xref: /freebsd/contrib/llvm-project/libcxx/include/future (revision 9c77fb6aaa366cbabc80ee1b834bcfe4df135491)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_FUTURE
11#define _LIBCPP_FUTURE
12
13/*
14    future synopsis
15
16namespace std
17{
18
19enum class future_errc
20{
21    future_already_retrieved = 1,
22    promise_already_satisfied,
23    no_state,
24    broken_promise
25};
26
27enum class launch
28{
29    async = 1,
30    deferred = 2,
31    any = async | deferred
32};
33
34enum class future_status
35{
36    ready,
37    timeout,
38    deferred
39};
40
41template <> struct is_error_code_enum<future_errc> : public true_type { };
42error_code make_error_code(future_errc e) noexcept;
43error_condition make_error_condition(future_errc e) noexcept;
44
45const error_category& future_category() noexcept;
46
47class future_error : public logic_error {
48public:
49    explicit future_error(future_errc e); // since C++17
50
51    const error_code& code() const noexcept;
52    const char*       what() const noexcept;
53
54private:
55    error_code ec_;             // exposition only
56};
57
58template <class R>
59class promise
60{
61public:
62    promise();
63    template <class Allocator>
64        promise(allocator_arg_t, const Allocator& a);
65    promise(promise&& rhs) noexcept;
66    promise(const promise& rhs) = delete;
67    ~promise();
68
69    // assignment
70    promise& operator=(promise&& rhs) noexcept;
71    promise& operator=(const promise& rhs) = delete;
72    void swap(promise& other) noexcept;
73
74    // retrieving the result
75    future<R> get_future();
76
77    // setting the result
78    void set_value(const R& r);
79    void set_value(R&& r);
80    void set_exception(exception_ptr p);
81
82    // setting the result with deferred notification
83    void set_value_at_thread_exit(const R& r);
84    void set_value_at_thread_exit(R&& r);
85    void set_exception_at_thread_exit(exception_ptr p);
86};
87
88template <class R>
89class promise<R&>
90{
91public:
92    promise();
93    template <class Allocator>
94        promise(allocator_arg_t, const Allocator& a);
95    promise(promise&& rhs) noexcept;
96    promise(const promise& rhs) = delete;
97    ~promise();
98
99    // assignment
100    promise& operator=(promise&& rhs) noexcept;
101    promise& operator=(const promise& rhs) = delete;
102    void swap(promise& other) noexcept;
103
104    // retrieving the result
105    future<R&> get_future();
106
107    // setting the result
108    void set_value(R& r);
109    void set_exception(exception_ptr p);
110
111    // setting the result with deferred notification
112    void set_value_at_thread_exit(R&);
113    void set_exception_at_thread_exit(exception_ptr p);
114};
115
116template <>
117class promise<void>
118{
119public:
120    promise();
121    template <class Allocator>
122        promise(allocator_arg_t, const Allocator& a);
123    promise(promise&& rhs) noexcept;
124    promise(const promise& rhs) = delete;
125    ~promise();
126
127    // assignment
128    promise& operator=(promise&& rhs) noexcept;
129    promise& operator=(const promise& rhs) = delete;
130    void swap(promise& other) noexcept;
131
132    // retrieving the result
133    future<void> get_future();
134
135    // setting the result
136    void set_value();
137    void set_exception(exception_ptr p);
138
139    // setting the result with deferred notification
140    void set_value_at_thread_exit();
141    void set_exception_at_thread_exit(exception_ptr p);
142};
143
144template <class R> void swap(promise<R>& x, promise<R>& y) noexcept;
145
146template <class R, class Alloc>
147    struct uses_allocator<promise<R>, Alloc> : public true_type {};
148
149template <class R>
150class future
151{
152public:
153    future() noexcept;
154    future(future&&) noexcept;
155    future(const future& rhs) = delete;
156    ~future();
157    future& operator=(const future& rhs) = delete;
158    future& operator=(future&&) noexcept;
159    shared_future<R> share() noexcept;
160
161    // retrieving the value
162    R get();
163
164    // functions to check state
165    bool valid() const noexcept;
166
167    void wait() const;
168    template <class Rep, class Period>
169        future_status
170        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
171    template <class Clock, class Duration>
172        future_status
173        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
174};
175
176template <class R>
177class future<R&>
178{
179public:
180    future() noexcept;
181    future(future&&) noexcept;
182    future(const future& rhs) = delete;
183    ~future();
184    future& operator=(const future& rhs) = delete;
185    future& operator=(future&&) noexcept;
186    shared_future<R&> share() noexcept;
187
188    // retrieving the value
189    R& get();
190
191    // functions to check state
192    bool valid() const noexcept;
193
194    void wait() const;
195    template <class Rep, class Period>
196        future_status
197        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
198    template <class Clock, class Duration>
199        future_status
200        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
201};
202
203template <>
204class future<void>
205{
206public:
207    future() noexcept;
208    future(future&&) noexcept;
209    future(const future& rhs) = delete;
210    ~future();
211    future& operator=(const future& rhs) = delete;
212    future& operator=(future&&) noexcept;
213    shared_future<void> share() noexcept;
214
215    // retrieving the value
216    void get();
217
218    // functions to check state
219    bool valid() const noexcept;
220
221    void wait() const;
222    template <class Rep, class Period>
223        future_status
224        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
225    template <class Clock, class Duration>
226        future_status
227        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
228};
229
230template <class R>
231class shared_future
232{
233public:
234    shared_future() noexcept;
235    shared_future(const shared_future& rhs);
236    shared_future(future<R>&&) noexcept;
237    shared_future(shared_future&& rhs) noexcept;
238    ~shared_future();
239    shared_future& operator=(const shared_future& rhs);
240    shared_future& operator=(shared_future&& rhs) noexcept;
241
242    // retrieving the value
243    const R& get() const;
244
245    // functions to check state
246    bool valid() const noexcept;
247
248    void wait() const;
249    template <class Rep, class Period>
250        future_status
251        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
252    template <class Clock, class Duration>
253        future_status
254        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
255};
256
257template <class R>
258class shared_future<R&>
259{
260public:
261    shared_future() noexcept;
262    shared_future(const shared_future& rhs);
263    shared_future(future<R&>&&) noexcept;
264    shared_future(shared_future&& rhs) noexcept;
265    ~shared_future();
266    shared_future& operator=(const shared_future& rhs);
267    shared_future& operator=(shared_future&& rhs) noexcept;
268
269    // retrieving the value
270    R& get() const;
271
272    // functions to check state
273    bool valid() const noexcept;
274
275    void wait() const;
276    template <class Rep, class Period>
277        future_status
278        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
279    template <class Clock, class Duration>
280        future_status
281        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
282};
283
284template <>
285class shared_future<void>
286{
287public:
288    shared_future() noexcept;
289    shared_future(const shared_future& rhs);
290    shared_future(future<void>&&) noexcept;
291    shared_future(shared_future&& rhs) noexcept;
292    ~shared_future();
293    shared_future& operator=(const shared_future& rhs);
294    shared_future& operator=(shared_future&& rhs) noexcept;
295
296    // retrieving the value
297    void get() const;
298
299    // functions to check state
300    bool valid() const noexcept;
301
302    void wait() const;
303    template <class Rep, class Period>
304        future_status
305        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
306    template <class Clock, class Duration>
307        future_status
308        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
309};
310
311template <class F, class... Args>
312  future<typename result_of<typename decay<F>::type(typename decay<Args>::type...)>::type>
313  async(F&& f, Args&&... args);
314
315template <class F, class... Args>
316  future<typename result_of<typename decay<F>::type(typename decay<Args>::type...)>::type>
317  async(launch policy, F&& f, Args&&... args);
318
319template <class> class packaged_task; // undefined
320
321template <class R, class... ArgTypes>
322class packaged_task<R(ArgTypes...)>
323{
324public:
325    // construction and destruction
326    packaged_task() noexcept;
