1 // <future> -*- C++ -*- 2 3 // Copyright (C) 2009-2014 Free Software Foundation, Inc. 4 // 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) 9 // any later version. 10 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. 15 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. 19 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/>. 24 25 /** @file include/future 26 * This is a Standard C++ Library header. 27 */ 28 29 #ifndef _GLIBCXX_FUTURE 30 #define _GLIBCXX_FUTURE 1 31 32 #pragma GCC system_header 33 34 #if __cplusplus < 201103L 35 # include <bits/c++0x_warning.h> 36 #else 37 38 #include <functional> 39 #include <mutex> 40 #include <thread> 41 #include <condition_variable> 42 #include <system_error> 43 #include <atomic> 44 #include <bits/functexcept.h> 45 #include <bits/unique_ptr.h> 46 #include <bits/shared_ptr.h> 47 #include <bits/uses_allocator.h> 48 #include <bits/alloc_traits.h> 49 #include <ext/aligned_buffer.h> 50 51 namespace std _GLIBCXX_VISIBILITY(default) 52 { 53 _GLIBCXX_BEGIN_NAMESPACE_VERSION 54 55 /** 56 * @defgroup futures Futures 57 * @ingroup concurrency 58 * 59 * Classes for futures support. 60 * @{ 61 */ 62 63 /// Error code for futures 64 enum class future_errc 65 { 66 future_already_retrieved = 1, 67 promise_already_satisfied, 68 no_state, 69 broken_promise 70 }; 71 72 /// Specialization. 73 template<> 74 struct is_error_code_enum<future_errc> : public true_type { }; 75 76 /// Points to a statically-allocated object derived from error_category. 77 const error_category& 78 future_category() noexcept; 79 80 /// Overload for make_error_code. 81 inline error_code 82 make_error_code(future_errc __errc) noexcept 83 { return error_code(static_cast<int>(__errc), future_category()); } 84 85 /// Overload for make_error_condition. 86 inline error_condition 87 make_error_condition(future_errc __errc) noexcept 88 { return error_condition(static_cast<int>(__errc), future_category()); } 89 90 /** 91 * @brief Exception type thrown by futures. 92 * @ingroup exceptions 93 */ 94 class future_error : public logic_error 95 { 96 error_code _M_code; 97 98 public: 99 explicit future_error(error_code __ec) 100 : logic_error("std::future_error"), _M_code(__ec) 101 { } 102 103 virtual ~future_error() noexcept; 104 105 virtual const char* 106 what() const noexcept; 107 108 const error_code& 109 code() const noexcept { return _M_code; } 110 }; 111 112 // Forward declarations. 113 template<typename _Res> 114 class future; 115 116 template<typename _Res> 117 class shared_future; 118 119 template<typename _Signature> 120 class packaged_task; 121 122 template<typename _Res> 123 class promise; 124 125 /// Launch code for futures 126 enum class launch 127 { 128 async = 1, 129 deferred = 2 130 }; 131 132 constexpr launch operator&(launch __x, launch __y) 133 { 134 return static_cast<launch>( 135 static_cast<int>(__x) & static_cast<int>(__y)); 136 } 137 138 constexpr launch operator|(launch __x, launch __y) 139 { 140 return static_cast<launch>( 141 static_cast<int>(__x) | static_cast<int>(__y)); 142 } 143 144 constexpr launch operator^(launch __x, launch __y) 145 { 146 return static_cast<launch>( 147 static_cast<int>(__x) ^ static_cast<int>(__y)); 148 } 149 150 constexpr launch operator~(launch __x) 151 { return static_cast<launch>(~static_cast<int>(__x)); } 152 153 inline launch& operator&=(launch& __x, launch __y) 154 { return __x = __x & __y; } 155 156 inline launch& operator|=(launch& __x, launch __y) 157 { return __x = __x | __y; } 158 159 inline launch& operator^=(launch& __x, launch __y) 160 { return __x = __x ^ __y; } 161 162 /// Status code for futures 163 enum class future_status 164 { 165 ready, 166 timeout, 167 deferred 168 }; 169 170 template<typename _Fn, typename... _Args> 171 future<typename result_of<_Fn(_Args...)>::type> 172 async(launch __policy, _Fn&& __fn, _Args&&... __args); 173 174 template<typename _Fn, typename... _Args> 175 future<typename result_of<_Fn(_Args...)>::type> 176 async(_Fn&& __fn, _Args&&... __args); 177 178 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) \ 179 && (ATOMIC_INT_LOCK_FREE > 1) 180 181 /// Base class and enclosing scope. 182 struct __future_base 183 { 184 /// Base class for results. 185 struct _Result_base 186 { 187 exception_ptr _M_error; 188 189 _Result_base(const _Result_base&) = delete; 190 _Result_base& operator=(const _Result_base&) = delete; 191 192 // _M_destroy() allows derived classes to control deallocation 193 virtual void _M_destroy() = 0; 194 195 struct _Deleter 196 { 197 void operator()(_Result_base* __fr) const { __fr->_M_destroy(); } 198 }; 199 200 protected: 201 _Result_base(); 202 virtual ~_Result_base(); 203 }; 204 205 /// Result. 206 template<typename _Res> 207 struct _Result : _Result_base 208 { 209 private: 210 __gnu_cxx::__aligned_buffer<_Res> _M_storage; 211 bool _M_initialized; 212 213 public: 214 typedef _Res result_type; 215 216 _Result() noexcept : _M_initialized() { } 217 218 ~_Result() 219 { 220 if (_M_initialized) 221 _M_value().