libstdc++
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00001 // shared_ptr and weak_ptr implementation details -*- C++ -*- 00002 00003 // Copyright (C) 2007-2018 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 // GCC Note: Based on files from version 1.32.0 of the Boost library. 00026 00027 // shared_count.hpp 00028 // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd. 00029 00030 // shared_ptr.hpp 00031 // Copyright (C) 1998, 1999 Greg Colvin and Beman Dawes. 00032 // Copyright (C) 2001, 2002, 2003 Peter Dimov 00033 00034 // weak_ptr.hpp 00035 // Copyright (C) 2001, 2002, 2003 Peter Dimov 00036 00037 // enable_shared_from_this.hpp 00038 // Copyright (C) 2002 Peter Dimov 00039 00040 // Distributed under the Boost Software License, Version 1.0. (See 00041 // accompanying file LICENSE_1_0.txt or copy at 00042 // http://www.boost.org/LICENSE_1_0.txt) 00043 00044 /** @file bits/shared_ptr_base.h 00045 * This is an internal header file, included by other library headers. 00046 * Do not attempt to use it directly. @headername{memory} 00047 */ 00048 00049 #ifndef _SHARED_PTR_BASE_H 00050 #define _SHARED_PTR_BASE_H 1 00051 00052 #include <typeinfo> 00053 #include <bits/allocated_ptr.h> 00054 #include <bits/refwrap.h> 00055 #include <bits/stl_function.h> 00056 #include <ext/aligned_buffer.h> 00057 00058 namespace std _GLIBCXX_VISIBILITY(default) 00059 { 00060 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00061 00062 #if _GLIBCXX_USE_DEPRECATED 00063 #pragma GCC diagnostic push 00064 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 00065 template<typename> class auto_ptr; 00066 #pragma GCC diagnostic pop 00067 #endif 00068 00069 /** 00070 * @brief Exception possibly thrown by @c shared_ptr. 00071 * @ingroup exceptions 00072 */ 00073 class bad_weak_ptr : public std::exception 00074 { 00075 public: 00076 virtual char const* what() const noexcept; 00077 00078 virtual ~bad_weak_ptr() noexcept; 00079 }; 00080 00081 // Substitute for bad_weak_ptr object in the case of -fno-exceptions. 00082 inline void 00083 __throw_bad_weak_ptr() 00084 { _GLIBCXX_THROW_OR_ABORT(bad_weak_ptr()); } 00085 00086 using __gnu_cxx::_Lock_policy; 00087 using __gnu_cxx::__default_lock_policy; 00088 using __gnu_cxx::_S_single; 00089 using __gnu_cxx::_S_mutex; 00090 using __gnu_cxx::_S_atomic; 00091 00092 // Empty helper class except when the template argument is _S_mutex. 00093 template<_Lock_policy _Lp> 00094 class _Mutex_base 00095 { 00096 protected: 00097 // The atomic policy uses fully-fenced builtins, single doesn't care. 00098 enum { _S_need_barriers = 0 }; 00099 }; 00100 00101 template<> 00102 class _Mutex_base<_S_mutex> 00103 : public __gnu_cxx::__mutex 00104 { 00105 protected: 00106 // This policy is used when atomic builtins are not available. 00107 // The replacement atomic operations might not have the necessary 00108 // memory barriers. 00109 enum { _S_need_barriers = 1 }; 00110 }; 00111 00112 template<_Lock_policy _Lp = __default_lock_policy> 00113 class _Sp_counted_base 00114 : public _Mutex_base<_Lp> 00115 { 00116 public: 00117 _Sp_counted_base() noexcept 00118 : _M_use_count(1), _M_weak_count(1) { } 00119 00120 virtual 00121 ~_Sp_counted_base() noexcept 00122 { } 00123 00124 // Called when _M_use_count drops to zero, to release the resources 00125 // managed by *this. 00126 virtual void 00127 _M_dispose() noexcept = 0; 00128 00129 // Called when _M_weak_count drops to zero. 00130 virtual void 00131 _M_destroy() noexcept 00132 { delete this; } 00133 00134 virtual void* 00135 _M_get_deleter(const std::type_info&) noexcept = 0; 00136 00137 void 00138 _M_add_ref_copy() 00139 { __gnu_cxx::__atomic_add_dispatch(&_M_use_count, 1); } 00140 00141 void 00142 _M_add_ref_lock(); 00143 00144 bool 00145 _M_add_ref_lock_nothrow(); 00146 00147 void 00148 _M_release() noexcept 00149 { 00150 // Be race-detector-friendly. For more info see bits/c++config. 00151 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_use_count); 00152 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, -1) == 1) 00153 { 00154 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_use_count); 00155 _M_dispose(); 00156 // There must be a memory barrier between dispose() and destroy() 00157 // to ensure that the effects of dispose() are observed in the 00158 // thread that runs destroy(). 00159 // See http://gcc.gnu.org/ml/libstdc++/2005-11/msg00136.html 00160 if (_Mutex_base<_Lp>::_S_need_barriers) 00161 { 00162 __atomic_thread_fence (__ATOMIC_ACQ_REL); 00163 } 00164 00165 // Be race-detector-friendly. For more info see bits/c++config. 00166 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count); 00167 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, 00168 -1) == 1) 00169 { 00170 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count); 00171 _M_destroy(); 00172 } 00173 } 00174 } 00175 00176 void 00177 _M_weak_add_ref() noexcept 00178 { __gnu_cxx::__atomic_add_dispatch(&_M_weak_count, 1); } 00179 00180 void 00181 _M_weak_release() noexcept 00182 { 00183 // Be race-detector-friendly. For more info see bits/c++config. 00184 _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count); 00185 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, -1) == 1) 00186 { 00187 _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count); 00188 if (_Mutex_base<_Lp>::_S_need_barriers) 00189 { 00190 // See _M_release(), 00191 // destroy() must observe results of dispose() 00192 __atomic_thread_fence (__ATOMIC_ACQ_REL); 00193 } 00194 _M_destroy(); 00195 } 00196 } 00197 00198 long 00199 _M_get_use_count() const noexcept 00200 { 00201 // No memory barrier is used here so there is no synchronization 00202 // with other threads. 00203 return __atomic_load_n(&_M_use_count, __ATOMIC_RELAXED); 00204 } 00205 00206 private: 00207 _Sp_counted_base(_Sp_counted_base const&) = delete; 00208 _Sp_counted_base& operator=(_Sp_counted_base const&) = delete; 00209 00210 _Atomic_word _M_use_count; // #shared 00211 _Atomic_word _M_weak_count; // #weak + (#shared != 0) 00212 }; 00213 00214 template<> 00215 inline void 00216 _Sp_counted_base<_S_single>:: 00217 _M_add_ref_lock() 00218 { 00219 if (_M_use_count == 0) 00220 __throw_bad_weak_ptr(); 00221 ++_M_use_count; 00222 } 00223 00224 template<> 00225 inline void 00226 _Sp_counted_base<_S_mutex>:: 00227 _M_add_ref_lock() 00228 { 00229 __gnu_cxx::__scoped_lock sentry(*this); 00230 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0) 00231 { 00232 _M_use_count = 0; 00233 __throw_bad_weak_ptr(); 00234 } 00235 } 00236 00237 template<> 00238 inline void 00239 _Sp_counted_base<_S_atomic>:: 00240 _M_add_ref_lock() 00241 { 00242 // Perform lock-free add-if-not-zero operation. 00243 _Atomic_word __count = _M_get_use_count(); 00244 do 00245 { 00246 if (__count == 0) 00247 __throw_bad_weak_ptr(); 00248 // Replace the current counter value with the old value + 1, as 00249 // long as it's not changed meanwhile. 