327    template <class F>
328        explicit packaged_task(F&& f);
329    template <class F, class Allocator>
330        packaged_task(allocator_arg_t, const Allocator& a, F&& f);              // removed in C++17
331    ~packaged_task();
332
333    // no copy
334    packaged_task(const packaged_task&) = delete;
335    packaged_task& operator=(const packaged_task&) = delete;
336
337    // move support
338    packaged_task(packaged_task&& other) noexcept;
339    packaged_task& operator=(packaged_task&& other) noexcept;
340    void swap(packaged_task& other) noexcept;
341
342    bool valid() const noexcept;
343
344    // result retrieval
345    future<R> get_future();
346
347    // execution
348    void operator()(ArgTypes... );
349    void make_ready_at_thread_exit(ArgTypes...);
350
351    void reset();
352};
353
354template <class R>
355  void swap(packaged_task<R(ArgTypes...)&, packaged_task<R(ArgTypes...)>&) noexcept;
356
357template <class R, class Alloc> struct uses_allocator<packaged_task<R>, Alloc>; // removed in C++17
358
359}  // std
360
361*/
362
363#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
364#  include <__cxx03/future>
365#else
366#  include <__config>
367
368#  if _LIBCPP_HAS_THREADS
369
370#    include <__assert>
371#    include <__chrono/duration.h>
372#    include <__chrono/steady_clock.h>
373#    include <__chrono/time_point.h>
374#    include <__condition_variable/condition_variable.h>
375#    include <__cstddef/nullptr_t.h>
376#    include <__exception/exception_ptr.h>
377#    include <__memory/addressof.h>
378#    include <__memory/allocator.h>
379#    include <__memory/allocator_arg_t.h>
380#    include <__memory/allocator_destructor.h>
381#    include <__memory/allocator_traits.h>
382#    include <__memory/compressed_pair.h>
383#    include <__memory/pointer_traits.h>
384#    include <__memory/shared_count.h>
385#    include <__memory/unique_ptr.h>
386#    include <__memory/uses_allocator.h>
387#    include <__mutex/lock_guard.h>
388#    include <__mutex/mutex.h>
389#    include <__mutex/unique_lock.h>
390#    include <__system_error/error_category.h>
391#    include <__system_error/error_code.h>
392#    include <__system_error/error_condition.h>
393#    include <__thread/thread.h>
394#    include <__type_traits/add_reference.h>
395#    include <__type_traits/aligned_storage.h>
396#    include <__type_traits/conditional.h>
397#    include <__type_traits/decay.h>
398#    include <__type_traits/enable_if.h>
399#    include <__type_traits/invoke.h>
400#    include <__type_traits/is_same.h>
401#    include <__type_traits/remove_cvref.h>
402#    include <__type_traits/remove_reference.h>
403#    include <__type_traits/strip_signature.h>
404#    include <__type_traits/underlying_type.h>
405#    include <__utility/auto_cast.h>
406#    include <__utility/forward.h>
407#    include <__utility/move.h>
408#    include <__utility/swap.h>
409#    include <stdexcept>
410#    include <tuple>
411#    include <version>
412
413#    if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
414#      pragma GCC system_header
415#    endif
416
417_LIBCPP_PUSH_MACROS
418#    include <__undef_macros>
419
420_LIBCPP_BEGIN_NAMESPACE_STD
421
422// enum class future_errc
423_LIBCPP_DECLARE_STRONG_ENUM(future_errc){
424    future_already_retrieved = 1, promise_already_satisfied, no_state, broken_promise};
425_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(future_errc)
426
427template <>
428struct is_error_code_enum<future_errc> : public true_type {};
429
430#    ifdef _LIBCPP_CXX03_LANG
431template <>
432struct is_error_code_enum<future_errc::__lx> : public true_type {};
433#    endif
434
435// enum class launch
436_LIBCPP_DECLARE_STRONG_ENUM(launch){async = 1, deferred = 2, any = async | deferred};
437_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(launch)
438
439#    ifndef _LIBCPP_CXX03_LANG
440
441using __launch_underlying_type _LIBCPP_NODEBUG = __underlying_type_t<launch>;
442
443inline _LIBCPP_HIDE_FROM_ABI constexpr launch operator&(launch __x, launch __y) {
444  return static_cast<launch>(static_cast<__launch_underlying_type>(__x) & static_cast<__launch_underlying_type>(__y));
445}
446
447inline _LIBCPP_HIDE_FROM_ABI constexpr launch operator|(launch __x, launch __y) {
448  return static_cast<launch>(static_cast<__launch_underlying_type>(__x) | static_cast<__launch_underlying_type>(__y));
449}
450
451inline _LIBCPP_HIDE_FROM_ABI constexpr launch operator^(launch __x, launch __y) {
452  return static_cast<launch>(static_cast<__launch_underlying_type>(__x) ^ static_cast<__launch_underlying_type>(__y));
453}
454
455inline _LIBCPP_HIDE_FROM_ABI constexpr launch operator~(launch __x) {
456  return static_cast<launch>(~static_cast<__launch_underlying_type>(__x) & 3);
457}
458
459inline _LIBCPP_HIDE_FROM_ABI launch& operator&=(launch& __x, launch __y) {
460  __x = __x & __y;
461  return __x;
462}
463
464inline _LIBCPP_HIDE_FROM_ABI launch& operator|=(launch& __x, launch __y) {
465  __x = __x | __y;
466  return __x;
467}
468
469inline _LIBCPP_HIDE_FROM_ABI launch& operator^=(launch& __x, launch __y) {
470  __x = __x ^ __y;
471  return __x;
472}
473
474#    endif // !_LIBCPP_CXX03_LANG
475
476// enum class future_status
477_LIBCPP_DECLARE_STRONG_ENUM(future_status){ready, timeout, deferred};
478_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(future_status)
479
480_LIBCPP_EXPORTED_FROM_ABI const error_category& future_category() _NOEXCEPT;
481
482inline _LIBCPP_HIDE_FROM_ABI error_code make_error_code(future_errc __e) _NOEXCEPT {
483  return error_code(static_cast<int>(__e), future_category());
484}
485
486inline _LIBCPP_HIDE_FROM_ABI error_condition make_error_condition(future_errc __e) _NOEXCEPT {
487  return error_condition(static_cast<int>(__e), future_category());
488}
489
490[[__noreturn__]] inline _LIBCPP_HIDE_FROM_ABI void __throw_future_error(future_errc __ev);
491
492class _LIBCPP_EXPORTED_FROM_ABI future_error : public logic_error {
493  error_code __ec_;
494
495  future_error(error_code);
496  friend void __throw_future_error(future_errc);
497  template <class>
498  friend class promise;
499
500public:
501#    if _LIBCPP_STD_VER >= 17
502  _LIBCPP_HIDE_FROM_ABI explicit future_error(future_errc __ec) : future_error(std::make_error_code(__ec)) {}
503#    endif
504
505  _LIBCPP_HIDE_FROM_ABI const error_code& code() const _NOEXCEPT { return __ec_; }
506
507  _LIBCPP_HIDE_FROM_ABI future_error(const future_error&) _NOEXCEPT = default;
508  ~future_error() _NOEXCEPT override;
509};
510
511// Declared above std::future_error
512void __throw_future_error(future_errc __ev) {
513#    if _LIBCPP_HAS_EXCEPTIONS
514  throw future_error(make_error_code(__ev));
515#    else
516  (void)__ev;
517  _LIBCPP_VERBOSE_ABORT("future_error was thrown in -fno-exceptions mode");
518#    endif
519}
520
521class _LIBCPP_EXPORTED_FROM_ABI __assoc_sub_state : public __shared_count {
522protected:
523  exception_ptr __exception_;
524  mutable mutex __mut_;
525  mutable condition_variable __cv_;
526  unsigned __state_;
527
528  void __on_zero_shared() _NOEXCEPT override;
529  void __sub_wait(unique_lock<mutex>& __lk);
530
531public:
532  enum { __constructed = 1, __future_attached = 2, ready = 4, deferred = 8 };
533
534  _LIBCPP_HIDE_FROM_ABI __assoc_sub_state() : __state_(0) {}
535
536  _LIBCPP_HIDE_FROM_ABI bool __has_value() const { return (__state_ & __constructed) || (__exception_ != nullptr); }
537
538  _LIBCPP_HIDE_FROM_ABI void __attach_future() {
539    lock_guard<mutex> __lk(__mut_);
540    bool __has_future_attached = (__state_ & __future_attached) != 0;
541    if (__has_future_attached)
542      std::__throw_future_error(future_errc::future_already_retrieved);
543    this->__add_shared();
544    __state_ |= __future_attached;
545  }
546
547  _LIBCPP_HIDE_FROM_ABI void __set_deferred() { __state_ |= deferred; }
548
549  void __make_ready();
550  _LIBCPP_HIDE_FROM_ABI bool __is_ready() const { return (__state_ & ready) != 0; }
551
552  void set_value();
553  void set_value_at_thread_exit();
554
555  void set_exception(exception_ptr __p);
556  void set_exception_at_thread_exit(exception_ptr __p);
557
558  void copy();
559
560  void wait();
561  template <class _Rep, class _Period>
562  future_status _LIBCPP_HIDE_FROM_ABI wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const;
563  template <class _Clock, class _Duration>
564  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
565    unique_lock<mutex> __lk(__mut_);
566    if (__state_ & deferred)
567      return future_status::deferred;
568    while (!(__state_ & ready) && _Clock::now() < __abs_time)
569      __cv_.wait_until(__lk, __abs_time);
570    if (__state_ & ready)
571      return future_status::ready;
572    return future_status::timeout;
573  }
574
575  virtual void __execute();
576};
577
578template <class _Rep, class _Period>
579inline future_status __assoc_sub_state::wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
580  return wait_until(chrono::steady_clock::now() + __rel_time);
581}
582