~_Res(); 222 } 223 224 // Return lvalue, future will add const or rvalue-reference 225 _Res& 226 _M_value() noexcept { return *_M_storage._M_ptr(); } 227 228 void 229 _M_set(const _Res& __res) 230 { 231 ::new (_M_storage._M_addr()) _Res(__res); 232 _M_initialized = true; 233 } 234 235 void 236 _M_set(_Res&& __res) 237 { 238 ::new (_M_storage._M_addr()) _Res(std::move(__res)); 239 _M_initialized = true; 240 } 241 242 private: 243 void _M_destroy() { delete this; } 244 }; 245 246 /// A unique_ptr based on the instantiating type. 247 template<typename _Res> 248 using _Ptr = unique_ptr<_Res, _Result_base::_Deleter>; 249 250 /// Result_alloc. 251 template<typename _Res, typename _Alloc> 252 struct _Result_alloc final : _Result<_Res>, _Alloc 253 { 254 typedef typename allocator_traits<_Alloc>::template 255 rebind_alloc<_Result_alloc> __allocator_type; 256 257 explicit 258 _Result_alloc(const _Alloc& __a) : _Result<_Res>(), _Alloc(__a) 259 { } 260 261 private: 262 void _M_destroy() 263 { 264 typedef allocator_traits<__allocator_type> __traits; 265 __allocator_type __a(*this); 266 __traits::destroy(__a, this); 267 __traits::deallocate(__a, this, 1); 268 } 269 }; 270 271 template<typename _Res, typename _Allocator> 272 static _Ptr<_Result_alloc<_Res, _Allocator>> 273 _S_allocate_result(const _Allocator& __a) 274 { 275 typedef _Result_alloc<_Res, _Allocator> __result_type; 276 typedef allocator_traits<typename __result_type::__allocator_type> 277 __traits; 278 typename __traits::allocator_type __a2(__a); 279 __result_type* __p = __traits::allocate(__a2, 1); 280 __try 281 { 282 __traits::construct(__a2, __p, __a); 283 } 284 __catch(...) 285 { 286 __traits::deallocate(__a2, __p, 1); 287 __throw_exception_again; 288 } 289 return _Ptr<__result_type>(__p); 290 } 291 292 template<typename _Res, typename _Tp> 293 static _Ptr<_Result<_Res>> 294 _S_allocate_result(const std::allocator<_Tp>& __a) 295 { 296 return _Ptr<_Result<_Res>>(new _Result<_Res>); 297 } 298 299 /// Base class for state between a promise and one or more 300 /// associated futures. 301 class _State_baseV2 302 { 303 typedef _Ptr<_Result_base> _Ptr_type; 304 305 _Ptr_type _M_result; 306 mutex _M_mutex; 307 condition_variable _M_cond; 308 atomic_flag _M_retrieved; 309 once_flag _M_once; 310 311 public: 312 _State_baseV2() noexcept : _M_result(), _M_retrieved(ATOMIC_FLAG_INIT) 313 { } 314 _State_baseV2(const _State_baseV2&) = delete; 315 _State_baseV2& operator=(const _State_baseV2&) = delete; 316 virtual ~_State_baseV2() = default; 317 318 _Result_base& 319 wait() 320 { 321 _M_complete_async(); 322 unique_lock<mutex> __lock(_M_mutex); 323 _M_cond.wait(__lock, [&] { return _M_ready(); }); 324 return *_M_result; 325 } 326 327 template<typename _Rep, typename _Period> 328 future_status 329 wait_for(const chrono::duration<_Rep, _Period>& __rel) 330 { 331 unique_lock<mutex> __lock(_M_mutex); 332 if (_M_ready()) 333 return future_status::ready; 334 if (_M_has_deferred()) 335 return future_status::deferred; 336 if (_M_cond.wait_for(__lock, __rel, [&] { return _M_ready(); })) 337 { 338 // _GLIBCXX_RESOLVE_LIB_DEFECTS 339 // 2100. timed waiting functions must also join 340 _M_complete_async(); 341 return future_status::ready; 342 } 343 return future_status::timeout; 344 } 345 346 template<typename _Clock, typename _Duration> 347 future_status 348 wait_until(const chrono::time_point<_Clock, _Duration>& __abs) 349 { 350 unique_lock<mutex> __lock(_M_mutex); 351 if (_M_ready()) 352 return future_status::ready; 353 if (_M_has_deferred()) 354 return future_status::deferred; 355 if (_M_cond.wait_until(__lock, __abs, [&] { return _M_ready(); })) 356 { 357 // _GLIBCXX_RESOLVE_LIB_DEFECTS 358 // 2100. timed waiting functions must also join 359 _M_complete_async(); 360 return future_status::ready; 361 } 362 return future_status::timeout; 363 } 364 365 void 366 _M_set_result(function<_Ptr_type()> __res, bool __ignore_failure = false) 367 { 368 bool __set = __ignore_failure; 369 // all calls to this function are serialized, 370 // side-effects of invoking __res only happen once 371 call_once(_M_once, &_State_baseV2::_M_do_set, this, ref(__res), 372 ref(__set)); 373 if (!__set) 374 __throw_future_error(int(future_errc::promise_already_satisfied)); 375 } 376 377 void 378 _M_break_promise(_Ptr_type __res) 379 { 380 if (static_cast<bool>(__res)) 381 { 382 error_code __ec(make_error_code(future_errc::broken_promise)); 383 __res->_M_error = make_exception_ptr(future_error(__ec)); 384 { 385 lock_guard<mutex> __lock(_M_mutex); 386 _M_result.swap(__res); 387 } 388 _M_cond.notify_all(); 389 } 390 } 391 392 // Called when this object is passed to a future. 393 void 394 _M_set_retrieved_flag() 395 { 396 if (_M_retrieved.test_and_set()) 397 __throw_future_error(int(future_errc::future_already_retrieved)); 398 } 399 400 template<typename _Res, typename _Arg> 401 struct _Setter; 402 403 // set lvalues 404 template<typename _Res, typename _Arg> 405 struct _Setter<_Res, _Arg&> 406 { 407 // check this is only used by promise<R>::set_value(const R&) 408 // or promise<R>::set_value(R&) 409 static_assert(is_same<_Res, _Arg&>::value // promise<R&> 410 || is_same<const _Res, _Arg>::value, // promise<R> 411 "Invalid specialisation"); 412 413 typename promise<_Res>::_Ptr_type operator()() 414 { 415 _State_baseV2::_S_check(_M_promise->_M_future); 416 _M_promise->_M_storage->_M_set(_M_arg); 417 return std::move(_M_promise->_M_storage); 418 } 419 promise<_Res>* _M_promise; 420 _Arg& _M_arg; 421 }; 422 423 // set rvalues 424 template<typename _Res> 425 