00250 } 00251 while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1, 00252 true, __ATOMIC_ACQ_REL, 00253 __ATOMIC_RELAXED)); 00254 } 00255 00256 template<> 00257 inline bool 00258 _Sp_counted_base<_S_single>:: 00259 _M_add_ref_lock_nothrow() 00260 { 00261 if (_M_use_count == 0) 00262 return false; 00263 ++_M_use_count; 00264 return true; 00265 } 00266 00267 template<> 00268 inline bool 00269 _Sp_counted_base<_S_mutex>:: 00270 _M_add_ref_lock_nothrow() 00271 { 00272 __gnu_cxx::__scoped_lock sentry(*this); 00273 if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0) 00274 { 00275 _M_use_count = 0; 00276 return false; 00277 } 00278 return true; 00279 } 00280 00281 template<> 00282 inline bool 00283 _Sp_counted_base<_S_atomic>:: 00284 _M_add_ref_lock_nothrow() 00285 { 00286 // Perform lock-free add-if-not-zero operation. 00287 _Atomic_word __count = _M_get_use_count(); 00288 do 00289 { 00290 if (__count == 0) 00291 return false; 00292 // Replace the current counter value with the old value + 1, as 00293 // long as it's not changed meanwhile. 00294 } 00295 while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1, 00296 true, __ATOMIC_ACQ_REL, 00297 __ATOMIC_RELAXED)); 00298 return true; 00299 } 00300 00301 template<> 00302 inline void 00303 _Sp_counted_base<_S_single>::_M_add_ref_copy() 00304 { ++_M_use_count; } 00305 00306 template<> 00307 inline void 00308 _Sp_counted_base<_S_single>::_M_release() noexcept 00309 { 00310 if (--_M_use_count == 0) 00311 { 00312 _M_dispose(); 00313 if (--_M_weak_count == 0) 00314 _M_destroy(); 00315 } 00316 } 00317 00318 template<> 00319 inline void 00320 _Sp_counted_base<_S_single>::_M_weak_add_ref() noexcept 00321 { ++_M_weak_count; } 00322 00323 template<> 00324 inline void 00325 _Sp_counted_base<_S_single>::_M_weak_release() noexcept 00326 { 00327 if (--_M_weak_count == 0) 00328 _M_destroy(); 00329 } 00330 00331 template<> 00332 inline long 00333 _Sp_counted_base<_S_single>::_M_get_use_count() const noexcept 00334 { return _M_use_count; } 00335 00336 00337 // Forward declarations. 00338 template<typename _Tp, _Lock_policy _Lp = __default_lock_policy> 00339 class __shared_ptr; 00340 00341 template<typename _Tp, _Lock_policy _Lp = __default_lock_policy> 00342 class __weak_ptr; 00343 00344 template<typename _Tp, _Lock_policy _Lp = __default_lock_policy> 00345 class __enable_shared_from_this; 00346 00347 template<typename _Tp> 00348 class shared_ptr; 00349 00350 template<typename _Tp> 00351 class weak_ptr; 00352 00353 template<typename _Tp> 00354 struct owner_less; 00355 00356 template<typename _Tp> 00357 class enable_shared_from_this; 00358 00359 template<_Lock_policy _Lp = __default_lock_policy> 00360 class __weak_count; 00361 00362 template<_Lock_policy _Lp = __default_lock_policy> 00363 class __shared_count; 00364 00365 00366 // Counted ptr with no deleter or allocator support 00367 template<typename _Ptr, _Lock_policy _Lp> 00368 class _Sp_counted_ptr final : public _Sp_counted_base<_Lp> 00369 { 00370 public: 00371 explicit 00372 _Sp_counted_ptr(_Ptr __p) noexcept 00373 : _M_ptr(__p) { } 00374 00375 virtual void 00376 _M_dispose() noexcept 00377 { delete _M_ptr; } 00378 00379 virtual void 00380 _M_destroy() noexcept 00381 { delete this; } 00382 00383 virtual void* 00384 _M_get_deleter(const std::type_info&) noexcept 00385 { return nullptr; } 00386 00387 _Sp_counted_ptr(const _Sp_counted_ptr&) = delete; 00388 _Sp_counted_ptr& operator=(const _Sp_counted_ptr&) = delete; 00389 00390 private: 00391 _Ptr _M_ptr; 00392 }; 00393 00394 template<> 00395 inline void 00396 _Sp_counted_ptr<nullptr_t, _S_single>::_M_dispose() noexcept { } 00397 00398 template<> 00399 inline void 00400 _Sp_counted_ptr<nullptr_t, _S_mutex>::_M_dispose() noexcept { } 00401 00402 template<> 00403 inline void 00404 _Sp_counted_ptr<nullptr_t, _S_atomic>::_M_dispose() noexcept { } 00405 00406 template<int _Nm, typename _Tp, 00407 bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)> 00408 struct _Sp_ebo_helper; 00409 00410 /// Specialization using EBO. 00411 template<int _Nm, typename _Tp> 00412 struct _Sp_ebo_helper<_Nm, _Tp, true> : private _Tp 00413 { 00414 explicit _Sp_ebo_helper(const _Tp& __tp) : _Tp(__tp) { } 00415 explicit _Sp_ebo_helper(_Tp&& __tp) : _Tp(std::move(__tp)) { } 00416 00417 static _Tp& 00418 _S_get(_Sp_ebo_helper& __eboh) { return static_cast<_Tp&>(__eboh); } 00419 }; 00420 00421 /// Specialization not using EBO. 00422 template<int _Nm, typename _Tp> 00423 struct _Sp_ebo_helper<_Nm, _Tp, false> 00424 { 00425 explicit _Sp_ebo_helper(const _Tp& __tp) : _M_tp(__tp) { } 00426 explicit _Sp_ebo_helper(_Tp&& __tp) : _M_tp(std::move(__tp)) { } 00427 00428 static _Tp& 00429 _S_get(_Sp_ebo_helper& __eboh) 00430 { return __eboh._M_tp; } 00431 00432 private: 00433 _Tp _M_tp; 00434 }; 00435 00436 // Support for custom deleter and/or allocator 00437 template<typename _Ptr, typename _Deleter, typename _Alloc, _Lock_policy _Lp> 00438 class _Sp_counted_deleter final : public _Sp_counted_base<_Lp> 00439 { 00440 class _Impl : _Sp_ebo_helper<0, _Deleter>, _Sp_ebo_helper<1, _Alloc> 00441 { 00442 typedef _Sp_ebo_helper<0, _Deleter> _Del_base; 00443 typedef _Sp_ebo_helper<1, _Alloc> _Alloc_base; 00444 00445 public: 00446 _Impl(_Ptr __p, _Deleter __d, const _Alloc& __a) noexcept 00447 : _M_ptr(__p), _Del_base(std::move(__d)), _Alloc_base(__a) 00448 { } 00449 00450 _Deleter& _M_del() noexcept { return _Del_base::_S_get(*this); } 00451 _Alloc& _M_alloc() noexcept { return _Alloc_base::_S_get(*this); } 00452 00453 _Ptr _M_ptr; 00454 }; 00455 00456 public: 00457 using __allocator_type = __alloc_rebind<_Alloc, _Sp_counted_deleter>; 00458 00459 // __d(__p) must not throw. 00460 _Sp_counted_deleter(_Ptr __p, _Deleter __d) noexcept 00461 : _M_impl(__p, std::move(__d), _Alloc()) { } 00462 00463 // __d(__p) must not throw. 00464 _Sp_counted_deleter(_Ptr __p, _Deleter __d, const _Alloc& __a) noexcept 00465 : _M_impl(__p, std::move(__d), __a) { } 00466 00467 ~_Sp_counted_deleter() noexcept { } 00468 00469 virtual void 00470 _M_dispose() noexcept 00471 { _M_impl._M_del()(_M_impl._M_ptr); } 00472 00473 virtual void 00474 _M_destroy() noexcept 00475 { 00476 __allocator_type __a(_M_impl._M_alloc()); 00477 __allocated_ptr<__allocator_type> __guard_ptr{ __a, this }; 00478 this->~_Sp_counted_deleter(); 00479 } 00480 00481 virtual void* 00482 _M_get_deleter(const std::type_info& __ti) noexcept 00483 { 00484 #if __cpp_rtti 00485 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00486 // 2400. shared_ptr's get_deleter() should use addressof() 00487 return __ti == typeid(_Deleter) 00488 ? std::__addressof(_M_impl._M_del()) 00489 : nullptr; 00490 #else 00491 return nullptr; 00492 #endif 00493 } 00494 00495 private: 00496 _Impl _M_impl; 00497 }; 00498 00499 // helpers for make_shared / allocate_shared 00500 00501 struct _Sp_make_shared_tag 00502 { 00503 #if !