583template <class _Rp>
584class _LIBCPP_HIDDEN __assoc_state : public __assoc_sub_state {
585  typedef __assoc_sub_state base;
586  _LIBCPP_SUPPRESS_DEPRECATED_PUSH
587  typedef typename aligned_storage<sizeof(_Rp), _LIBCPP_ALIGNOF(_Rp)>::type _Up;
588  _LIBCPP_SUPPRESS_DEPRECATED_POP
589
590protected:
591  _Up __value_;
592
593  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;
594
595public:
596  template <class _Arg>
597  _LIBCPP_HIDE_FROM_ABI void set_value(_Arg&& __arg);
598
599  template <class _Arg>
600  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(_Arg&& __arg);
601
602  _LIBCPP_HIDE_FROM_ABI _Rp move();
603  _LIBCPP_HIDE_FROM_ABI _Rp& copy();
604};
605
606template <class _Rp>
607void __assoc_state<_Rp>::__on_zero_shared() _NOEXCEPT {
608  if (this->__state_ & base::__constructed)
609    reinterpret_cast<_Rp*>(std::addressof(__value_))->~_Rp();
610  delete this;
611}
612
613template <class _Rp>
614template <class _Arg>
615void __assoc_state<_Rp>::set_value(_Arg&& __arg) {
616  unique_lock<mutex> __lk(this->__mut_);
617  if (this->__has_value())
618    std::__throw_future_error(future_errc::promise_already_satisfied);
619  ::new ((void*)std::addressof(__value_)) _Rp(std::forward<_Arg>(__arg));
620  this->__state_ |= base::__constructed | base::ready;
621  __cv_.notify_all();
622}
623
624template <class _Rp>
625template <class _Arg>
626void __assoc_state<_Rp>::set_value_at_thread_exit(_Arg&& __arg) {
627  unique_lock<mutex> __lk(this->__mut_);
628  if (this->__has_value())
629    std::__throw_future_error(future_errc::promise_already_satisfied);
630  ::new ((void*)std::addressof(__value_)) _Rp(std::forward<_Arg>(__arg));
631  this->__state_ |= base::__constructed;
632  __thread_local_data()->__make_ready_at_thread_exit(this);
633}
634
635template <class _Rp>
636_Rp __assoc_state<_Rp>::move() {
637  unique_lock<mutex> __lk(this->__mut_);
638  this->__sub_wait(__lk);
639  if (this->__exception_ != nullptr)
640    std::rethrow_exception(this->__exception_);
641  return std::move(*reinterpret_cast<_Rp*>(std::addressof(__value_)));
642}
643
644template <class _Rp>
645_Rp& __assoc_state<_Rp>::copy() {
646  unique_lock<mutex> __lk(this->__mut_);
647  this->__sub_wait(__lk);
648  if (this->__exception_ != nullptr)
649    std::rethrow_exception(this->__exception_);
650  return *reinterpret_cast<_Rp*>(std::addressof(__value_));
651}
652
653template <class _Rp>
654class __assoc_state<_Rp&> : public __assoc_sub_state {
655  typedef __assoc_sub_state base;
656  typedef _Rp* _Up;
657
658protected:
659  _Up __value_;
660
661  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;
662
663public:
664  _LIBCPP_HIDE_FROM_ABI void set_value(_Rp& __arg);
665  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(_Rp& __arg);
666
667  _LIBCPP_HIDE_FROM_ABI _Rp& copy();
668};
669
670template <class _Rp>
671void __assoc_state<_Rp&>::__on_zero_shared() _NOEXCEPT {
672  delete this;
673}
674
675template <class _Rp>
676void __assoc_state<_Rp&>::set_value(_Rp& __arg) {
677  unique_lock<mutex> __lk(this->__mut_);
678  if (this->__has_value())
679    std::__throw_future_error(future_errc::promise_already_satisfied);
680  __value_ = std::addressof(__arg);
681  this->__state_ |= base::__constructed | base::ready;
682  __cv_.notify_all();
683}
684
685template <class _Rp>
686void __assoc_state<_Rp&>::set_value_at_thread_exit(_Rp& __arg) {
687  unique_lock<mutex> __lk(this->__mut_);
688  if (this->__has_value())
689    std::__throw_future_error(future_errc::promise_already_satisfied);
690  __value_ = std::addressof(__arg);
691  this->__state_ |= base::__constructed;
692  __thread_local_data()->__make_ready_at_thread_exit(this);
693}
694
695template <class _Rp>
696_Rp& __assoc_state<_Rp&>::copy() {
697  unique_lock<mutex> __lk(this->__mut_);
698  this->__sub_wait(__lk);
699  if (this->__exception_ != nullptr)
700    std::rethrow_exception(this->__exception_);
701  return *__value_;
702}
703
704template <class _Rp, class _Alloc>
705class __assoc_state_alloc : public __assoc_state<_Rp> {
706  typedef __assoc_state<_Rp> base;
707  _Alloc __alloc_;
708
709  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __on_zero_shared() _NOEXCEPT;
710
711public:
712  _LIBCPP_HIDE_FROM_ABI explicit __assoc_state_alloc(const _Alloc& __a) : __alloc_(__a) {}
713};
714
715template <class _Rp, class _Alloc>
716void __assoc_state_alloc<_Rp, _Alloc>::__on_zero_shared() _NOEXCEPT {
717  if (this->__state_ & base::__constructed)
718    reinterpret_cast<_Rp*>(std::addressof(this->__value_))->~_Rp();
719  typedef typename __allocator_traits_rebind<_Alloc, __assoc_state_alloc>::type _Al;
720  typedef allocator_traits<_Al> _ATraits;
721  typedef pointer_traits<typename _ATraits::pointer> _PTraits;
722  _Al __a(__alloc_);
723  this->~__assoc_state_alloc();
724  __a.deallocate(_PTraits::pointer_to(*this), 1);
725}
726
727template <class _Rp, class _Alloc>
728class __assoc_state_alloc<_Rp&, _Alloc> : public __assoc_state<_Rp&> {
729  typedef __assoc_state<_Rp&> base;
730  _Alloc __alloc_;
731
732  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __on_zero_shared() _NOEXCEPT;
733
734public:
735  _LIBCPP_HIDE_FROM_ABI explicit __assoc_state_alloc(const _Alloc& __a) : __alloc_(__a) {}
736};
737
738template <class _Rp, class _Alloc>
739void __assoc_state_alloc<_Rp&, _Alloc>::__on_zero_shared() _NOEXCEPT {
740  typedef typename __allocator_traits_rebind<_Alloc, __assoc_state_alloc>::type _Al;
741  typedef allocator_traits<_Al> _ATraits;
742  typedef pointer_traits<typename _ATraits::pointer> _PTraits;
743  _Al __a(__alloc_);
744  this->~__assoc_state_alloc();
745  __a.deallocate(_PTraits::pointer_to(*this), 1);
746}
747
748template <class _Alloc>
749class __assoc_sub_state_alloc : public __assoc_sub_state {
750  typedef __assoc_sub_state base;
751  _Alloc __alloc_;
752
753  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;
754
755public:
756  _LIBCPP_HIDE_FROM_ABI explicit __assoc_sub_state_alloc(const _Alloc& __a) : __alloc_(__a) {}
757};
758
759template <class _Alloc>
760void __assoc_sub_state_alloc<_Alloc>::__on_zero_shared() _NOEXCEPT {
761  typedef typename __allocator_traits_rebind<_Alloc, __assoc_sub_state_alloc>::type _Al;
762  typedef allocator_traits<_Al> _ATraits;
763  typedef pointer_traits<typename _ATraits::pointer> _PTraits;
764  _Al __a(__alloc_);
765  this->~__assoc_sub_state_alloc();
766  __a.deallocate(_PTraits::pointer_to(*this), 1);
767}
768
769template <class _Rp, class _Fp>
770class __deferred_assoc_state : public __assoc_state<_Rp> {
771  typedef __assoc_state<_Rp> base;
772
773  _Fp __func_;
774
775public:
776  _LIBCPP_HIDE_FROM_ABI explicit __deferred_assoc_state(_Fp&& __f);
777
778  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __execute();
779};
780
781template <class _Rp, class _Fp>
782inline __deferred_assoc_state<_Rp, _Fp>::__deferred_assoc_state(_Fp&& __f) : __func_(std::forward<_Fp>(__f)) {
783  this->__set_deferred();
784}
785
786template <class _Rp, class _Fp>
787void __deferred_assoc_state<_Rp, _Fp>::__execute() {
788#    if _LIBCPP_HAS_EXCEPTIONS
789  try {
790#    endif // _LIBCPP_HAS_EXCEPTIONS
791    this->set_value(__func_());
792#    if _LIBCPP_HAS_EXCEPTIONS
793  } catch (...) {
794    this->set_exception(current_exception());
795  }
796#    endif // _LIBCPP_HAS_EXCEPTIONS
797}
798
799template <class _Fp>
800class __deferred_assoc_state<void, _Fp> : public __assoc_sub_state {
801  typedef __assoc_sub_state base;
802
803  _Fp __func_;
804
805public:
806  _LIBCPP_HIDE_FROM_ABI explicit __deferred_assoc_state(_Fp&& __f);
807
808  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __execute() override;
809};
810
811template <class _Fp>
812inline __deferred_assoc_state<void, _Fp>::__deferred_assoc_state(_Fp&& __f) : __func_(std::forward<_Fp>(__f)) {
813  this->__set_deferred();
814}
815
816template <class _Fp>
817void __deferred_assoc_state<void, _Fp>::__execute() {
818#    if _LIBCPP_HAS_EXCEPTIONS
819  try {
820#    endif // _LIBCPP_HAS_EXCEPTIONS
821    __func_();
822    this->set_value();
823#    if _LIBCPP_HAS_EXCEPTIONS
824  } catch (...) {
825    this->set_exception(current_exception());
826  }
827#    endif // _LIBCPP_HAS_EXCEPTIONS
828}
829
830template <class _Rp, class _Fp>
831class __async_assoc_state : public __assoc_state<_Rp> {
832  typedef __assoc_state<_Rp> base;
833
834  _Fp __func_;
835
836  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __on_zero_shared() _NOEXCEPT;
837
838public:
839  _LIBCPP_HIDE_FROM_ABI explicit __async_assoc_state(_Fp&& __f);
840
841  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __execute();
842};
843
844template <class _Rp, class _Fp>
845inline __async_assoc_state<_Rp, _Fp>::__async_assoc_state(_Fp&& __f) : __func_(std::forward<_Fp>(__f)) {}
846
847template <class _Rp, class _Fp>
848void __async_assoc_state<_Rp, _Fp>::__execute() {
849#    if _LIBCPP_HAS_EXCEPTIONS
850  try {
851#    endif // _LIBCPP_HAS_EXCEPTIONS
852    this->set_value(__func_());
853#    if _LIBCPP_HAS_EXCEPTIONS
854  } catch (...) {