struct _Setter<_Res, _Res&&> 426 { 427 typename promise<_Res>::_Ptr_type operator()() 428 { 429 _State_baseV2::_S_check(_M_promise->_M_future); 430 _M_promise->_M_storage->_M_set(std::move(_M_arg)); 431 return std::move(_M_promise->_M_storage); 432 } 433 promise<_Res>* _M_promise; 434 _Res& _M_arg; 435 }; 436 437 struct __exception_ptr_tag { }; 438 439 // set exceptions 440 template<typename _Res> 441 struct _Setter<_Res, __exception_ptr_tag> 442 { 443 typename promise<_Res>::_Ptr_type operator()() 444 { 445 _State_baseV2::_S_check(_M_promise->_M_future); 446 _M_promise->_M_storage->_M_error = _M_ex; 447 return std::move(_M_promise->_M_storage); 448 } 449 450 promise<_Res>* _M_promise; 451 exception_ptr& _M_ex; 452 }; 453 454 template<typename _Res, typename _Arg> 455 static _Setter<_Res, _Arg&&> 456 __setter(promise<_Res>* __prom, _Arg&& __arg) 457 { 458 return _Setter<_Res, _Arg&&>{ __prom, __arg }; 459 } 460 461 template<typename _Res> 462 static _Setter<_Res, __exception_ptr_tag> 463 __setter(exception_ptr& __ex, promise<_Res>* __prom) 464 { 465 return _Setter<_Res, __exception_ptr_tag>{ __prom, __ex }; 466 } 467 468 static _Setter<void, void> 469 __setter(promise<void>* __prom); 470 471 template<typename _Tp> 472 static void 473 _S_check(const shared_ptr<_Tp>& __p) 474 { 475 if (!static_cast<bool>(__p)) 476 __throw_future_error((int)future_errc::no_state); 477 } 478 479 private: 480 void 481 _M_do_set(function<_Ptr_type()>& __f, bool& __set) 482 { 483 _Ptr_type __res = __f(); 484 { 485 lock_guard<mutex> __lock(_M_mutex); 486 _M_result.swap(__res); 487 } 488 _M_cond.notify_all(); 489 __set = true; 490 } 491 492 bool _M_ready() const noexcept { return static_cast<bool>(_M_result); } 493 494 // Wait for completion of async function. 495 virtual void _M_complete_async() { } 496 497 // Return true if state contains a deferred function. 498 virtual bool _M_has_deferred() const { return false; } 499 }; 500 501 #ifdef _GLIBCXX_ASYNC_ABI_COMPAT 502 class _State_base; 503 class _Async_state_common; 504 #else 505 using _State_base = _State_baseV2; 506 class _Async_state_commonV2; 507 #endif 508 509 template<typename _BoundFn, typename = typename _BoundFn::result_type> 510 class _Deferred_state; 511 512 template<typename _BoundFn, typename = typename _BoundFn::result_type> 513 class _Async_state_impl; 514 515 template<typename _Signature> 516 class _Task_state_base; 517 518 template<typename _Fn, typename _Alloc, typename _Signature> 519 class _Task_state; 520 521 template<typename _BoundFn> 522 static std::shared_ptr<_State_base> 523 _S_make_deferred_state(_BoundFn&& __fn); 524 525 template<typename _BoundFn> 526 static std::shared_ptr<_State_base> 527 _S_make_async_state(_BoundFn&& __fn); 528 529 template<typename _Res_ptr, 530 typename _Res = typename _Res_ptr::element_type::result_type> 531 struct _Task_setter; 532 533 template<typename _Res_ptr, typename _BoundFn> 534 static _Task_setter<_Res_ptr> 535 _S_task_setter(_Res_ptr& __ptr, _BoundFn&& __call) 536 { 537 return _Task_setter<_Res_ptr>{ __ptr, std::ref(__call) }; 538 } 539 }; 540 541 /// Partial specialization for reference types. 542 template<typename _Res> 543 struct __future_base::_Result<_Res&> : __future_base::_Result_base 544 { 545 typedef _Res& result_type; 546 547 _Result() noexcept : _M_value_ptr() { } 548 549 void _M_set(_Res& __res) noexcept { _M_value_ptr = &__res; } 550 551 _Res& _M_get() noexcept { return *_M_value_ptr; } 552 553 private: 554 _Res* _M_value_ptr; 555 556 void _M_destroy() { delete this; } 557 }; 558 559 /// Explicit specialization for void. 560 template<> 561 struct __future_base::_Result<void> : __future_base::_Result_base 562 { 563 typedef void result_type; 564 565 private: 566 void _M_destroy() { delete this; } 567 }; 568 569 #ifndef _GLIBCXX_ASYNC_ABI_COMPAT 570 571 /// Common implementation for future and shared_future. 572 template<typename _Res> 573 class __basic_future : public __future_base 574 { 575 protected: 576 typedef shared_ptr<_State_base> __state_type; 577 typedef __future_base::_Result<_Res>& __result_type; 578 579 private: 580 __state_type _M_state; 581 582 public: 583 // Disable copying. 584 __basic_future(const __basic_future&) = delete; 585 __basic_future& operator=(const __basic_future&) = delete; 586 587 bool 588 valid() const noexcept { return static_cast<bool>(_M_state); } 589 590 void 591 wait() const 592 { 593 _State_base::_S_check(_M_state); 594 _M_state->wait(); 595 } 596 597 template<typename _Rep, typename _Period> 598 future_status 599 wait_for(const chrono::duration<_Rep, _Period>& __rel) const 600 { 601 _State_base::_S_check(_M_state); 602 return _M_state->wait_for(__rel); 603 } 604 605 template<typename _Clock, typename _Duration> 606 future_status 607 wait_until(const chrono::time_point<_Clock, _Duration>& __abs) const 608 { 609 _State_base::_S_check(_M_state); 610 return _M_state->wait_until(__abs); 611 } 612 613 protected: 614 /// Wait for the state to be ready and rethrow any stored exception 615 __result_type 616 _M_get_result() const 617 { 618 _State_base::_S_check(_M_state); 619 _Result_base& __res = _M_state->wait(); 620 if (!