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The C and C++ Include Header Files
/usr/include/c++/13/bits/unique_ptr.h
$ cat -n /usr/include/c++/13/bits/unique_ptr.h 1 // unique_ptr implementation -*- C++ -*- 2 3 // Copyright (C) 2008-2023 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 bits/unique_ptr.h 26 * This is an internal header file, included by other library headers. 27 * Do not attempt to use it directly. @headername{memory} 28 */ 29 30 #ifndef _UNIQUE_PTR_H 31 #define _UNIQUE_PTR_H 1 32 33 #include <bits/c++config.h> 34 #include <debug/assertions.h> 35 #include <type_traits> 36 #include <tuple> 37 #include <bits/stl_function.h> 38 #include <bits/functional_hash.h> 39 #if __cplusplus >= 202002L 40 # include <compare> 41 # if _GLIBCXX_HOSTED 42 # include <ostream> 43 # endif 44 #endif 45 46 /* Duplicate definition with ptr_traits.h. */ 47 #if __cplusplus > 202002L && defined(__cpp_constexpr_dynamic_alloc) 48 # define __cpp_lib_constexpr_memory 202202L 49 #elif __cplusplus > 201703L 50 # define __cpp_lib_constexpr_memory 201811L 51 #endif 52 53 namespace std _GLIBCXX_VISIBILITY(default) 54 { 55 _GLIBCXX_BEGIN_NAMESPACE_VERSION 56 57 /** 58 * @addtogroup pointer_abstractions 59 * @{ 60 */ 61 62 #if _GLIBCXX_USE_DEPRECATED 63 #pragma GCC diagnostic push 64 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 65 template<typename> class auto_ptr; 66 #pragma GCC diagnostic pop 67 #endif 68 69 /** Primary template of default_delete, used by unique_ptr for single objects 70 * 71 * @headerfile memory 72 * @since C++11 73 */ 74 template<typename _Tp> 75 struct default_delete 76 { 77 /// Default constructor 78 constexpr default_delete() noexcept = default; 79 80 /** @brief Converting constructor. 81 * 82 * Allows conversion from a deleter for objects of another type, `_Up`, 83 * only if `_Up*` is convertible to `_Tp*`. 84 */ 85 template<typename _Up, 86 typename = _Require<is_convertible<_Up*, _Tp*>>> 87 _GLIBCXX23_CONSTEXPR 88 default_delete(const default_delete<_Up>&) noexcept { } 89 90 /// Calls `delete __ptr` 91 _GLIBCXX23_CONSTEXPR 92 void 93 operator()(_Tp* __ptr) const 94 { 95 static_assert(!is_void<_Tp>::value, 96 "can't delete pointer to incomplete type"); 97 static_assert(sizeof(_Tp)>0, 98 "can't delete pointer to incomplete type"); 99 delete __ptr; 100 } 101 }; 102 103 // _GLIBCXX_RESOLVE_LIB_DEFECTS 104 // DR 740 - omit specialization for array objects with a compile time length 105 106 /** Specialization of default_delete for arrays, used by `unique_ptr<T[]>` 107 * 108 * @headerfile memory 109 * @since C++11 110 */ 111 template<typename _Tp> 112 struct default_delete<_Tp[]> 113 { 114 public: 115 /// Default constructor 116 constexpr default_delete() noexcept = default; 117 118 /** @brief Converting constructor. 119 * 120 * Allows conversion from a deleter for arrays of another type, such as 121 * a const-qualified version of `_Tp`. 122 * 123 * Conversions from types derived from `_Tp` are not allowed because 124 * it is undefined to `delete[]` an array of derived types through a 125 * pointer to the base type. 126 */ 127 template<typename _Up, 128 typename = _Require<is_convertible<_Up(*)[], _Tp(*)[]>>> 129 _GLIBCXX23_CONSTEXPR 130 default_delete(const default_delete<_Up[]>&) noexcept { } 131 132 /// Calls `delete[] __ptr` 133 template<typename _Up> 134 _GLIBCXX23_CONSTEXPR 135 typename enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type 136 operator()(_Up* __ptr) const 137 { 138 static_assert(sizeof(_Tp)>0, 139 "can't delete pointer to incomplete type"); 140 delete [] __ptr; 141 } 142 }; 143 144 /// @cond undocumented 145 146 // Manages the pointer and deleter of a unique_ptr 147 template <typename _Tp, typename _Dp> 148 class __uniq_ptr_impl 149 { 150 template <typename _Up, typename _Ep, typename = void> 151 struct _Ptr 152 { 153 using type = _Up*; 154 }; 155 156 template <typename _Up, typename _Ep> 157 struct 158 _Ptr<_Up, _Ep, __void_t<typename remove_reference<_Ep>::type::pointer>> 159 { 160 using type = typename remove_reference<_Ep>::type::pointer; 161 }; 162 163 public: 164 using _DeleterConstraint = enable_if< 165 __and_<__not_<is_pointer<_Dp>>, 166 is_default_constructible<_Dp>>::value>; 167 168 using pointer = typename _Ptr<_Tp, _Dp>::type; 169 170 static_assert( !is_rvalue_reference<_Dp>::value, 171 "unique_ptr's deleter type must be a function object type" 172 " or an lvalue reference type" ); 173 174 __uniq_ptr_impl() = default; 