855    this->set_exception(current_exception());
856  }
857#    endif // _LIBCPP_HAS_EXCEPTIONS
858}
859
860template <class _Rp, class _Fp>
861void __async_assoc_state<_Rp, _Fp>::__on_zero_shared() _NOEXCEPT {
862  this->wait();
863  base::__on_zero_shared();
864}
865
866template <class _Fp>
867class __async_assoc_state<void, _Fp> : public __assoc_sub_state {
868  typedef __assoc_sub_state base;
869
870  _Fp __func_;
871
872  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __on_zero_shared() _NOEXCEPT override;
873
874public:
875  _LIBCPP_HIDE_FROM_ABI explicit __async_assoc_state(_Fp&& __f);
876
877  _LIBCPP_HIDE_FROM_ABI_VIRTUAL void __execute() override;
878};
879
880template <class _Fp>
881inline __async_assoc_state<void, _Fp>::__async_assoc_state(_Fp&& __f) : __func_(std::forward<_Fp>(__f)) {}
882
883template <class _Fp>
884void __async_assoc_state<void, _Fp>::__execute() {
885#    if _LIBCPP_HAS_EXCEPTIONS
886  try {
887#    endif // _LIBCPP_HAS_EXCEPTIONS
888    __func_();
889    this->set_value();
890#    if _LIBCPP_HAS_EXCEPTIONS
891  } catch (...) {
892    this->set_exception(current_exception());
893  }
894#    endif // _LIBCPP_HAS_EXCEPTIONS
895}
896
897template <class _Fp>
898void __async_assoc_state<void, _Fp>::__on_zero_shared() _NOEXCEPT {
899  this->wait();
900  base::__on_zero_shared();
901}
902
903template <class _Rp>
904class promise;
905template <class _Rp>
906class shared_future;
907
908// future
909
910template <class _Rp>
911class future;
912
913template <class _Rp, class _Fp>
914_LIBCPP_HIDE_FROM_ABI future<_Rp> __make_deferred_assoc_state(_Fp&& __f);
915
916template <class _Rp, class _Fp>
917_LIBCPP_HIDE_FROM_ABI future<_Rp> __make_async_assoc_state(_Fp&& __f);
918
919template <class _Rp>
920class future {
921  __assoc_state<_Rp>* __state_;
922
923  explicit _LIBCPP_HIDE_FROM_ABI future(__assoc_state<_Rp>* __state);
924
925  template <class>
926  friend class promise;
927  template <class>
928  friend class shared_future;
929
930  template <class _R1, class _Fp>
931  friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
932  template <class _R1, class _Fp>
933  friend future<_R1> __make_async_assoc_state(_Fp&& __f);
934
935public:
936  _LIBCPP_HIDE_FROM_ABI future() _NOEXCEPT : __state_(nullptr) {}
937  _LIBCPP_HIDE_FROM_ABI future(future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
938  future(const future&)            = delete;
939  future& operator=(const future&) = delete;
940  _LIBCPP_HIDE_FROM_ABI future& operator=(future&& __rhs) _NOEXCEPT {
941    future(std::move(__rhs)).swap(*this);
942    return *this;
943  }
944
945  _LIBCPP_HIDE_FROM_ABI ~future();
946  _LIBCPP_HIDE_FROM_ABI shared_future<_Rp> share() _NOEXCEPT;
947
948  // retrieving the value
949  _LIBCPP_HIDE_FROM_ABI _Rp get();
950
951  _LIBCPP_HIDE_FROM_ABI void swap(future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
952
953  // functions to check state
954  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
955
956  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
957  template <class _Rep, class _Period>
958  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
959    return __state_->wait_for(__rel_time);
960  }
961  template <class _Clock, class _Duration>
962  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
963    return __state_->wait_until(__abs_time);
964  }
965};
966
967template <class _Rp>
968future<_Rp>::future(__assoc_state<_Rp>* __state) : __state_(__state) {
969  __state_->__attach_future();
970}
971
972struct __release_shared_count {
973  _LIBCPP_HIDE_FROM_ABI void operator()(__shared_count* __p) { __p->__release_shared(); }
974};
975
976template <class _Rp>
977future<_Rp>::~future() {
978  if (__state_)
979    __state_->__release_shared();
980}
981
982template <class _Rp>
983_Rp future<_Rp>::get() {
984  unique_ptr<__shared_count, __release_shared_count> __guard(__state_);
985  __assoc_state<_Rp>* __s = __state_;
986  __state_                = nullptr;
987  return __s->move();
988}
989
990template <class _Rp>
991class future<_Rp&> {
992  __assoc_state<_Rp&>* __state_;
993
994  explicit _LIBCPP_HIDE_FROM_ABI future(__assoc_state<_Rp&>* __state);
995
996  template <class>
997  friend class promise;
998  template <class>
999  friend class shared_future;
1000
1001  template <class _R1, class _Fp>
1002  friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
1003  template <class _R1, class _Fp>
1004  friend future<_R1> __make_async_assoc_state(_Fp&& __f);
1005
1006public:
1007  _LIBCPP_HIDE_FROM_ABI future() _NOEXCEPT : __state_(nullptr) {}
1008  _LIBCPP_HIDE_FROM_ABI future(future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
1009  future(const future&)            = delete;
1010  future& operator=(const future&) = delete;
1011  _LIBCPP_HIDE_FROM_ABI future& operator=(future&& __rhs) _NOEXCEPT {
1012    future(std::move(__rhs)).swap(*this);
1013    return *this;
1014  }
1015
1016  _LIBCPP_HIDE_FROM_ABI ~future();
1017  _LIBCPP_HIDE_FROM_ABI shared_future<_Rp&> share() _NOEXCEPT;
1018
1019  // retrieving the value
1020  _LIBCPP_HIDE_FROM_ABI _Rp& get();
1021
1022  _LIBCPP_HIDE_FROM_ABI void swap(future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1023
1024  // functions to check state
1025  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
1026
1027  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
1028  template <class _Rep, class _Period>
1029  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
1030    return __state_->wait_for(__rel_time);
1031  }
1032  template <class _Clock, class _Duration>
1033  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
1034    return __state_->wait_until(__abs_time);
1035  }
1036};
1037
1038template <class _Rp>
1039future<_Rp&>::future(__assoc_state<_Rp&>* __state) : __state_(__state) {
1040  __state_->__attach_future();
1041}
1042
1043template <class _Rp>
1044future<_Rp&>::~future() {
1045  if (__state_)
1046    __state_->__release_shared();
1047}
1048
1049template <class _Rp>
1050_Rp& future<_Rp&>::get() {
1051  unique_ptr<__shared_count, __release_shared_count> __guard(__state_);
1052  __assoc_state<_Rp&>* __s = __state_;
1053  __state_                 = nullptr;
1054  return __s->copy();
1055}
1056
1057template <>
1058class _LIBCPP_EXPORTED_FROM_ABI future<void> {
1059  __assoc_sub_state* __state_;
1060
1061  explicit future(__assoc_sub_state* __state);
1062
1063  template <class>
1064  friend class promise;
1065  template <class>
1066  friend class shared_future;
1067
1068  template <class _R1, class _Fp>
1069  friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
1070  template <class _R1, class _Fp>
1071  friend future<_R1> __make_async_assoc_state(_Fp&& __f);
1072
1073public:
1074  _LIBCPP_HIDE_FROM_ABI future() _NOEXCEPT : __state_(nullptr) {}
1075  _LIBCPP_HIDE_FROM_ABI future(future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
1076  future(const future&)            = delete;
1077  future& operator=(const future&) = delete;
1078  _LIBCPP_HIDE_FROM_ABI future& operator=(future&& __rhs) _NOEXCEPT {
1079    future(std::move(__rhs)).swap(*this);
1080    return *this;
1081  }
1082
1083  ~future();
1084  _LIBCPP_HIDE_FROM_ABI shared_future<void> share() _NOEXCEPT;
1085
1086  // retrieving the value
1087  void get();
1088
1089  _LIBCPP_HIDE_FROM_ABI void swap(future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1090
1091  // functions to check state
1092  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
1093
1094  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
1095  template <class _Rep, class _Period>
1096  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
1097    return __state_->wait_for(__rel_time);
1098  }
1099  template <class _Clock, class _Duration>
1100  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
1101    return __state_->wait_until(__abs_time);
1102  }
1103};
1104
1105template <class _Rp>
1106inline _LIBCPP_HIDE_FROM_ABI void swap(future<_Rp>& __x, future<_Rp>& __y) _NOEXCEPT {
1107  __x.swap(__y);
1108}
1109
1110// promise<R>
1111
1112template <class _Callable>
1113class packaged_task;
1114
1115template <class _Rp>
1116class promise {
1117  __assoc_state<_Rp>* __state_;
1118
1119  _LIBCPP_HIDE_FROM_ABI explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
1120
1121  template <class>
1122  friend class packaged_task;
1123
1124public:
1125  _LIBCPP_HIDE_FROM_ABI promise();
1126  template <class _Alloc>
1127  _LIBCPP_HIDE_FROM_ABI promise(allocator_arg_t, const _Alloc& __a);
1128  _LIBCPP_HIDE_FROM_ABI promise(promise&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
1129  promise(const promise& __rhs) = delete;
1130  _LIBCPP_HIDE_FROM_ABI ~promise();
1131
1132  // assignment
1133  _LIBCPP_HIDE_FROM_ABI promise& operator=(promise&& __rhs) _NOEXCEPT {
1134    promise(std::move(__rhs)).swap(*this);
1135    return *this;
1136  }
1137  promise& operator=(const promise& __rhs) = delete;
1138
1139  _LIBCPP_HIDE_FROM_ABI void swap(promise& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1140
1141  // retrieving the result