(__res._M_error == 0)) 621 rethrow_exception(__res._M_error); 622 return static_cast<__result_type>(__res); 623 } 624 625 void _M_swap(__basic_future& __that) noexcept 626 { 627 _M_state.swap(__that._M_state); 628 } 629 630 // Construction of a future by promise::get_future() 631 explicit 632 __basic_future(const __state_type& __state) : _M_state(__state) 633 { 634 _State_base::_S_check(_M_state); 635 _M_state->_M_set_retrieved_flag(); 636 } 637 638 // Copy construction from a shared_future 639 explicit 640 __basic_future(const shared_future<_Res>&) noexcept; 641 642 // Move construction from a shared_future 643 explicit 644 __basic_future(shared_future<_Res>&&) noexcept; 645 646 // Move construction from a future 647 explicit 648 __basic_future(future<_Res>&&) noexcept; 649 650 constexpr __basic_future() noexcept : _M_state() { } 651 652 struct _Reset 653 { 654 explicit _Reset(__basic_future& __fut) noexcept : _M_fut(__fut) { } 655 ~_Reset() { _M_fut._M_state.reset(); } 656 __basic_future& _M_fut; 657 }; 658 }; 659 660 661 /// Primary template for future. 662 template<typename _Res> 663 class future : public __basic_future<_Res> 664 { 665 friend class promise<_Res>; 666 template<typename> friend class packaged_task; 667 template<typename _Fn, typename... _Args> 668 friend future<typename result_of<_Fn(_Args...)>::type> 669 async(launch, _Fn&&, _Args&&...); 670 671 typedef __basic_future<_Res> _Base_type; 672 typedef typename _Base_type::__state_type __state_type; 673 674 explicit 675 future(const __state_type& __state) : _Base_type(__state) { } 676 677 public: 678 constexpr future() noexcept : _Base_type() { } 679 680 /// Move constructor 681 future(future&& __uf) noexcept : _Base_type(std::move(__uf)) { } 682 683 // Disable copying 684 future(const future&) = delete; 685 future& operator=(const future&) = delete; 686 687 future& operator=(future&& __fut) noexcept 688 { 689 future(std::move(__fut))._M_swap(*this); 690 return *this; 691 } 692 693 /// Retrieving the value 694 _Res 695 get() 696 { 697 typename _Base_type::_Reset __reset(*this); 698 return std::move(this->_M_get_result()._M_value()); 699 } 700 701 shared_future<_Res> share(); 702 }; 703 704 /// Partial specialization for future<R&> 705 template<typename _Res> 706 class future<_Res&> : public __basic_future<_Res&> 707 { 708 friend class promise<_Res&>; 709 template<typename> friend class packaged_task; 710 template<typename _Fn, typename... _Args> 711 friend future<typename result_of<_Fn(_Args...)>::type> 712 async(launch, _Fn&&, _Args&&...); 713 714 typedef __basic_future<_Res&> _Base_type; 715 typedef typename _Base_type::__state_type __state_type; 716 717 explicit 718 future(const __state_type& __state) : _Base_type(__state) { } 719 720 public: 721 constexpr future() noexcept : _Base_type() { } 722 723 /// Move constructor 724 future(future&& __uf) noexcept : _Base_type(std::move(__uf)) { } 725 726 // Disable copying 727 future(const future&) = delete; 728 future& operator=(const future&) = delete; 729 730 future& operator=(future&& __fut) noexcept 731 { 732 future(std::move(__fut))._M_swap(*this); 733 return *this; 734 } 735 736 /// Retrieving the value 737 _Res& 738 get() 739 { 740 typename _Base_type::_Reset __reset(*this); 741 return this->_M_get_result()._M_get(); 742 } 743 744 shared_future<_Res&> share(); 745 }; 746 747 /// Explicit specialization for future<void> 748 template<> 749 class future<void> : public __basic_future<void> 750 { 751 friend class promise<void>; 752 template<typename> friend class packaged_task; 753 template<typename _Fn, typename... _Args> 754 friend future<typename result_of<_Fn(_Args...)>::type> 755 async(launch, _Fn&&, _Args&&...); 756 757 typedef __basic_future<void> _Base_type; 758 typedef typename _Base_type::__state_type __state_type; 759 760 explicit 761 future(const __state_type& __state) : _Base_type(__state) { } 762 763 public: 764 constexpr future() noexcept : _Base_type() { } 765 766 /// Move constructor 767 future(future&& __uf) noexcept : _Base_type(std::move(__uf)) { } 768 769 // Disable copying 770 future(const future&) = delete; 771 future& operator=(const future&) = delete; 772 773 future& operator=(future&& __fut) noexcept 774 { 775 future(std::move(__fut))._M_swap(*this); 776 return *this; 777 } 778 779 /// Retrieving the value 780 void 781 get() 782 { 783 typename _Base_type::_Reset __reset(*this); 784 this->_M_get_result(); 785 } 786 787 shared_future<void> share(); 788 }; 789 790 791 /// Primary template for shared_future. 792 template<typename _Res> 793 class shared_future : public __basic_future<_Res> 794 { 795 typedef __basic_future<_Res> _Base_type; 796 797 public: 798 constexpr shared_future() noexcept : _Base_type() { } 799 800 /// Copy constructor 801 shared_future(const shared_future& __sf) : _Base_type(__sf) { } 802 803 /// Construct from a future rvalue 804 shared_future(future<_Res>&& __uf) noexcept 805 : _Base_type(std::move(__uf)) 806 { } 807 808 /// Construct from a shared_future rvalue 809 shared_future(shared_future&& __sf) noexcept 810 : _Base_type(std::move(__sf)) 811 { } 812 813 shared_future& operator=(const shared_future& __sf) 814 { 815 shared_future(__sf)._M_swap(*this); 816 return *this; 817 } 818 819 shared_future& operator=(shared_future&& __sf) noexcept 820 { 821 shared_future(std::move(__sf))._M_swap(*this); 822 return *this; 823 } 824 825 /// Retrieving the value 826 