175 _GLIBCXX23_CONSTEXPR 176 __uniq_ptr_impl(pointer __p) : _M_t() { _M_ptr() = __p; } 177 178 template<typename _Del> 179 _GLIBCXX23_CONSTEXPR 180 __uniq_ptr_impl(pointer __p, _Del&& __d) 181 : _M_t(__p, std::forward<_Del>(__d)) { } 182 183 _GLIBCXX23_CONSTEXPR 184 __uniq_ptr_impl(__uniq_ptr_impl&& __u) noexcept 185 : _M_t(std::move(__u._M_t)) 186 { __u._M_ptr() = nullptr; } 187 188 _GLIBCXX23_CONSTEXPR 189 __uniq_ptr_impl& operator=(__uniq_ptr_impl&& __u) noexcept 190 { 191 reset(__u.release()); 192 _M_deleter() = std::forward<_Dp>(__u._M_deleter()); 193 return *this; 194 } 195 196 _GLIBCXX23_CONSTEXPR 197 pointer& _M_ptr() noexcept { return std::get<0>(_M_t); } 198 _GLIBCXX23_CONSTEXPR 199 pointer _M_ptr() const noexcept { return std::get<0>(_M_t); } 200 _GLIBCXX23_CONSTEXPR 201 _Dp& _M_deleter() noexcept { return std::get<1>(_M_t); } 202 _GLIBCXX23_CONSTEXPR 203 const _Dp& _M_deleter() const noexcept { return std::get<1>(_M_t); } 204 205 _GLIBCXX23_CONSTEXPR 206 void reset(pointer __p) noexcept 207 { 208 const pointer __old_p = _M_ptr(); 209 _M_ptr() = __p; 210 if (__old_p) 211 _M_deleter()(__old_p); 212 } 213 214 _GLIBCXX23_CONSTEXPR 215 pointer release() noexcept 216 { 217 pointer __p = _M_ptr(); 218 _M_ptr() = nullptr; 219 return __p; 220 } 221 222 _GLIBCXX23_CONSTEXPR 223 void 224 swap(__uniq_ptr_impl& __rhs) noexcept 225 { 226 using std::swap; 227 swap(this->_M_ptr(), __rhs._M_ptr()); 228 swap(this->_M_deleter(), __rhs._M_deleter()); 229 } 230 231 private: 232 tuple<pointer, _Dp> _M_t; 233 }; 234 235 // Defines move construction + assignment as either defaulted or deleted. 236 template <typename _Tp, typename _Dp, 237 bool = is_move_constructible<_Dp>::value, 238 bool = is_move_assignable<_Dp>::value> 239 struct __uniq_ptr_data : __uniq_ptr_impl<_Tp, _Dp> 240 { 241 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl; 242 __uniq_ptr_data(__uniq_ptr_data&&) = default; 243 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = default; 244 }; 245 246 template <typename _Tp, typename _Dp> 247 struct __uniq_ptr_data<_Tp, _Dp, true, false> : __uniq_ptr_impl<_Tp, _Dp> 248 { 249 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl; 250 __uniq_ptr_data(__uniq_ptr_data&&) = default; 251 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = delete; 252 }; 253 254 template <typename _Tp, typename _Dp> 255 struct __uniq_ptr_data<_Tp, _Dp, false, true> : __uniq_ptr_impl<_Tp, _Dp> 256 { 257 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl; 258 __uniq_ptr_data(__uniq_ptr_data&&) = delete; 259 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = default; 260 }; 261 262 template <typename _Tp, typename _Dp> 263 struct __uniq_ptr_data<_Tp, _Dp, false, false> : __uniq_ptr_impl<_Tp, _Dp> 264 { 265 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl; 266 __uniq_ptr_data(__uniq_ptr_data&&) = delete; 267 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = delete; 268 }; 269 /// @endcond 270 271 // 20.7.1.2 unique_ptr for single objects. 272 273 /// A move-only smart pointer that manages unique ownership of a resource. 274 /// @headerfile memory 275 /// @since C++11 276 template <typename _Tp, typename _Dp = default_delete<_Tp>> 277 class unique_ptr 278 { 279 template <typename _Up> 280 using _DeleterConstraint = 281 typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type; 282 283 __uniq_ptr_data<_Tp, _Dp> _M_t; 284 285 public: 286 using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer; 287 using element_type = _Tp; 288 using deleter_type = _Dp; 289 290 private: 291 // helper template for detecting a safe conversion from another 292 // unique_ptr 293 template<typename _Up, typename _Ep> 294 using __safe_conversion_up = __and_< 295 is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>, 296 __not_<is_array<_Up>> 297 >; 298 299 public: 300 // Constructors. 301 302 /// Default constructor, creates a unique_ptr that owns nothing. 303 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 304 constexpr unique_ptr() noexcept 305 : _M_t() 306 { } 307 308 /** Takes ownership of a pointer. 309 * 310 * @param __p A pointer to an object of @c element_type 311 * 312 * The deleter will be value-initialized. 313 */ 314 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 315 _GLIBCXX23_CONSTEXPR 316 explicit 317 unique_ptr(pointer __p) noexcept 318 : _M_t(__p) 319 { } 320 321 /** Takes ownership of a pointer. 322 * 323 * @param __p A pointer to an object of @c element_type 324 * @param __d A reference to a deleter. 