
+ 
+#ifdef _LIBCPP_ATOMIC_ONLY_USE_BUILTINS 
+ 
+template<typename _Tp> 
+struct __cxx_atomic_lock_impl { 
+ 
+  _LIBCPP_INLINE_VISIBILITY 
+  __cxx_atomic_lock_impl() _NOEXCEPT 
+    : __a_value(), __a_lock(0) {} 
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR explicit 
+  __cxx_atomic_lock_impl(_Tp value) _NOEXCEPT 
+    : __a_value(value), __a_lock(0) {} 
+ 
+  _Tp __a_value; 
+  mutable __cxx_atomic_base_impl<_LIBCPP_ATOMIC_FLAG_TYPE> __a_lock; 
+ 
+  _LIBCPP_INLINE_VISIBILITY void __lock() const volatile { 
+    while(1 == __cxx_atomic_exchange(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(true), memory_order_acquire)) 
+        /*spin*/; 
+  } 
+  _LIBCPP_INLINE_VISIBILITY void __lock() const { 
+    while(1 == __cxx_atomic_exchange(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(true), memory_order_acquire)) 
+        /*spin*/; 
+  } 
+  _LIBCPP_INLINE_VISIBILITY void __unlock() const volatile { 
+    __cxx_atomic_store(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(false), memory_order_release); 
+  } 
+  _LIBCPP_INLINE_VISIBILITY void __unlock() const { 
+    __cxx_atomic_store(&__a_lock, _LIBCPP_ATOMIC_FLAG_TYPE(false), memory_order_release); 
+  } 
+  _LIBCPP_INLINE_VISIBILITY _Tp __read() const volatile { 
+    __lock(); 
+    _Tp __old; 
+    __cxx_atomic_assign_volatile(__old, __a_value); 
+    __unlock(); 
+    return __old; 
+  } 
+  _LIBCPP_INLINE_VISIBILITY _Tp __read() const { 
+    __lock(); 
+    _Tp __old = __a_value; 
+    __unlock(); 
+    return __old; 
+  } 
+}; 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_init(volatile __cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val) { 
+  __cxx_atomic_assign_volatile(__a->__a_value, __val); 
+} 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_init(__cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val) { 
+  __a->__a_value = __val; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_store(volatile __cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val, memory_order) { 
+  __a->__lock(); 
+  __cxx_atomic_assign_volatile(__a->__a_value, __val); 
+  __a->__unlock(); 
+} 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void __cxx_atomic_store(__cxx_atomic_lock_impl<_Tp>* __a,  _Tp __val, memory_order) { 
+  __a->__lock(); 
+  __a->__a_value = __val; 
+  __a->__unlock(); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_load(const volatile __cxx_atomic_lock_impl<_Tp>* __a, memory_order) { 
+  return __a->__read(); 
+} 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_load(const __cxx_atomic_lock_impl<_Tp>* __a, memory_order) { 
+  return __a->__read(); 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_exchange(volatile __cxx_atomic_lock_impl<_Tp>* __a, _Tp __value, memory_order) { 
+  __a->__lock(); 
+  _Tp __old; 
+  __cxx_atomic_assign_volatile(__old, __a->__a_value); 
+  __cxx_atomic_assign_volatile(__a->__a_value, __value); 
+  __a->__unlock(); 
+  return __old; 
+} 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_exchange(__cxx_atomic_lock_impl<_Tp>* __a, _Tp __value, memory_order) { 
+  __a->__lock(); 
+  _Tp __old = __a->__a_value; 
+  __a->__a_value = __value; 
+  __a->__unlock(); 
+  return __old; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_strong(volatile __cxx_atomic_lock_impl<_Tp>* __a, 
+                                          _Tp* __expected, _Tp __value, memory_order, memory_order) { 
+  _Tp __temp; 
+  __a->__lock(); 
+  __cxx_atomic_assign_volatile(__temp, __a->__a_value); 
+  bool __ret = (_VSTD::memcmp(&__temp, __expected, sizeof(_Tp)) == 0); 
+  if(__ret) 
+    __cxx_atomic_assign_volatile(__a->__a_value, __value); 
+  else 
+    __cxx_atomic_assign_volatile(*__expected, __a->__a_value); 
+  __a->__unlock(); 
+  return __ret; 
+} 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_strong(__cxx_atomic_lock_impl<_Tp>* __a, 
+                                          _Tp* __expected, _Tp __value, memory_order, memory_order) { 
+  __a->__lock(); 
+  bool __ret = (_VSTD::memcmp(&__a->__a_value, __expected, sizeof(_Tp)) == 0); 
+  if(__ret) 
+    _VSTD::memcpy(&__a->__a_value, &__value, sizeof(_Tp)); 
+  else 
+    _VSTD::memcpy(__expected, &__a->__a_value, sizeof(_Tp)); 
+  __a->__unlock(); 
+  return __ret; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_weak(volatile __cxx_atomic_lock_impl<_Tp>* __a, 
+                                        _Tp* __expected, _Tp __value, memory_order, memory_order) { 
+  _Tp __temp; 
+  __a->__lock(); 
+  __cxx_atomic_assign_volatile(__temp, __a->__a_value); 
+  bool __ret = (_VSTD::memcmp(&__temp, __expected, sizeof(_Tp)) == 0); 
+  if(__ret) 
+    __cxx_atomic_assign_volatile(__a->__a_value, __value); 
+  else 
+    __cxx_atomic_assign_volatile(*__expected, __a->__a_value); 
+  __a->__unlock(); 
+  return __ret; 