__cpp_rtti 00504 private: 00505 template<typename _Tp, _Lock_policy _Lp> 00506 friend class __shared_ptr; 00507 template<typename _Tp, typename _Alloc, _Lock_policy _Lp> 00508 friend class _Sp_counted_ptr_inplace; 00509 00510 static const type_info& 00511 _S_ti() noexcept _GLIBCXX_VISIBILITY(default) 00512 { 00513 alignas(type_info) static constexpr _Sp_make_shared_tag __tag; 00514 return reinterpret_cast<const type_info&>(__tag); 00515 } 00516 #endif 00517 }; 00518 00519 template<typename _Tp, typename _Alloc, _Lock_policy _Lp> 00520 class _Sp_counted_ptr_inplace final : public _Sp_counted_base<_Lp> 00521 { 00522 class _Impl : _Sp_ebo_helper<0, _Alloc> 00523 { 00524 typedef _Sp_ebo_helper<0, _Alloc> _A_base; 00525 00526 public: 00527 explicit _Impl(_Alloc __a) noexcept : _A_base(__a) { } 00528 00529 _Alloc& _M_alloc() noexcept { return _A_base::_S_get(*this); } 00530 00531 __gnu_cxx::__aligned_buffer<_Tp> _M_storage; 00532 }; 00533 00534 public: 00535 using __allocator_type = __alloc_rebind<_Alloc, _Sp_counted_ptr_inplace>; 00536 00537 template<typename... _Args> 00538 _Sp_counted_ptr_inplace(_Alloc __a, _Args&&... __args) 00539 : _M_impl(__a) 00540 { 00541 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00542 // 2070. allocate_shared should use allocator_traits<A>::construct 00543 allocator_traits<_Alloc>::construct(__a, _M_ptr(), 00544 std::forward<_Args>(__args)...); // might throw 00545 } 00546 00547 ~_Sp_counted_ptr_inplace() noexcept { } 00548 00549 virtual void 00550 _M_dispose() noexcept 00551 { 00552 allocator_traits<_Alloc>::destroy(_M_impl._M_alloc(), _M_ptr()); 00553 } 00554 00555 // Override because the allocator needs to know the dynamic type 00556 virtual void 00557 _M_destroy() noexcept 00558 { 00559 __allocator_type __a(_M_impl._M_alloc()); 00560 __allocated_ptr<__allocator_type> __guard_ptr{ __a, this }; 00561 this->~_Sp_counted_ptr_inplace(); 00562 } 00563 00564 // Sneaky trick so __shared_ptr can get the managed pointer 00565 virtual void* 00566 _M_get_deleter(const std::type_info& __ti) noexcept 00567 { 00568 #if __cpp_rtti 00569 if (__ti == typeid(_Sp_make_shared_tag)) 00570 #else 00571 if (&__ti == &_Sp_make_shared_tag::_S_ti()) 00572 #endif 00573 return const_cast<typename remove_cv<_Tp>::type*>(_M_ptr()); 00574 return nullptr; 00575 } 00576 00577 private: 00578 _Tp* _M_ptr() noexcept { return _M_impl._M_storage._M_ptr(); } 00579 00580 _Impl _M_impl; 00581 }; 00582 00583 // The default deleter for shared_ptr<T[]> and shared_ptr<T[N]>. 00584 struct __sp_array_delete 00585 { 00586 template<typename _Yp> 00587 void operator()(_Yp* __p) const { delete[] __p; } 00588 }; 00589 00590 template<_Lock_policy _Lp> 00591 class __shared_count 00592 { 00593 public: 00594 constexpr __shared_count() noexcept : _M_pi(0) 00595 { } 00596 00597 template<typename _Ptr> 00598 explicit 00599 __shared_count(_Ptr __p) : _M_pi(0) 00600 { 00601 __try 00602 { 00603 _M_pi = new _Sp_counted_ptr<_Ptr, _Lp>(__p); 00604 } 00605 __catch(...) 00606 { 00607 delete __p; 00608 __throw_exception_again; 00609 } 00610 } 00611 00612 template<typename _Ptr> 00613 __shared_count(_Ptr __p, /* is_array = */ false_type) 00614 : __shared_count(__p) 00615 { } 00616 00617 template<typename _Ptr> 00618 __shared_count(_Ptr __p, /* is_array = */ true_type) 00619 : __shared_count(__p, __sp_array_delete{}, allocator<void>()) 00620 { } 00621 00622 template<typename _Ptr, typename _Deleter> 00623 __shared_count(_Ptr __p, _Deleter __d) 00624 : __shared_count(__p, std::move(__d), allocator<void>()) 00625 { } 00626 00627 template<typename _Ptr, typename _Deleter, typename _Alloc> 00628 __shared_count(_Ptr __p, _Deleter __d, _Alloc __a) : _M_pi(0) 00629 { 00630 typedef _Sp_counted_deleter<_Ptr, _Deleter, _Alloc, _Lp> _Sp_cd_type; 00631 __try 00632 { 00633 typename _Sp_cd_type::__allocator_type __a2(__a); 00634 auto __guard = std::__allocate_guarded(__a2); 00635 _Sp_cd_type* __mem = __guard.get(); 00636 ::new (__mem) _Sp_cd_type(__p, std::move(__d), std::move(__a)); 00637 _M_pi = __mem; 00638 __guard = nullptr; 00639 } 00640 __catch(...) 00641 { 00642 __d(__p); // Call _Deleter on __p. 00643 __throw_exception_again; 00644 } 00645 } 00646 00647 template<typename _Tp, typename _Alloc, typename... _Args> 00648 __shared_count(_Sp_make_shared_tag, _Tp*, const _Alloc& __a, 00649 _Args&&... __args) 00650 : _M_pi(0) 00651 { 00652 typedef _Sp_counted_ptr_inplace<_Tp, _Alloc, _Lp> _Sp_cp_type; 00653 typename _Sp_cp_type::__allocator_type __a2(__a); 00654 auto __guard = std::__allocate_guarded(__a2); 00655 _Sp_cp_type* __mem = __guard.get(); 00656 ::new (__mem) _Sp_cp_type(std::move(__a), 00657 std::forward<_Args>(__args)...); 00658 _M_pi = __mem; 00659 __guard = nullptr; 00660 } 00661 00662 #if _GLIBCXX_USE_DEPRECATED 00663 #pragma GCC diagnostic push 00664 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 00665 // Special case for auto_ptr<_Tp> to provide the strong guarantee. 00666 template<typename _Tp> 00667 explicit 00668 __shared_count(std::auto_ptr<_Tp>&& __r); 00669 #pragma GCC diagnostic pop 00670 #endif 00671 00672 // Special case for unique_ptr<_Tp,_Del> to provide the strong guarantee. 00673 template<typename _Tp, typename _Del> 00674 explicit 00675 __shared_count(std::unique_ptr<_Tp, _Del>&& __r) : _M_pi(0) 00676 { 00677 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00678 // 2415. Inconsistency between unique_ptr and shared_ptr 00679 if (__r.get() == nullptr) 00680 return; 00681 00682 using _Ptr = typename unique_ptr<_Tp, _Del>::pointer; 00683 using _Del2 = typename conditional<is_reference<_Del>::value, 00684 reference_wrapper<typename remove_reference<_Del>::type>, 00685 _Del>::type; 00686 using _Sp_cd_type 00687 = _Sp_counted_deleter<_Ptr, _Del2, allocator<void>, _Lp>; 00688 using _Alloc = allocator<_Sp_cd_type>; 00689 using _Alloc_traits = allocator_traits<_Alloc>; 00690 _Alloc __a; 00691 _Sp_cd_type* __mem = _Alloc_traits::allocate(__a, 1); 00692 _Alloc_traits::construct(__a, __mem, __r.release(), 00693 __r.get_deleter()); // non-throwing 00694 _M_pi = __mem; 00695 } 00696 00697 // Throw bad_weak_ptr when __r._M_get_use_count() == 0. 00698 explicit __shared_count(const __weak_count<_Lp>& __r); 00699 00700 // Does not throw if __r._M_get_use_count() == 0, caller must check. 00701 explicit __shared_count(const __weak_count<_Lp>& __r, std::nothrow_t); 00702 00703 ~__shared_count() noexcept 00704 { 00705 if (_M_pi != nullptr) 00706 _M_pi->_M_release(); 00707 } 00708 00709 __shared_count(const __shared_count& __r) noexcept 00710 : _M_pi(__r._M_pi) 00711 { 00712 if (_M_pi != 0) 00713 _M_pi->_M_add_ref_copy(); 00714 } 00715 00716 __shared_count& 00717 operator=(const __shared_count& __r) noexcept 00718 { 00719 _Sp_counted_base<_Lp>* __tmp = __r._M_pi; 00720 if (__tmp != _M_pi) 00721 { 00722 if (__tmp != 0) 00723 __tmp->_M_add_ref_copy(); 00724 if (_M_pi != 0) 00725 _M_pi->_M_release(); 00726 _M_pi = __tmp; 00727 } 00728 return *this; 00729 } 00730 00731 void 00732 _M_swap(__shared_count& __r) noexcept 00733 { 00734 _Sp_counted_base<_Lp>* __tmp = __r._M_pi; 00735 __r._M_pi = _M_pi; 00736 _M_pi = __tmp; 00737 } 00738 00739 long 00740 _M_get_use_count() const noexcept 00741 { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; } 00742 00743 bool 00744 _M_unique() const noexcept 00745 { return this->_M_get_use_count() == 1; } 00746 00747 void* 00748 _M_get_deleter(const std::type_info& __ti) const noexcept 00749 { return _M_pi ? _M_pi->_M_get_deleter(__ti) : nullptr; } 00750 00751 bool 00752 _M_less(const __shared_count& __rhs) const noexcept 00753 { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } 00754 00755 bool 00756 _M_less(const __weak_count<_Lp>& __rhs) const noexcept 00757 { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } 00758 00759 // Friend function injected into enclosing namespace and found by ADL 00760 friend inline bool 00761 operator==(const __shared_count& __a, const __shared_count& __b) noexcept 00762 { return __a._M_pi == __b._M_pi; } 00763 00764 private: 00765 friend class __weak_count<_Lp>; 00766 00767 _Sp_counted_base<_Lp>* _M_pi; 00768 }; 00769 00770 00771 template<_Lock_policy _Lp> 00772 class __weak_count 00773 { 00774 public: 00775 constexpr __weak_count() noexcept : _M_pi(nullptr) 00776 { } 00777 00778 __weak_count(const __shared_count<_Lp>& __r) noexcept 00779 : _M_pi(__r._M_pi) 00780 { 00781 if (_M_pi != nullptr) 00782 _M_pi->_M_weak_add_ref(); 00783 } 00784 00785 __weak_count(const __weak_count& __r) noexcept 00786 : _M_pi(__r._M_pi) 00787 { 00788 if (_M_pi != nullptr) 00789 _M_pi->_M_weak_add_ref(); 00790 } 00791 00792 __weak_count(__weak_count&& __r) noexcept 00793 : _M_pi(__r._M_pi) 00794 { __r._M_pi = nullptr; } 00795 00796 ~__weak_count() noexcept 00797 { 00798 if (_M_pi != nullptr) 00799 _M_pi->_M_weak_release(); 00800 } 00801 00802 __weak_count& 00803 operator=(const __shared_count<_Lp>& __r) noexcept 00804 { 00805 _Sp_counted_base<_Lp>* __tmp = __r._M_pi; 00806 if (__tmp != nullptr) 00807 __tmp->_M_weak_add_ref(); 00808 if (_M_pi != nullptr) 00809 _M_pi->_M_weak_release(); 00810 _M_pi = __tmp; 00811 return *this; 00812 } 00813 00814 __weak_count& 00815 operator=(const __weak_count& __r) noexcept 00816 { 00817 _Sp_counted_base<_Lp>* __tmp = __r._M_pi; 00818 if (__tmp != nullptr) 00819 __tmp->_M_weak_add_ref(); 00820 if (_M_pi != nullptr) 00821 _M_pi->_M_weak_release(); 00822 _M_pi = __tmp; 00823 return *this; 00824 } 00825 00826 __weak_count& 00827 operator=(__weak_count&& __r) noexcept 00828 { 00829 if (_M_pi != nullptr) 00830 _M_pi->_M_weak_release(); 00831 _M_pi = __r._M_pi; 00832 __r._M_pi = nullptr; 00833 return *this; 00834 } 00835 00836 void 00837 _M_swap(__weak_count& __r) noexcept 00838 { 00839 _Sp_counted_base<_Lp>* __tmp = __r._M_pi; 00840 __r._M_pi = _M_pi; 00841 _M_pi = __tmp; 00842 } 00843 00844 long 00845 _M_get_use_count() const noexcept 00846 { return _M_pi != nullptr ? _M_pi->_M_get_use_count() : 0; } 00847 00848 bool 00849 _M_less(const __weak_count& __rhs) const noexcept 00850 { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } 00851 00852 bool 00853 _M_less(const __shared_count<_Lp>& __rhs) const noexcept 00854 { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } 00855 00856 // Friend function injected into enclosing namespace and found by ADL 00857 friend inline bool 00858 operator==(const __weak_count& __a, const __weak_count& __b) noexcept 00859 { return __a._M_pi == __b._M_pi; } 00860 00861 private: 00862 friend class __shared_count<_Lp>; 00863 00864 _Sp_counted_base<_Lp>* _M_pi; 00865 }; 00866 00867 // Now that __weak_count is defined we can define this constructor: 00868 template<_Lock_policy _Lp> 00869 inline 00870 __shared_count<_Lp>::__shared_count(const __weak_count<_Lp>& __r) 00871 : _M_pi(__r._M_pi) 00872 { 00873 if (_M_pi != nullptr) 00874 _M_pi->_M_add_ref_lock(); 00875 else 00876 __throw_bad_weak_ptr(); 00877 } 00878 00879 // Now that __weak_count is defined we can define this constructor: 00880 template<_Lock_policy _Lp> 00881 inline 00882 __shared_count<_Lp>:: 00883 __shared_count(const __weak_count<_Lp>& __r, std::nothrow_t) 00884 : _M_pi(__r._M_pi) 00885 { 00886 if (_M_pi != nullptr) 00887 if (!_M_pi->_M_add_ref_lock_nothrow()) 00888 _M_pi = nullptr; 00889 } 00890 00891 #define __cpp_lib_shared_ptr_arrays 201603 00892 00893 // Helper traits for shared_ptr of array: 00894 00895 // A pointer type Y* is said to be compatible with a pointer type T* when 00896 // either Y* is convertible to T* or Y is U[N] and T is U cv []. 00897 template<typename _Yp_ptr, typename _Tp_ptr> 00898 struct __sp_compatible_with 00899 : false_type 00900 { }; 00901 00902 template<typename _Yp, typename _Tp> 00903 struct __sp_compatible_with<_Yp*, _Tp*> 00904 : is_convertible<_Yp*, _Tp*>::type 00905 { }; 00906 00907 template<typename _Up, size_t _Nm> 00908 struct __sp_compatible_with<_Up(*)[_Nm], _Up(*)[]> 00909 : true_type 00910 { }; 00911 00912 template<typename _Up, size_t _Nm> 00913 struct __sp_compatible_with<_Up(*)[_Nm], const _Up(*)[]> 00914 : true_type 00915 { }; 00916 00917 template<typename _Up, size_t _Nm> 00918 struct __sp_compatible_with<_Up(*)[_Nm], volatile _Up(*)[]> 00919 : true_type 00920 { }; 00921 00922 template<typename _Up, size_t _Nm> 00923 struct __sp_compatible_with<_Up(*)[_Nm], const volatile _Up(*)[]> 00924 : true_type 00925 { }; 00926 00927 // Test conversion from Y(*)[N] to U(*)[N] without forming invalid type Y[N]. 00928 template<typename _Up, size_t _Nm, typename _Yp, typename = void> 00929 struct __sp_is_constructible_arrN 00930 : false_type 00931 { }; 00932 00933 template<typename _Up, size_t _Nm, typename _Yp> 00934 struct __sp_is_constructible_arrN<_Up, _Nm, _Yp, __void_t<_Yp[_Nm]>> 00935 : is_convertible<_Yp(*)[_Nm], _Up(*)[_Nm]>::type 00936 { }; 00937 00938 // Test conversion from Y(*)[] to U(*)[] without forming invalid type Y[]. 00939 template<typename _Up, typename _Yp, typename = void> 00940 struct __sp_is_constructible_arr 00941 : false_type 00942 { }; 00943 00944 template<typename _Up, typename _Yp> 00945 struct __sp_is_constructible_arr<_Up, _Yp, __void_t<_Yp[]>> 00946 : is_convertible<_Yp(*)[], _Up(*)[]>::type 00947 { }; 00948 00949 // Trait to check if shared_ptr<T> can be constructed from Y*. 00950 template<typename _Tp, typename _Yp> 00951 struct __sp_is_constructible; 00952 00953 // When T is U[N], Y(*)[N] shall be convertible to T*; 00954 template<typename _Up, size_t _Nm, typename _Yp> 00955 struct __sp_is_constructible<_Up[_Nm], _Yp> 00956 : __sp_is_constructible_arrN<_Up, _Nm, _Yp>::type 00957 { }; 00958 00959 // when T is U[], Y(*)[] shall be convertible to T*; 00960 template<typename _Up, typename _Yp> 00961 struct __sp_is_constructible<_Up[], _Yp> 00962 : __sp_is_constructible_arr<_Up, _Yp>::type 00963 { }; 00964 00965 // otherwise, Y* shall be convertible to T*. 00966 template<typename _Tp, typename _Yp> 00967 struct __sp_is_constructible 00968 : is_convertible<_Yp*, _Tp*>::type 00969 { }; 00970 00971 00972 // Define operator* and operator-> for shared_ptr<T>. 00973 template<typename _Tp, _Lock_policy _Lp, 00974 bool = is_array<_Tp>::value, bool = is_void<_Tp>::value> 00975 class __shared_ptr_access 00976 { 00977 public: 00978 using element_type = _Tp; 00979 00980 element_type& 00981 operator*() const noexcept 00982 { 00983 __glibcxx_assert(_M_get() != nullptr); 00984 return *_M_get(); 00985 } 00986 00987 element_type* 00988 operator->() const noexcept 00989 { 00990 _GLIBCXX_DEBUG_PEDASSERT(_M_get() != nullptr); 00991 return _M_get(); 00992 } 00993 00994 private: 00995 element_type* 00996 _M_get() const noexcept 00997 { return static_cast<const __shared_ptr<_Tp, _Lp>*>(this)->get(); } 00998 }; 00999 01000 // Define operator-> for shared_ptr<cv void>. 