3 // Copyright (C) 2008-2021 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file include/atomic
26 * This is a Standard C++ Library header.
29 // Based on "C++ Atomic Types and Operations" by Hans Boehm and Lawrence Crowl.
30 // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2427.html
32 #ifndef _GLIBCXX_ATOMIC
33 #define _GLIBCXX_ATOMIC 1
35 #pragma GCC system_header
37 #if __cplusplus < 201103L
38 # include <bits/c++0x_warning.h>
41 #include <bits/atomic_base.h>
43 namespace std _GLIBCXX_VISIBILITY(default)
45 _GLIBCXX_BEGIN_NAMESPACE_VERSION
52 #if __cplusplus >= 201703L
53 # define __cpp_lib_atomic_is_always_lock_free 201603
56 template<typename _Tp>
60 // NB: No operators or fetch-operations for this type.
64 using value_type = bool;
67 __atomic_base<bool> _M_base;
70 atomic() noexcept = default;
71 ~atomic() noexcept = default;
72 atomic(const atomic&) = delete;
73 atomic& operator=(const atomic&) = delete;
74 atomic& operator=(const atomic&) volatile = delete;
76 constexpr atomic(bool __i) noexcept : _M_base(__i) { }
79 operator=(bool __i) noexcept
80 { return _M_base.operator=(__i); }
83 operator=(bool __i) volatile noexcept
84 { return _M_base.operator=(__i); }
86 operator bool() const noexcept
87 { return _M_base.load(); }
89 operator bool() const volatile noexcept
90 { return _M_base.load(); }
93 is_lock_free() const noexcept { return _M_base.is_lock_free(); }
96 is_lock_free() const volatile noexcept { return _M_base.is_lock_free(); }
98 #if __cplusplus >= 201703L
99 static constexpr bool is_always_lock_free = ATOMIC_BOOL_LOCK_FREE == 2;
103 store(bool __i, memory_order __m = memory_order_seq_cst) noexcept
104 { _M_base.store(__i, __m); }
107 store(bool __i, memory_order __m = memory_order_seq_cst) volatile noexcept
108 { _M_base.store(__i, __m); }
111 load(memory_order __m = memory_order_seq_cst) const noexcept
112 { return _M_base.load(__m); }
115 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
116 { return _M_base.load(__m); }
119 exchange(bool __i, memory_order __m = memory_order_seq_cst) noexcept
120 { return _M_base.exchange(__i, __m); }
124 memory_order __m = memory_order_seq_cst) volatile noexcept
125 { return _M_base.exchange(__i, __m); }
128 compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
129 memory_order __m2) noexcept
130 { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }
133 compare_exchange_weak(bool& __i1, bool __i2, memory_order __m1,
134 memory_order __m2) volatile noexcept
135 { return _M_base.compare_exchange_weak(__i1, __i2, __m1, __m2); }
138 compare_exchange_weak(bool& __i1, bool __i2,
139 memory_order __m = memory_order_seq_cst) noexcept
140 { return _M_base.compare_exchange_weak(__i1, __i2, __m); }
143 compare_exchange_weak(bool& __i1, bool __i2,
144 memory_order __m = memory_order_seq_cst) volatile noexcept
145 { return _M_base.compare_exchange_weak(__i1, __i2, __m); }
148 compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
149 memory_order __m2) noexcept
150 { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }
153 compare_exchange_strong(bool& __i1, bool __i2, memory_order __m1,
154 memory_order __m2) volatile noexcept
155 { return _M_base.compare_exchange_strong(__i1, __i2, __m1, __m2); }
158 compare_exchange_strong(bool& __i1, bool __i2,
159 memory_order __m = memory_order_seq_cst) noexcept
160 { return _M_base.compare_exchange_strong(__i1, __i2, __m); }
163 compare_exchange_strong(bool& __i1, bool __i2,
164 memory_order __m = memory_order_seq_cst) volatile noexcept
165 { return _M_base.compare_exchange_strong(__i1, __i2, __m); }
167 #if __cpp_lib_atomic_wait
169 wait(bool __old, memory_order __m = memory_order_seq_cst) const noexcept
170 { _M_base.wait(__old, __m); }
172 // TODO add const volatile overload
175 notify_one() const noexcept
176 { _M_base.notify_one(); }
179 notify_all() const noexcept
180 { _M_base.notify_all(); }
181 #endif // __cpp_lib_atomic_wait
184 #if __cplusplus <= 201703L
185 # define _GLIBCXX20_INIT(I)
187 # define _GLIBCXX20_INIT(I) = I
191 * @brief Generic atomic type, primary class template.
193 * @tparam _Tp Type to be made atomic, must be trivially copyable.
195 template<typename _Tp>
198 using value_type = _Tp;
201 // Align 1/2/4/8/16-byte types to at least their size.
202 static constexpr int _S_min_alignment
203 = (sizeof(_Tp) & (sizeof(_Tp) - 1)) || sizeof(_Tp) > 16
206 static constexpr int _S_alignment
207 = _S_min_alignment > alignof(_Tp) ? _S_min_alignment : alignof(_Tp);
209 alignas(_S_alignment) _Tp _M_i _GLIBCXX20_INIT(_Tp());
211 static_assert(__is_trivially_copyable(_Tp),
212 "std::atomic requires a trivially copyable type");
214 static_assert(sizeof(_Tp) > 0,
215 "Incomplete or zero-sized types are not supported");
217 #if __cplusplus > 201703L
218 static_assert(is_copy_constructible_v<_Tp>);
219 static_assert(is_move_constructible_v<_Tp>);
220 static_assert(is_copy_assignable_v<_Tp>);
221 static_assert(is_move_assignable_v<_Tp>);
226 ~atomic() noexcept = default;
227 atomic(const atomic&) = delete;
228 atomic& operator=(const atomic&) = delete;
229 atomic& operator=(const atomic&) volatile = delete;
231 constexpr atomic(_Tp __i) noexcept : _M_i(__i) { }
233 operator _Tp() const noexcept
236 operator _Tp() const volatile noexcept
240 operator=(_Tp __i) noexcept
241 { store(__i); return __i; }
244 operator=(_Tp __i) volatile noexcept
245 { store(__i); return __i; }
248 is_lock_free() const noexcept
250 // Produce a fake, minimally aligned pointer.