const _Res& 827 get() const { return this->_M_get_result()._M_value(); } 828 }; 829 830 /// Partial specialization for shared_future<R&> 831 template<typename _Res> 832 class shared_future<_Res&> : public __basic_future<_Res&> 833 { 834 typedef __basic_future<_Res&> _Base_type; 835 836 public: 837 constexpr shared_future() noexcept : _Base_type() { } 838 839 /// Copy constructor 840 shared_future(const shared_future& __sf) : _Base_type(__sf) { } 841 842 /// Construct from a future rvalue 843 shared_future(future<_Res&>&& __uf) noexcept 844 : _Base_type(std::move(__uf)) 845 { } 846 847 /// Construct from a shared_future rvalue 848 shared_future(shared_future&& __sf) noexcept 849 : _Base_type(std::move(__sf)) 850 { } 851 852 shared_future& operator=(const shared_future& __sf) 853 { 854 shared_future(__sf)._M_swap(*this); 855 return *this; 856 } 857 858 shared_future& operator=(shared_future&& __sf) noexcept 859 { 860 shared_future(std::move(__sf))._M_swap(*this); 861 return *this; 862 } 863 864 /// Retrieving the value 865 _Res& 866 get() const { return this->_M_get_result()._M_get(); } 867 }; 868 869 /// Explicit specialization for shared_future<void> 870 template<> 871 class shared_future<void> : public __basic_future<void> 872 { 873 typedef __basic_future<void> _Base_type; 874 875 public: 876 constexpr shared_future() noexcept : _Base_type() { } 877 878 /// Copy constructor 879 shared_future(const shared_future& __sf) : _Base_type(__sf) { } 880 881 /// Construct from a future rvalue 882 shared_future(future<void>&& __uf) noexcept 883 : _Base_type(std::move(__uf)) 884 { } 885 886 /// Construct from a shared_future rvalue 887 shared_future(shared_future&& __sf) noexcept 888 : _Base_type(std::move(__sf)) 889 { } 890 891 shared_future& operator=(const shared_future& __sf) 892 { 893 shared_future(__sf)._M_swap(*this); 894 return *this; 895 } 896 897 shared_future& operator=(shared_future&& __sf) noexcept 898 { 899 shared_future(std::move(__sf))._M_swap(*this); 900 return *this; 901 } 902 903 // Retrieving the value 904 void 905 get() const { this->_M_get_result(); } 906 }; 907 908 // Now we can define the protected __basic_future constructors. 909 template<typename _Res> 910 inline __basic_future<_Res>:: 911 __basic_future(const shared_future<_Res>& __sf) noexcept 912 : _M_state(__sf._M_state) 913 { } 914 915 template<typename _Res> 916 inline __basic_future<_Res>:: 917 __basic_future(shared_future<_Res>&& __sf) noexcept 918 : _M_state(std::move(__sf._M_state)) 919 { } 920 921 template<typename _Res> 922 inline __basic_future<_Res>:: 923 __basic_future(future<_Res>&& __uf) noexcept 924 : _M_state(std::move(__uf._M_state)) 925 { } 926 927 template<typename _Res> 928 inline shared_future<_Res> 929 future<_Res>::share() 930 { return shared_future<_Res>(std::move(*this)); } 931 932 template<typename _Res> 933 inline shared_future<_Res&> 934 future<_Res&>::share() 935 { return shared_future<_Res&>(std::move(*this)); } 936 937 inline shared_future<void> 938 future<void>::share() 939 { return shared_future<void>(std::move(*this)); } 940 941 /// Primary template for promise 942 template<typename _Res> 943 class promise 944 { 945 typedef __future_base::_State_base _State; 946 typedef __future_base::_Result<_Res> _Res_type; 947 typedef __future_base::_Ptr<_Res_type> _Ptr_type; 948 template<typename, typename> friend class _State::_Setter; 949 950 shared_ptr<_State> _M_future; 951 _Ptr_type _M_storage; 952 953 public: 954 promise() 955 : _M_future(std::make_shared<_State>()), 956 _M_storage(new _Res_type()) 957 { } 958 959 promise(promise&& __rhs) noexcept 960 : _M_future(std::move(__rhs._M_future)), 961 _M_storage(std::move(__rhs._M_storage)) 962 { } 963 964 template<typename _Allocator> 965 promise(allocator_arg_t, const _Allocator& __a) 966 : _M_future(std::allocate_shared<_State>(__a)), 967 _M_storage(__future_base::_S_allocate_result<_Res>(__a)) 968 { } 969 970 template<typename _Allocator> 971 promise(allocator_arg_t, const _Allocator&, promise&& __rhs) 972 : _M_future(std::move(__rhs._M_future)), 973 _M_storage(std::move(__rhs._M_storage)) 974 { } 975 976 promise(const promise&) = delete; 977 978 ~promise() 979 { 980 if (static_cast<bool>(_M_future) && !_M_future.unique()) 981 _M_future->_M_break_promise(std::move(_M_storage)); 982 } 983 984 // Assignment 985 promise& 986 operator=(promise&& __rhs) noexcept 987 { 988 promise(std::move(__rhs)).swap(*this); 989 return *this; 990 } 991 992 promise& operator=(const promise&) = delete; 993 994 void 995 swap(promise& __rhs) noexcept 996 { 997 _M_future.swap(__rhs._M_future); 998 _M_storage.swap(__rhs._M_storage); 999 } 1000 1001 // Retrieving the result 1002 future<_Res> 1003 get_future() 1004 { return future<_Res>(_M_future); } 1005 1006 // Setting the result 1007 void 1008 set_value(const _Res& __r) 1009 { 1010 auto __setter = _State::__setter(this, __r); 1011 _M_future->_M_set_result(std::move(__setter)); 1012 } 1013 1014 void 1015 set_value(_Res&& __r) 1016 { 1017 auto __setter = _State::__setter(this, std::move(__r)); 1018 _M_future->_M_set_result(std::move(__setter)); 1019 } 1020 1021 void 1022 set_exception(exception_ptr __p) 1023 { 1024 auto __setter = _State::__setter(__p, this); 1025 _M_future->_M_set_result(std::move(__setter)); 1026 } 