+} 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool __cxx_atomic_compare_exchange_weak(__cxx_atomic_lock_impl<_Tp>* __a, 
+                                        _Tp* __expected, _Tp __value, memory_order, memory_order) { 
+  __a->__lock(); 
+  bool __ret = (_VSTD::memcmp(&__a->__a_value, __expected, sizeof(_Tp)) == 0); 
+  if(__ret) 
+    _VSTD::memcpy(&__a->__a_value, &__value, sizeof(_Tp)); 
+  else 
+    _VSTD::memcpy(__expected, &__a->__a_value, sizeof(_Tp)); 
+  __a->__unlock(); 
+  return __ret; 
+} 
+ 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_add(volatile __cxx_atomic_lock_impl<_Tp>* __a, 
+                           _Td __delta, memory_order) { 
+  __a->__lock(); 
+  _Tp __old; 
+  __cxx_atomic_assign_volatile(__old, __a->__a_value); 
+  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old + __delta)); 
+  __a->__unlock(); 
+  return __old; 
+} 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_add(__cxx_atomic_lock_impl<_Tp>* __a, 
+                           _Td __delta, memory_order) { 
+  __a->__lock(); 
+  _Tp __old = __a->__a_value; 
+  __a->__a_value += __delta; 
+  __a->__unlock(); 
+  return __old; 
+} 
+ 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp* __cxx_atomic_fetch_add(volatile __cxx_atomic_lock_impl<_Tp*>* __a, 
+                           ptrdiff_t __delta, memory_order) { 
+  __a->__lock(); 
+  _Tp* __old; 
+  __cxx_atomic_assign_volatile(__old, __a->__a_value); 
+  __cxx_atomic_assign_volatile(__a->__a_value, __old + __delta); 
+  __a->__unlock(); 
+  return __old; 
+} 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp* __cxx_atomic_fetch_add(__cxx_atomic_lock_impl<_Tp*>* __a, 
+                           ptrdiff_t __delta, memory_order) { 
+  __a->__lock(); 
+  _Tp* __old = __a->__a_value; 
+  __a->__a_value += __delta; 
+  __a->__unlock(); 
+  return __old; 
+} 
+ 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_sub(volatile __cxx_atomic_lock_impl<_Tp>* __a, 
+                           _Td __delta, memory_order) { 
+  __a->__lock(); 
+  _Tp __old; 
+  __cxx_atomic_assign_volatile(__old, __a->__a_value); 
+  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old - __delta)); 
+  __a->__unlock(); 
+  return __old; 
+} 
+template <typename _Tp, typename _Td> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_sub(__cxx_atomic_lock_impl<_Tp>* __a, 
+                           _Td __delta, memory_order) { 
+  __a->__lock(); 
+  _Tp __old = __a->__a_value; 
+  __a->__a_value -= __delta; 
+  __a->__unlock(); 
+  return __old; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_and(volatile __cxx_atomic_lock_impl<_Tp>* __a, 
+                           _Tp __pattern, memory_order) { 
+  __a->__lock(); 
+  _Tp __old; 
+  __cxx_atomic_assign_volatile(__old, __a->__a_value); 
+  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old & __pattern)); 
+  __a->__unlock(); 
+  return __old; 
+} 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_and(__cxx_atomic_lock_impl<_Tp>* __a, 
+                           _Tp __pattern, memory_order) { 
+  __a->__lock(); 
+  _Tp __old = __a->__a_value; 
+  __a->__a_value &= __pattern; 
+  __a->__unlock(); 
+  return __old; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_or(volatile __cxx_atomic_lock_impl<_Tp>* __a, 
+                          _Tp __pattern, memory_order) { 
+  __a->__lock(); 
+  _Tp __old; 
+  __cxx_atomic_assign_volatile(__old, __a->__a_value); 
+  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old | __pattern)); 
+  __a->__unlock(); 
+  return __old; 
+} 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_or(__cxx_atomic_lock_impl<_Tp>* __a, 
+                          _Tp __pattern, memory_order) { 
+  __a->__lock(); 
+  _Tp __old = __a->__a_value; 
+  __a->__a_value |= __pattern; 
+  __a->__unlock(); 
+  return __old; 
+} 
+ 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_xor(volatile __cxx_atomic_lock_impl<_Tp>* __a, 
+                           _Tp __pattern, memory_order) { 
+  __a->__lock(); 
+  _Tp __old; 
+  __cxx_atomic_assign_volatile(__old, __a->__a_value); 
+  __cxx_atomic_assign_volatile(__a->__a_value, _Tp(__old ^ __pattern)); 
+  __a->__unlock(); 
+  return __old; 
+} 
+template <typename _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp __cxx_atomic_fetch_xor(__cxx_atomic_lock_impl<_Tp>* __a, 
+                           _Tp __pattern, memory_order) { 
+  __a->__lock(); 
+  _Tp __old = __a->__a_value; 
+  __a->__a_value ^= __pattern; 
+  __a->__unlock(); 
+  return __old; 
+} 
+ 
+#ifdef __cpp_lib_atomic_is_always_lock_free 
+ 
+template<typename _Tp> struct __cxx_is_always_lock_free { 
+    enum { __value = __atomic_always_lock_free(sizeof(_Tp), 0) }; }; 
+ 
+#else 
+ 
+template<typename _Tp> struct __cxx_is_always_lock_free { enum { __value = false }; }; 
+// Implementations must match the C ATOMIC_*_LOCK_FREE macro values. 