01001 template<typename _Tp, _Lock_policy _Lp> 01002 class __shared_ptr_access<_Tp, _Lp, false, true> 01003 { 01004 public: 01005 using element_type = _Tp; 01006 01007 element_type* 01008 operator->() const noexcept 01009 { 01010 auto __ptr = static_cast<const __shared_ptr<_Tp, _Lp>*>(this)->get(); 01011 _GLIBCXX_DEBUG_PEDASSERT(__ptr != nullptr); 01012 return __ptr; 01013 } 01014 }; 01015 01016 // Define operator[] for shared_ptr<T[]> and shared_ptr<T[N]>. 01017 template<typename _Tp, _Lock_policy _Lp> 01018 class __shared_ptr_access<_Tp, _Lp, true, false> 01019 { 01020 public: 01021 using element_type = typename remove_extent<_Tp>::type; 01022 01023 #if __cplusplus <= 201402L 01024 [[__deprecated__("shared_ptr<T[]>::operator* is absent from C++17")]] 01025 element_type& 01026 operator*() const noexcept 01027 { 01028 __glibcxx_assert(_M_get() != nullptr); 01029 return *_M_get(); 01030 } 01031 01032 [[__deprecated__("shared_ptr<T[]>::operator-> is absent from C++17")]] 01033 element_type* 01034 operator->() const noexcept 01035 { 01036 _GLIBCXX_DEBUG_PEDASSERT(_M_get() != nullptr); 01037 return _M_get(); 01038 } 01039 #endif 01040 01041 element_type& 01042 operator[](ptrdiff_t __i) const 01043 { 01044 __glibcxx_assert(_M_get() != nullptr); 01045 __glibcxx_assert(!extent<_Tp>::value || __i < extent<_Tp>::value); 01046 return _M_get()[__i]; 01047 } 01048 01049 private: 01050 element_type* 01051 _M_get() const noexcept 01052 { return static_cast<const __shared_ptr<_Tp, _Lp>*>(this)->get(); } 01053 }; 01054 01055 template<typename _Tp, _Lock_policy _Lp> 01056 class __shared_ptr 01057 : public __shared_ptr_access<_Tp, _Lp> 01058 { 01059 public: 01060 using element_type = typename remove_extent<_Tp>::type; 01061 01062 private: 01063 // Constraint for taking ownership of a pointer of type _Yp*: 01064 template<typename _Yp> 01065 using _SafeConv 01066 = typename enable_if<__sp_is_constructible<_Tp, _Yp>::value>::type; 01067 01068 // Constraint for construction from shared_ptr and weak_ptr: 01069 template<typename _Yp, typename _Res = void> 01070 using _Compatible = typename 01071 enable_if<__sp_compatible_with<_Yp*, _Tp*>::value, _Res>::type; 01072 01073 // Constraint for assignment from shared_ptr and weak_ptr: 01074 template<typename _Yp> 01075 using _Assignable = _Compatible<_Yp, __shared_ptr&>; 01076 01077 // Constraint for construction from unique_ptr: 01078 template<typename _Yp, typename _Del, typename _Res = void, 01079 typename _Ptr = typename unique_ptr<_Yp, _Del>::pointer> 01080 using _UniqCompatible = typename enable_if<__and_< 01081 __sp_compatible_with<_Yp*, _Tp*>, is_convertible<_Ptr, element_type*> 01082 >::value, _Res>::type; 01083 01084 // Constraint for assignment from unique_ptr: 01085 template<typename _Yp, typename _Del> 01086 using _UniqAssignable = _UniqCompatible<_Yp, _Del, __shared_ptr&>; 01087 01088 public: 01089 01090 #if __cplusplus > 201402L 01091 using weak_type = __weak_ptr<_Tp, _Lp>; 01092 #endif 01093 01094 constexpr __shared_ptr() noexcept 01095 : _M_ptr(0), _M_refcount() 01096 { } 01097 01098 template<typename _Yp, typename = _SafeConv<_Yp>> 01099 explicit 01100 __shared_ptr(_Yp* __p) 01101 : _M_ptr(__p), _M_refcount(__p, typename is_array<_Tp>::type()) 01102 { 01103 static_assert( !is_void<_Yp>::value, "incomplete type" ); 01104 static_assert( sizeof(_Yp) > 0, "incomplete type" ); 01105 _M_enable_shared_from_this_with(__p); 01106 } 01107 01108 template<typename _Yp, typename _Deleter, typename = _SafeConv<_Yp>> 01109 __shared_ptr(_Yp* __p, _Deleter __d) 01110 : _M_ptr(__p), _M_refcount(__p, std::move(__d)) 01111 { 01112 static_assert(__is_invocable<_Deleter&, _Yp*&>::value, 01113 "deleter expression d(p) is well-formed"); 01114 _M_enable_shared_from_this_with(__p); 01115 } 01116 01117 template<typename _Yp, typename _Deleter, typename _Alloc, 01118 typename = _SafeConv<_Yp>> 01119 __shared_ptr(_Yp* __p, _Deleter __d, _Alloc __a) 01120 : _M_ptr(__p), _M_refcount(__p, std::move(__d), std::move(__a)) 01121 { 01122 static_assert(__is_invocable<_Deleter&, _Yp*&>::value, 01123 "deleter expression d(p) is well-formed"); 01124 _M_enable_shared_from_this_with(__p); 01125 } 01126 01127 template<typename _Deleter> 01128 __shared_ptr(nullptr_t __p, _Deleter __d) 01129 : _M_ptr(0), _M_refcount(__p, std::move(__d)) 01130 { } 01131 01132 template<typename _Deleter, typename _Alloc> 01133 __shared_ptr(nullptr_t __p, _Deleter __d, _Alloc __a) 01134 : _M_ptr(0), _M_refcount(__p, std::move(__d), std::move(__a)) 01135 { } 01136 01137 template<typename _Yp> 01138 __shared_ptr(const __shared_ptr<_Yp, _Lp>& __r, 01139 element_type* __p) noexcept 01140 : _M_ptr(__p), _M_refcount(__r._M_refcount) // never throws 01141 { } 01142 01143 __shared_ptr(const __shared_ptr&) noexcept = default; 01144 __shared_ptr& operator=(const __shared_ptr&) noexcept = default; 01145 ~__shared_ptr() = default; 01146 01147 template<typename _Yp, typename = _Compatible<_Yp>> 01148 __shared_ptr(const __shared_ptr<_Yp, _Lp>& __r) noexcept 01149 : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) 01150 { } 01151 01152 __shared_ptr(__shared_ptr&& __r) noexcept 01153 : _M_ptr(__r._M_ptr), _M_refcount() 01154 { 01155 _M_refcount._M_swap(__r._M_refcount); 01156 __r._M_ptr = 0; 01157 } 01158 01159 template<typename _Yp, typename = _Compatible<_Yp>> 01160 __shared_ptr(__shared_ptr<_Yp, _Lp>&& __r) noexcept 01161 : _M_ptr(__r._M_ptr), _M_refcount() 01162 { 01163 _M_refcount._M_swap(__r._M_refcount); 01164 __r._M_ptr = 0; 01165 } 01166 01167 template<typename _Yp, typename = _Compatible<_Yp>> 01168 explicit __shared_ptr(const __weak_ptr<_Yp, _Lp>& __r) 01169 : _M_refcount(__r._M_refcount) // may throw 01170 { 01171 // It is now safe to copy __r._M_ptr, as 01172 // _M_refcount(__r._M_refcount) did not throw. 01173 _M_ptr = __r._M_ptr; 01174 } 01175 01176 // If an exception is thrown this constructor has no effect. 01177 template<typename _Yp, typename _Del, 01178 typename = _UniqCompatible<_Yp, _Del>> 01179 __shared_ptr(unique_ptr<_Yp, _Del>&& __r) 01180 : _M_ptr(__r.get()), _M_refcount() 01181 { 01182 auto __raw = __to_address(__r.get()); 01183 _M_refcount = __shared_count<_Lp>(std::move(__r)); 01184 _M_enable_shared_from_this_with(__raw); 01185 } 01186 01187 #if __cplusplus <= 201402L && _GLIBCXX_USE_DEPRECATED 01188 protected: 01189 // If an exception is thrown this constructor has no effect. 