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1 // unique_ptr implementation -*- C++ -*- 2 3 // Copyright (C) 2008-2025 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 <bits/ostream.h> 43 # endif 44 #endif 45 46 namespace std _GLIBCXX_VISIBILITY(default) 47 { 48 _GLIBCXX_BEGIN_NAMESPACE_VERSION 49 50 /** 51 * @addtogroup pointer_abstractions 52 * @{ 53 */ 54 55 #if _GLIBCXX_USE_DEPRECATED 56 #pragma GCC diagnostic push 57 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 58 template<typename> class auto_ptr; 59 #pragma GCC diagnostic pop 60 #endif 61 62 /** Primary template of default_delete, used by unique_ptr for single objects 63 * 64 * @headerfile memory 65 * @since C++11 66 */ 67 template<typename _Tp> 68 struct default_delete 69 { 70 /// Default constructor 71 constexpr default_delete() noexcept = default; 72 73 /** @brief Converting constructor. 74 * 75 * Allows conversion from a deleter for objects of another type, `_Up`, 76 * only if `_Up*` is convertible to `_Tp*`. 77 */ 78 template<typename _Up, 79 typename = _Require<is_convertible<_Up*, _Tp*>>> 80 _GLIBCXX23_CONSTEXPR 81 default_delete(const default_delete<_Up>&) noexcept { } 82 83 /// Calls `delete __ptr` 84 _GLIBCXX23_CONSTEXPR 85 void 86 operator()(_Tp* __ptr) const 87 { 88 static_assert(!is_void<_Tp>::value, 89 "can't delete pointer to incomplete type"); 90 static_assert(sizeof(_Tp)>0, 91 "can't delete pointer to incomplete type"); 92 delete __ptr; 93 } 94 }; 95 96 // _GLIBCXX_RESOLVE_LIB_DEFECTS 97 // DR 740 - omit specialization for array objects with a compile time length 98 99 /** Specialization of default_delete for arrays, used by `unique_ptr<T[]>` 100 * 101 * @headerfile memory 102 * @since C++11 103 */ 104 template<typename _Tp> 105 struct default_delete<_Tp[]> 106 { 107 public: 108 /// Default constructor 109 constexpr default_delete() noexcept = default; 110 111 /** @brief Converting constructor. 112 * 113 * Allows conversion from a deleter for arrays of another type, such as 114 * a const-qualified version of `_Tp`. 115 * 116 * Conversions from types derived from `_Tp` are not allowed because 117 * it is undefined to `delete[]` an array of derived types through a 118 * pointer to the base type. 119 */ 120 template<typename _Up, 121 typename = _Require<is_convertible<_Up(*)[], _Tp(*)[]>>> 122 _GLIBCXX23_CONSTEXPR 123 default_delete(const default_delete<_Up[]>&) noexcept { } 124 125 /// Calls `delete[] __ptr` 126 template<typename _Up> 127 _GLIBCXX23_CONSTEXPR 128 typename enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type 129 operator()(_Up* __ptr) const 130 { 131 static_assert(sizeof(_Tp)>0, 132 "can't delete pointer to incomplete type"); 133 delete [] __ptr; 134 } 135 }; 136 137 /// @cond undocumented 138 139 // Manages the pointer and deleter of a unique_ptr 140 template <typename _Tp, typename _Dp> 141 class __uniq_ptr_impl 142 { 143 template <typename _Up, typename _Ep, typename = void> 144 struct _Ptr 145 { 146 using type = _Up*; 147 }; 148 149 template <typename _Up, typename _Ep> 150 struct 151 _Ptr<_Up, _Ep, __void_t<typename remove_reference<_Ep>::type::pointer>> 152 { 153 using type = typename remove_reference<_Ep>::type::pointer; 154 }; 155 156 public: 157 using _DeleterConstraint = enable_if< 158 __and_<__not_<is_pointer<_Dp>>, 159 is_default_constructible<_Dp>>::value>; 160 161 using pointer = typename _Ptr<_Tp, _Dp>::type; 162 163 static_assert( !is_rvalue_reference<_Dp>::value, 164 "unique_ptr's deleter type must be a function object type" 165 " or an lvalue reference type" ); 166 167 __uniq_ptr_impl() = default; 168 _GLIBCXX23_CONSTEXPR 169 __uniq_ptr_impl(pointer __p) : _M_t() { _M_ptr() = __p; } 170 171 template<typename _Del> 172 _GLIBCXX23_CONSTEXPR 