+template<> struct __cxx_is_always_lock_free<bool> { enum { __value = 2 == ATOMIC_BOOL_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<signed char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<unsigned char> { enum { __value = 2 == ATOMIC_CHAR_LOCK_FREE }; }; 
+#ifndef _LIBCPP_HAS_NO_CHAR8_T 
+template<> struct __cxx_is_always_lock_free<char8_t> { enum { __value = 2 == ATOMIC_CHAR8_T_LOCK_FREE }; }; 
+#endif 
+template<> struct __cxx_is_always_lock_free<char16_t> { enum { __value = 2 == ATOMIC_CHAR16_T_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<char32_t> { enum { __value = 2 == ATOMIC_CHAR32_T_LOCK_FREE }; }; 
+#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS 
+template<> struct __cxx_is_always_lock_free<wchar_t> { enum { __value = 2 == ATOMIC_WCHAR_T_LOCK_FREE }; }; 
+#endif 
+template<> struct __cxx_is_always_lock_free<short> { enum { __value = 2 == ATOMIC_SHORT_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<unsigned short> { enum { __value = 2 == ATOMIC_SHORT_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<int> { enum { __value = 2 == ATOMIC_INT_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<unsigned int> { enum { __value = 2 == ATOMIC_INT_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<long> { enum { __value = 2 == ATOMIC_LONG_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<unsigned long> { enum { __value = 2 == ATOMIC_LONG_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<long long> { enum { __value = 2 == ATOMIC_LLONG_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<unsigned long long> { enum { __value = 2 == ATOMIC_LLONG_LOCK_FREE }; }; 
+template<typename _Tp> struct __cxx_is_always_lock_free<_Tp*> { enum { __value = 2 == ATOMIC_POINTER_LOCK_FREE }; }; 
+template<> struct __cxx_is_always_lock_free<std::nullptr_t> { enum { __value = 2 == ATOMIC_POINTER_LOCK_FREE }; }; 
+ 
+#endif //__cpp_lib_atomic_is_always_lock_free 
+ 
+template <typename _Tp, 
+          typename _Base = typename conditional<__cxx_is_always_lock_free<_Tp>::__value, 
+                                                __cxx_atomic_base_impl<_Tp>, 
+                                                __cxx_atomic_lock_impl<_Tp> >::type> 
+#else 
+template <typename _Tp, 
+          typename _Base = __cxx_atomic_base_impl<_Tp> > 
+#endif //_LIBCPP_ATOMIC_ONLY_USE_BUILTINS 
+struct __cxx_atomic_impl : public _Base { 
+    static_assert(is_trivially_copyable<_Tp>::value, 
+      "std::atomic<Tp> requires that 'Tp' be a trivially copyable type"); 
+ 
+  _LIBCPP_INLINE_VISIBILITY __cxx_atomic_impl() _NOEXCEPT _LIBCPP_DEFAULT 
+  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR explicit __cxx_atomic_impl(_Tp value) _NOEXCEPT 
+    : _Base(value) {} 
+}; 
+ 
+#ifdef __linux__ 
+    using __cxx_contention_t = int32_t; 
+#else 
+    using __cxx_contention_t = int64_t; 
+#endif //__linux__ 
+ 
+using __cxx_atomic_contention_t = __cxx_atomic_impl<__cxx_contention_t>; 
+ 
+#ifndef _LIBCPP_HAS_NO_PLATFORM_WAIT 
+ 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_one(void const volatile*); 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_all(void const volatile*); 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI __cxx_contention_t __libcpp_atomic_monitor(void const volatile*); 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __libcpp_atomic_wait(void const volatile*, __cxx_contention_t); 
+ 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_one(__cxx_atomic_contention_t const volatile*); 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __cxx_atomic_notify_all(__cxx_atomic_contention_t const volatile*); 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI __cxx_contention_t __libcpp_atomic_monitor(__cxx_atomic_contention_t const volatile*); 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_EXPORTED_FROM_ABI void __libcpp_atomic_wait(__cxx_atomic_contention_t const volatile*, __cxx_contention_t); 
+ 
+template <class _Atp, class _Fn> 
+struct __libcpp_atomic_wait_backoff_impl { 
+    _Atp* __a; 
+    _Fn __test_fn; 
+    _LIBCPP_AVAILABILITY_SYNC 
+    _LIBCPP_INLINE_VISIBILITY bool operator()(chrono::nanoseconds __elapsed) const 
+    { 
+        if(__elapsed > chrono::microseconds(64)) 
+        { 
+            auto const __monitor = __libcpp_atomic_monitor(__a); 
+            if(__test_fn()) 
+                return true; 
+            __libcpp_atomic_wait(__a, __monitor); 
+        } 
+        else if(__elapsed > chrono::microseconds(4)) 
+            __libcpp_thread_yield(); 
+        else 
+            {} // poll 
+        return false; 
+    } 
+}; 
+ 
+template <class _Atp, class _Fn> 
+_LIBCPP_AVAILABILITY_SYNC 
+_LIBCPP_INLINE_VISIBILITY bool __cxx_atomic_wait(_Atp* __a, _Fn && __test_fn) 
+{ 
+    __libcpp_atomic_wait_backoff_impl<_Atp, typename decay<_Fn>::type> __backoff_fn = {__a, __test_fn}; 
+    return __libcpp_thread_poll_with_backoff(__test_fn, __backoff_fn); 
+} 
+ 
+#else // _LIBCPP_HAS_NO_PLATFORM_WAIT 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY void __cxx_atomic_notify_all(__cxx_atomic_impl<_Tp> const volatile*) { } 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY void __cxx_atomic_notify_one(__cxx_atomic_impl<_Tp> const volatile*) { } 
+template <class _Atp, class _Fn> 
+_LIBCPP_INLINE_VISIBILITY bool __cxx_atomic_wait(_Atp*, _Fn && __test_fn) 
+{ 
+    return __libcpp_thread_poll_with_backoff(__test_fn, __libcpp_timed_backoff_policy()); 
+} 
+ 
+#endif // _LIBCPP_HAS_NO_PLATFORM_WAIT 
+ 
+template <class _Atp, class _Tp> 
+struct __cxx_atomic_wait_test_fn_impl { 
+    _Atp* __a; 
+    _Tp __val; 
+    memory_order __order; 
+    _LIBCPP_INLINE_VISIBILITY bool operator()() const 
+    { 
+        return !__cxx_nonatomic_compare_equal(__cxx_atomic_load(__a, __order), __val); 
+    } 
+}; 
+ 
+template <class _Atp, class _Tp> 
+_LIBCPP_AVAILABILITY_SYNC 
+_LIBCPP_INLINE_VISIBILITY bool __cxx_atomic_wait(_Atp* __a, _Tp const __val, memory_order __order) 
+{ 
+    __cxx_atomic_wait_test_fn_impl<_Atp, _Tp> __test_fn = {__a, __val, __order}; 
+    return __cxx_atomic_wait(__a, __test_fn); 
+} 
+ 
+// general atomic<T> 
+ 
+template <class _Tp, bool = is_integral<_Tp>::value && !is_same<_Tp, bool>::value> 
+struct __atomic_base  // false 
+{ 
+    mutable __cxx_atomic_impl<_Tp> __a_; 
+ 
+#if defined(__cpp_lib_atomic_is_always_lock_free) 
+  static _LIBCPP_CONSTEXPR bool is_always_lock_free = __atomic_always_lock_free(sizeof(__a_), 0); 
+#endif 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool is_lock_free() const volatile _NOEXCEPT 
+        {return __cxx_atomic_is_lock_free(sizeof(_Tp));} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool is_lock_free() const _NOEXCEPT 