325 * 326 * The deleter will be initialized with @p __d 327 */ 328 template<typename _Del = deleter_type, 329 typename = _Require<is_copy_constructible<_Del>>> 330 _GLIBCXX23_CONSTEXPR 331 unique_ptr(pointer __p, const deleter_type& __d) noexcept 332 : _M_t(__p, __d) { } 333 334 /** Takes ownership of a pointer. 335 * 336 * @param __p A pointer to an object of @c element_type 337 * @param __d An rvalue reference to a (non-reference) deleter. 338 * 339 * The deleter will be initialized with @p std::move(__d) 340 */ 341 template<typename _Del = deleter_type, 342 typename = _Require<is_move_constructible<_Del>>> 343 _GLIBCXX23_CONSTEXPR 344 unique_ptr(pointer __p, 345 __enable_if_t<!is_lvalue_reference<_Del>::value, 346 _Del&&> __d) noexcept 347 : _M_t(__p, std::move(__d)) 348 { } 349 350 template<typename _Del = deleter_type, 351 typename _DelUnref = typename remove_reference<_Del>::type> 352 _GLIBCXX23_CONSTEXPR 353 unique_ptr(pointer, 354 __enable_if_t<is_lvalue_reference<_Del>::value, 355 _DelUnref&&>) = delete; 356 357 /// Creates a unique_ptr that owns nothing. 358 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 359 constexpr unique_ptr(nullptr_t) noexcept 360 : _M_t() 361 { } 362 363 // Move constructors. 364 365 /// Move constructor. 366 unique_ptr(unique_ptr&&) = default; 367 368 /** @brief Converting constructor from another type 369 * 370 * Requires that the pointer owned by @p __u is convertible to the 371 * type of pointer owned by this object, @p __u does not own an array, 372 * and @p __u has a compatible deleter type. 373 */ 374 template<typename _Up, typename _Ep, typename = _Require< 375 __safe_conversion_up<_Up, _Ep>, 376 __conditional_t<is_reference<_Dp>::value, 377 is_same<_Ep, _Dp>, 378 is_convertible<_Ep, _Dp>>>> 379 _GLIBCXX23_CONSTEXPR 380 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept 381 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) 382 { } 383 384 #if _GLIBCXX_USE_DEPRECATED 385 #pragma GCC diagnostic push 386 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 387 /// Converting constructor from @c auto_ptr 388 template<typename _Up, typename = _Require< 389 is_convertible<_Up*, _Tp*>, is_same<_Dp, default_delete<_Tp>>>> 390 unique_ptr(auto_ptr<_Up>&& __u) noexcept; 391 #pragma GCC diagnostic pop 392 #endif 393 394 /// Destructor, invokes the deleter if the stored pointer is not null. 395 #if __cplusplus > 202002L && __cpp_constexpr_dynamic_alloc 396 constexpr 397 #endif 398 ~unique_ptr() noexcept 399 { 400 static_assert(__is_invocable<deleter_type&, pointer>::value, 401 "unique_ptr's deleter must be invocable with a pointer"); 402 auto& __ptr = _M_t._M_ptr(); 403 if (__ptr != nullptr) 404 get_deleter()(std::move(__ptr)); 405 __ptr = pointer(); 406 } 407 408 // Assignment. 409 410 /** @brief Move assignment operator. 411 * 412 * Invokes the deleter if this object owns a pointer. 413 */ 414 unique_ptr& operator=(unique_ptr&&) = default; 415 416 /** @brief Assignment from another type. 417 * 418 * @param __u The object to transfer ownership from, which owns a 419 * convertible pointer to a non-array object. 420 * 421 * Invokes the deleter if this object owns a pointer. 422 */ 423 template<typename _Up, typename _Ep> 424 _GLIBCXX23_CONSTEXPR 425 typename enable_if< __and_< 426 __safe_conversion_up<_Up, _Ep>, 427 is_assignable<deleter_type&, _Ep&&> 428 >::value, 429 unique_ptr&>::type 430 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept 431 { 432 reset(__u.release()); 433 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 434 return *this; 435 } 436 437 /// Reset the %unique_ptr to empty, invoking the deleter if necessary. 438 _GLIBCXX23_CONSTEXPR 439 unique_ptr& 440 operator=(nullptr_t) noexcept 441 { 442 reset(); 443 return *this; 444 } 445 446 // Observers. 447 448 /// Dereference the stored pointer. 449 _GLIBCXX23_CONSTEXPR 450 typename add_lvalue_reference<element_type>::type 451 operator*() const noexcept(noexcept(*std::declval<pointer>())) 452 { 453 __glibcxx_assert(get() != pointer()); 454 return *get(); 455 } 456 457 /// Return the stored pointer. 458 _GLIBCXX23_CONSTEXPR 459 pointer 460 operator->() const noexcept 461 { 462 _GLIBCXX_DEBUG_PEDASSERT(get() != pointer()); 463 return get(); 464 } 465 466 /// Return the stored pointer. 467 _GLIBCXX23_CONSTEXPR 468 pointer 469 get() const noexcept 470 { return _M_t._M_ptr(); } 471 472 /// Return a reference to the stored deleter. 