251 return __atomic_is_lock_free(sizeof(_M_i),
252 reinterpret_cast<void *>(-_S_alignment));
256 is_lock_free() const volatile noexcept
258 // Produce a fake, minimally aligned pointer.
259 return __atomic_is_lock_free(sizeof(_M_i),
260 reinterpret_cast<void *>(-_S_alignment));
263 #if __cplusplus >= 201703L
264 static constexpr bool is_always_lock_free
265 = __atomic_always_lock_free(sizeof(_M_i), 0);
269 store(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
271 __atomic_store(std::__addressof(_M_i), std::__addressof(__i), int(__m));
275 store(_Tp __i, memory_order __m = memory_order_seq_cst) volatile noexcept
277 __atomic_store(std::__addressof(_M_i), std::__addressof(__i), int(__m));
281 load(memory_order __m = memory_order_seq_cst) const noexcept
283 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
284 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
285 __atomic_load(std::__addressof(_M_i), __ptr, int(__m));
290 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
292 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
293 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
294 __atomic_load(std::__addressof(_M_i), __ptr, int(__m));
299 exchange(_Tp __i, memory_order __m = memory_order_seq_cst) noexcept
301 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
302 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
303 __atomic_exchange(std::__addressof(_M_i), std::__addressof(__i),
310 memory_order __m = memory_order_seq_cst) volatile noexcept
312 alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
313 _Tp* __ptr = reinterpret_cast<_Tp*>(__buf);
314 __atomic_exchange(std::__addressof(_M_i), std::__addressof(__i),
320 compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s,
321 memory_order __f) noexcept
323 return __atomic_compare_exchange(std::__addressof(_M_i),
324 std::__addressof(__e),
325 std::__addressof(__i),
326 true, int(__s), int(__f));
330 compare_exchange_weak(_Tp& __e, _Tp __i, memory_order __s,
331 memory_order __f) volatile noexcept
333 return __atomic_compare_exchange(std::__addressof(_M_i),
334 std::__addressof(__e),
335 std::__addressof(__i),
336 true, int(__s), int(__f));
340 compare_exchange_weak(_Tp& __e, _Tp __i,
341 memory_order __m = memory_order_seq_cst) noexcept
342 { return compare_exchange_weak(__e, __i, __m,
343 __cmpexch_failure_order(__m)); }
346 compare_exchange_weak(_Tp& __e, _Tp __i,
347 memory_order __m = memory_order_seq_cst) volatile noexcept
348 { return compare_exchange_weak(__e, __i, __m,
349 __cmpexch_failure_order(__m)); }
352 compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s,
353 memory_order __f) noexcept
355 return __atomic_compare_exchange(std::__addressof(_M_i),
356 std::__addressof(__e),
357 std::__addressof(__i),
358 false, int(__s), int(__f));
362 compare_exchange_strong(_Tp& __e, _Tp __i, memory_order __s,
363 memory_order __f) volatile noexcept
365 return __atomic_compare_exchange(std::__addressof(_M_i),
366 std::__addressof(__e),
367 std::__addressof(__i),
368 false, int(__s), int(__f));
372 compare_exchange_strong(_Tp& __e, _Tp __i,
373 memory_order __m = memory_order_seq_cst) noexcept
374 { return compare_exchange_strong(__e, __i, __m,
375 __cmpexch_failure_order(__m)); }
378 compare_exchange_strong(_Tp& __e, _Tp __i,
379 memory_order __m = memory_order_seq_cst) volatile noexcept
380 { return compare_exchange_strong(__e, __i, __m,
381 __cmpexch_failure_order(__m)); }
383 #if __cpp_lib_atomic_wait
385 wait(_Tp __old, memory_order __m = memory_order_seq_cst) const noexcept
387 std::__atomic_wait_address_v(&_M_i, __old,
388 [__m, this] { return this->load(__m); });
391 // TODO add const volatile overload
394 notify_one() const noexcept
395 { std::__atomic_notify_address(&_M_i, false); }
398 notify_all() const noexcept
399 { std::__atomic_notify_address(&_M_i, true); }
400 #endif // __cpp_lib_atomic_wait
403 #undef _GLIBCXX20_INIT
405 /// Partial specialization for pointer types.