+        {return static_cast<__atomic_base const volatile*>(this)->is_lock_free();} 
+    _LIBCPP_INLINE_VISIBILITY 
+    void store(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) 
+        {__cxx_atomic_store(&__a_, __d, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    void store(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) 
+        {__cxx_atomic_store(&__a_, __d, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp load(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT 
+      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) 
+        {return __cxx_atomic_load(&__a_, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp load(memory_order __m = memory_order_seq_cst) const _NOEXCEPT 
+      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) 
+        {return __cxx_atomic_load(&__a_, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    operator _Tp() const volatile _NOEXCEPT {return load();} 
+    _LIBCPP_INLINE_VISIBILITY 
+    operator _Tp() const _NOEXCEPT          {return load();} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {return __cxx_atomic_exchange(&__a_, __d, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {return __cxx_atomic_exchange(&__a_, __d, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool compare_exchange_weak(_Tp& __e, _Tp __d, 
+                               memory_order __s, memory_order __f) volatile _NOEXCEPT 
+      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) 
+        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool compare_exchange_weak(_Tp& __e, _Tp __d, 
+                               memory_order __s, memory_order __f) _NOEXCEPT 
+      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) 
+        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool compare_exchange_strong(_Tp& __e, _Tp __d, 
+                                 memory_order __s, memory_order __f) volatile _NOEXCEPT 
+      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) 
+        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool compare_exchange_strong(_Tp& __e, _Tp __d, 
+                                 memory_order __s, memory_order __f) _NOEXCEPT 
+      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) 
+        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool compare_exchange_weak(_Tp& __e, _Tp __d, 
+                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool compare_exchange_weak(_Tp& __e, _Tp __d, 
+                               memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {return __cxx_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool compare_exchange_strong(_Tp& __e, _Tp __d, 
+                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool compare_exchange_strong(_Tp& __e, _Tp __d, 
+                                 memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {return __cxx_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);} 
+ 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void wait(_Tp __v, memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT 
+        {__cxx_atomic_wait(&__a_, __v, __m);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void wait(_Tp __v, memory_order __m = memory_order_seq_cst) const _NOEXCEPT 
+        {__cxx_atomic_wait(&__a_, __v, __m);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_one() volatile _NOEXCEPT 
+        {__cxx_atomic_notify_one(&__a_);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_one() _NOEXCEPT 
+        {__cxx_atomic_notify_one(&__a_);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_all() volatile _NOEXCEPT 
+        {__cxx_atomic_notify_all(&__a_);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY void notify_all() _NOEXCEPT 
+        {__cxx_atomic_notify_all(&__a_);} 
+ 
+#if _LIBCPP_STD_VER > 17 
+    _LIBCPP_INLINE_VISIBILITY constexpr 
+    __atomic_base() noexcept(is_nothrow_default_constructible_v<_Tp>) : __a_(_Tp()) {} 
+#else 
+    _LIBCPP_INLINE_VISIBILITY 
+    __atomic_base() _NOEXCEPT _LIBCPP_DEFAULT 
+#endif 
+ 
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR 
+    __atomic_base(_Tp __d) _NOEXCEPT : __a_(__d) {} 
+ 
+#ifdef _LIBCPP_COMPILER_MSVC 
+#pragma warning ( push ) 
+#pragma warning ( disable : 4522 ) 
+#endif 
+#ifndef _LIBCPP_CXX03_LANG 
+    __atomic_base(const __atomic_base&) = delete; 
+#else 
+private: 
+    _LIBCPP_INLINE_VISIBILITY 
+    __atomic_base(const __atomic_base&); 
+#endif 
+#ifdef _LIBCPP_COMPILER_MSVC 
+#pragma warning ( pop ) 
+#endif 
+}; 
+ 
+#if defined(__cpp_lib_atomic_is_always_lock_free) 
+template <class _Tp, bool __b> 
+_LIBCPP_CONSTEXPR bool __atomic_base<_Tp, __b>::is_always_lock_free; 
+#endif 
+ 
+// atomic<Integral> 
+ 
+template <class _Tp> 
+struct __atomic_base<_Tp, true> 
+    : public __atomic_base<_Tp, false> 
+{ 
+    typedef __atomic_base<_Tp, false> __base; 
+ 
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 
+    __atomic_base() _NOEXCEPT _LIBCPP_DEFAULT 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __base(__d) {} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {return __cxx_atomic_fetch_add(&this->__a_, __op, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {return __cxx_atomic_fetch_add(&this->__a_, __op, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {return __cxx_atomic_fetch_sub(&this->__a_, __op, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {return __cxx_atomic_fetch_and(&this->__a_, __op, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {return __cxx_atomic_fetch_and(&this->__a_, __op, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {return __cxx_atomic_fetch_or(&this->__a_, __op, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {return __cxx_atomic_fetch_or(&this->__a_, __op, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {return __cxx_atomic_fetch_xor(&this->__a_, __op, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {return __cxx_atomic_fetch_xor(&this->__a_, __op, __m);} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator++(int) volatile _NOEXCEPT      {return fetch_add(_Tp(1));} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator++(int) _NOEXCEPT               {return fetch_add(_Tp(1));} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator--(int) volatile _NOEXCEPT      {return fetch_sub(_Tp(1));} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator--(int) _NOEXCEPT               {return fetch_sub(_Tp(1));} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator++() volatile _NOEXCEPT         {return fetch_add(_Tp(1)) + _Tp(1);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator++() _NOEXCEPT                  {return fetch_add(_Tp(1)) + _Tp(1);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator--() volatile _NOEXCEPT         {return fetch_sub(_Tp(1)) - _Tp(1);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator--() _NOEXCEPT                  {return fetch_sub(_Tp(1)) - _Tp(1);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator+=(_Tp __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator+=(_Tp __op) _NOEXCEPT          {return fetch_add(__op) + __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator-=(_Tp __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator-=(_Tp __op) _NOEXCEPT          {return fetch_sub(__op) - __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator&=(_Tp __op) volatile _NOEXCEPT {return fetch_and(__op) & __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator&=(_Tp __op) _NOEXCEPT          {return fetch_and(__op) & __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator|=(_Tp __op) volatile _NOEXCEPT {return fetch_or(__op) | __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator|=(_Tp __op) _NOEXCEPT          {return fetch_or(__op) | __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator^=(_Tp __op) volatile _NOEXCEPT {return fetch_xor(__op) ^ __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator^=(_Tp __op) _NOEXCEPT          {return fetch_xor(__op) ^ __op;} 
+}; 
+ 
+// atomic<T> 
+ 
+template <class _Tp> 
+struct atomic 
+    : public __atomic_base<_Tp> 
+{ 
+    typedef __atomic_base<_Tp> __base; 
+    typedef _Tp value_type; 
+    typedef value_type difference_type; 
+ 
+#if _LIBCPP_STD_VER > 17 
+    _LIBCPP_INLINE_VISIBILITY 
+    atomic() = default; 
+#else 
+    _LIBCPP_INLINE_VISIBILITY 
+    atomic() _NOEXCEPT _LIBCPP_DEFAULT 
+#endif 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _LIBCPP_CONSTEXPR atomic(_Tp __d) _NOEXCEPT : __base(__d) {} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator=(_Tp __d) volatile _NOEXCEPT 
+        {__base::store(__d); return __d;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp operator=(_Tp __d) _NOEXCEPT 
+        {__base::store(__d); return __d;} 
+ 
+    atomic& operator=(const atomic&) = delete; 
+    atomic& operator=(const atomic&) volatile = delete; 
+}; 
+ 
+// atomic<T*> 
+ 
+template <class _Tp> 
+struct atomic<_Tp*> 
+    : public __atomic_base<_Tp*> 
+{ 
+    typedef __atomic_base<_Tp*> __base; 
+    typedef _Tp* value_type; 
+    typedef ptrdiff_t difference_type; 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    atomic() _NOEXCEPT _LIBCPP_DEFAULT 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _LIBCPP_CONSTEXPR atomic(_Tp* __d) _NOEXCEPT : __base(__d) {} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator=(_Tp* __d) volatile _NOEXCEPT 
+        {__base::store(__d); return __d;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator=(_Tp* __d) _NOEXCEPT 
+        {__base::store(__d); return __d;} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT { 
+        // __atomic_fetch_add accepts function pointers, guard against them. 
+        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed"); 
+        return __cxx_atomic_fetch_add(&this->__a_, __op, __m); 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT { 
+        // __atomic_fetch_add accepts function pointers, guard against them. 
+        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed"); 
+        return __cxx_atomic_fetch_add(&this->__a_, __op, __m); 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT { 
+        // __atomic_fetch_add accepts function pointers, guard against them. 
+        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed"); 
+        return __cxx_atomic_fetch_sub(&this->__a_, __op, __m); 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT { 
+        // __atomic_fetch_add accepts function pointers, guard against them. 
+        static_assert(!is_function<typename remove_pointer<_Tp>::type>::value, "Pointer to function isn't allowed"); 
+        return __cxx_atomic_fetch_sub(&this->__a_, __op, __m); 
+    } 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator++(int) volatile _NOEXCEPT            {return fetch_add(1);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator++(int) _NOEXCEPT                     {return fetch_add(1);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator--(int) volatile _NOEXCEPT            {return fetch_sub(1);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator--(int) _NOEXCEPT                     {return fetch_sub(1);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator++() volatile _NOEXCEPT               {return fetch_add(1) + 1;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator++() _NOEXCEPT                        {return fetch_add(1) + 1;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator--() volatile _NOEXCEPT               {return fetch_sub(1) - 1;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator--() _NOEXCEPT                        {return fetch_sub(1) - 1;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator+=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator+=(ptrdiff_t __op) _NOEXCEPT          {return fetch_add(__op) + __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator-=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;} 
+    _LIBCPP_INLINE_VISIBILITY 
+    _Tp* operator-=(ptrdiff_t __op) _NOEXCEPT          {return fetch_sub(__op) - __op;} 
+ 
+    atomic& operator=(const atomic&) = delete; 
+    atomic& operator=(const atomic&) volatile = delete; 
+}; 
+ 
+// atomic_is_lock_free 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_is_lock_free(const volatile atomic<_Tp>* __o) _NOEXCEPT 
+{ 
+    return __o->is_lock_free(); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_is_lock_free(const atomic<_Tp>* __o) _NOEXCEPT 
+{ 
+    return __o->is_lock_free(); 
+} 
+ 
+// atomic_init 
+ 
+template <class _Tp> 
+_LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_init(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    __cxx_atomic_init(&__o->__a_, __d); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_init(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    __cxx_atomic_init(&__o->__a_, __d); 
+} 
+ 
+// atomic_store 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_store(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    __o->store(__d); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_store(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    __o->store(__d); 
+} 
+ 
+// atomic_store_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_store_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT 
+  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) 
+{ 
+    __o->store(__d, __m); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_store_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT 