473 _GLIBCXX23_CONSTEXPR 474 deleter_type& 475 get_deleter() noexcept 476 { return _M_t._M_deleter(); } 477 478 /// Return a reference to the stored deleter. 479 _GLIBCXX23_CONSTEXPR 480 const deleter_type& 481 get_deleter() const noexcept 482 { return _M_t._M_deleter(); } 483 484 /// Return @c true if the stored pointer is not null. 485 _GLIBCXX23_CONSTEXPR 486 explicit operator bool() const noexcept 487 { return get() == pointer() ? false : true; } 488 489 // Modifiers. 490 491 /// Release ownership of any stored pointer. 492 _GLIBCXX23_CONSTEXPR 493 pointer 494 release() noexcept 495 { return _M_t.release(); } 496 497 /** @brief Replace the stored pointer. 498 * 499 * @param __p The new pointer to store. 500 * 501 * The deleter will be invoked if a pointer is already owned. 502 */ 503 _GLIBCXX23_CONSTEXPR 504 void 505 reset(pointer __p = pointer()) noexcept 506 { 507 static_assert(__is_invocable<deleter_type&, pointer>::value, 508 "unique_ptr's deleter must be invocable with a pointer"); 509 _M_t.reset(std::move(__p)); 510 } 511 512 /// Exchange the pointer and deleter with another object. 513 _GLIBCXX23_CONSTEXPR 514 void 515 swap(unique_ptr& __u) noexcept 516 { 517 static_assert(__is_swappable<_Dp>::value, "deleter must be swappable"); 518 _M_t.swap(__u._M_t); 519 } 520 521 // Disable copy from lvalue. 522 unique_ptr(const unique_ptr&) = delete; 523 unique_ptr& operator=(const unique_ptr&) = delete; 524 }; 525 526 // 20.7.1.3 unique_ptr for array objects with a runtime length 527 // [unique.ptr.runtime] 528 // _GLIBCXX_RESOLVE_LIB_DEFECTS 529 // DR 740 - omit specialization for array objects with a compile time length 530 531 /// A move-only smart pointer that manages unique ownership of an array. 532 /// @headerfile memory 533 /// @since C++11 534 template<typename _Tp, typename _Dp> 535 class unique_ptr<_Tp[], _Dp> 536 { 537 template <typename _Up> 538 using _DeleterConstraint = 539 typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type; 540 541 __uniq_ptr_data<_Tp, _Dp> _M_t; 542 543 // like is_base_of<_Tp, _Up> but false if unqualified types are the same 544 template<typename _Up> 545 using __is_derived_Tp 546 = __and_< is_base_of<_Tp, _Up>, 547 __not_<is_same<__remove_cv_t<_Tp>, __remove_cv_t<_Up>>> >; 548 549 public: 550 using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer; 551 using element_type = _Tp; 552 using deleter_type = _Dp; 553 554 // helper template for detecting a safe conversion from another 555 // unique_ptr 556 template<typename _Up, typename _Ep, 557 typename _UPtr = unique_ptr<_Up, _Ep>, 558 typename _UP_pointer = typename _UPtr::pointer, 559 typename _UP_element_type = typename _UPtr::element_type> 560 using __safe_conversion_up = __and_< 561 is_array<_Up>, 562 is_same<pointer, element_type*>, 563 is_same<_UP_pointer, _UP_element_type*>, 564 is_convertible<_UP_element_type(*)[], element_type(*)[]> 565 >; 566 567 // helper template for detecting a safe conversion from a raw pointer 568 template<typename _Up> 569 using __safe_conversion_raw = __and_< 570 __or_<__or_<is_same<_Up, pointer>, 571 is_same<_Up, nullptr_t>>, 572 __and_<is_pointer<_Up>, 573 is_same<pointer, element_type*>, 574 is_convertible< 575 typename remove_pointer<_Up>::type(*)[], 576 element_type(*)[]> 577 > 578 > 579 >; 580 581 // Constructors. 582 583 /// Default constructor, creates a unique_ptr that owns nothing. 584 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 585 constexpr unique_ptr() noexcept 586 : _M_t() 587 { } 588 589 /** Takes ownership of a pointer. 590 * 591 * @param __p A pointer to an array of a type safely convertible 592 * to an array of @c element_type 593 * 594 * The deleter will be value-initialized. 595 */ 596 template<typename _Up, 597 typename _Vp = _Dp, 598 typename = _DeleterConstraint<_Vp>, 599 typename = typename enable_if< 600 __safe_conversion_raw<_Up>::value, bool>::type> 601 _GLIBCXX23_CONSTEXPR 602 explicit 603 unique_ptr(_Up __p) noexcept 604 : _M_t(__p) 605 { } 606 607 /** Takes ownership of a pointer. 608 * 609 * @param __p A pointer to an array of a type safely convertible 610 * to an array of @c element_type 611 * @param __d A reference to a deleter. 612 * 613 * The deleter will be initialized with @p __d 614 */ 615 template<typename _Up, typename _Del = deleter_type, 616 typename = _Require<__safe_conversion_raw<_Up>, 617 is_copy_constructible<_Del>>> 618 _GLIBCXX23_CONSTEXPR 619 unique_ptr(_Up __p, const deleter_type& __d) noexcept 620 : _M_t(__p, __d) { } 621 622 /** Takes ownership of a pointer. 