173 __uniq_ptr_impl(pointer __p, _Del&& __d) 174 : _M_t(__p, std::forward<_Del>(__d)) { } 175 176 _GLIBCXX23_CONSTEXPR 177 __uniq_ptr_impl(__uniq_ptr_impl&& __u) noexcept 178 : _M_t(std::move(__u._M_t)) 179 { __u._M_ptr() = nullptr; } 180 181 _GLIBCXX23_CONSTEXPR 182 __uniq_ptr_impl& operator=(__uniq_ptr_impl&& __u) noexcept 183 { 184 reset(__u.release()); 185 _M_deleter() = std::forward<_Dp>(__u._M_deleter()); 186 return *this; 187 } 188 189 _GLIBCXX23_CONSTEXPR 190 pointer& _M_ptr() noexcept { return std::get<0>(_M_t); } 191 _GLIBCXX23_CONSTEXPR 192 pointer _M_ptr() const noexcept { return std::get<0>(_M_t); } 193 _GLIBCXX23_CONSTEXPR 194 _Dp& _M_deleter() noexcept { return std::get<1>(_M_t); } 195 _GLIBCXX23_CONSTEXPR 196 const _Dp& _M_deleter() const noexcept { return std::get<1>(_M_t); } 197 198 _GLIBCXX23_CONSTEXPR 199 void reset(pointer __p) noexcept 200 { 201 const pointer __old_p = _M_ptr(); 202 _M_ptr() = __p; 203 if (__old_p) 204 _M_deleter()(__old_p); 205 } 206 207 _GLIBCXX23_CONSTEXPR 208 pointer release() noexcept 209 { 210 pointer __p = _M_ptr(); 211 _M_ptr() = nullptr; 212 return __p; 213 } 214 215 _GLIBCXX23_CONSTEXPR 216 void 217 swap(__uniq_ptr_impl& __rhs) noexcept 218 { 219 using std::swap; 220 swap(this->_M_ptr(), __rhs._M_ptr()); 221 swap(this->_M_deleter(), __rhs._M_deleter()); 222 } 223 224 private: 225 tuple<pointer, _Dp> _M_t; 226 }; 227 228 // Defines move construction + assignment as either defaulted or deleted. 229 template <typename _Tp, typename _Dp, 230 bool = is_move_constructible<_Dp>::value, 231 bool = is_move_assignable<_Dp>::value> 232 struct __uniq_ptr_data : __uniq_ptr_impl<_Tp, _Dp> 233 { 234 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl; 235 __uniq_ptr_data(__uniq_ptr_data&&) = default; 236 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = default; 237 }; 238 239 template <typename _Tp, typename _Dp> 240 struct __uniq_ptr_data<_Tp, _Dp, true, false> : __uniq_ptr_impl<_Tp, _Dp> 241 { 242 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl; 243 __uniq_ptr_data(__uniq_ptr_data&&) = default; 244 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = delete; 245 }; 246 247 template <typename _Tp, typename _Dp> 248 struct __uniq_ptr_data<_Tp, _Dp, false, true> : __uniq_ptr_impl<_Tp, _Dp> 249 { 250 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl; 251 __uniq_ptr_data(__uniq_ptr_data&&) = delete; 252 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = default; 253 }; 254 255 template <typename _Tp, typename _Dp> 256 struct __uniq_ptr_data<_Tp, _Dp, false, false> : __uniq_ptr_impl<_Tp, _Dp> 257 { 258 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl; 259 __uniq_ptr_data(__uniq_ptr_data&&) = delete; 260 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = delete; 261 }; 262 /// @endcond 263 264 // 20.7.1.2 unique_ptr for single objects. 265 266 /// A move-only smart pointer that manages unique ownership of a resource. 267 /// @headerfile memory 268 /// @since C++11 269 template <typename _Tp, typename _Dp = default_delete<_Tp>> 270 class unique_ptr 271 { 272 template <typename _Up> 273 using _DeleterConstraint = 274 typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type; 275 276 __uniq_ptr_data<_Tp, _Dp> _M_t; 277 278 public: 279 using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer; 280 using element_type = _Tp; 281 using deleter_type = _Dp; 282 283 private: 284 // helper template for detecting a safe conversion from another 285 // unique_ptr 286 template<typename _Up, typename _Ep> 287 using __safe_conversion_up = __and_< 288 is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>, 289 __not_<is_array<_Up>> 290 >; 291 292 public: 293 // Constructors. 294 295 /// Default constructor, creates a unique_ptr that owns nothing. 