+  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) 
+{ 
+    __o->store(__d, __m); 
+} 
+ 
+// atomic_load 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_load(const volatile atomic<_Tp>* __o) _NOEXCEPT 
+{ 
+    return __o->load(); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_load(const atomic<_Tp>* __o) _NOEXCEPT 
+{ 
+    return __o->load(); 
+} 
+ 
+// atomic_load_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_load_explicit(const volatile atomic<_Tp>* __o, memory_order __m) _NOEXCEPT 
+  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) 
+{ 
+    return __o->load(__m); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_load_explicit(const atomic<_Tp>* __o, memory_order __m) _NOEXCEPT 
+  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) 
+{ 
+    return __o->load(__m); 
+} 
+ 
+// atomic_exchange 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_exchange(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    return __o->exchange(__d); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_exchange(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    return __o->exchange(__d); 
+} 
+ 
+// atomic_exchange_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_exchange_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->exchange(__d, __m); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_exchange_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __d, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->exchange(__d, __m); 
+} 
+ 
+// atomic_compare_exchange_weak 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_compare_exchange_weak(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    return __o->compare_exchange_weak(*__e, __d); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_compare_exchange_weak(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    return __o->compare_exchange_weak(*__e, __d); 
+} 
+ 
+// atomic_compare_exchange_strong 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_compare_exchange_strong(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    return __o->compare_exchange_strong(*__e, __d); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_compare_exchange_strong(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d) _NOEXCEPT 
+{ 
+    return __o->compare_exchange_strong(*__e, __d); 
+} 
+ 
+// atomic_compare_exchange_weak_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_compare_exchange_weak_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, 
+                                      typename atomic<_Tp>::value_type __d, 
+                                      memory_order __s, memory_order __f) _NOEXCEPT 
+  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) 
+{ 
+    return __o->compare_exchange_weak(*__e, __d, __s, __f); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_compare_exchange_weak_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d, 
+                                      memory_order __s, memory_order __f) _NOEXCEPT 
+  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) 
+{ 
+    return __o->compare_exchange_weak(*__e, __d, __s, __f); 
+} 
+ 
+// atomic_compare_exchange_strong_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_compare_exchange_strong_explicit(volatile atomic<_Tp>* __o, 
+                                        typename atomic<_Tp>::value_type* __e, typename atomic<_Tp>::value_type __d, 
+                                        memory_order __s, memory_order __f) _NOEXCEPT 
+  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) 
+{ 
+    return __o->compare_exchange_strong(*__e, __d, __s, __f); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_compare_exchange_strong_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type* __e, 
+                                        typename atomic<_Tp>::value_type __d, 
+                                        memory_order __s, memory_order __f) _NOEXCEPT 
+  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f) 
+{ 
+    return __o->compare_exchange_strong(*__e, __d, __s, __f); 
+} 
+ 
+// atomic_wait 
+ 
+template <class _Tp> 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+void atomic_wait(const volatile atomic<_Tp>* __o, 
+                 typename atomic<_Tp>::value_type __v) _NOEXCEPT 
+{ 
+    return __o->wait(__v); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+void atomic_wait(const atomic<_Tp>* __o, 
+                 typename atomic<_Tp>::value_type __v) _NOEXCEPT 
+{ 
+    return __o->wait(__v); 
+} 
+ 
+// atomic_wait_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+void atomic_wait_explicit(const volatile atomic<_Tp>* __o, 
+                          typename atomic<_Tp>::value_type __v, 
+                          memory_order __m) _NOEXCEPT 
+  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) 
+{ 
+    return __o->wait(__v, __m); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+void atomic_wait_explicit(const atomic<_Tp>* __o, 
+                          typename atomic<_Tp>::value_type __v, 
+                          memory_order __m) _NOEXCEPT 
+  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) 
+{ 
+    return __o->wait(__v, __m); 
+} 
+ 
+// atomic_notify_one 
+ 
+template <class _Tp> 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+void atomic_notify_one(volatile atomic<_Tp>* __o) _NOEXCEPT 
+{ 
+    __o->notify_one(); 
+} 
+template <class _Tp> 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+void atomic_notify_one(atomic<_Tp>* __o) _NOEXCEPT 
+{ 
+    __o->notify_one(); 
+} 
+ 
+// atomic_notify_one 
+ 
+template <class _Tp> 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+void atomic_notify_all(volatile atomic<_Tp>* __o) _NOEXCEPT 
+{ 
+    __o->notify_all(); 
+} 
+template <class _Tp> 
+_LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+void atomic_notify_all(atomic<_Tp>* __o) _NOEXCEPT 
+{ 
+    __o->notify_all(); 
+} 
+ 
+// atomic_fetch_add 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_fetch_add(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_add(__op); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp 
+atomic_fetch_add(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_add(__op); 
+} 
+ 
+// atomic_fetch_add_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp atomic_fetch_add_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_add(__op, __m); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp atomic_fetch_add_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_add(__op, __m); 
+} 
+ 