623 * 624 * @param __p A pointer to an array of a type safely convertible 625 * to an array of @c element_type 626 * @param __d A reference to a deleter. 627 * 628 * The deleter will be initialized with @p std::move(__d) 629 */ 630 template<typename _Up, typename _Del = deleter_type, 631 typename = _Require<__safe_conversion_raw<_Up>, 632 is_move_constructible<_Del>>> 633 _GLIBCXX23_CONSTEXPR 634 unique_ptr(_Up __p, 635 __enable_if_t<!is_lvalue_reference<_Del>::value, 636 _Del&&> __d) noexcept 637 : _M_t(std::move(__p), std::move(__d)) 638 { } 639 640 template<typename _Up, typename _Del = deleter_type, 641 typename _DelUnref = typename remove_reference<_Del>::type, 642 typename = _Require<__safe_conversion_raw<_Up>>> 643 unique_ptr(_Up, 644 __enable_if_t<is_lvalue_reference<_Del>::value, 645 _DelUnref&&>) = delete; 646 647 /// Move constructor. 648 unique_ptr(unique_ptr&&) = default; 649 650 /// Creates a unique_ptr that owns nothing. 651 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 652 constexpr unique_ptr(nullptr_t) noexcept 653 : _M_t() 654 { } 655 656 template<typename _Up, typename _Ep, typename = _Require< 657 __safe_conversion_up<_Up, _Ep>, 658 __conditional_t<is_reference<_Dp>::value, 659 is_same<_Ep, _Dp>, 660 is_convertible<_Ep, _Dp>>>> 661 _GLIBCXX23_CONSTEXPR 662 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept 663 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) 664 { } 665 666 /// Destructor, invokes the deleter if the stored pointer is not null. 667 #if __cplusplus > 202002L && __cpp_constexpr_dynamic_alloc 668 constexpr 669 #endif 670 ~unique_ptr() 671 { 672 auto& __ptr = _M_t._M_ptr(); 673 if (__ptr != nullptr) 674 get_deleter()(__ptr); 675 __ptr = pointer(); 676 } 677 678 // Assignment. 679 680 /** @brief Move assignment operator. 681 * 682 * Invokes the deleter if this object owns a pointer. 683 */ 684 unique_ptr& 685 operator=(unique_ptr&&) = default; 686 687 /** @brief Assignment from another type. 688 * 689 * @param __u The object to transfer ownership from, which owns a 690 * convertible pointer to an array object. 691 * 692 * Invokes the deleter if this object owns a pointer. 693 */ 694 template<typename _Up, typename _Ep> 695 _GLIBCXX23_CONSTEXPR 696 typename 697 enable_if<__and_<__safe_conversion_up<_Up, _Ep>, 698 is_assignable<deleter_type&, _Ep&&> 699 >::value, 700 unique_ptr&>::type 701 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept 702 { 703 reset(__u.release()); 704 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 705 return *this; 706 } 707 708 /// Reset the %unique_ptr to empty, invoking the deleter if necessary. 709 _GLIBCXX23_CONSTEXPR 710 unique_ptr& 711 operator=(nullptr_t) noexcept 712 { 713 reset(); 714 return *this; 715 } 716 717 // Observers. 718 719 /// Access an element of owned array. 720 _GLIBCXX23_CONSTEXPR 721 typename std::add_lvalue_reference<element_type>::type 722 operator[](size_t __i) const 723 { 724 __glibcxx_assert(get() != pointer()); 725 return get()[__i]; 726 } 727 728 /// Return the stored pointer. 729 _GLIBCXX23_CONSTEXPR 730 pointer 731 get() const noexcept 732 { return _M_t._M_ptr(); } 733 734 /// Return a reference to the stored deleter. 735 _GLIBCXX23_CONSTEXPR 736 deleter_type& 737 get_deleter() noexcept 738 { return _M_t._M_deleter(); } 739 740 /// Return a reference to the stored deleter. 741 _GLIBCXX23_CONSTEXPR 742 const deleter_type& 743 get_deleter() const noexcept 744 { return _M_t._M_deleter(); } 745 746 /// Return @c true if the stored pointer is not null. 747 _GLIBCXX23_CONSTEXPR 748 explicit operator bool() const noexcept 749 { return get() == pointer() ? false : true; } 750 751 // Modifiers. 752 753 /// Release ownership of any stored pointer. 754 _GLIBCXX23_CONSTEXPR 755 pointer 756 release() noexcept 757 { return _M_t.release(); } 758 759 /** @brief Replace the stored pointer. 760 * 761 * @param __p The new pointer to store. 762 * 763 * The deleter will be invoked if a pointer is already owned. 764 */ 765 template <typename _Up, 766 typename = _Require< 767 __or_<is_same<_Up, pointer>, 768 __and_<is_same<pointer, element_type*>, 769 is_pointer<_Up>, 770 is_convertible< 771 typename remove_pointer<_Up>::type(*)[], 772 element_type(*)[] 773 > 774 > 775 > 776 >> 777 _GLIBCXX23_CONSTEXPR 778 void 779 reset(_Up __p) noexcept 780 { _M_t.reset(std::move(__p)); } 781 782 _GLIBCXX23_CONSTEXPR 783 void reset(nullptr_t = nullptr) noexcept 784 { reset(pointer()); } 785 786 /// Exchange the pointer and deleter with another object. 