406 template<typename _Tp>
409 using value_type = _Tp*;
410 using difference_type = ptrdiff_t;
412 typedef _Tp* __pointer_type;
413 typedef __atomic_base<_Tp*> __base_type;
416 atomic() noexcept = default;
417 ~atomic() noexcept = default;
418 atomic(const atomic&) = delete;
419 atomic& operator=(const atomic&) = delete;
420 atomic& operator=(const atomic&) volatile = delete;
422 constexpr atomic(__pointer_type __p) noexcept : _M_b(__p) { }
424 operator __pointer_type() const noexcept
425 { return __pointer_type(_M_b); }
427 operator __pointer_type() const volatile noexcept
428 { return __pointer_type(_M_b); }
431 operator=(__pointer_type __p) noexcept
432 { return _M_b.operator=(__p); }
435 operator=(__pointer_type __p) volatile noexcept
436 { return _M_b.operator=(__p); }
439 operator++(int) noexcept
441 #if __cplusplus >= 201703L
442 static_assert( is_object<_Tp>::value, "pointer to object type" );
448 operator++(int) volatile noexcept
450 #if __cplusplus >= 201703L
451 static_assert( is_object<_Tp>::value, "pointer to object type" );
457 operator--(int) noexcept
459 #if __cplusplus >= 201703L
460 static_assert( is_object<_Tp>::value, "pointer to object type" );
466 operator--(int) volatile noexcept
468 #if __cplusplus >= 201703L
469 static_assert( is_object<_Tp>::value, "pointer to object type" );
475 operator++() noexcept
477 #if __cplusplus >= 201703L
478 static_assert( is_object<_Tp>::value, "pointer to object type" );
484 operator++() volatile noexcept
486 #if __cplusplus >= 201703L
487 static_assert( is_object<_Tp>::value, "pointer to object type" );
493 operator--() noexcept
495 #if __cplusplus >= 201703L
496 static_assert( is_object<_Tp>::value, "pointer to object type" );
502 operator--() volatile noexcept
504 #if __cplusplus >= 201703L
505 static_assert( is_object<_Tp>::value, "pointer to object type" );
511 operator+=(ptrdiff_t __d) noexcept
513 #if __cplusplus >= 201703L
514 static_assert( is_object<_Tp>::value, "pointer to object type" );
516 return _M_b.operator+=(__d);
520 operator+=(ptrdiff_t __d) volatile noexcept
522 #if __cplusplus >= 201703L
523 static_assert( is_object<_Tp>::value, "pointer to object type" );
525 return _M_b.operator+=(__d);
529 operator-=(ptrdiff_t __d) noexcept
531 #if __cplusplus >= 201703L
532 static_assert( is_object<_Tp>::value, "pointer to object type" );
534 return _M_b.operator-=(__d);
538 operator-=(ptrdiff_t __d) volatile noexcept
540 #if __cplusplus >= 201703L
541 static_assert( is_object<_Tp>::value, "pointer to object type" );
543 return _M_b.operator-=(__d);
547 is_lock_free() const noexcept
548 { return _M_b.is_lock_free(); }
551 is_lock_free() const volatile noexcept
552 { return _M_b.is_lock_free(); }
554 #if __cplusplus >= 201703L
555 static constexpr bool is_always_lock_free = ATOMIC_POINTER_LOCK_FREE == 2;
559 store(__pointer_type __p,
560 memory_order __m = memory_order_seq_cst) noexcept
561 { return _M_b.store(__p, __m); }
564 store(__pointer_type __p,
565 memory_order __m = memory_order_seq_cst) volatile noexcept
566 { return _M_b.store(__p, __m); }
569 load(memory_order __m = memory_order_seq_cst) const noexcept
570 { return _M_b.load(__m); }
573 load(memory_order __m = memory_order_seq_cst) const volatile noexcept
574 { return _M_b.load(__m); }
577 exchange(__pointer_type __p,
578 memory_order __m = memory_order_seq_cst) noexcept
579 { return _M_b.exchange(__p, __m); }
582 exchange(__pointer_type __p,
583 memory_order __m = memory_order_seq_cst) volatile noexcept
584 { return _M_b.exchange(__p, __m); }
587 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
588 memory_order __m1, memory_order __m2) noexcept
589 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
592 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
594 memory_order __m2) volatile noexcept
595 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
598 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
599 memory_order __m = memory_order_seq_cst) noexcept
601 return compare_exchange_weak(__p1, __p2, __m,
602 __cmpexch_failure_order(__m));
606 compare_exchange_weak(__pointer_type& __p1, __pointer_type __p2,
607 memory_order __m = memory_order_seq_cst) volatile noexcept
609 return compare_exchange_weak(__p1, __p2, __m,
610 __cmpexch_failure_order(__m));
614 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
615 memory_order __m1, memory_order __m2) noexcept
616 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
619 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
621 memory_order __m2) volatile noexcept
622 { return _M_b.compare_exchange_strong(__p1, __p2, __m1, __m2); }
625 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
626 memory_order __m = memory_order_seq_cst) noexcept
628 return _M_b.compare_exchange_strong(__p1, __p2, __m,
629 __cmpexch_failure_order(__m));
633 compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,
634 memory_order __m = memory_order_seq_cst) volatile noexcept
636 return _M_b.compare_exchange_strong(__p1, __p2, __m,
637 __cmpexch_failure_order(__m));
640 #if __cpp_lib_atomic_wait
642 wait(__pointer_type __old, memory_order __m = memory_order_seq_cst) const noexcept
643 { _M_b.wait(__old, __m); }
645 // TODO add const volatile overload
648 notify_one() const noexcept
649 { _M_b.notify_one(); }
652 notify_all() const noexcept
653 { _M_b.notify_all(); }
654 #endif // __cpp_lib_atomic_wait
656 fetch_add(ptrdiff_t __d,
657 memory_order __m = memory_order_seq_cst) noexcept
659 #if __cplusplus >= 201703L
660 static_assert( is_object<_Tp>::value, "pointer to object type" );
662 return _M_b.fetch_add(__d, __m);
666 fetch_add(ptrdiff_t __d,
667 memory_order __m = memory_order_seq_cst) volatile noexcept
669 #if __cplusplus >= 201703L
670 static_assert( is_object<_Tp>::value, "pointer to object type" );
672 return _M_b.fetch_add(__d, __m);
676 fetch_sub(ptrdiff_t __d,
677 memory_order __m = memory_order_seq_cst) noexcept
679 #if __cplusplus >= 201703L
680 static_assert( is_object<_Tp>::value, "pointer to object type" );
682 return _M_b.fetch_sub(__d, __m);
686 fetch_sub(ptrdiff_t __d,
687 memory_order __m = memory_order_seq_cst) volatile noexcept
689 #if __cplusplus >= 201703L
690 static_assert( is_object<_Tp>::value, "pointer to object type" );
692 return _M_b.fetch_sub(__d, __m);
697 /// Explicit specialization for char.