01190 template<typename _Tp1, typename _Del, 01191 typename enable_if<__and_< 01192 __not_<is_array<_Tp>>, is_array<_Tp1>, 01193 is_convertible<typename unique_ptr<_Tp1, _Del>::pointer, _Tp*> 01194 >::value, bool>::type = true> 01195 __shared_ptr(unique_ptr<_Tp1, _Del>&& __r, __sp_array_delete) 01196 : _M_ptr(__r.get()), _M_refcount() 01197 { 01198 auto __raw = __to_address(__r.get()); 01199 _M_refcount = __shared_count<_Lp>(std::move(__r)); 01200 _M_enable_shared_from_this_with(__raw); 01201 } 01202 public: 01203 #endif 01204 01205 #if _GLIBCXX_USE_DEPRECATED 01206 #pragma GCC diagnostic push 01207 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 01208 // Postcondition: use_count() == 1 and __r.get() == 0 01209 template<typename _Yp, typename = _Compatible<_Yp>> 01210 __shared_ptr(auto_ptr<_Yp>&& __r); 01211 #pragma GCC diagnostic pop 01212 #endif 01213 01214 constexpr __shared_ptr(nullptr_t) noexcept : __shared_ptr() { } 01215 01216 template<typename _Yp> 01217 _Assignable<_Yp> 01218 operator=(const __shared_ptr<_Yp, _Lp>& __r) noexcept 01219 { 01220 _M_ptr = __r._M_ptr; 01221 _M_refcount = __r._M_refcount; // __shared_count::op= doesn't throw 01222 return *this; 01223 } 01224 01225 #if _GLIBCXX_USE_DEPRECATED 01226 #pragma GCC diagnostic push 01227 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 01228 template<typename _Yp> 01229 _Assignable<_Yp> 01230 operator=(auto_ptr<_Yp>&& __r) 01231 { 01232 __shared_ptr(std::move(__r)).swap(*this); 01233 return *this; 01234 } 01235 #pragma GCC diagnostic pop 01236 #endif 01237 01238 __shared_ptr& 01239 operator=(__shared_ptr&& __r) noexcept 01240 { 01241 __shared_ptr(std::move(__r)).swap(*this); 01242 return *this; 01243 } 01244 01245 template<class _Yp> 01246 _Assignable<_Yp> 01247 operator=(__shared_ptr<_Yp, _Lp>&& __r) noexcept 01248 { 01249 __shared_ptr(std::move(__r)).swap(*this); 01250 return *this; 01251 } 01252 01253 template<typename _Yp, typename _Del> 01254 _UniqAssignable<_Yp, _Del> 01255 operator=(unique_ptr<_Yp, _Del>&& __r) 01256 { 01257 __shared_ptr(std::move(__r)).swap(*this); 01258 return *this; 01259 } 01260 01261 void 01262 reset() noexcept 01263 { __shared_ptr().swap(*this); } 01264 01265 template<typename _Yp> 01266 _SafeConv<_Yp> 01267 reset(_Yp* __p) // _Yp must be complete. 01268 { 01269 // Catch self-reset errors. 01270 __glibcxx_assert(__p == 0 || __p != _M_ptr); 01271 __shared_ptr(__p).swap(*this); 01272 } 01273 01274 template<typename _Yp, typename _Deleter> 01275 _SafeConv<_Yp> 01276 reset(_Yp* __p, _Deleter __d) 01277 { __shared_ptr(__p, std::move(__d)).swap(*this); } 01278 01279 template<typename _Yp, typename _Deleter, typename _Alloc> 01280 _SafeConv<_Yp> 01281 reset(_Yp* __p, _Deleter __d, _Alloc __a) 01282 { __shared_ptr(__p, std::move(__d), std::move(__a)).swap(*this); } 01283 01284 element_type* 01285 get() const noexcept 01286 { return _M_ptr; } 01287 01288 explicit operator bool() const // never throws 01289 { return _M_ptr == 0 ? false : true; } 01290 01291 bool 01292 unique() const noexcept 01293 { return _M_refcount._M_unique(); } 01294 01295 long 01296 use_count() const noexcept 01297 { return _M_refcount._M_get_use_count(); } 01298 01299 void 01300 swap(__shared_ptr<_Tp, _Lp>& __other) noexcept 01301 { 01302 std::swap(_M_ptr, __other._M_ptr); 01303 _M_refcount._M_swap(__other._M_refcount); 01304 } 01305 01306 template<typename _Tp1> 01307 bool 01308 owner_before(__shared_ptr<_Tp1, _Lp> const& __rhs) const noexcept 01309 { return _M_refcount._M_less(__rhs._M_refcount); } 01310 01311 template<typename _Tp1> 01312 bool 01313 owner_before(__weak_ptr<_Tp1, _Lp> const& __rhs) const noexcept 01314 { return _M_refcount._M_less(__rhs._M_refcount); } 01315 01316 protected: 01317 // This constructor is non-standard, it is used by allocate_shared. 01318 template<typename _Alloc, typename... _Args> 01319 __shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a, 01320 _Args&&... __args) 01321 : _M_ptr(), _M_refcount(__tag, (_Tp*)0, __a, 01322 std::forward<_Args>(__args)...) 01323 { 01324 // _M_ptr needs to point to the newly constructed object. 01325 // This relies on _Sp_counted_ptr_inplace::_M_get_deleter. 01326 #if __cpp_rtti 01327 void* __p = _M_refcount._M_get_deleter(typeid(__tag)); 01328 #else 01329 void* __p = _M_refcount._M_get_deleter(_Sp_make_shared_tag::_S_ti()); 01330 #endif 01331 _M_ptr = static_cast<_Tp*>(__p); 01332 _M_enable_shared_from_this_with(_M_ptr); 01333 } 01334 01335 template<typename _Tp1, _Lock_policy _Lp1, typename _Alloc, 01336 typename... _Args> 01337 friend __shared_ptr<_Tp1, _Lp1> 01338 __allocate_shared(const _Alloc& __a, _Args&&... __args); 01339 01340 // This constructor is used by __weak_ptr::lock() and 01341 // shared_ptr::shared_ptr(const weak_ptr&, std::nothrow_t). 01342 __shared_ptr(const __weak_ptr<_Tp, _Lp>& __r, std::nothrow_t) 01343 : _M_refcount(__r._M_refcount, std::nothrow) 01344 { 01345 _M_ptr = _M_refcount._M_get_use_count() ? __r._M_ptr : nullptr; 01346 } 01347 01348 friend class __weak_ptr<_Tp, _Lp>; 01349 01350 private: 01351 01352 template<typename _Yp> 01353 using __esft_base_t = decltype(__enable_shared_from_this_base( 01354 std::declval<const __shared_count<_Lp>&>(), 01355 std::declval<_Yp*>())); 01356 01357 // Detect an accessible and unambiguous enable_shared_from_this base. 01358 template<typename _Yp, typename = void> 01359 struct __has_esft_base 01360 : false_type { }; 01361 01362 template<typename _Yp> 01363 struct __has_esft_base<_Yp, __void_t<__esft_base_t<_Yp>>> 01364 : __not_<is_array<_Tp>> { }; // No enable shared_from_this for arrays 01365 01366 template<typename _Yp, typename _Yp2 = typename remove_cv<_Yp>::type> 01367 typename enable_if<__has_esft_base<_Yp2>::value>::type 01368 _M_enable_shared_from_this_with(_Yp* __p) noexcept 01369 { 01370 if (auto __base = __enable_shared_from_this_base(_M_refcount, __p)) 01371 __base->_M_weak_assign(const_cast<_Yp2*>(__p), _M_refcount); 01372 } 01373 01374 template<typename _Yp, typename _Yp2 = typename remove_cv<_Yp>::type> 01375 typename enable_if<!__has_esft_base<_Yp2>::value>::type 01376 _M_enable_shared_from_this_with(_Yp*) noexcept 01377 { } 01378 01379 void* 01380 _M_get_deleter(const std::type_info& __ti) const noexcept 01381 { return _M_refcount._M_get_deleter(__ti); } 01382 01383 template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr; 01384 template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr; 01385 01386 template<typename _Del, typename _Tp1, _Lock_policy _Lp1> 01387 friend _Del* get_deleter(const __shared_ptr<_Tp1, _Lp1>&) noexcept; 01388 01389 template<typename _Del, typename _Tp1> 01390 friend _Del* get_deleter(const shared_ptr<_Tp1>&) noexcept; 01391 01392 element_type* _M_ptr; // Contained pointer. 01393 __shared_count<_Lp> _M_refcount; // Reference counter. 01394 }; 01395 01396 01397 // 20.7.2.2.7 shared_ptr comparisons 01398 template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> 01399 inline bool 01400 operator==(const __shared_ptr<_Tp1, _Lp>& __a, 01401 const __shared_ptr<_Tp2, _Lp>& __b) noexcept 01402 { return __a.get() == __b.get(); } 01403 01404 template<typename _Tp, _Lock_policy _Lp> 01405 inline bool 01406 operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept 01407 { return !__a; } 01408 01409 template<typename _Tp, _Lock_policy _Lp> 01410 inline bool 01411 operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept 01412 { return !__a; } 01413 01414 template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> 01415 inline bool 01416 operator!=(const __shared_ptr<_Tp1, _Lp>& __a, 01417 const __shared_ptr<_Tp2, _Lp>& __b) noexcept 01418 { return __a.get() != __b.get(); } 01419 01420 template<typename _Tp, _Lock_policy _Lp> 01421 inline bool 01422 operator!=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept 01423 { return (bool)__a; } 01424 01425 template<typename _Tp, _Lock_policy _Lp> 01426 inline bool 01427 operator!