787 _GLIBCXX23_CONSTEXPR 788 void 789 swap(unique_ptr& __u) noexcept 790 { 791 static_assert(__is_swappable<_Dp>::value, "deleter must be swappable"); 792 _M_t.swap(__u._M_t); 793 } 794 795 // Disable copy from lvalue. 796 unique_ptr(const unique_ptr&) = delete; 797 unique_ptr& operator=(const unique_ptr&) = delete; 798 }; 799 800 /// @{ 801 /// @relates unique_ptr 802 803 /// Swap overload for unique_ptr 804 template<typename _Tp, typename _Dp> 805 inline 806 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 807 // Constrained free swap overload, see p0185r1 808 _GLIBCXX23_CONSTEXPR 809 typename enable_if<__is_swappable<_Dp>::value>::type 810 #else 811 void 812 #endif 813 swap(unique_ptr<_Tp, _Dp>& __x, 814 unique_ptr<_Tp, _Dp>& __y) noexcept 815 { __x.swap(__y); } 816 817 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 818 template<typename _Tp, typename _Dp> 819 typename enable_if<!__is_swappable<_Dp>::value>::type 820 swap(unique_ptr<_Tp, _Dp>&, 821 unique_ptr<_Tp, _Dp>&) = delete; 822 #endif 823 824 /// Equality operator for unique_ptr objects, compares the owned pointers 825 template<typename _Tp, typename _Dp, 826 typename _Up, typename _Ep> 827 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 828 inline bool 829 operator==(const unique_ptr<_Tp, _Dp>& __x, 830 const unique_ptr<_Up, _Ep>& __y) 831 { return __x.get() == __y.get(); } 832 833 /// unique_ptr comparison with nullptr 834 template<typename _Tp, typename _Dp> 835 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 836 inline bool 837 operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept 838 { return !__x; } 839 840 #ifndef __cpp_lib_three_way_comparison 841 /// unique_ptr comparison with nullptr 842 template<typename _Tp, typename _Dp> 843 _GLIBCXX_NODISCARD 844 inline bool 845 operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept 846 { return !__x; } 847 848 /// Inequality operator for unique_ptr objects, compares the owned pointers 849 template<typename _Tp, typename _Dp, 850 typename _Up, typename _Ep> 851 _GLIBCXX_NODISCARD 852 inline bool 853 operator!=(const unique_ptr<_Tp, _Dp>& __x, 854 const unique_ptr<_Up, _Ep>& __y) 855 { return __x.get() != __y.get(); } 856 857 /// unique_ptr comparison with nullptr 858 template<typename _Tp, typename _Dp> 859 _GLIBCXX_NODISCARD 860 inline bool 861 operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept 862 { return (bool)__x; } 863 864 /// unique_ptr comparison with nullptr 865 template<typename _Tp, typename _Dp> 866 _GLIBCXX_NODISCARD 867 inline bool 868 operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept 869 { return (bool)__x; } 870 #endif // three way comparison 871 872 /// Relational operator for unique_ptr objects, compares the owned pointers 873 template<typename _Tp, typename _Dp, 874 typename _Up, typename _Ep> 875 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 876 inline bool 877 operator<(const unique_ptr<_Tp, _Dp>& __x, 878 const unique_ptr<_Up, _Ep>& __y) 879 { 880 typedef typename 881 std::common_type<typename unique_ptr<_Tp, _Dp>::pointer, 882 typename unique_ptr<_Up, _Ep>::pointer>::type _CT; 883 return std::less<_CT>()(__x.get(), __y.get()); 884 } 885 886 /// unique_ptr comparison with nullptr 887 template<typename _Tp, typename _Dp> 888 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 889 inline bool 890 operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 891 { 892 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), 893 nullptr); 894 } 895 896 /// unique_ptr comparison with nullptr 897 template<typename _Tp, typename _Dp> 898 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 899 inline bool 900 operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 901 { 902 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, 903 __x.get()); 904 } 905 906 /// Relational operator for unique_ptr objects, compares the owned pointers 907 template<typename _Tp, typename _Dp, 908 typename _Up, typename _Ep> 909 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 910 inline bool 911 operator<=(const unique_ptr<_Tp, _Dp>& __x, 912 const unique_ptr<_Up, _Ep>& __y) 913 { return !(__y < __x); } 914 915 /// unique_ptr comparison with nullptr 916 template<typename _Tp, typename _Dp> 917 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 918 inline bool 919 operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 920 { return !