699 struct atomic<char> : __atomic_base<char>
701 typedef char __integral_type;
702 typedef __atomic_base<char> __base_type;
704 atomic() noexcept = default;
705 ~atomic() noexcept = default;
706 atomic(const atomic&) = delete;
707 atomic& operator=(const atomic&) = delete;
708 atomic& operator=(const atomic&) volatile = delete;
710 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
712 using __base_type::operator __integral_type;
713 using __base_type::operator=;
715 #if __cplusplus >= 201703L
716 static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
720 /// Explicit specialization for signed char.
722 struct atomic<signed char> : __atomic_base<signed char>
724 typedef signed char __integral_type;
725 typedef __atomic_base<signed char> __base_type;
727 atomic() noexcept= default;
728 ~atomic() noexcept = default;
729 atomic(const atomic&) = delete;
730 atomic& operator=(const atomic&) = delete;
731 atomic& operator=(const atomic&) volatile = delete;
733 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
735 using __base_type::operator __integral_type;
736 using __base_type::operator=;
738 #if __cplusplus >= 201703L
739 static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
743 /// Explicit specialization for unsigned char.
745 struct atomic<unsigned char> : __atomic_base<unsigned char>
747 typedef unsigned char __integral_type;
748 typedef __atomic_base<unsigned char> __base_type;
750 atomic() noexcept= default;
751 ~atomic() noexcept = default;
752 atomic(const atomic&) = delete;
753 atomic& operator=(const atomic&) = delete;
754 atomic& operator=(const atomic&) volatile = delete;
756 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
758 using __base_type::operator __integral_type;
759 using __base_type::operator=;
761 #if __cplusplus >= 201703L
762 static constexpr bool is_always_lock_free = ATOMIC_CHAR_LOCK_FREE == 2;
766 /// Explicit specialization for short.
768 struct atomic<short> : __atomic_base<short>
770 typedef short __integral_type;
771 typedef __atomic_base<short> __base_type;
773 atomic() noexcept = default;
774 ~atomic() noexcept = default;
775 atomic(const atomic&) = delete;
776 atomic& operator=(const atomic&) = delete;
777 atomic& operator=(const atomic&) volatile = delete;
779 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
781 using __base_type::operator __integral_type;
782 using __base_type::operator=;
784 #if __cplusplus >= 201703L
785 static constexpr bool is_always_lock_free = ATOMIC_SHORT_LOCK_FREE == 2;
789 /// Explicit specialization for unsigned short.
791 struct atomic<unsigned short> : __atomic_base<unsigned short>
793 typedef unsigned short __integral_type;
794 typedef __atomic_base<unsigned short> __base_type;
796 atomic() noexcept = default;
797 ~atomic() noexcept = default;
798 atomic(const atomic&) = delete;
799 atomic& operator=(const atomic&) = delete;
800 atomic& operator=(const atomic&) volatile = delete;
802 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
804 using __base_type::operator __integral_type;
805 using __base_type::operator=;
807 #if __cplusplus >= 201703L
808 static constexpr bool is_always_lock_free = ATOMIC_SHORT_LOCK_FREE == 2;
812 /// Explicit specialization for int.
814 struct atomic<int> : __atomic_base<int>
816 typedef int __integral_type;
817 typedef __atomic_base<int> __base_type;
819 atomic() noexcept = default;
820 ~atomic() noexcept = default;
821 atomic(const atomic&) = delete;
822 atomic& operator=(const atomic&) = delete;
823 atomic& operator=(const atomic&) volatile = delete;
825 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
827 using __base_type::operator __integral_type;
828 using __base_type::operator=;
830 #if __cplusplus >= 201703L
831 static constexpr bool is_always_lock_free = ATOMIC_INT_LOCK_FREE == 2;
835 /// Explicit specialization for unsigned int.
837 struct atomic<unsigned int> : __atomic_base<unsigned int>
839 typedef unsigned int __integral_type;
840 typedef __atomic_base<unsigned int> __base_type;
842 atomic() noexcept = default;
843 ~atomic() noexcept = default;
844 atomic(const atomic&) = delete;
845 atomic& operator=(const atomic&) = delete;
846 atomic& operator=(const atomic&) volatile = delete;
848 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
850 using __base_type::operator __integral_type;
851 using __base_type::operator=;
853 #if __cplusplus >= 201703L
854 static constexpr bool is_always_lock_free = ATOMIC_INT_LOCK_FREE == 2;
858 /// Explicit specialization for long.
860 struct atomic<long> : __atomic_base<long>
862 typedef long __integral_type;
863 typedef __atomic_base<long> __base_type;
865 atomic() noexcept = default;
866 ~atomic() noexcept = default;
867 atomic(const atomic&) = delete;
868 atomic& operator=(const atomic&) = delete;
869 atomic& operator=(const atomic&) volatile = delete;
871 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
873 using __base_type::operator __integral_type;
874 using __base_type::operator=;
876 #if __cplusplus >= 201703L
877 static constexpr bool is_always_lock_free = ATOMIC_LONG_LOCK_FREE == 2;
881 /// Explicit specialization for unsigned long.
883 struct atomic<unsigned long> : __atomic_base<unsigned long>
885 typedef unsigned long __integral_type;
886 typedef __atomic_base<unsigned long> __base_type;
888 atomic() noexcept = default;
889 ~atomic() noexcept = default;
890 atomic(const atomic&) = delete;
891 atomic& operator=(const atomic&) = delete;
892 atomic& operator=(const atomic&) volatile = delete;
894 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
896 using __base_type::operator __integral_type;
897 using __base_type::operator=;
899 #if __cplusplus >= 201703L
900 static constexpr bool is_always_lock_free = ATOMIC_LONG_LOCK_FREE == 2;
904 /// Explicit specialization for long long.