=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept 01428 { return (bool)__a; } 01429 01430 template<typename _Tp, typename _Up, _Lock_policy _Lp> 01431 inline bool 01432 operator<(const __shared_ptr<_Tp, _Lp>& __a, 01433 const __shared_ptr<_Up, _Lp>& __b) noexcept 01434 { 01435 using _Tp_elt = typename __shared_ptr<_Tp, _Lp>::element_type; 01436 using _Up_elt = typename __shared_ptr<_Up, _Lp>::element_type; 01437 using _Vp = typename common_type<_Tp_elt*, _Up_elt*>::type; 01438 return less<_Vp>()(__a.get(), __b.get()); 01439 } 01440 01441 template<typename _Tp, _Lock_policy _Lp> 01442 inline bool 01443 operator<(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept 01444 { 01445 using _Tp_elt = typename __shared_ptr<_Tp, _Lp>::element_type; 01446 return less<_Tp_elt*>()(__a.get(), nullptr); 01447 } 01448 01449 template<typename _Tp, _Lock_policy _Lp> 01450 inline bool 01451 operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept 01452 { 01453 using _Tp_elt = typename __shared_ptr<_Tp, _Lp>::element_type; 01454 return less<_Tp_elt*>()(nullptr, __a.get()); 01455 } 01456 01457 template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> 01458 inline bool 01459 operator<=(const __shared_ptr<_Tp1, _Lp>& __a, 01460 const __shared_ptr<_Tp2, _Lp>& __b) noexcept 01461 { return !(__b < __a); } 01462 01463 template<typename _Tp, _Lock_policy _Lp> 01464 inline bool 01465 operator<=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept 01466 { return !(nullptr < __a); } 01467 01468 template<typename _Tp, _Lock_policy _Lp> 01469 inline bool 01470 operator<=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept 01471 { return !(__a < nullptr); } 01472 01473 template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> 01474 inline bool 01475 operator>(const __shared_ptr<_Tp1, _Lp>& __a, 01476 const __shared_ptr<_Tp2, _Lp>& __b) noexcept 01477 { return (__b < __a); } 01478 01479 template<typename _Tp, _Lock_policy _Lp> 01480 inline bool 01481 operator>(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept 01482 { return nullptr < __a; } 01483 01484 template<typename _Tp, _Lock_policy _Lp> 01485 inline bool 01486 operator>(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept 01487 { return __a < nullptr; } 01488 01489 template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> 01490 inline bool 01491 operator>=(const __shared_ptr<_Tp1, _Lp>& __a, 01492 const __shared_ptr<_Tp2, _Lp>& __b) noexcept 01493 { return !(__a < __b); } 01494 01495 template<typename _Tp, _Lock_policy _Lp> 01496 inline bool 01497 operator>=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept 01498 { return !(__a < nullptr); } 01499 01500 template<typename _Tp, _Lock_policy _Lp> 01501 inline bool 01502 operator>=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept 01503 { return !(nullptr < __a); } 01504 01505 template<typename _Sp> 01506 struct _Sp_less : public binary_function<_Sp, _Sp, bool> 01507 { 01508 bool 01509 operator()(const _Sp& __lhs, const _Sp& __rhs) const noexcept 01510 { 01511 typedef typename _Sp::element_type element_type; 01512 return std::less<element_type*>()(__lhs.get(), __rhs.get()); 01513 } 01514 }; 01515 01516 template<typename _Tp, _Lock_policy _Lp> 01517 struct less<__shared_ptr<_Tp, _Lp>> 01518 : public _Sp_less<__shared_ptr<_Tp, _Lp>> 01519 { }; 01520 01521 // 20.7.2.2.8 shared_ptr specialized algorithms. 01522 template<typename _Tp, _Lock_policy _Lp> 01523 inline void 01524 swap(__shared_ptr<_Tp, _Lp>& __a, __shared_ptr<_Tp, _Lp>& __b) noexcept 01525 { __a.swap(__b); } 01526 01527 // 20.7.2.2.9 shared_ptr casts 01528 01529 // The seemingly equivalent code: 01530 // shared_ptr<_Tp, _Lp>(static_cast<_Tp*>(__r.get())) 01531 // will eventually result in undefined behaviour, attempting to 01532 // delete the same object twice. 01533 /// static_pointer_cast 01534 template<typename _Tp, typename _Tp1, _Lock_policy _Lp> 01535 inline __shared_ptr<_Tp, _Lp> 01536 static_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept 01537 { 01538 using _Sp = __shared_ptr<_Tp, _Lp>; 01539 return _Sp(__r, static_cast<typename _Sp::element_type*>(__r.get())); 01540 } 01541 01542 // The seemingly equivalent code: 01543 // shared_ptr<_Tp, _Lp>(const_cast<_Tp*>(__r.get())) 01544 // will eventually result in undefined behaviour, attempting to 01545 // delete the same object twice. 01546 /// const_pointer_cast 01547 template<typename _Tp, typename _Tp1, _Lock_policy _Lp> 01548 inline __shared_ptr<_Tp, _Lp> 01549 const_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept 01550 { 01551 using _Sp = __shared_ptr<_Tp, _Lp>; 01552 return _Sp(__r, const_cast<typename _Sp::element_type*>(__r.get())); 01553 } 01554 01555 // The seemingly equivalent code: 01556 // shared_ptr<_Tp, _Lp>(dynamic_cast<_Tp*>(__r.get())) 01557 // will eventually result in undefined behaviour, attempting to 01558 // delete the same object twice. 01559 /// dynamic_pointer_cast 01560 template<typename _Tp, typename _Tp1, _Lock_policy _Lp> 01561 inline __shared_ptr<_Tp, _Lp> 01562 dynamic_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept 01563 { 01564 using _Sp = __shared_ptr<_Tp, _Lp>; 01565 if (auto* __p = dynamic_cast<typename _Sp::element_type*>(__r.get())) 01566 return _Sp(__r, __p); 01567 return _Sp(); 01568 } 01569 01570 #if __cplusplus > 201402L 01571 template<typename _Tp, typename _Tp1, _Lock_policy _Lp> 01572 inline __shared_ptr<_Tp, _Lp> 01573 reinterpret_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept 01574 { 01575 using _Sp = __shared_ptr<_Tp, _Lp>; 01576 return _Sp(__r, reinterpret_cast<typename _Sp::element_type*>(__r.get())); 01577 } 01578 #endif 01579 01580 template<typename _Tp, _Lock_policy _Lp> 01581 class __weak_ptr 01582 { 01583 template<typename _Yp, typename _Res = void> 01584 using _Compatible = typename 01585 enable_if<__sp_compatible_with<_Yp*, _Tp*>::value, _Res>::type; 01586 01587 // Constraint for assignment from shared_ptr and weak_ptr: 01588 template<typename _Yp> 01589 using _Assignable = _Compatible<_Yp, __weak_ptr&>; 01590 01591 public: 01592 using element_type = typename remove_extent<_Tp>::type; 01593 01594 constexpr __weak_ptr() noexcept 01595 : _M_ptr(nullptr), _M_refcount() 01596 { } 01597 01598 __weak_ptr(const __weak_ptr&) noexcept = default; 01599 01600 ~__weak_ptr() = default; 01601 01602 // The "obvious" converting constructor implementation: 01603 // 01604 // template<typename _Tp1> 01605 // __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r) 01606 // : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws 01607 // { } 01608 // 01609 // has a serious problem. 01610 // 01611 // __r._M_ptr may already have been invalidated. The _M_ptr(__r._M_ptr) 01612 // conversion may require access to *__r._M_ptr (virtual inheritance). 01613 // 01614 // It is not possible to avoid spurious access violations since 01615 // in multithreaded programs __r._M_ptr may be invalidated at any point. 