(nullptr < __x); } 921 922 /// unique_ptr comparison with nullptr 923 template<typename _Tp, typename _Dp> 924 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 925 inline bool 926 operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 927 { return !(__x < nullptr); } 928 929 /// Relational operator for unique_ptr objects, compares the owned pointers 930 template<typename _Tp, typename _Dp, 931 typename _Up, typename _Ep> 932 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 933 inline bool 934 operator>(const unique_ptr<_Tp, _Dp>& __x, 935 const unique_ptr<_Up, _Ep>& __y) 936 { return (__y < __x); } 937 938 /// unique_ptr comparison with nullptr 939 template<typename _Tp, typename _Dp> 940 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 941 inline bool 942 operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 943 { 944 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, 945 __x.get()); 946 } 947 948 /// unique_ptr comparison with nullptr 949 template<typename _Tp, typename _Dp> 950 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 951 inline bool 952 operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 953 { 954 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), 955 nullptr); 956 } 957 958 /// Relational operator for unique_ptr objects, compares the owned pointers 959 template<typename _Tp, typename _Dp, 960 typename _Up, typename _Ep> 961 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 962 inline bool 963 operator>=(const unique_ptr<_Tp, _Dp>& __x, 964 const unique_ptr<_Up, _Ep>& __y) 965 { return !(__x < __y); } 966 967 /// unique_ptr comparison with nullptr 968 template<typename _Tp, typename _Dp> 969 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 970 inline bool 971 operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 972 { return !(__x < nullptr); } 973 974 /// unique_ptr comparison with nullptr 975 template<typename _Tp, typename _Dp> 976 _GLIBCXX_NODISCARD inline bool 977 operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 978 { return !(nullptr < __x); } 979 980 #ifdef __cpp_lib_three_way_comparison 981 template<typename _Tp, typename _Dp, typename _Up, typename _Ep> 982 requires three_way_comparable_with<typename unique_ptr<_Tp, _Dp>::pointer, 983 typename unique_ptr<_Up, _Ep>::pointer> 984 _GLIBCXX23_CONSTEXPR 985 inline 986 compare_three_way_result_t<typename unique_ptr<_Tp, _Dp>::pointer, 987 typename unique_ptr<_Up, _Ep>::pointer> 988 operator<=>(const unique_ptr<_Tp, _Dp>& __x, 989 const unique_ptr<_Up, _Ep>& __y) 990 { return compare_three_way()(__x.get(), __y.get()); } 991 992 template<typename _Tp, typename _Dp> 993 requires three_way_comparable<typename unique_ptr<_Tp, _Dp>::pointer> 994 _GLIBCXX23_CONSTEXPR 995 inline 996 compare_three_way_result_t<typename unique_ptr<_Tp, _Dp>::pointer> 997 operator<=>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 998 { 999 using pointer = typename unique_ptr<_Tp, _Dp>::pointer; 1000 return compare_three_way()(__x.get(), static_cast<pointer>(nullptr)); 1001 } 1002 #endif 1003 /// @} relates unique_ptr 1004 1005 /// @cond undocumented 1006 template<typename _Up, typename _Ptr = typename _Up::pointer, 1007 bool = __poison_hash<_Ptr>::__enable_hash_call> 1008 struct __uniq_ptr_hash 1009 #if ! _GLIBCXX_INLINE_VERSION 1010 : private __poison_hash<_Ptr> 1011 #endif 1012 { 1013 size_t 1014 operator()(const _Up& __u) const 1015 noexcept(noexcept(std::declval<hash<_Ptr>>()(std::declval<_Ptr>()))) 1016 { return hash<_Ptr>()(__u.get()); } 1017 }; 1018 1019 template<typename _Up, typename _Ptr> 1020 struct __uniq_ptr_hash<_Up, _Ptr, false> 1021 : private __poison_hash<_Ptr> 1022 { }; 1023 /// @endcond 1024 1025 /// std::hash specialization for unique_ptr. 1026 template<typename _Tp, typename _Dp> 1027 struct hash<unique_ptr<_Tp, _Dp>> 1028 : public __hash_base<size_t, unique_ptr<_Tp, _Dp>>, 1029 public __uniq_ptr_hash<unique_ptr<_Tp, _Dp>> 1030 { }; 1031 1032 #if __cplusplus >= 201402L && _GLIBCXX_HOSTED 1033 #define __cpp_lib_make_unique 201304L 1034 1035 /// @cond undocumented 1036 namespace __detail 1037 { 1038 template<typename _Tp> 1039 struct _MakeUniq 1040 { typedef unique_ptr<_Tp> __single_object; }; 1041 1042 template<typename _Tp> 1043 struct _MakeUniq<_Tp[]> 1044 { typedef unique_ptr<_Tp[]> __array; }; 1045 1046 template<typename _Tp, size_t _Bound> 1047 struct _MakeUniq<_Tp[_Bound]> 1048 { struct __invalid_type { }; }; 1049 1050 template<typename _Tp> 1051 using __unique_ptr_t = typename _MakeUniq<_Tp>::__single_object; 1052 template<typename _Tp> 1053 using __unique_ptr_array_t = typename _MakeUniq<_Tp>::__array; 1054 template<typename _Tp> 1055 using __invalid_make_unique_t = typename _MakeUniq<_Tp>::__invalid_type; 1056 } 1057 /// @endcond 1058 1059 /** Create an object owned by a `unique_ptr`. 