1027 }; 1028 1029 template<typename _Res> 1030 inline void 1031 swap(promise<_Res>& __x, promise<_Res>& __y) noexcept 1032 { __x.swap(__y); } 1033 1034 template<typename _Res, typename _Alloc> 1035 struct uses_allocator<promise<_Res>, _Alloc> 1036 : public true_type { }; 1037 1038 1039 /// Partial specialization for promise<R&> 1040 template<typename _Res> 1041 class promise<_Res&> 1042 { 1043 typedef __future_base::_State_base _State; 1044 typedef __future_base::_Result<_Res&> _Res_type; 1045 typedef __future_base::_Ptr<_Res_type> _Ptr_type; 1046 template<typename, typename> friend class _State::_Setter; 1047 1048 shared_ptr<_State> _M_future; 1049 _Ptr_type _M_storage; 1050 1051 public: 1052 promise() 1053 : _M_future(std::make_shared<_State>()), 1054 _M_storage(new _Res_type()) 1055 { } 1056 1057 promise(promise&& __rhs) noexcept 1058 : _M_future(std::move(__rhs._M_future)), 1059 _M_storage(std::move(__rhs._M_storage)) 1060 { } 1061 1062 template<typename _Allocator> 1063 promise(allocator_arg_t, const _Allocator& __a) 1064 : _M_future(std::allocate_shared<_State>(__a)), 1065 _M_storage(__future_base::_S_allocate_result<_Res&>(__a)) 1066 { } 1067 1068 template<typename _Allocator> 1069 promise(allocator_arg_t, const _Allocator&, promise&& __rhs) 1070 : _M_future(std::move(__rhs._M_future)), 1071 _M_storage(std::move(__rhs._M_storage)) 1072 { } 1073 1074 promise(const promise&) = delete; 1075 1076 ~promise() 1077 { 1078 if (static_cast<bool>(_M_future) && !_M_future.unique()) 1079 _M_future->_M_break_promise(std::move(_M_storage)); 1080 } 1081 1082 // Assignment 1083 promise& 1084 operator=(promise&& __rhs) noexcept 1085 { 1086 promise(std::move(__rhs)).swap(*this); 1087 return *this; 1088 } 1089 1090 promise& operator=(const promise&) = delete; 1091 1092 void 1093 swap(promise& __rhs) noexcept 1094 { 1095 _M_future.swap(__rhs._M_future); 1096 _M_storage.swap(__rhs._M_storage); 1097 } 1098 1099 // Retrieving the result 1100 future<_Res&> 1101 get_future() 1102 { return future<_Res&>(_M_future); } 1103 1104 // Setting the result 1105 void 1106 set_value(_Res& __r) 1107 { 1108 auto __setter = _State::__setter(this, __r); 1109 _M_future->_M_set_result(std::move(__setter)); 1110 } 1111 1112 void 1113 set_exception(exception_ptr __p) 1114 { 1115 auto __setter = _State::__setter(__p, this); 1116 _M_future->_M_set_result(std::move(__setter)); 1117 } 1118 }; 1119 1120 /// Explicit specialization for promise<void> 1121 template<> 1122 class promise<void> 1123 { 1124 typedef __future_base::_State_base _State; 1125 typedef __future_base::_Result<void> _Res_type; 1126 typedef __future_base::_Ptr<_Res_type> _Ptr_type; 1127 template<typename, typename> friend class _State::_Setter; 1128 1129 shared_ptr<_State> _M_future; 1130 _Ptr_type _M_storage; 1131 1132 public: 1133 promise() 1134 : _M_future(std::make_shared<_State>()), 1135 _M_storage(new _Res_type()) 1136 { } 1137 1138 promise(promise&& __rhs) noexcept 1139 : _M_future(std::move(__rhs._M_future)), 1140 _M_storage(std::move(__rhs._M_storage)) 1141 { } 1142 1143 template<typename _Allocator> 1144 promise(allocator_arg_t, const _Allocator& __a) 1145 : _M_future(std::allocate_shared<_State>(__a)), 1146 _M_storage(__future_base::_S_allocate_result<void>(__a)) 1147 { } 1148 1149 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1150 // 2095. missing constructors needed for uses-allocator construction 1151 template<typename _Allocator> 1152 promise(allocator_arg_t, const _Allocator&, promise&& __rhs) 1153 : _M_future(std::move(__rhs._M_future)), 1154 _M_storage(std::move(__rhs._M_storage)) 1155 { } 1156 1157 promise(const promise&) = delete; 1158 1159 ~promise() 1160 { 1161 if (static_cast<bool>(_M_future) && !_M_future.unique()) 1162 _M_future->_M_break_promise(std::move(_M_storage)); 1163 } 1164 1165 // Assignment 1166 promise& 1167 operator=(promise&& __rhs) noexcept 1168 { 1169 promise(std::move(__rhs)).swap(*this); 1170 return *this; 1171 } 1172 1173 promise& operator=(const promise&) = delete; 1174 1175 void 1176 swap(promise& __rhs) noexcept 1177 { 1178 _M_future.swap(__rhs._M_future); 1179 _M_storage.swap(__rhs._M_storage); 1180 } 1181 1182 // Retrieving the result 1183 future<void> 1184 get_future() 1185 { return future<void>(_M_future); } 1186 1187 // Setting the result 1188 void set_value(); 1189 1190 void 1191 set_exception(exception_ptr __p) 1192 { 1193 auto __setter = _State::__setter(__p, this); 1194 _M_future->_M_set_result(std::move(__setter)); 1195 } 1196 }; 1197 1198 // set void 1199 template<> 1200 struct __future_base::_State_base::_Setter<void, void> 1201 { 1202 promise<void>::_Ptr_type operator()() 1203 { 1204 _State_base::_S_check(_M_promise->_M_future); 1205 return std::move(_M_promise->_M_storage); 1206 } 1207 1208 promise<void>* _M_promise; 1209 }; 1210 1211 inline __future_base::_State_base::_Setter<void, void> 1212 __future_base::_State_base::__setter(promise<void>* __prom) 1213 { 1214 return _Setter<void, void>{ __prom }; 1215 } 1216 1217 inline void 1218 promise<void>::set_value() 1219 { 1220 auto __setter = _State::__setter(this); 1221 _M_future->_M_set_result(std::move(__setter)); 1222 } 1223 1224 1225 template<typename _Ptr_type, typename _Res> 1226 struct __future_base::_Task_setter 1227 { 1228 _Ptr_type operator()() 1229 { 1230 __try 1231 { 1232 _M_result->_M_set(_M_fn()); 1233 } 1234 __catch(...) 