+// atomic_fetch_sub 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp atomic_fetch_sub(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_sub(__op); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp atomic_fetch_sub(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_sub(__op); 
+} 
+ 
+// atomic_fetch_sub_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp atomic_fetch_sub_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_sub(__op, __m); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+_Tp atomic_fetch_sub_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::difference_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_sub(__op, __m); 
+} 
+ 
+// atomic_fetch_and 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_and(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_and(__op); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_and(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_and(__op); 
+} 
+ 
+// atomic_fetch_and_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_and_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_and(__op, __m); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_and_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_and(__op, __m); 
+} 
+ 
+// atomic_fetch_or 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_or(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_or(__op); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_or(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_or(__op); 
+} 
+ 
+// atomic_fetch_or_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_or_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_or(__op, __m); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_or_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_or(__op, __m); 
+} 
+ 
+// atomic_fetch_xor 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_xor(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_xor(__op); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_xor(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op) _NOEXCEPT 
+{ 
+    return __o->fetch_xor(__op); 
+} 
+ 
+// atomic_fetch_xor_explicit 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_xor_explicit(volatile atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_xor(__op, __m); 
+} 
+ 
+template <class _Tp> 
+_LIBCPP_INLINE_VISIBILITY 
+typename enable_if 
+< 
+    is_integral<_Tp>::value && !is_same<_Tp, bool>::value, 
+    _Tp 
+>::type 
+atomic_fetch_xor_explicit(atomic<_Tp>* __o, typename atomic<_Tp>::value_type __op, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->fetch_xor(__op, __m); 
+} 
+ 
+// flag type and operations 
+ 
+typedef struct atomic_flag 
+{ 
+    __cxx_atomic_impl<_LIBCPP_ATOMIC_FLAG_TYPE> __a_; 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool test(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT 
+        {return _LIBCPP_ATOMIC_FLAG_TYPE(true) == __cxx_atomic_load(&__a_, __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool test(memory_order __m = memory_order_seq_cst) const _NOEXCEPT 
+        {return _LIBCPP_ATOMIC_FLAG_TYPE(true) == __cxx_atomic_load(&__a_, __m);} 
+ 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool test_and_set(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {return __cxx_atomic_exchange(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(true), __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    bool test_and_set(memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {return __cxx_atomic_exchange(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(true), __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    void clear(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT 
+        {__cxx_atomic_store(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(false), __m);} 
+    _LIBCPP_INLINE_VISIBILITY 
+    void clear(memory_order __m = memory_order_seq_cst) _NOEXCEPT 
+        {__cxx_atomic_store(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(false), __m);} 
+ 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+    void wait(bool __v, memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT 
+        {__cxx_atomic_wait(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(__v), __m);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+    void wait(bool __v, memory_order __m = memory_order_seq_cst) const _NOEXCEPT 
+        {__cxx_atomic_wait(&__a_, _LIBCPP_ATOMIC_FLAG_TYPE(__v), __m);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+    void notify_one() volatile _NOEXCEPT 
+        {__cxx_atomic_notify_one(&__a_);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+    void notify_one() _NOEXCEPT 
+        {__cxx_atomic_notify_one(&__a_);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+    void notify_all() volatile _NOEXCEPT 
+        {__cxx_atomic_notify_all(&__a_);} 
+    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY 
+    void notify_all() _NOEXCEPT 
+        {__cxx_atomic_notify_all(&__a_);} 
+ 
+#if _LIBCPP_STD_VER > 17 
+    _LIBCPP_INLINE_VISIBILITY constexpr 
+    atomic_flag() _NOEXCEPT : __a_(false) {} 
+#else 
+    _LIBCPP_INLINE_VISIBILITY 
+    atomic_flag() _NOEXCEPT _LIBCPP_DEFAULT 
+#endif 
+ 
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR 
+    atomic_flag(bool __b) _NOEXCEPT : __a_(__b) {} // EXTENSION 
+ 
+#ifdef _LIBCPP_COMPILER_MSVC 
+#pragma warning ( push ) 
+#pragma warning ( disable : 4522 ) 
+#endif 
+#ifndef _LIBCPP_CXX03_LANG 
+    atomic_flag(const atomic_flag&) = delete; 
+    atomic_flag& operator=(const atomic_flag&) = delete; 
+    atomic_flag& operator=(const atomic_flag&) volatile = delete; 
+#else 
+private: 
+    _LIBCPP_INLINE_VISIBILITY 
+    atomic_flag(const atomic_flag&); 
+    _LIBCPP_INLINE_VISIBILITY 
+    atomic_flag& operator=(const atomic_flag&); 
+    _LIBCPP_INLINE_VISIBILITY 
+    atomic_flag& operator=(const atomic_flag&) volatile; 
+#endif 
+#ifdef _LIBCPP_COMPILER_MSVC 
+#pragma warning ( pop ) 
+#endif 
+} atomic_flag; 
+ 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_flag_test(const volatile atomic_flag* __o) _NOEXCEPT 
+{ 
+    return __o->test(); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_flag_test(const atomic_flag* __o) _NOEXCEPT 
+{ 
+    return __o->test(); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_flag_test_explicit(const volatile atomic_flag* __o, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->test(__m); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_flag_test_explicit(const atomic_flag* __o, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->test(__m); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_flag_test_and_set(volatile atomic_flag* __o) _NOEXCEPT 
+{ 
+    return __o->test_and_set(); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_flag_test_and_set(atomic_flag* __o) _NOEXCEPT 
+{ 