1060 * @tparam _Tp A non-array object type. 1061 * @param __args Constructor arguments for the new object. 1062 * @returns A `unique_ptr<_Tp>` that owns the new object. 1063 * @since C++14 1064 * @relates unique_ptr 1065 */ 1066 template<typename _Tp, typename... _Args> 1067 _GLIBCXX23_CONSTEXPR 1068 inline __detail::__unique_ptr_t<_Tp> 1069 make_unique(_Args&&... __args) 1070 { return unique_ptr<_Tp>(new _Tp(std::forward<_Args>(__args)...)); } 1071 1072 /** Create an array owned by a `unique_ptr`. 1073 * @tparam _Tp An array type of unknown bound, such as `U[]`. 1074 * @param __num The number of elements of type `U` in the new array. 1075 * @returns A `unique_ptr<U[]>` that owns the new array. 1076 * @since C++14 1077 * @relates unique_ptr 1078 * 1079 * The array elements are value-initialized. 1080 */ 1081 template<typename _Tp> 1082 _GLIBCXX23_CONSTEXPR 1083 inline __detail::__unique_ptr_array_t<_Tp> 1084 make_unique(size_t __num) 1085 { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]()); } 1086 1087 /** Disable std::make_unique for arrays of known bound. 1088 * @tparam _Tp An array type of known bound, such as `U[N]`. 1089 * @since C++14 1090 * @relates unique_ptr 1091 */ 1092 template<typename _Tp, typename... _Args> 1093 __detail::__invalid_make_unique_t<_Tp> 1094 make_unique(_Args&&...) = delete; 1095 1096 #if __cplusplus > 201703L 1097 /** Create a default-initialied object owned by a `unique_ptr`. 1098 * @tparam _Tp A non-array object type. 1099 * @returns A `unique_ptr<_Tp>` that owns the new object. 1100 * @since C++20 1101 * @relates unique_ptr 1102 */ 1103 template<typename _Tp> 1104 _GLIBCXX23_CONSTEXPR 1105 inline __detail::__unique_ptr_t<_Tp> 1106 make_unique_for_overwrite() 1107 { return unique_ptr<_Tp>(new _Tp); } 1108 1109 /** Create a default-initialized array owned by a `unique_ptr`. 1110 * @tparam _Tp An array type of unknown bound, such as `U[]`. 1111 * @param __num The number of elements of type `U` in the new array. 1112 * @returns A `unique_ptr<U[]>` that owns the new array. 1113 * @since C++20 1114 * @relates unique_ptr 1115 */ 1116 template<typename _Tp> 1117 _GLIBCXX23_CONSTEXPR 1118 inline __detail::__unique_ptr_array_t<_Tp> 1119 make_unique_for_overwrite(size_t __num) 1120 { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]); } 1121 1122 /** Disable std::make_unique_for_overwrite for arrays of known bound. 1123 * @tparam _Tp An array type of known bound, such as `U[N]`. 1124 * @since C++20 1125 * @relates unique_ptr 1126 */ 1127 template<typename _Tp, typename... _Args> 1128 __detail::__invalid_make_unique_t<_Tp> 1129 make_unique_for_overwrite(_Args&&...) = delete; 1130 #endif // C++20 1131 1132 #endif // C++14 && HOSTED 1133 1134 #if __cplusplus > 201703L && __cpp_concepts && _GLIBCXX_HOSTED 1135 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1136 // 2948. unique_ptr does not define operator<< for stream output 1137 /// Stream output operator for unique_ptr 1138 /// @relates unique_ptr 1139 /// @since C++20 1140 template<typename _CharT, typename _Traits, typename _Tp, typename _Dp> 1141 inline basic_ostream<_CharT, _Traits>& 1142 operator<<(basic_ostream<_CharT, _Traits>& __os, 1143 const unique_ptr<_Tp, _Dp>& __p) 1144 requires requires { __os << __p.get(); } 1145 { 1146 __os << __p.get(); 1147 return __os; 1148 } 1149 #endif // C++20 && HOSTED 1150 1151 /// @} group pointer_abstractions 1152 1153 #if __cplusplus >= 201703L 1154 namespace __detail::__variant 1155 { 1156 template<typename> struct _Never_valueless_alt; // see <variant> 1157 1158 // Provide the strong exception-safety guarantee when emplacing a 1159 // unique_ptr into a variant. 1160 template<typename _Tp, typename _Del> 1161 struct _Never_valueless_alt<std::unique_ptr<_Tp, _Del>> 1162 : std::true_type 1163 { }; 1164 } // namespace __detail::__variant 1165 #endif // C++17 1166 1167 _GLIBCXX_END_NAMESPACE_VERSION 1168 } // namespace 1169 1170 #endif /* _UNIQUE_PTR_H */
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