1235 { 1236 _M_result->_M_error = current_exception(); 1237 } 1238 return std::move(_M_result); 1239 } 1240 _Ptr_type& _M_result; 1241 std::function<_Res()> _M_fn; 1242 }; 1243 1244 template<typename _Ptr_type> 1245 struct __future_base::_Task_setter<_Ptr_type, void> 1246 { 1247 _Ptr_type operator()() 1248 { 1249 __try 1250 { 1251 _M_fn(); 1252 } 1253 __catch(...) 1254 { 1255 _M_result->_M_error = current_exception(); 1256 } 1257 return std::move(_M_result); 1258 } 1259 _Ptr_type& _M_result; 1260 std::function<void()> _M_fn; 1261 }; 1262 1263 template<typename _Res, typename... _Args> 1264 struct __future_base::_Task_state_base<_Res(_Args...)> 1265 : __future_base::_State_base 1266 { 1267 typedef _Res _Res_type; 1268 1269 template<typename _Alloc> 1270 _Task_state_base(const _Alloc& __a) 1271 : _M_result(_S_allocate_result<_Res>(__a)) 1272 { } 1273 1274 virtual void 1275 _M_run(_Args... __args) = 0; 1276 1277 virtual shared_ptr<_Task_state_base> 1278 _M_reset() = 0; 1279 1280 typedef __future_base::_Ptr<_Result<_Res>> _Ptr_type; 1281 _Ptr_type _M_result; 1282 }; 1283 1284 template<typename _Fn, typename _Alloc, typename _Res, typename... _Args> 1285 struct __future_base::_Task_state<_Fn, _Alloc, _Res(_Args...)> final 1286 : __future_base::_Task_state_base<_Res(_Args...)> 1287 { 1288 template<typename _Fn2> 1289 _Task_state(_Fn2&& __fn, const _Alloc& __a) 1290 : _Task_state_base<_Res(_Args...)>(__a), 1291 _M_impl(std::forward<_Fn2>(__fn), __a) 1292 { } 1293 1294 private: 1295 virtual void 1296 _M_run(_Args... __args) 1297 { 1298 // bound arguments decay so wrap lvalue references 1299 auto __boundfn = std::__bind_simple(std::ref(_M_impl._M_fn), 1300 _S_maybe_wrap_ref(std::forward<_Args>(__args))...); 1301 auto __setter = _S_task_setter(this->_M_result, std::move(__boundfn)); 1302 this->_M_set_result(std::move(__setter)); 1303 } 1304 1305 virtual shared_ptr<_Task_state_base<_Res(_Args...)>> 1306 _M_reset(); 1307 1308 template<typename _Tp> 1309 static reference_wrapper<_Tp> 1310 _S_maybe_wrap_ref(_Tp& __t) 1311 { return std::ref(__t); } 1312 1313 template<typename _Tp> 1314 static 1315 typename enable_if<!is_lvalue_reference<_Tp>::value, _Tp>::type&& 1316 _S_maybe_wrap_ref(_Tp&& __t) 1317 { return std::forward<_Tp>(__t); } 1318 1319 struct _Impl : _Alloc 1320 { 1321 template<typename _Fn2> 1322 _Impl(_Fn2&& __fn, const _Alloc& __a) 1323 : _Alloc(__a), _M_fn(std::forward<_Fn2>(__fn)) { } 1324 _Fn _M_fn; 1325 } _M_impl; 1326 }; 1327 1328 template<typename _Signature, typename _Fn, typename _Alloc> 1329 static shared_ptr<__future_base::_Task_state_base<_Signature>> 1330 __create_task_state(_Fn&& __fn, const _Alloc& __a) 1331 { 1332 typedef typename decay<_Fn>::type _Fn2; 1333 typedef __future_base::_Task_state<_Fn2, _Alloc, _Signature> _State; 1334 return std::allocate_shared<_State>(__a, std::forward<_Fn>(__fn), __a); 1335 } 1336 1337 template<typename _Fn, typename _Alloc, typename _Res, typename... _Args> 1338 shared_ptr<__future_base::_Task_state_base<_Res(_Args...)>> 1339 __future_base::_Task_state<_Fn, _Alloc, _Res(_Args...)>::_M_reset() 1340 { 1341 return __create_task_state<_Res(_Args...)>(std::move(_M_impl._M_fn), 1342 static_cast<_Alloc&>(_M_impl)); 1343 } 1344 1345 template<typename _Task, typename _Fn, bool 1346 = is_same<_Task, typename decay<_Fn>::type>::value> 1347 struct __constrain_pkgdtask 1348 { typedef void __type; }; 1349 1350 template<typename _Task, typename _Fn> 1351 struct __constrain_pkgdtask<_Task, _Fn, true> 1352 { }; 1353 1354 /// packaged_task 1355 template<typename _Res, typename... _ArgTypes> 1356 class packaged_task<_Res(_ArgTypes...)> 1357 { 1358 typedef __future_base::_Task_state_base<_Res(_ArgTypes...)> _State_type; 1359 shared_ptr<_State_type> _M_state; 1360 1361 public: 1362 // Construction and destruction 1363 packaged_task() noexcept { } 1364 1365 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1366 // 2095. missing constructors needed for uses-allocator construction 1367 template<typename _Allocator> 1368 packaged_task(allocator_arg_t, const _Allocator& __a) noexcept 1369 { } 1370 1371 template<typename _Fn, typename = typename 1372 __constrain_pkgdtask<packaged_task, _Fn>::__type> 1373 explicit 1374 packaged_task(_Fn&& __fn) 1375 : packaged_task(allocator_arg, std::allocator<int>(), 1376 std::forward<_Fn>(__fn)) 1377 { } 1378 1379 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1380 // 2097. packaged_task constructors should be constrained 1381 template<typename _Fn, typename _Alloc, typename = typename 1382 __constrain_pkgdtask<packaged_task, _Fn>::__type> 1383 explicit 1384 packaged_task(allocator_arg_t, const _Alloc& __a, _Fn&& __fn) 1385 : _M_state(__create_task_state<_Res(_ArgTypes...)>( 1386 std::forward<_Fn>(__fn), __a)) 1387 { } 1388 1389 ~packaged_task() 1390 { 1391 if (static_cast<bool>(_M_state) && !