906 struct atomic<long long> : __atomic_base<long long>
908 typedef long long __integral_type;
909 typedef __atomic_base<long long> __base_type;
911 atomic() noexcept = default;
912 ~atomic() noexcept = default;
913 atomic(const atomic&) = delete;
914 atomic& operator=(const atomic&) = delete;
915 atomic& operator=(const atomic&) volatile = delete;
917 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
919 using __base_type::operator __integral_type;
920 using __base_type::operator=;
922 #if __cplusplus >= 201703L
923 static constexpr bool is_always_lock_free = ATOMIC_LLONG_LOCK_FREE == 2;
927 /// Explicit specialization for unsigned long long.
929 struct atomic<unsigned long long> : __atomic_base<unsigned long long>
931 typedef unsigned long long __integral_type;
932 typedef __atomic_base<unsigned long long> __base_type;
934 atomic() noexcept = default;
935 ~atomic() noexcept = default;
936 atomic(const atomic&) = delete;
937 atomic& operator=(const atomic&) = delete;
938 atomic& operator=(const atomic&) volatile = delete;
940 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
942 using __base_type::operator __integral_type;
943 using __base_type::operator=;
945 #if __cplusplus >= 201703L
946 static constexpr bool is_always_lock_free = ATOMIC_LLONG_LOCK_FREE == 2;
950 /// Explicit specialization for wchar_t.
952 struct atomic<wchar_t> : __atomic_base<wchar_t>
954 typedef wchar_t __integral_type;
955 typedef __atomic_base<wchar_t> __base_type;
957 atomic() noexcept = default;
958 ~atomic() noexcept = default;
959 atomic(const atomic&) = delete;
960 atomic& operator=(const atomic&) = delete;
961 atomic& operator=(const atomic&) volatile = delete;
963 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
965 using __base_type::operator __integral_type;
966 using __base_type::operator=;
968 #if __cplusplus >= 201703L
969 static constexpr bool is_always_lock_free = ATOMIC_WCHAR_T_LOCK_FREE == 2;
973 #ifdef _GLIBCXX_USE_CHAR8_T
974 /// Explicit specialization for char8_t.
976 struct atomic<char8_t> : __atomic_base<char8_t>
978 typedef char8_t __integral_type;
979 typedef __atomic_base<char8_t> __base_type;
981 atomic() noexcept = default;
982 ~atomic() noexcept = default;
983 atomic(const atomic&) = delete;
984 atomic& operator=(const atomic&) = delete;
985 atomic& operator=(const atomic&) volatile = delete;
987 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
989 using __base_type::operator __integral_type;
990 using __base_type::operator=;
992 #if __cplusplus > 201402L
993 static constexpr bool is_always_lock_free = ATOMIC_CHAR8_T_LOCK_FREE == 2;
998 /// Explicit specialization for char16_t.
1000 struct atomic<char16_t> : __atomic_base<char16_t>
1002 typedef char16_t __integral_type;
1003 typedef __atomic_base<char16_t> __base_type;
1005 atomic() noexcept = default;
1006 ~atomic() noexcept = default;
1007 atomic(const atomic&) = delete;
1008 atomic& operator=(const atomic&) = delete;
1009 atomic& operator=(const atomic&) volatile = delete;
1011 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
1013 using __base_type::operator __integral_type;
1014 using __base_type::operator=;
1016 #if __cplusplus >= 201703L
1017 static constexpr bool is_always_lock_free = ATOMIC_CHAR16_T_LOCK_FREE == 2;
1021 /// Explicit specialization for char32_t.
1023 struct atomic<char32_t> : __atomic_base<char32_t>
1025 typedef char32_t __integral_type;
1026 typedef __atomic_base<char32_t> __base_type;
1028 atomic() noexcept = default;
1029 ~atomic() noexcept = default;
1030 atomic(const atomic&) = delete;
1031 atomic& operator=(const atomic&) = delete;
1032 atomic& operator=(const atomic&) volatile = delete;
1034 constexpr atomic(__integral_type __i) noexcept : __base_type(__i) { }
1036 using __base_type::operator __integral_type;
1037 using __base_type::operator=;
1039 #if __cplusplus >= 201703L
1040 static constexpr bool is_always_lock_free = ATOMIC_CHAR32_T_LOCK_FREE == 2;
1046 typedef atomic<bool> atomic_bool;
1049 typedef atomic<char> atomic_char;
1052 typedef atomic<signed char> atomic_schar;
1055 typedef atomic<unsigned char> atomic_uchar;
1058 typedef atomic<short> atomic_short;
1061 typedef atomic<unsigned short> atomic_ushort;
1064 typedef atomic<int> atomic_int;
1067 typedef atomic<unsigned int> atomic_uint;
1070 typedef atomic<long> atomic_long;
1073 typedef atomic<unsigned long> atomic_ulong;
1076 typedef atomic<long long> atomic_llong;
1079 typedef atomic<unsigned long long> atomic_ullong;
1082 typedef atomic<wchar_t> atomic_wchar_t;
1084 #ifdef _GLIBCXX_USE_CHAR8_T
1086 typedef atomic<char8_t> atomic_char8_t;
1090 typedef atomic<char16_t> atomic_char16_t;
1093 typedef atomic<char32_t> atomic_char32_t;