1142  _LIBCPP_HIDE_FROM_ABI future<_Rp> get_future();
1143
1144  // setting the result
1145  _LIBCPP_HIDE_FROM_ABI void set_value(const _Rp& __r);
1146  _LIBCPP_HIDE_FROM_ABI void set_value(_Rp&& __r);
1147  _LIBCPP_HIDE_FROM_ABI void set_exception(exception_ptr __p);
1148
1149  // setting the result with deferred notification
1150  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(const _Rp& __r);
1151  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(_Rp&& __r);
1152  _LIBCPP_HIDE_FROM_ABI void set_exception_at_thread_exit(exception_ptr __p);
1153};
1154
1155template <class _Rp>
1156promise<_Rp>::promise() : __state_(new __assoc_state<_Rp>) {}
1157
1158template <class _Rp>
1159template <class _Alloc>
1160promise<_Rp>::promise(allocator_arg_t, const _Alloc& __a0) {
1161  typedef __assoc_state_alloc<_Rp, _Alloc> _State;
1162  typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
1163  typedef __allocator_destructor<_A2> _D2;
1164  _A2 __a(__a0);
1165  unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
1166  ::new ((void*)std::addressof(*__hold.get())) _State(__a0);
1167  __state_ = std::addressof(*__hold.release());
1168}
1169
1170template <class _Rp>
1171promise<_Rp>::~promise() {
1172  if (__state_) {
1173    if (!__state_->__has_value() && __state_->use_count() > 1)
1174      __state_->set_exception(make_exception_ptr(future_error(make_error_code(future_errc::broken_promise))));
1175    __state_->__release_shared();
1176  }
1177}
1178
1179template <class _Rp>
1180future<_Rp> promise<_Rp>::get_future() {
1181  if (__state_ == nullptr)
1182    std::__throw_future_error(future_errc::no_state);
1183  return future<_Rp>(__state_);
1184}
1185
1186template <class _Rp>
1187void promise<_Rp>::set_value(const _Rp& __r) {
1188  if (__state_ == nullptr)
1189    std::__throw_future_error(future_errc::no_state);
1190  __state_->set_value(__r);
1191}
1192
1193template <class _Rp>
1194void promise<_Rp>::set_value(_Rp&& __r) {
1195  if (__state_ == nullptr)
1196    std::__throw_future_error(future_errc::no_state);
1197  __state_->set_value(std::move(__r));
1198}
1199
1200template <class _Rp>
1201void promise<_Rp>::set_exception(exception_ptr __p) {
1202  _LIBCPP_ASSERT_NON_NULL(__p != nullptr, "promise::set_exception: received nullptr");
1203  if (__state_ == nullptr)
1204    std::__throw_future_error(future_errc::no_state);
1205  __state_->set_exception(__p);
1206}
1207
1208template <class _Rp>
1209void promise<_Rp>::set_value_at_thread_exit(const _Rp& __r) {
1210  if (__state_ == nullptr)
1211    std::__throw_future_error(future_errc::no_state);
1212  __state_->set_value_at_thread_exit(__r);
1213}
1214
1215template <class _Rp>
1216void promise<_Rp>::set_value_at_thread_exit(_Rp&& __r) {
1217  if (__state_ == nullptr)
1218    std::__throw_future_error(future_errc::no_state);
1219  __state_->set_value_at_thread_exit(std::move(__r));
1220}
1221
1222template <class _Rp>
1223void promise<_Rp>::set_exception_at_thread_exit(exception_ptr __p) {
1224  _LIBCPP_ASSERT_NON_NULL(__p != nullptr, "promise::set_exception_at_thread_exit: received nullptr");
1225  if (__state_ == nullptr)
1226    std::__throw_future_error(future_errc::no_state);
1227  __state_->set_exception_at_thread_exit(__p);
1228}
1229
1230// promise<R&>
1231
1232template <class _Rp>
1233class promise<_Rp&> {
1234  __assoc_state<_Rp&>* __state_;
1235
1236  _LIBCPP_HIDE_FROM_ABI explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
1237
1238  template <class>
1239  friend class packaged_task;
1240
1241public:
1242  _LIBCPP_HIDE_FROM_ABI promise();
1243  template <class _Allocator>
1244  _LIBCPP_HIDE_FROM_ABI promise(allocator_arg_t, const _Allocator& __a);
1245  _LIBCPP_HIDE_FROM_ABI promise(promise&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
1246  promise(const promise& __rhs) = delete;
1247  _LIBCPP_HIDE_FROM_ABI ~promise();
1248
1249  // assignment
1250  _LIBCPP_HIDE_FROM_ABI promise& operator=(promise&& __rhs) _NOEXCEPT {
1251    promise(std::move(__rhs)).swap(*this);
1252    return *this;
1253  }
1254  promise& operator=(const promise& __rhs) = delete;
1255
1256  _LIBCPP_HIDE_FROM_ABI void swap(promise& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1257
1258  // retrieving the result
1259  _LIBCPP_HIDE_FROM_ABI future<_Rp&> get_future();
1260
1261  // setting the result
1262  _LIBCPP_HIDE_FROM_ABI void set_value(_Rp& __r);
1263  _LIBCPP_HIDE_FROM_ABI void set_exception(exception_ptr __p);
1264
1265  // setting the result with deferred notification
1266  _LIBCPP_HIDE_FROM_ABI void set_value_at_thread_exit(_Rp&);
1267  _LIBCPP_HIDE_FROM_ABI void set_exception_at_thread_exit(exception_ptr __p);
1268};
1269
1270template <class _Rp>
1271promise<_Rp&>::promise() : __state_(new __assoc_state<_Rp&>) {}
1272
1273template <class _Rp>
1274template <class _Alloc>
1275promise<_Rp&>::promise(allocator_arg_t, const _Alloc& __a0) {
1276  typedef __assoc_state_alloc<_Rp&, _Alloc> _State;
1277  typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
1278  typedef __allocator_destructor<_A2> _D2;
1279  _A2 __a(__a0);
1280  unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
1281  ::new ((void*)std::addressof(*__hold.get())) _State(__a0);
1282  __state_ = std::addressof(*__hold.release());
1283}
1284
1285template <class _Rp>
1286promise<_Rp&>::~promise() {
1287  if (__state_) {
1288    if (!__state_->__has_value() && __state_->use_count() > 1)
1289      __state_->set_exception(make_exception_ptr(future_error(make_error_code(future_errc::broken_promise))));
1290    __state_->__release_shared();
1291  }
1292}
1293
1294template <class _Rp>
1295future<_Rp&> promise<_Rp&>::get_future() {
1296  if (__state_ == nullptr)
1297    std::__throw_future_error(future_errc::no_state);
1298  return future<_Rp&>(__state_);
1299}
1300
1301template <class _Rp>
1302void promise<_Rp&>::set_value(_Rp& __r) {
1303  if (__state_ == nullptr)
1304    std::__throw_future_error(future_errc::no_state);
1305  __state_->set_value(__r);
1306}
1307
1308template <class _Rp>
1309void promise<_Rp&>::set_exception(exception_ptr __p) {
1310  _LIBCPP_ASSERT_NON_NULL(__p != nullptr, "promise::set_exception: received nullptr");
1311  if (__state_ == nullptr)
1312    std::__throw_future_error(future_errc::no_state);
1313  __state_->set_exception(__p);
1314}
1315
1316template <class _Rp>
1317void promise<_Rp&>::set_value_at_thread_exit(_Rp& __r) {
1318  if (__state_ == nullptr)
1319    std::__throw_future_error(future_errc::no_state);
1320  __state_->set_value_at_thread_exit(__r);
1321}
1322
1323template <class _Rp>
1324void promise<_Rp&>::set_exception_at_thread_exit(exception_ptr __p) {
1325  _LIBCPP_ASSERT_NON_NULL(__p != nullptr, "promise::set_exception_at_thread_exit: received nullptr");
1326  if (__state_ == nullptr)
1327    std::__throw_future_error(future_errc::no_state);
1328  __state_->set_exception_at_thread_exit(__p);
1329}
1330
1331// promise<void>
1332
1333template <>
1334class _LIBCPP_EXPORTED_FROM_ABI promise<void> {
1335  __assoc_sub_state* __state_;
1336
1337  _LIBCPP_HIDE_FROM_ABI explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
1338
1339  template <class>
1340  friend class packaged_task;
1341
1342public:
1343  promise();
1344  template <class _Alloc>
1345  _LIBCPP_HIDE_FROM_ABI promise(allocator_arg_t, const _Alloc& __a0) {
1346    typedef __assoc_sub_state_alloc<_Alloc> _State;
1347    typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
1348    typedef __allocator_destructor<_A2> _D2;
1349    _A2 __a(__a0);
1350    unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
1351    ::new ((void*)std::addressof(*__hold.get())) _State(__a0);
1352    __state_ = std::addressof(*__hold.release());
1353  }
1354
1355  _LIBCPP_HIDE_FROM_ABI promise(promise&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) { __rhs.__state_ = nullptr; }
1356  promise(const promise& __rhs) = delete;
1357  ~promise();
1358
1359  // assignment
1360  _LIBCPP_HIDE_FROM_ABI promise& operator=(promise&& __rhs) _NOEXCEPT {
1361    promise(std::move(__rhs)).swap(*this);
1362    return *this;
1363  }
1364  promise& operator=(const promise& __rhs) = delete;
1365
1366  _LIBCPP_HIDE_FROM_ABI void swap(promise& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1367
1368  // retrieving the result
1369  future<void> get_future();
1370
1371  // setting the result
1372  void set_value();
1373  void set_exception(exception_ptr __p);
1374
1375  // setting the result with deferred notification
1376  void set_value_at_thread_exit();
1377  void set_exception_at_thread_exit(exception_ptr __p);
1378};
1379
1380template <class _Rp>
1381inline _LIBCPP_HIDE_FROM_ABI void swap(promise<_Rp>& __x, promise<_Rp>& __y) _NOEXCEPT {
1382  __x.swap(__y);
1383}
1384
1385template <class _Rp, class _Alloc>
1386struct uses_allocator<promise<_Rp>, _Alloc> : public true_type {};
1387
1388// packaged_task
1389
1390template <class _Fp>
1391class __packaged_task_base;
1392
1393template <class _Rp, class... _ArgTypes>
1394class __packaged_task_base<_Rp(_ArgTypes...)> {
1395public:
1396  _LIBCPP_HIDE_FROM_ABI __packaged_task_base() {}
1397  __packaged_task_base(const __packaged_task_base&)            = delete;
1398  __packaged_task_base& operator=(const __packaged_task_base&) = delete;
1399  _LIBCPP_HIDE_FROM_ABI_VIRTUAL
1400  virtual ~__packaged_task_base() {}
1401  virtual void __move_to(__packaged_task_base*) _NOEXCEPT = 0;
1402  virtual void destroy()                                  = 0;
1403  virtual void destroy_deallocate()                       = 0;
1404  virtual _Rp operator()(_ArgTypes&&...)                  = 0;
1405};
1406
1407template <class _FD, class _Alloc, class _FB>
1408class __packaged_task_func;
1409
1410template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1411class __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)> : public __packaged_task_base<_Rp(_ArgTypes...)> {
1412  _LIBCPP_COMPRESSED_PAIR(_Fp, __func_, _Alloc, __alloc_);
1413
1414public:
1415  _LIBCPP_HIDE_FROM_ABI explicit __packaged_task_func(const _Fp& __f) : __func_(__f) {}
1416  _LIBCPP_HIDE_FROM_ABI explicit __packaged_task_func(_Fp&& __f) : __func_(std::move(__f)) {}
1417  _LIBCPP_HIDE_FROM_ABI __packaged_task_func(const _Fp& __f, const _Alloc& __a) : __func_(__f), __alloc_(__a) {}
1418  _LIBCPP_HIDE_FROM_ABI __packaged_task_func(_Fp&& __f, const _Alloc& __a) : __func_(std::move(__f)), __alloc_(__a) {}
1419  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void __move_to(__packaged_task_base<_Rp(_ArgTypes...)>*) _NOEXCEPT;
1420  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void destroy();
1421  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual void destroy_deallocate();
1422  _LIBCPP_HIDE_FROM_ABI_VIRTUAL virtual _Rp operator()(_ArgTypes&&... __args);
1423};
1424
1425template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1426void __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__move_to(
1427    __packaged_task_base<_Rp(_ArgTypes...)>* __p) _NOEXCEPT {
1428  ::new ((void*)__p) __packaged_task_func(std::move(__func_), std::move(__alloc_));
1429}
1430
1431template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1432void __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy() {
1433  __func_.~_Fp();
1434  __alloc_.~_Alloc();
1435}
1436
1437template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1438void __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy_deallocate() {
1439  typedef typename __allocator_traits_rebind<_Alloc, __packaged_task_func>::type _Ap;
1440  typedef allocator_traits<_Ap> _ATraits;
1441  typedef pointer_traits<typename _ATraits::pointer> _PTraits;
1442  _Ap __a(__alloc_);
1443  __func_.~_Fp();
1444  __alloc_.~_Alloc();
1445  __a.deallocate(_PTraits::pointer_to(*this), 1);
1446}
1447
1448template <class _Fp, class _Alloc, class _Rp, class... _ArgTypes>
1449_Rp __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::operator()(_ArgTypes&&... __arg) {
1450  return std::__invoke(__func_, std::forward<_ArgTypes>(__arg)...);
1451}
1452
1453template <class _Callable>
1454class __packaged_task_function;
1455
1456template <class _Rp, class... _ArgTypes>
1457class __packaged_task_function<_Rp(_ArgTypes...)> {
1458  typedef __packaged_task_base<_Rp(_ArgTypes...)> __base;
1459
1460  _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI __base* __get_buf() { return (__base*)&__buf_; }
1461
1462  _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1463  typename aligned_storage<3 * sizeof(void*)>::type __buf_;
1464  _LIBCPP_SUPPRESS_DEPRECATED_POP
1465  __base* __f_;
1466
1467public:
1468  typedef _Rp result_type;
1469
1470  // construct/copy/destroy:
1471  _LIBCPP_HIDE_FROM_ABI __packaged_task_function() _NOEXCEPT : __f_(nullptr) {}
1472  template <class _Fp>
1473  _LIBCPP_HIDE_FROM_ABI __packaged_task_function(_Fp&& __f);
1474  template <class _Fp, class _Alloc>
1475  _LIBCPP_HIDE_FROM_ABI __packaged_task_function(allocator_arg_t, const _Alloc& __a, _Fp&& __f);
1476
1477  _LIBCPP_HIDE_FROM_ABI __packaged_task_function(__packaged_task_function&&) _NOEXCEPT;
1478  _LIBCPP_HIDE_FROM_ABI __packaged_task_function& operator=(__packaged_task_function&&) _NOEXCEPT;
1479
1480  __packaged_task_function(const __packaged_task_function&)            = delete;
1481  __packaged_task_function& operator=(const __packaged_task_function&) = delete;
1482
1483  _LIBCPP_HIDE_FROM_ABI ~__packaged_task_function();
1484
1485  _LIBCPP_HIDE_FROM_ABI void swap(__packaged_task_function&) _NOEXCEPT;
1486
1487  _LIBCPP_HIDE_FROM_ABI _Rp operator()(_ArgTypes...) const;
1488};
1489
1490template <class _Rp, class... _ArgTypes>
1491__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(__packaged_task_function&& __f) _NOEXCEPT {
1492  if (__f.__f_ == nullptr)
1493    __f_ = nullptr;
1494  else if (__f.__f_ == __f.__get_buf()) {
1495    __f.__f_->__move_to(__get_buf());
1496    __f_ = (__base*)&__buf_;
1497  } else {
1498    __f_     = __f.__f_;
1499    __f.__f_ = nullptr;
1500  }
1501}
1502
1503template <class _Rp, class... _ArgTypes>
1504template <class _Fp>
1505__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(_Fp&& __f) : __f_(nullptr) {
1506  typedef __libcpp_remove_reference_t<__decay_t<_Fp> > _FR;
1507  typedef __packaged_task_func<_FR, allocator<_FR>, _Rp(_ArgTypes...)> _FF;
1508  if (sizeof(_FF) <= sizeof(__buf_)) {
1509    ::new ((void*)&__buf_) _FF(std::forward<_Fp>(__f));
1510    __f_ = (__base*)&__buf_;
1511  } else {
1512    typedef allocator<_FF> _Ap;
1513    _Ap __a;
1514    typedef __allocator_destructor<_Ap> _Dp;
1515    unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
1516    ::new ((void*)__hold.get()) _FF(std::forward<_Fp>(__f), allocator<_FR>(__a));
1517    __f_ = __hold.release();
1518  }
1519}
1520
1521template <class _Rp, class... _ArgTypes>
1522template <class _Fp, class _Alloc>
1523__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(allocator_arg_t, const _Alloc& __a0, _Fp&& __f)
1524    : __f_(nullptr) {
1525  typedef __libcpp_remove_reference_t<__decay_t<_Fp> > _FR;
1526  typedef __packaged_task_func<_FR, _Alloc, _Rp(_ArgTypes...)> _FF;
1527  if (sizeof(_FF) <= sizeof(__buf_)) {
1528    __f_ = (__base*)&__buf_;
1529    ::new ((void*)__f_) _FF(std::forward<_Fp>(__f));
1530  } else {
1531    typedef typename __allocator_traits_rebind<_Alloc, _FF>::type _Ap;
1532    _Ap __a(__a0);
1533    typedef __allocator_destructor<_Ap> _Dp;
1534    unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
1535    ::new ((void*)std::addressof(*__hold.get())) _FF(std::forward<_Fp>(__f), _Alloc(__a));
1536    __f_ = std::addressof(*__hold.release());
1537  }
1538}
1539
1540template <class _Rp, class... _ArgTypes>
1541__packaged_task_function<_Rp(_ArgTypes...)>&
1542__packaged_task_function<_Rp(_ArgTypes...)>::operator=(__packaged_task_function&& __f) _NOEXCEPT {
1543  if (__f_ == __get_buf())
1544    __f_->destroy();
1545  else if (__f_)
1546    __f_->destroy_deallocate();
1547  __f_ = nullptr;
1548  if (__f.__f_ == nullptr)
1549    __f_ = nullptr;
1550  else if (__f.__f_ == __f.__get_buf()) {
1551    __f.__f_->__move_to(__get_buf());
1552    __f_ = __get_buf();
1553  } else {
1554    __f_     = __f.__f_;
1555    __f.__f_ = nullptr;
1556  }
1557  return *this;
1558}
1559
1560template <class _Rp, class... _ArgTypes>
1561__packaged_task_function<_Rp(_ArgTypes...)>::~__packaged_task_function() {
1562  if (__f_ == __get_buf())
1563    __f_->destroy();
1564  else if (__f_)
1565    __f_->destroy_deallocate();
1566}
1567
1568template <class _Rp, class... _ArgTypes>
1569_LIBCPP_NO_CFI void __packaged_task_function<_Rp(_ArgTypes...)>::swap(__packaged_task_function& __f) _NOEXCEPT {
1570  if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_) {
1571    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1572    typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
1573    _LIBCPP_SUPPRESS_DEPRECATED_POP
1574    __base* __t = (__base*)&__tempbuf;
1575    __f_->__move_to(__t);
1576    __f_->destroy();
1577    __f_ = nullptr;
1578    __f.__f_->__move_to((__base*)&__buf_);
1579    __f.__f_->destroy();
1580    __f.__f_ = nullptr;
1581    __f_     = (__base*)&__buf_;
1582    __t->__move_to((__base*)&__f.__buf_);
1583    __t->destroy();
1584    __f.__f_ = (__base*)&__f.__buf_;
1585  } else if (__f_ == (__base*)&__buf_) {
1586    __f_->__move_to((__base*)&__f.__buf_);
1587    __f_->destroy();
1588    __f_     = __f.__f_;
1589    __f.__f_ = (__base*)&__f.__buf_;
1590  } else if (__f.__f_ == (__base*)&__f.__buf_) {
1591    __f.__f_->__move_to((__base*)&__buf_);
1592    __f.__f_->destroy();
1593    __f.__f_ = __f_;
1594    __f_     = (__base*)&__buf_;
1595  } else
1596    std::swap(__f_, __f.__f_);
1597}
1598
1599template <class _Rp, class... _ArgTypes>
1600inline _Rp __packaged_task_function<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __arg) const {
1601  return (*__f_)(std::forward<_ArgTypes>(__arg)...);
1602}
1603
1604template <class _Rp, class... _ArgTypes>
1605class packaged_task<_Rp(_ArgTypes...)> {
1606private:
1607  __packaged_task_function<_Rp(_ArgTypes...)> __f_;
1608  promise<_Rp> __p_;
1609
1610public:
1611  // construction and destruction
1612  _LIBCPP_HIDE_FROM_ABI packaged_task() _NOEXCEPT : __p_(nullptr) {}
1613
1614  template <class _Fp, __enable_if_t<!is_same<__remove_cvref_t<_Fp>, packaged_task>::value, int> = 0>
1615  _LIBCPP_HIDE_FROM_ABI explicit packaged_task(_Fp&& __f) : __f_(std::forward<_Fp>(__f)) {}
1616
1617#    if _LIBCPP_STD_VER <= 14
1618  template <class _Fp, class _Allocator, __enable_if_t<!is_same<__remove_cvref_t<_Fp>, packaged_task>::value, int> = 0>
1619  _LIBCPP_HIDE_FROM_ABI packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
1620      : __f_(allocator_arg_t(), __a, std::forward<_Fp>(__f)), __p_(allocator_arg_t(), __a) {}
1621#    endif
1622  // ~packaged_task() = default;
1623
1624  // no copy
1625  packaged_task(const packaged_task&)            = delete;
1626  packaged_task& operator=(const packaged_task&) = delete;
1627
1628  // move support
1629  _LIBCPP_HIDE_FROM_ABI packaged_task(packaged_task&& __other) _NOEXCEPT
1630      : __f_(std::move(__other.__f_)),
1631        __p_(std::move(__other.__p_)) {}
1632  _LIBCPP_HIDE_FROM_ABI packaged_task& operator=(packaged_task&& __other) _NOEXCEPT {
1633    __f_ = std::move(__other.__f_);
1634    __p_ = std::move(__other.__p_);
1635    return *this;
1636  }
1637  _LIBCPP_HIDE_FROM_ABI void swap(packaged_task& __other) _NOEXCEPT {
1638    __f_.swap(__other.__f_);
1639    __p_.swap(__other.__p_);
1640  }
1641
1642  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __p_.__state_ != nullptr; }
1643
1644  // result retrieval
1645  _LIBCPP_HIDE_FROM_ABI future<_Rp> get_future() { return __p_.get_future(); }
1646
1647  // execution
1648  _LIBCPP_HIDE_FROM_ABI void operator()(_ArgTypes... __args);
1649  _LIBCPP_HIDE_FROM_ABI void make_ready_at_thread_exit(_ArgTypes... __args);
1650
1651  _LIBCPP_HIDE_FROM_ABI void reset();
1652};
1653
1654template <class _Rp, class... _ArgTypes>
1655void packaged_task<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __args) {
1656  if (__p_.__state_ == nullptr)
1657    std::__throw_future_error(future_errc::no_state);
1658  if (__p_.__state_->__has_value())
1659    std::__throw_future_error(future_errc::promise_already_satisfied);
1660#    if _LIBCPP_HAS_EXCEPTIONS
1661  try {
1662#    endif // _LIBCPP_HAS_EXCEPTIONS
1663    __p_.set_value(__f_(std::forward<_ArgTypes>(__args)...));
1664#    if _LIBCPP_HAS_EXCEPTIONS
1665  } catch (...) {
1666    __p_.set_exception(current_exception());
1667  }
1668#    endif // _LIBCPP_HAS_EXCEPTIONS
1669}
1670
1671template <class _Rp, class... _ArgTypes>
1672void packaged_task<_Rp(_ArgTypes...)>::make_ready_at_thread_exit(_ArgTypes... __args) {
1673  if (__p_.__state_ == nullptr)
1674    std::__throw_future_error(future_errc::no_state);
1675  if (__p_.__state_->__has_value())
1676    std::__throw_future_error(future_errc::promise_already_satisfied);
1677#    if _LIBCPP_HAS_EXCEPTIONS
1678  try {
1679#    endif // _LIBCPP_HAS_EXCEPTIONS
1680    __p_.set_value_at_thread_exit(__f_(std::forward<_ArgTypes>(__args)...));
1681#    if _LIBCPP_HAS_EXCEPTIONS
1682  } catch (...) {
1683    __p_.set_exception_at_thread_exit(current_exception());
1684  }
1685#    endif // _LIBCPP_HAS_EXCEPTIONS
1686}
1687
1688template <class _Rp, class... _ArgTypes>
1689void packaged_task<_Rp(_ArgTypes...)>::reset() {
1690  if (!valid())
1691    std::__throw_future_error(future_errc::no_state);
1692  __p_ = promise<_Rp>();
1693}
1694
1695template <class... _ArgTypes>
1696class packaged_task<void(_ArgTypes...)> {
1697private:
1698  __packaged_task_function<void(_ArgTypes...)> __f_;
1699  promise<void> __p_;
1700
1701public:
1702  // construction and destruction
1703  _LIBCPP_HIDE_FROM_ABI packaged_task() _NOEXCEPT : __p_(nullptr) {}
1704  template <class _Fp, __enable_if_t<!is_same<__remove_cvref_t<_Fp>, packaged_task>::value, int> = 0>
1705  _LIBCPP_HIDE_FROM_ABI explicit packaged_task(_Fp&& __f) : __f_(std::forward<_Fp>(__f)) {}
1706#    if _LIBCPP_STD_VER <= 14
1707  template <class _Fp, class _Allocator, __enable_if_t<!is_same<__remove_cvref_t<_Fp>, packaged_task>::value, int> = 0>
1708  _LIBCPP_HIDE_FROM_ABI packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
1709      : __f_(allocator_arg_t(), __a, std::forward<_Fp>(__f)), __p_(allocator_arg_t(), __a) {}
1710#    endif
1711  // ~packaged_task() = default;
1712
1713  // no copy
1714  packaged_task(const packaged_task&)            = delete;
1715  packaged_task& operator=(const packaged_task&) = delete;
1716
1717  // move support
1718  _LIBCPP_HIDE_FROM_ABI packaged_task(packaged_task&& __other) _NOEXCEPT
1719      : __f_(std::move(__other.__f_)),
1720        __p_(std::move(__other.__p_)) {}
1721  _LIBCPP_HIDE_FROM_ABI packaged_task& operator=(packaged_task&& __other) _NOEXCEPT {
1722    __f_ = std::move(__other.__f_);
1723    __p_ = std::move(__other.__p_);
1724    return *this;
1725  }
1726  _LIBCPP_HIDE_FROM_ABI void swap(packaged_task& __other) _NOEXCEPT {
1727    __f_.swap(__other.__f_);
1728    __p_.swap(__other.__p_);
1729  }
1730
1731  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __p_.__state_ != nullptr; }
1732
1733  // result retrieval
1734  _LIBCPP_HIDE_FROM_ABI future<void> get_future() { return __p_.get_future(); }
1735
1736  // execution
1737  _LIBCPP_HIDE_FROM_ABI void operator()(_ArgTypes... __args);
1738  _LIBCPP_HIDE_FROM_ABI void make_ready_at_thread_exit(_ArgTypes... __args);
1739
1740  _LIBCPP_HIDE_FROM_ABI void reset();
1741};
1742
1743#    if _LIBCPP_STD_VER >= 17
1744
1745template <class _Rp, class... _Args>
1746packaged_task(_Rp (*)(_Args...)) -> packaged_task<_Rp(_Args...)>;
1747
1748template <class _Fp, class _Stripped = typename __strip_signature<decltype(&_Fp::operator())>::type>
1749packaged_task(_Fp) -> packaged_task<_Stripped>;
1750
1751#    endif
1752
1753template <class... _ArgTypes>
1754void packaged_task<void(_ArgTypes...)>::operator()(_ArgTypes... __args) {
1755  if (__p_.__state_ == nullptr)
1756    std::__throw_future_error(future_errc::no_state);
1757  if (__p_.__state_->__has_value())
1758    std::__throw_future_error(future_errc::promise_already_satisfied);
1759#    if _LIBCPP_HAS_EXCEPTIONS
1760  try {
1761#    endif // _LIBCPP_HAS_EXCEPTIONS
1762    __f_(std::forward<_ArgTypes>(__args)...);
1763    __p_.set_value();
1764#    if _LIBCPP_HAS_EXCEPTIONS
1765  } catch (...) {
1766    __p_.set_exception(current_exception());
1767  }
1768#    endif // _LIBCPP_HAS_EXCEPTIONS
1769}
1770
1771template <class... _ArgTypes>
1772void packaged_task<void(_ArgTypes...)>::make_ready_at_thread_exit(_ArgTypes... __args) {
1773  if (__p_.__state_ == nullptr)
1774    std::__throw_future_error(future_errc::no_state);
1775  if (__p_.__state_->__has_value())
1776    std::__throw_future_error(future_errc::promise_already_satisfied);
1777#    if _LIBCPP_HAS_EXCEPTIONS
1778  try {
1779#    endif // _LIBCPP_HAS_EXCEPTIONS
1780    __f_(std::forward<_ArgTypes>(__args)...);
1781    __p_.set_value_at_thread_exit();
1782#    if _LIBCPP_HAS_EXCEPTIONS
1783  } catch (...) {
1784    __p_.set_exception_at_thread_exit(current_exception());
1785  }
1786#    endif // _LIBCPP_HAS_EXCEPTIONS
1787}
1788
1789template <class... _ArgTypes>
1790void packaged_task<void(_ArgTypes...)>::reset() {
1791  if (!valid())
1792    std::__throw_future_error(future_errc::no_state);
1793  __p_ = promise<void>();
1794}
1795
1796template <class _Rp, class... _ArgTypes>
1797inline _LIBCPP_HIDE_FROM_ABI void
1798swap(packaged_task<_Rp(_ArgTypes...)>& __x, packaged_task<_Rp(_ArgTypes...)>& __y) _NOEXCEPT {
1799  __x.swap(__y);
1800}
1801
1802#    if _LIBCPP_STD_VER <= 14
1803template <class _Callable, class _Alloc>
1804struct uses_allocator<packaged_task<_Callable>, _Alloc> : public true_type {};
1805#    endif
1806
1807template <class _Rp, class _Fp>
1808_LIBCPP_HIDE_FROM_ABI future<_Rp> __make_deferred_assoc_state(_Fp&& __f) {
1809  unique_ptr<__deferred_assoc_state<_Rp, _Fp>, __release_shared_count> __h(
1810      new __deferred_assoc_state<_Rp, _Fp>(std::forward<_Fp>(__f)));
1811  return future<_Rp>(__h.get());
1812}
1813
1814template <class _Rp, class _Fp>
1815_LIBCPP_HIDE_FROM_ABI future<_Rp> __make_async_assoc_state(_Fp&& __f) {
1816  unique_ptr<__async_assoc_state<_Rp, _Fp>, __release_shared_count> __h(
1817      new __async_assoc_state<_Rp, _Fp>(std::forward<_Fp>(__f)));
1818#    if _LIBCPP_HAS_EXCEPTIONS
1819  try {
1820#    endif
1821    std::thread(&__async_assoc_state<_Rp, _Fp>::__execute, __h.get()).detach();
1822#    if _LIBCPP_HAS_EXCEPTIONS
1823  } catch (...) {
1824    __h->__make_ready();
1825    throw;
1826  }
1827#    endif
1828  return future<_Rp>(__h.get());
1829}
1830
1831#    ifndef _LIBCPP_CXX03_LANG
1832
1833template <class _Fp, class... _Args>
1834class _LIBCPP_HIDDEN __async_func {
1835  tuple<_Fp, _Args...> __f_;
1836
1837public:
1838  using _Rp _LIBCPP_NODEBUG = __invoke_result_t<_Fp, _Args...>;
1839
1840  _LIBCPP_HIDE_FROM_ABI explicit __async_func(_Fp&& __f, _Args&&... __args)
1841      : __f_(std::move(__f), std::move(__args)...) {}
1842
1843  _LIBCPP_HIDE_FROM_ABI __async_func(__async_func&& __f) : __f_(std::move(__f.__f_)) {}