_M_state.unique()) 1392 _M_state->_M_break_promise(std::move(_M_state->_M_result)); 1393 } 1394 1395 // No copy 1396 packaged_task(const packaged_task&) = delete; 1397 packaged_task& operator=(const packaged_task&) = delete; 1398 1399 template<typename _Allocator> 1400 packaged_task(allocator_arg_t, const _Allocator&, 1401 const packaged_task&) = delete; 1402 1403 // Move support 1404 packaged_task(packaged_task&& __other) noexcept 1405 { this->swap(__other); } 1406 1407 template<typename _Allocator> 1408 packaged_task(allocator_arg_t, const _Allocator&, 1409 packaged_task&& __other) noexcept 1410 { this->swap(__other); } 1411 1412 packaged_task& operator=(packaged_task&& __other) noexcept 1413 { 1414 packaged_task(std::move(__other)).swap(*this); 1415 return *this; 1416 } 1417 1418 void 1419 swap(packaged_task& __other) noexcept 1420 { _M_state.swap(__other._M_state); } 1421 1422 bool 1423 valid() const noexcept 1424 { return static_cast<bool>(_M_state); } 1425 1426 // Result retrieval 1427 future<_Res> 1428 get_future() 1429 { return future<_Res>(_M_state); } 1430 1431 // Execution 1432 void 1433 operator()(_ArgTypes... __args) 1434 { 1435 __future_base::_State_base::_S_check(_M_state); 1436 _M_state->_M_run(std::forward<_ArgTypes>(__args)...); 1437 } 1438 1439 void 1440 reset() 1441 { 1442 __future_base::_State_base::_S_check(_M_state); 1443 packaged_task __tmp; 1444 __tmp._M_state = _M_state; 1445 _M_state = _M_state->_M_reset(); 1446 } 1447 }; 1448 1449 /// swap 1450 template<typename _Res, typename... _ArgTypes> 1451 inline void 1452 swap(packaged_task<_Res(_ArgTypes...)>& __x, 1453 packaged_task<_Res(_ArgTypes...)>& __y) noexcept 1454 { __x.swap(__y); } 1455 1456 template<typename _Res, typename _Alloc> 1457 struct uses_allocator<packaged_task<_Res>, _Alloc> 1458 : public true_type { }; 1459 1460 1461 template<typename _BoundFn, typename _Res> 1462 class __future_base::_Deferred_state final 1463 : public __future_base::_State_base 1464 { 1465 public: 1466 explicit 1467 _Deferred_state(_BoundFn&& __fn) 1468 : _M_result(new _Result<_Res>()), _M_fn(std::move(__fn)) 1469 { } 1470 1471 private: 1472 typedef __future_base::_Ptr<_Result<_Res>> _Ptr_type; 1473 _Ptr_type _M_result; 1474 _BoundFn _M_fn; 1475 1476 // Run the deferred function. 1477 virtual void 1478 _M_complete_async() 1479 { 1480 // safe to call multiple times so ignore failure 1481 _M_set_result(_S_task_setter(_M_result, _M_fn), true); 1482 } 1483 1484 virtual bool 1485 _M_has_deferred() const { return static_cast<bool>(_M_result); } 1486 }; 1487 1488 class __future_base::_Async_state_commonV2 1489 : public __future_base::_State_base 1490 { 1491 protected: 1492 ~_Async_state_commonV2() = default; 1493 1494 // Make waiting functions block until the thread completes, as if joined. 1495 virtual void _M_complete_async() { _M_join(); } 1496 1497 void _M_join() { std::call_once(_M_once, &thread::join, ref(_M_thread)); } 1498 1499 thread _M_thread; 1500 once_flag _M_once; 1501 }; 1502 1503 template<typename _BoundFn, typename _Res> 1504 class __future_base::_Async_state_impl final 1505 : public __future_base::_Async_state_commonV2 1506 { 1507 public: 1508 explicit 1509 _Async_state_impl(_BoundFn&& __fn) 1510 : _M_result(new _Result<_Res>()), _M_fn(std::move(__fn)) 1511 { 1512 _M_thread = std::thread{ [this] { 1513 _M_set_result(_S_task_setter(_M_result, _M_fn)); 1514 } }; 1515 } 1516 1517 ~_Async_state_impl() { _M_join(); } 1518 1519 private: 1520 typedef __future_base::_Ptr<_Result<_Res>> _Ptr_type; 1521 _Ptr_type _M_result; 1522 _BoundFn _M_fn; 1523 }; 1524 1525 template<typename _BoundFn> 1526 inline std::shared_ptr<__future_base::_State_base> 1527 __future_base::_S_make_deferred_state(_BoundFn&& __fn) 1528 { 1529 typedef typename remove_reference<_BoundFn>::type __fn_type; 1530 typedef _Deferred_state<__fn_type> __state_type; 1531 return std::make_shared<__state_type>(std::move(__fn)); 1532 } 1533 1534 template<typename _BoundFn> 1535 inline std::shared_ptr<__future_base::_State_base> 1536 __future_base::_S_make_async_state(_BoundFn&& __fn) 1537 { 1538 typedef typename remove_reference<_BoundFn>::type __fn_type; 1539 typedef _Async_state_impl<__fn_type> __state_type; 1540 return std::make_shared<__state_type>(std::move(__fn)); 1541 } 1542 1543 1544 /// async 1545 template<typename _Fn, typename... _Args> 1546 future<typename result_of<_Fn(_Args...)>::type> 1547 async(launch __policy, _Fn&& __fn, _Args&&... __args) 1548 { 1549 typedef typename result_of<_Fn(_Args...)>::type result_type; 1550 std::shared_ptr<__future_base::_State_base> __state; 1551 if ((__policy & (launch::async|launch::deferred)) == launch::async) 1552 { 1553 __state = __future_base::_S_make_async_state(std::__bind_simple( 1554 std::forward<_Fn>(__fn), std::forward<_Args>(__args)...)); 1555 } 1556 else 1557 { 1558 __state = __future_base::_S_make_deferred_state(std::__bind_simple( 1559 std::forward<_Fn>(__fn), std::forward<_Args>(__args)...)); 1560 } 1561 return future<result_type>(__state); 1562 } 1563 1564 /// async, potential overload 1565 template<typename _Fn, typename... _Args> 1566 inline future<typename result_of<_Fn(_Args...)>::type> 1567 async(_Fn&& __fn, _Args&&... __args) 1568 { 1569 return async(launch::async|launch::deferred, std::forward<_Fn>(__fn), 1570 std::forward<_Args>(__args)...); 1571 } 1572 1573 #endif // _GLIBCXX_ASYNC_ABI_COMPAT 1574 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1 1575 // && ATOMIC_INT_LOCK_FREE 1576 1577 // @} group futures 1578 _GLIBCXX_END_NAMESPACE_VERSION 1579 } // namespace 1580 1581 #endif // C++11 1582 1583 #endif // _GLIBCXX_FUTURE 1584