1095 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
1096 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1097 // 2441. Exact-width atomic typedefs should be provided
1100 typedef atomic<int8_t> atomic_int8_t;
1103 typedef atomic<uint8_t> atomic_uint8_t;
1106 typedef atomic<int16_t> atomic_int16_t;
1109 typedef atomic<uint16_t> atomic_uint16_t;
1112 typedef atomic<int32_t> atomic_int32_t;
1115 typedef atomic<uint32_t> atomic_uint32_t;
1118 typedef atomic<int64_t> atomic_int64_t;
1121 typedef atomic<uint64_t> atomic_uint64_t;
1124 /// atomic_int_least8_t
1125 typedef atomic<int_least8_t> atomic_int_least8_t;
1127 /// atomic_uint_least8_t
1128 typedef atomic<uint_least8_t> atomic_uint_least8_t;
1130 /// atomic_int_least16_t
1131 typedef atomic<int_least16_t> atomic_int_least16_t;
1133 /// atomic_uint_least16_t
1134 typedef atomic<uint_least16_t> atomic_uint_least16_t;
1136 /// atomic_int_least32_t
1137 typedef atomic<int_least32_t> atomic_int_least32_t;
1139 /// atomic_uint_least32_t
1140 typedef atomic<uint_least32_t> atomic_uint_least32_t;
1142 /// atomic_int_least64_t
1143 typedef atomic<int_least64_t> atomic_int_least64_t;
1145 /// atomic_uint_least64_t
1146 typedef atomic<uint_least64_t> atomic_uint_least64_t;
1149 /// atomic_int_fast8_t
1150 typedef atomic<int_fast8_t> atomic_int_fast8_t;
1152 /// atomic_uint_fast8_t
1153 typedef atomic<uint_fast8_t> atomic_uint_fast8_t;
1155 /// atomic_int_fast16_t
1156 typedef atomic<int_fast16_t> atomic_int_fast16_t;
1158 /// atomic_uint_fast16_t
1159 typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
1161 /// atomic_int_fast32_t
1162 typedef atomic<int_fast32_t> atomic_int_fast32_t;
1164 /// atomic_uint_fast32_t
1165 typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
1167 /// atomic_int_fast64_t
1168 typedef atomic<int_fast64_t> atomic_int_fast64_t;
1170 /// atomic_uint_fast64_t
1171 typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
1176 typedef atomic<intptr_t> atomic_intptr_t;
1178 /// atomic_uintptr_t
1179 typedef atomic<uintptr_t> atomic_uintptr_t;
1182 typedef atomic<size_t> atomic_size_t;
1184 /// atomic_ptrdiff_t
1185 typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
1187 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
1189 typedef atomic<intmax_t> atomic_intmax_t;
1191 /// atomic_uintmax_t
1192 typedef atomic<uintmax_t> atomic_uintmax_t;
1195 // Function definitions, atomic_flag operations.
1197 atomic_flag_test_and_set_explicit(atomic_flag* __a,
1198 memory_order __m) noexcept
1199 { return __a->test_and_set(__m); }
1202 atomic_flag_test_and_set_explicit(volatile atomic_flag* __a,
1203 memory_order __m) noexcept
1204 { return __a->test_and_set(__m); }
1207 atomic_flag_clear_explicit(atomic_flag* __a, memory_order __m) noexcept
1208 { __a->clear(__m); }
1211 atomic_flag_clear_explicit(volatile atomic_flag* __a,
1212 memory_order __m) noexcept
1213 { __a->clear(__m); }
1216 atomic_flag_test_and_set(atomic_flag* __a) noexcept
1217 { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
1220 atomic_flag_test_and_set(volatile atomic_flag* __a) noexcept
1221 { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
1224 atomic_flag_clear(atomic_flag* __a) noexcept
1225 { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
1228 atomic_flag_clear(volatile atomic_flag* __a) noexcept
1229 { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
1232 template<typename _Tp>
1233 using __atomic_val_t = typename atomic<_Tp>::value_type;
1234 template<typename _Tp>
1235 using __atomic_diff_t = typename atomic<_Tp>::difference_type;
1237 // [atomics.nonmembers] Non-member functions.
1238 // Function templates generally applicable to atomic types.
1239 template<typename _ITp>
1241 atomic_is_lock_free(const atomic<_ITp>* __a) noexcept
1242 { return __a->is_lock_free(); }
1244 template<typename _ITp>
1246 atomic_is_lock_free(const volatile atomic<_ITp>* __a) noexcept
1247 { return __a->is_lock_free(); }
1249 template<typename _ITp>
1251 atomic_init(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1252 { __a->store(__i, memory_order_relaxed); }
1254 template<typename _ITp>
1256 atomic_init(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1257 { __a->store(__i, memory_order_relaxed); }
1259 template<typename _ITp>
1261 atomic_store_explicit(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
1262 memory_order __m) noexcept
1263 { __a->store(__i, __m); }
1265 template<typename _ITp>
1267 atomic_store_explicit(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
1268 memory_order __m) noexcept
1269 { __a->store(__i, __m); }
1271 template<typename _ITp>