1844
1845  _LIBCPP_HIDE_FROM_ABI _Rp operator()() {
1846    typedef typename __make_tuple_indices<1 + sizeof...(_Args), 1>::type _Index;
1847    return __execute(_Index());
1848  }
1849
1850private:
1851  template <size_t... _Indices>
1852  _LIBCPP_HIDE_FROM_ABI _Rp __execute(__tuple_indices<_Indices...>) {
1853    return std::__invoke(std::move(std::get<0>(__f_)), std::move(std::get<_Indices>(__f_))...);
1854  }
1855};
1856
1857inline _LIBCPP_HIDE_FROM_ABI bool __does_policy_contain(launch __policy, launch __value) {
1858  return (int(__policy) & int(__value)) != 0;
1859}
1860
1861template <class _Fp, class... _Args>
1862[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI future<__invoke_result_t<__decay_t<_Fp>, __decay_t<_Args>...> >
1863async(launch __policy, _Fp&& __f, _Args&&... __args) {
1864  typedef __async_func<__decay_t<_Fp>, __decay_t<_Args>...> _BF;
1865  typedef typename _BF::_Rp _Rp;
1866
1867#      if _LIBCPP_HAS_EXCEPTIONS
1868  try {
1869#      endif
1870    if (__does_policy_contain(__policy, launch::async))
1871      return std::__make_async_assoc_state<_Rp>(
1872          _BF(_LIBCPP_AUTO_CAST(std::forward<_Fp>(__f)), _LIBCPP_AUTO_CAST(std::forward<_Args>(__args))...));
1873#      if _LIBCPP_HAS_EXCEPTIONS
1874  } catch (...) {
1875    if (__policy == launch::async)
1876      throw;
1877  }
1878#      endif
1879
1880  if (__does_policy_contain(__policy, launch::deferred))
1881    return std::__make_deferred_assoc_state<_Rp>(
1882        _BF(_LIBCPP_AUTO_CAST(std::forward<_Fp>(__f)), _LIBCPP_AUTO_CAST(std::forward<_Args>(__args))...));
1883  return future<_Rp>{};
1884}
1885
1886template <class _Fp, class... _Args>
1887[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI future<__invoke_result_t<__decay_t<_Fp>, __decay_t<_Args>...> >
1888async(_Fp&& __f, _Args&&... __args) {
1889  return std::async(launch::any, std::forward<_Fp>(__f), std::forward<_Args>(__args)...);
1890}
1891
1892#    endif // C++03
1893
1894// shared_future
1895
1896template <class _Rp>
1897class shared_future {
1898  __assoc_state<_Rp>* __state_;
1899
1900public:
1901  _LIBCPP_HIDE_FROM_ABI shared_future() _NOEXCEPT : __state_(nullptr) {}
1902  _LIBCPP_HIDE_FROM_ABI shared_future(const shared_future& __rhs) _NOEXCEPT : __state_(__rhs.__state_) {
1903    if (__state_)
1904      __state_->__add_shared();
1905  }
1906  _LIBCPP_HIDE_FROM_ABI shared_future(future<_Rp>&& __f) _NOEXCEPT : __state_(__f.__state_) { __f.__state_ = nullptr; }
1907  _LIBCPP_HIDE_FROM_ABI shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) {
1908    __rhs.__state_ = nullptr;
1909  }
1910  _LIBCPP_HIDE_FROM_ABI ~shared_future();
1911  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(const shared_future& __rhs) _NOEXCEPT;
1912  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(shared_future&& __rhs) _NOEXCEPT {
1913    shared_future(std::move(__rhs)).swap(*this);
1914    return *this;
1915  }
1916
1917  // retrieving the value
1918  _LIBCPP_HIDE_FROM_ABI const _Rp& get() const { return __state_->copy(); }
1919
1920  _LIBCPP_HIDE_FROM_ABI void swap(shared_future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1921
1922  // functions to check state
1923  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
1924
1925  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
1926  template <class _Rep, class _Period>
1927  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
1928    return __state_->wait_for(__rel_time);
1929  }
1930  template <class _Clock, class _Duration>
1931  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
1932    return __state_->wait_until(__abs_time);
1933  }
1934};
1935
1936template <class _Rp>
1937shared_future<_Rp>::~shared_future() {
1938  if (__state_)
1939    __state_->__release_shared();
1940}
1941
1942template <class _Rp>
1943shared_future<_Rp>& shared_future<_Rp>::operator=(const shared_future& __rhs) _NOEXCEPT {
1944  if (__rhs.__state_)
1945    __rhs.__state_->__add_shared();
1946  if (__state_)
1947    __state_->__release_shared();
1948  __state_ = __rhs.__state_;
1949  return *this;
1950}
1951
1952template <class _Rp>
1953class shared_future<_Rp&> {
1954  __assoc_state<_Rp&>* __state_;
1955
1956public:
1957  _LIBCPP_HIDE_FROM_ABI shared_future() _NOEXCEPT : __state_(nullptr) {}
1958  _LIBCPP_HIDE_FROM_ABI shared_future(const shared_future& __rhs) : __state_(__rhs.__state_) {
1959    if (__state_)
1960      __state_->__add_shared();
1961  }
1962  _LIBCPP_HIDE_FROM_ABI shared_future(future<_Rp&>&& __f) _NOEXCEPT : __state_(__f.__state_) { __f.__state_ = nullptr; }
1963  _LIBCPP_HIDE_FROM_ABI shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) {
1964    __rhs.__state_ = nullptr;
1965  }
1966  _LIBCPP_HIDE_FROM_ABI ~shared_future();
1967  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(const shared_future& __rhs);
1968  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(shared_future&& __rhs) _NOEXCEPT {
1969    shared_future(std::move(__rhs)).swap(*this);
1970    return *this;
1971  }
1972
1973  // retrieving the value
1974  _LIBCPP_HIDE_FROM_ABI _Rp& get() const { return __state_->copy(); }
1975
1976  _LIBCPP_HIDE_FROM_ABI void swap(shared_future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
1977
1978  // functions to check state
1979  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
1980
1981  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
1982  template <class _Rep, class _Period>
1983  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
1984    return __state_->wait_for(__rel_time);
1985  }
1986  template <class _Clock, class _Duration>
1987  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
1988    return __state_->wait_until(__abs_time);
1989  }
1990};
1991
1992template <class _Rp>
1993shared_future<_Rp&>::~shared_future() {
1994  if (__state_)
1995    __state_->__release_shared();
1996}
1997
1998template <class _Rp>
1999shared_future<_Rp&>& shared_future<_Rp&>::operator=(const shared_future& __rhs) {
2000  if (__rhs.__state_)
2001    __rhs.__state_->__add_shared();
2002  if (__state_)
2003    __state_->__release_shared();
2004  __state_ = __rhs.__state_;
2005  return *this;
2006}
2007
2008template <>
2009class _LIBCPP_EXPORTED_FROM_ABI shared_future<void> {
2010  __assoc_sub_state* __state_;
2011
2012public:
2013  _LIBCPP_HIDE_FROM_ABI shared_future() _NOEXCEPT : __state_(nullptr) {}
2014  _LIBCPP_HIDE_FROM_ABI shared_future(const shared_future& __rhs) : __state_(__rhs.__state_) {
2015    if (__state_)
2016      __state_->__add_shared();
2017  }
2018  _LIBCPP_HIDE_FROM_ABI shared_future(future<void>&& __f) _NOEXCEPT : __state_(__f.__state_) { __f.__state_ = nullptr; }
2019  _LIBCPP_HIDE_FROM_ABI shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_) {
2020    __rhs.__state_ = nullptr;
2021  }
2022  ~shared_future();
2023  shared_future& operator=(const shared_future& __rhs);
2024  _LIBCPP_HIDE_FROM_ABI shared_future& operator=(shared_future&& __rhs) _NOEXCEPT {
2025    shared_future(std::move(__rhs)).swap(*this);
2026    return *this;
2027  }
2028
2029  // retrieving the value
2030  _LIBCPP_HIDE_FROM_ABI void get() const { __state_->copy(); }
2031
2032  _LIBCPP_HIDE_FROM_ABI void swap(shared_future& __rhs) _NOEXCEPT { std::swap(__state_, __rhs.__state_); }
2033
2034  // functions to check state
2035  _LIBCPP_HIDE_FROM_ABI bool valid() const _NOEXCEPT { return __state_ != nullptr; }
2036
2037  _LIBCPP_HIDE_FROM_ABI void wait() const { __state_->wait(); }
2038  template <class _Rep, class _Period>
2039  _LIBCPP_HIDE_FROM_ABI future_status wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const {
2040    return __state_->wait_for(__rel_time);
2041  }
2042  template <class _Clock, class _Duration>
2043  _LIBCPP_HIDE_FROM_ABI future_status wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const {
2044    return __state_->wait_until(__abs_time);
2045  }
2046};
2047
2048template <class _Rp>
2049inline _LIBCPP_HIDE_FROM_ABI void swap(shared_future<_Rp>& __x, shared_future<_Rp>& __y) _NOEXCEPT {
2050  __x.swap(__y);
2051}
2052
2053template <class _Rp>
2054inline shared_future<_Rp> future<_Rp>::share() _NOEXCEPT {
2055  return shared_future<_Rp>(std::move(*this));
2056}
2057
2058template <class _Rp>
2059inline shared_future<_Rp&> future<_Rp&>::share() _NOEXCEPT {
2060  return shared_future<_Rp&>(std::move(*this));
2061}
2062
2063inline shared_future<void> future<void>::share() _NOEXCEPT { return shared_future<void>(std::move(*this)); }
2064
2065_LIBCPP_END_NAMESPACE_STD
2066
2067_LIBCPP_POP_MACROS
2068
2069#  endif // _LIBCPP_HAS_THREADS
2070
2071#  if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 17
2072#    include <chrono>
2073#  endif
2074
2075#  if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
2076#    include <atomic>
2077#    include <cstdlib>
2078#    include <exception>
2079#    include <iosfwd>
2080#    include <system_error>
2081#    include <thread>
2082#  endif
2083#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
2084
2085#endif // _LIBCPP_FUTURE
2086