01616 template<typename _Yp, typename = _Compatible<_Yp>> 01617 __weak_ptr(const __weak_ptr<_Yp, _Lp>& __r) noexcept 01618 : _M_refcount(__r._M_refcount) 01619 { _M_ptr = __r.lock().get(); } 01620 01621 template<typename _Yp, typename = _Compatible<_Yp>> 01622 __weak_ptr(const __shared_ptr<_Yp, _Lp>& __r) noexcept 01623 : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) 01624 { } 01625 01626 __weak_ptr(__weak_ptr&& __r) noexcept 01627 : _M_ptr(__r._M_ptr), _M_refcount(std::move(__r._M_refcount)) 01628 { __r._M_ptr = nullptr; } 01629 01630 template<typename _Yp, typename = _Compatible<_Yp>> 01631 __weak_ptr(__weak_ptr<_Yp, _Lp>&& __r) noexcept 01632 : _M_ptr(__r.lock().get()), _M_refcount(std::move(__r._M_refcount)) 01633 { __r._M_ptr = nullptr; } 01634 01635 __weak_ptr& 01636 operator=(const __weak_ptr& __r) noexcept = default; 01637 01638 template<typename _Yp> 01639 _Assignable<_Yp> 01640 operator=(const __weak_ptr<_Yp, _Lp>& __r) noexcept 01641 { 01642 _M_ptr = __r.lock().get(); 01643 _M_refcount = __r._M_refcount; 01644 return *this; 01645 } 01646 01647 template<typename _Yp> 01648 _Assignable<_Yp> 01649 operator=(const __shared_ptr<_Yp, _Lp>& __r) noexcept 01650 { 01651 _M_ptr = __r._M_ptr; 01652 _M_refcount = __r._M_refcount; 01653 return *this; 01654 } 01655 01656 __weak_ptr& 01657 operator=(__weak_ptr&& __r) noexcept 01658 { 01659 _M_ptr = __r._M_ptr; 01660 _M_refcount = std::move(__r._M_refcount); 01661 __r._M_ptr = nullptr; 01662 return *this; 01663 } 01664 01665 template<typename _Yp> 01666 _Assignable<_Yp> 01667 operator=(__weak_ptr<_Yp, _Lp>&& __r) noexcept 01668 { 01669 _M_ptr = __r.lock().get(); 01670 _M_refcount = std::move(__r._M_refcount); 01671 __r._M_ptr = nullptr; 01672 return *this; 01673 } 01674 01675 __shared_ptr<_Tp, _Lp> 01676 lock() const noexcept 01677 { return __shared_ptr<element_type, _Lp>(*this, std::nothrow); } 01678 01679 long 01680 use_count() const noexcept 01681 { return _M_refcount._M_get_use_count(); } 01682 01683 bool 01684 expired() const noexcept 01685 { return _M_refcount._M_get_use_count() == 0; } 01686 01687 template<typename _Tp1> 01688 bool 01689 owner_before(const __shared_ptr<_Tp1, _Lp>& __rhs) const noexcept 01690 { return _M_refcount._M_less(__rhs._M_refcount); } 01691 01692 template<typename _Tp1> 01693 bool 01694 owner_before(const __weak_ptr<_Tp1, _Lp>& __rhs) const noexcept 01695 { return _M_refcount._M_less(__rhs._M_refcount); } 01696 01697 void 01698 reset() noexcept 01699 { __weak_ptr().swap(*this); } 01700 01701 void 01702 swap(__weak_ptr& __s) noexcept 01703 { 01704 std::swap(_M_ptr, __s._M_ptr); 01705 _M_refcount._M_swap(__s._M_refcount); 01706 } 01707 01708 private: 01709 // Used by __enable_shared_from_this. 01710 void 01711 _M_assign(_Tp* __ptr, const __shared_count<_Lp>& __refcount) noexcept 01712 { 01713 if (use_count() == 0) 01714 { 01715 _M_ptr = __ptr; 01716 _M_refcount = __refcount; 01717 } 01718 } 01719 01720 template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr; 01721 template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr; 01722 friend class __enable_shared_from_this<_Tp, _Lp>; 01723 friend class enable_shared_from_this<_Tp>; 01724 01725 element_type* _M_ptr; // Contained pointer. 01726 __weak_count<_Lp> _M_refcount; // Reference counter. 01727 }; 01728 01729 // 20.7.2.3.6 weak_ptr specialized algorithms. 01730 template<typename _Tp, _Lock_policy _Lp> 01731 inline void 01732 swap(__weak_ptr<_Tp, _Lp>& __a, __weak_ptr<_Tp, _Lp>& __b) noexcept 01733 { __a.swap(__b); } 01734 01735 template<typename _Tp, typename _Tp1> 01736 struct _Sp_owner_less : public binary_function<_Tp, _Tp, bool> 01737 { 01738 bool 01739 operator()(const _Tp& __lhs, const _Tp& __rhs) const noexcept 01740 { return __lhs.owner_before(__rhs); } 01741 01742 bool 01743 operator()(const _Tp& __lhs, const _Tp1& __rhs) const noexcept 01744 { return __lhs.owner_before(__rhs); } 01745 01746 bool 01747 operator()(const _Tp1& __lhs, const _Tp& __rhs) const noexcept 01748 { return __lhs.owner_before(__rhs); } 01749 }; 01750 01751 template<> 01752 struct _Sp_owner_less<void, void> 01753 { 01754 template<typename _Tp, typename _Up> 01755 auto 01756 operator()(const _Tp& __lhs, const _Up& __rhs) const noexcept 01757 -> decltype(__lhs.owner_before(__rhs)) 01758 { return __lhs.owner_before(__rhs); } 01759 01760 using is_transparent = void; 01761 }; 01762 01763 template<typename _Tp, _Lock_policy _Lp> 01764 struct owner_less<__shared_ptr<_Tp, _Lp>> 01765 : public _Sp_owner_less<__shared_ptr<_Tp, _Lp>, __weak_ptr<_Tp, _Lp>> 01766 { }; 01767 01768 template<typename _Tp, _Lock_policy _Lp> 01769 struct owner_less<__weak_ptr<_Tp, _Lp>> 01770 : public _Sp_owner_less<__weak_ptr<_Tp, _Lp>, __shared_ptr<_Tp, _Lp>> 01771 { }; 01772 01773 01774 template<typename _Tp, _Lock_policy _Lp> 01775 class __enable_shared_from_this 01776 { 01777 protected: 01778 constexpr __enable_shared_from_this() noexcept { } 01779 01780 __enable_shared_from_this(const __enable_shared_from_this&) noexcept { } 01781 01782 __enable_shared_from_this& 01783 operator=(const __enable_shared_from_this&) noexcept 01784 { return *this; } 01785 01786 ~__enable_shared_from_this() { } 01787 01788 public: 01789 __shared_ptr<_Tp, _Lp> 01790 shared_from_this() 01791 { return __shared_ptr<_Tp, _Lp>(this->_M_weak_this); } 01792 01793 __shared_ptr<const _Tp, _Lp> 01794 shared_from_this() const 01795 { return __shared_ptr<const _Tp, _Lp>(this->_M_weak_this); } 01796 01797 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 01798 __weak_ptr<_Tp, _Lp> 01799 weak_from_this() noexcept 01800 { return this->_M_weak_this; } 01801 01802 __weak_ptr<const _Tp, _Lp> 01803 weak_from_this() const noexcept 01804 { return this->_M_weak_this; } 01805 #endif 01806 01807 private: 01808 template<typename _Tp1> 01809 void 01810 _M_weak_assign(_Tp1* __p, const __shared_count<_Lp>& __n) const noexcept 01811 { _M_weak_this._M_assign(__p, __n); } 01812 01813 friend const __enable_shared_from_this* 01814 __enable_shared_from_this_base(const __shared_count<_Lp>&, 01815 const __enable_shared_from_this* __p) 01816 { return __p; } 01817 01818 template<typename, _Lock_policy> 01819 friend class __shared_ptr; 01820 01821 mutable __weak_ptr<_Tp, _Lp> _M_weak_this; 01822 }; 01823 01824 template<typename _Tp, _Lock_policy _Lp, typename _Alloc, typename... _Args> 01825 inline __shared_ptr<_Tp, _Lp> 01826 __allocate_shared(const _Alloc& __a, _Args&&... __args) 01827 { 01828 return __shared_ptr<_Tp, _Lp>(_Sp_make_shared_tag(), __a, 01829 std::forward<_Args>(__args)...); 01830 } 01831 01832 template<typename _Tp, _Lock_policy _Lp, typename... _Args> 01833 inline __shared_ptr<_Tp, _Lp> 01834 __make_shared(_Args&&... __args) 01835 { 01836 typedef typename std::remove_const<_Tp>::type _Tp_nc; 01837 return std::__allocate_shared<_Tp, _Lp>(std::allocator<_Tp_nc>(), 01838 std::forward<_Args>(__args)...); 01839 } 01840 01841 /// std::hash specialization for __shared_ptr. 01842 template<typename _Tp, _Lock_policy _Lp> 01843 struct hash<__shared_ptr<_Tp, _Lp>> 01844 : public __hash_base<size_t, __shared_ptr<_Tp, _Lp>> 01845 { 01846 size_t 01847 operator()(const __shared_ptr<_Tp, _Lp>& __s) const noexcept 01848 { 01849 return hash<typename __shared_ptr<_Tp, _Lp>::element_type*>()( 01850 __s.get()); 01851 } 01852 }; 01853 01854 _GLIBCXX_END_NAMESPACE_VERSION 01855 } // namespace 01856 01857 #endif // _SHARED_PTR_BASE_H