1273 atomic_load_explicit(const atomic<_ITp>* __a, memory_order __m) noexcept
1274 { return __a->load(__m); }
1276 template<typename _ITp>
1278 atomic_load_explicit(const volatile atomic<_ITp>* __a,
1279 memory_order __m) noexcept
1280 { return __a->load(__m); }
1282 template<typename _ITp>
1284 atomic_exchange_explicit(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i,
1285 memory_order __m) noexcept
1286 { return __a->exchange(__i, __m); }
1288 template<typename _ITp>
1290 atomic_exchange_explicit(volatile atomic<_ITp>* __a,
1291 __atomic_val_t<_ITp> __i,
1292 memory_order __m) noexcept
1293 { return __a->exchange(__i, __m); }
1295 template<typename _ITp>
1297 atomic_compare_exchange_weak_explicit(atomic<_ITp>* __a,
1298 __atomic_val_t<_ITp>* __i1,
1299 __atomic_val_t<_ITp> __i2,
1301 memory_order __m2) noexcept
1302 { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
1304 template<typename _ITp>
1306 atomic_compare_exchange_weak_explicit(volatile atomic<_ITp>* __a,
1307 __atomic_val_t<_ITp>* __i1,
1308 __atomic_val_t<_ITp> __i2,
1310 memory_order __m2) noexcept
1311 { return __a->compare_exchange_weak(*__i1, __i2, __m1, __m2); }
1313 template<typename _ITp>
1315 atomic_compare_exchange_strong_explicit(atomic<_ITp>* __a,
1316 __atomic_val_t<_ITp>* __i1,
1317 __atomic_val_t<_ITp> __i2,
1319 memory_order __m2) noexcept
1320 { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
1322 template<typename _ITp>
1324 atomic_compare_exchange_strong_explicit(volatile atomic<_ITp>* __a,
1325 __atomic_val_t<_ITp>* __i1,
1326 __atomic_val_t<_ITp> __i2,
1328 memory_order __m2) noexcept
1329 { return __a->compare_exchange_strong(*__i1, __i2, __m1, __m2); }
1332 template<typename _ITp>
1334 atomic_store(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1335 { atomic_store_explicit(__a, __i, memory_order_seq_cst); }
1337 template<typename _ITp>
1339 atomic_store(volatile atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1340 { atomic_store_explicit(__a, __i, memory_order_seq_cst); }
1342 template<typename _ITp>
1344 atomic_load(const atomic<_ITp>* __a) noexcept
1345 { return atomic_load_explicit(__a, memory_order_seq_cst); }
1347 template<typename _ITp>
1349 atomic_load(const volatile atomic<_ITp>* __a) noexcept
1350 { return atomic_load_explicit(__a, memory_order_seq_cst); }
1352 template<typename _ITp>
1354 atomic_exchange(atomic<_ITp>* __a, __atomic_val_t<_ITp> __i) noexcept
1355 { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
1357 template<typename _ITp>
1359 atomic_exchange(volatile atomic<_ITp>* __a,
1360 __atomic_val_t<_ITp> __i) noexcept
1361 { return atomic_exchange_explicit(__a, __i, memory_order_seq_cst); }
1363 template<typename _ITp>
1365 atomic_compare_exchange_weak(atomic<_ITp>* __a,
1366 __atomic_val_t<_ITp>* __i1,
1367 __atomic_val_t<_ITp> __i2) noexcept
1369 return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
1370 memory_order_seq_cst,
1371 memory_order_seq_cst);
1374 template<typename _ITp>
1376 atomic_compare_exchange_weak(volatile atomic<_ITp>* __a,
1377 __atomic_val_t<_ITp>* __i1,
1378 __atomic_val_t<_ITp> __i2) noexcept
1380 return atomic_compare_exchange_weak_explicit(__a, __i1, __i2,
1381 memory_order_seq_cst,
1382 memory_order_seq_cst);
1385 template<typename _ITp>
1387 atomic_compare_exchange_strong(atomic<_ITp>* __a,
1388 __atomic_val_t<_ITp>* __i1,
1389 __atomic_val_t<_ITp> __i2) noexcept
1391 return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
1392 memory_order_seq_cst,
1393 memory_order_seq_cst);
1396 template<typename _ITp>
1398 atomic_compare_exchange_strong(volatile atomic<_ITp>* __a,
1399 __atomic_val_t<_ITp>* __i1,
1400 __atomic_val_t<_ITp> __i2) noexcept
1402 return atomic_compare_exchange_strong_explicit(__a, __i1, __i2,
1403 memory_order_seq_cst,
1404 memory_order_seq_cst);
1408 #if __cpp_lib_atomic_wait
1409 template<typename _Tp>
1411 atomic_wait(const atomic<_Tp>* __a,
1412 typename std::atomic<_Tp>::value_type __old) noexcept
1413 { __a->wait(__old); }
1415 template<typename _Tp>
1417 atomic_wait_explicit(const atomic<_Tp>* __a,
1418 typename std::atomic<_Tp>::value_type __old,
1419 std::memory_order __m) noexcept
1420 { __a->wait(__old, __m); }
1422 template<typename _Tp>
1424 atomic_notify_one(const atomic<_Tp>* __a) noexcept
1425 { __a->notify_one(); }
1427 template<typename _Tp>
1429 atomic_notify_all(const atomic<_Tp>* __a) noexcept
1430 { __a->notify_all(); }
1431 #endif // __cpp_lib_atomic_wait
1433 // Function templates for atomic_integral and atomic_pointer operations only.
1434 // Some operations (and, or, xor) are only available for atomic integrals,
1435 // which is implemented by taking a parameter of type __atomic_base<_ITp>*.