+    return __o->test_and_set(); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_flag_test_and_set_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->test_and_set(__m); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+bool 
+atomic_flag_test_and_set_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT 
+{ 
+    return __o->test_and_set(__m); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_flag_clear(volatile atomic_flag* __o) _NOEXCEPT 
+{ 
+    __o->clear(); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_flag_clear(atomic_flag* __o) _NOEXCEPT 
+{ 
+    __o->clear(); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_flag_clear_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT 
+{ 
+    __o->clear(__m); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_flag_clear_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT 
+{ 
+    __o->clear(__m); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC 
+void 
+atomic_flag_wait(const volatile atomic_flag* __o, bool __v) _NOEXCEPT 
+{ 
+    __o->wait(__v); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC 
+void 
+atomic_flag_wait(const atomic_flag* __o, bool __v) _NOEXCEPT 
+{ 
+    __o->wait(__v); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC 
+void 
+atomic_flag_wait_explicit(const volatile atomic_flag* __o, 
+                          bool __v, memory_order __m) _NOEXCEPT 
+{ 
+    __o->wait(__v, __m); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC 
+void 
+atomic_flag_wait_explicit(const atomic_flag* __o, 
+                          bool __v, memory_order __m) _NOEXCEPT 
+{ 
+    __o->wait(__v, __m); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC 
+void 
+atomic_flag_notify_one(volatile atomic_flag* __o) _NOEXCEPT 
+{ 
+    __o->notify_one(); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC 
+void 
+atomic_flag_notify_one(atomic_flag* __o) _NOEXCEPT 
+{ 
+    __o->notify_one(); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC 
+void 
+atomic_flag_notify_all(volatile atomic_flag* __o) _NOEXCEPT 
+{ 
+    __o->notify_all(); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_AVAILABILITY_SYNC 
+void 
+atomic_flag_notify_all(atomic_flag* __o) _NOEXCEPT 
+{ 
+    __o->notify_all(); 
+} 
+ 
+// fences 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_thread_fence(memory_order __m) _NOEXCEPT 
+{ 
+    __cxx_atomic_thread_fence(__m); 
+} 
+ 
+inline _LIBCPP_INLINE_VISIBILITY 
+void 
+atomic_signal_fence(memory_order __m) _NOEXCEPT 
+{ 
+    __cxx_atomic_signal_fence(__m); 
+} 
+ 
+// Atomics for standard typedef types 
+ 
+typedef atomic<bool>               atomic_bool; 
+typedef atomic<char>               atomic_char; 
+typedef atomic<signed char>        atomic_schar; 
+typedef atomic<unsigned char>      atomic_uchar; 
+typedef atomic<short>              atomic_short; 
+typedef atomic<unsigned short>     atomic_ushort; 
+typedef atomic<int>                atomic_int; 
+typedef atomic<unsigned int>       atomic_uint; 
+typedef atomic<long>               atomic_long; 
+typedef atomic<unsigned long>      atomic_ulong; 
+typedef atomic<long long>          atomic_llong; 
+typedef atomic<unsigned long long> atomic_ullong; 
+#ifndef _LIBCPP_HAS_NO_CHAR8_T 
+typedef atomic<char8_t>            atomic_char8_t; 
+#endif 
+typedef atomic<char16_t>           atomic_char16_t; 
+typedef atomic<char32_t>           atomic_char32_t; 
+#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS 
+typedef atomic<wchar_t>            atomic_wchar_t; 
+#endif 
+ 
+typedef atomic<int_least8_t>   atomic_int_least8_t; 
+typedef atomic<uint_least8_t>  atomic_uint_least8_t; 
+typedef atomic<int_least16_t>  atomic_int_least16_t; 
+typedef atomic<uint_least16_t> atomic_uint_least16_t; 
+typedef atomic<int_least32_t>  atomic_int_least32_t; 
+typedef atomic<uint_least32_t> atomic_uint_least32_t; 
+typedef atomic<int_least64_t>  atomic_int_least64_t; 
+typedef atomic<uint_least64_t> atomic_uint_least64_t; 
+ 
+typedef atomic<int_fast8_t>   atomic_int_fast8_t; 
+typedef atomic<uint_fast8_t>  atomic_uint_fast8_t; 
+typedef atomic<int_fast16_t>  atomic_int_fast16_t; 
+typedef atomic<uint_fast16_t> atomic_uint_fast16_t; 
+typedef atomic<int_fast32_t>  atomic_int_fast32_t; 
+typedef atomic<uint_fast32_t> atomic_uint_fast32_t; 
+typedef atomic<int_fast64_t>  atomic_int_fast64_t; 
+typedef atomic<uint_fast64_t> atomic_uint_fast64_t; 
+ 
+typedef atomic< int8_t>  atomic_int8_t; 
+typedef atomic<uint8_t>  atomic_uint8_t; 
+typedef atomic< int16_t> atomic_int16_t; 
+typedef atomic<uint16_t> atomic_uint16_t; 
+typedef atomic< int32_t> atomic_int32_t; 
+typedef atomic<uint32_t> atomic_uint32_t; 
+typedef atomic< int64_t> atomic_int64_t; 
+typedef atomic<uint64_t> atomic_uint64_t; 
+ 
+typedef atomic<intptr_t>  atomic_intptr_t; 
+typedef atomic<uintptr_t> atomic_uintptr_t; 
+typedef atomic<size_t>    atomic_size_t; 
+typedef atomic<ptrdiff_t> atomic_ptrdiff_t; 
+typedef atomic<intmax_t>  atomic_intmax_t; 
+typedef atomic<uintmax_t> atomic_uintmax_t; 
+ 
+// atomic_*_lock_free : prefer the contention type most highly, then the largest lock-free type 
+ 
+#ifdef __cpp_lib_atomic_is_always_lock_free 
+# define _LIBCPP_CONTENTION_LOCK_FREE __atomic_always_lock_free(sizeof(__cxx_contention_t), 0) 
+#else 
+# define _LIBCPP_CONTENTION_LOCK_FREE false 
+#endif 
+ 
+#if ATOMIC_LLONG_LOCK_FREE == 2 
+typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, long long>::type          __libcpp_signed_lock_free; 
+typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned long long>::type __libcpp_unsigned_lock_free; 
+#elif ATOMIC_INT_LOCK_FREE == 2 
+typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, int>::type                __libcpp_signed_lock_free; 
+typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned int>::type       __libcpp_unsigned_lock_free; 
+#elif ATOMIC_SHORT_LOCK_FREE == 2 
+typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, short>::type              __libcpp_signed_lock_free; 
+typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned short>::type     __libcpp_unsigned_lock_free; 
+#elif ATOMIC_CHAR_LOCK_FREE == 2 
+typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, char>::type               __libcpp_signed_lock_free; 
+typedef conditional<_LIBCPP_CONTENTION_LOCK_FREE, __cxx_contention_t, unsigned char>::type      __libcpp_unsigned_lock_free; 
+#else 
+    // No signed/unsigned lock-free types 
+#endif 
+ 
+typedef atomic<__libcpp_signed_lock_free> atomic_signed_lock_free; 
+typedef atomic<__libcpp_unsigned_lock_free> atomic_unsigned_lock_free; 
+ 
+#define ATOMIC_FLAG_INIT {false} 
+#define ATOMIC_VAR_INIT(__v) {__v} 
+ 
+_LIBCPP_END_NAMESPACE_STD 
+ 
+#endif // _LIBCPP_ATOMIC