1437 template<typename _ITp>
1439 atomic_fetch_add_explicit(atomic<_ITp>* __a,
1440 __atomic_diff_t<_ITp> __i,
1441 memory_order __m) noexcept
1442 { return __a->fetch_add(__i, __m); }
1444 template<typename _ITp>
1446 atomic_fetch_add_explicit(volatile atomic<_ITp>* __a,
1447 __atomic_diff_t<_ITp> __i,
1448 memory_order __m) noexcept
1449 { return __a->fetch_add(__i, __m); }
1451 template<typename _ITp>
1453 atomic_fetch_sub_explicit(atomic<_ITp>* __a,
1454 __atomic_diff_t<_ITp> __i,
1455 memory_order __m) noexcept
1456 { return __a->fetch_sub(__i, __m); }
1458 template<typename _ITp>
1460 atomic_fetch_sub_explicit(volatile atomic<_ITp>* __a,
1461 __atomic_diff_t<_ITp> __i,
1462 memory_order __m) noexcept
1463 { return __a->fetch_sub(__i, __m); }
1465 template<typename _ITp>
1467 atomic_fetch_and_explicit(__atomic_base<_ITp>* __a,
1468 __atomic_val_t<_ITp> __i,
1469 memory_order __m) noexcept
1470 { return __a->fetch_and(__i, __m); }
1472 template<typename _ITp>
1474 atomic_fetch_and_explicit(volatile __atomic_base<_ITp>* __a,
1475 __atomic_val_t<_ITp> __i,
1476 memory_order __m) noexcept
1477 { return __a->fetch_and(__i, __m); }
1479 template<typename _ITp>
1481 atomic_fetch_or_explicit(__atomic_base<_ITp>* __a,
1482 __atomic_val_t<_ITp> __i,
1483 memory_order __m) noexcept
1484 { return __a->fetch_or(__i, __m); }
1486 template<typename _ITp>
1488 atomic_fetch_or_explicit(volatile __atomic_base<_ITp>* __a,
1489 __atomic_val_t<_ITp> __i,
1490 memory_order __m) noexcept
1491 { return __a->fetch_or(__i, __m); }
1493 template<typename _ITp>
1495 atomic_fetch_xor_explicit(__atomic_base<_ITp>* __a,
1496 __atomic_val_t<_ITp> __i,
1497 memory_order __m) noexcept
1498 { return __a->fetch_xor(__i, __m); }
1500 template<typename _ITp>
1502 atomic_fetch_xor_explicit(volatile __atomic_base<_ITp>* __a,
1503 __atomic_val_t<_ITp> __i,
1504 memory_order __m) noexcept
1505 { return __a->fetch_xor(__i, __m); }
1507 template<typename _ITp>
1509 atomic_fetch_add(atomic<_ITp>* __a,
1510 __atomic_diff_t<_ITp> __i) noexcept
1511 { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
1513 template<typename _ITp>
1515 atomic_fetch_add(volatile atomic<_ITp>* __a,
1516 __atomic_diff_t<_ITp> __i) noexcept
1517 { return atomic_fetch_add_explicit(__a, __i, memory_order_seq_cst); }
1519 template<typename _ITp>
1521 atomic_fetch_sub(atomic<_ITp>* __a,
1522 __atomic_diff_t<_ITp> __i) noexcept
1523 { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
1525 template<typename _ITp>
1527 atomic_fetch_sub(volatile atomic<_ITp>* __a,
1528 __atomic_diff_t<_ITp> __i) noexcept
1529 { return atomic_fetch_sub_explicit(__a, __i, memory_order_seq_cst); }
1531 template<typename _ITp>
1533 atomic_fetch_and(__atomic_base<_ITp>* __a,
1534 __atomic_val_t<_ITp> __i) noexcept
1535 { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
1537 template<typename _ITp>
1539 atomic_fetch_and(volatile __atomic_base<_ITp>* __a,
1540 __atomic_val_t<_ITp> __i) noexcept
1541 { return atomic_fetch_and_explicit(__a, __i, memory_order_seq_cst); }
1543 template<typename _ITp>
1545 atomic_fetch_or(__atomic_base<_ITp>* __a,
1546 __atomic_val_t<_ITp> __i) noexcept
1547 { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
1549 template<typename _ITp>
1551 atomic_fetch_or(volatile __atomic_base<_ITp>* __a,
1552 __atomic_val_t<_ITp> __i) noexcept
1553 { return atomic_fetch_or_explicit(__a, __i, memory_order_seq_cst); }
1555 template<typename _ITp>
1557 atomic_fetch_xor(__atomic_base<_ITp>* __a,
1558 __atomic_val_t<_ITp> __i) noexcept
1559 { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
1561 template<typename _ITp>
1563 atomic_fetch_xor(volatile __atomic_base<_ITp>* __a,
1564 __atomic_val_t<_ITp> __i) noexcept
1565 { return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
1567 #if __cplusplus > 201703L
1568 #define __cpp_lib_atomic_float 201711L
1570 struct atomic<float> : __atomic_float<float>
1572 atomic() noexcept = default;
1575 atomic(float __fp) noexcept : __atomic_float<float>(__fp)
1578 atomic& operator=(const atomic&) volatile = delete;
1579 atomic& operator=(const atomic&) = delete;
1581 using __atomic_float<float>::operator=;
1585 struct atomic<double> : __atomic_float<double>
1587 atomic() noexcept = default;
1590 atomic(double __fp) noexcept : __atomic_float<double>(__fp)
1593 atomic& operator=(const atomic&) volatile = delete;
1594 atomic& operator=(const atomic&) = delete;
1596 using __atomic_float<double>::operator=;
1600 struct atomic<long double> : __atomic_float<long double>
1602 atomic() noexcept = default;
1605 atomic(long double __fp) noexcept : __atomic_float<long double>(__fp)
1608 atomic& operator=(const atomic&) volatile = delete;
1609 atomic& operator=(const atomic&) = delete;
1611 using __atomic_float<long double>::operator=;
1614 #define __cpp_lib_atomic_ref 201806L
1616 /// Class template to provide atomic operations on a non-atomic variable.
1617 template<typename _Tp>
1618 struct atomic_ref : __atomic_ref<_Tp>
1621 atomic_ref(_Tp& __t) noexcept : __atomic_ref<_Tp>(__t)
1624 atomic_ref& operator=(const atomic_ref&) = delete;
1626 atomic_ref(const atomic_ref&) = default;
1628 using __atomic_ref<_Tp>::operator=;
1633 /// @} group atomics
1635 _GLIBCXX_END_NAMESPACE_VERSION
1640 #endif // _GLIBCXX_ATOMIC