296 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 297 constexpr unique_ptr() noexcept 298 : _M_t() 299 { } 300 301 /** Takes ownership of a pointer. 302 * 303 * @param __p A pointer to an object of @c element_type 304 * 305 * The deleter will be value-initialized. 306 */ 307 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 308 _GLIBCXX23_CONSTEXPR 309 explicit 310 unique_ptr(pointer __p) noexcept 311 : _M_t(__p) 312 { } 313 314 /** Takes ownership of a pointer. 315 * 316 * @param __p A pointer to an object of @c element_type 317 * @param __d A reference to a deleter. 318 * 319 * The deleter will be initialized with @p __d 320 */ 321 template<typename _Del = deleter_type, 322 typename = _Require<is_copy_constructible<_Del>>> 323 _GLIBCXX23_CONSTEXPR 324 unique_ptr(pointer __p, const deleter_type& __d) noexcept 325 : _M_t(__p, __d) { } 326 327 /** Takes ownership of a pointer. 328 * 329 * @param __p A pointer to an object of @c element_type 330 * @param __d An rvalue reference to a (non-reference) deleter. 331 * 332 * The deleter will be initialized with @p std::move(__d) 333 */ 334 template<typename _Del = deleter_type, 335 typename = _Require<is_move_constructible<_Del>>> 336 _GLIBCXX23_CONSTEXPR 337 unique_ptr(pointer __p, 338 __enable_if_t<!is_lvalue_reference<_Del>::value, 339 _Del&&> __d) noexcept 340 : _M_t(__p, std::move(__d)) 341 { } 342 343 template<typename _Del = deleter_type, 344 typename _DelUnref = typename remove_reference<_Del>::type> 345 _GLIBCXX23_CONSTEXPR 346 unique_ptr(pointer, 347 __enable_if_t<is_lvalue_reference<_Del>::value, 348 _DelUnref&&>) = delete; 349 350 /// Creates a unique_ptr that owns nothing. 351 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 352 constexpr unique_ptr(nullptr_t) noexcept 353 : _M_t() 354 { } 355 356 // Move constructors. 357 358 /// Move constructor. 359 unique_ptr(unique_ptr&&) = default; 360 361 /** @brief Converting constructor from another type 362 * 363 * Requires that the pointer owned by @p __u is convertible to the 364 * type of pointer owned by this object, @p __u does not own an array, 365 * and @p __u has a compatible deleter type. 366 */ 367 template<typename _Up, typename _Ep, typename = _Require< 368 __safe_conversion_up<_Up, _Ep>, 369 __conditional_t<is_reference<_Dp>::value, 370 is_same<_Ep, _Dp>, 371 is_convertible<_Ep, _Dp>>>> 372 _GLIBCXX23_CONSTEXPR 373 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept 374 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) 375 { } 376 377 #if _GLIBCXX_USE_DEPRECATED 378 #pragma GCC diagnostic push 379 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 380 /// Converting constructor from @c auto_ptr 381 template<typename _Up, 382 typename = _Require<is_convertible<_Up*, pointer>, 383 is_same<_Dp, default_delete<_Tp>>>> 384 unique_ptr(auto_ptr<_Up>&& __u) noexcept; 385 #pragma GCC diagnostic pop 386 #endif 387 388 /// Destructor, invokes the deleter if the stored pointer is not null. 389 #if __cplusplus > 202002L && __cpp_constexpr_dynamic_alloc 390 constexpr 391 #endif 392 ~unique_ptr() noexcept 393 { 394 static_assert(__is_invocable<deleter_type&, pointer>::value, 395 "unique_ptr's deleter must be invocable with a pointer"); 396 auto& __ptr = _M_t._M_ptr(); 397 if (__ptr != nullptr) 398 get_deleter()(std::move(__ptr)); 399 __ptr = pointer(); 400 } 401 402 // Assignment. 403 404 /** @brief Move assignment operator. 405 * 406 * Invokes the deleter if this object owns a pointer. 407 */ 408 unique_ptr& operator=(unique_ptr&&) = default; 409 410 /** @brief Assignment from another type. 411 * 412 * @param __u The object to transfer ownership from, which owns a 413 * convertible pointer to a non-array object. 414 * 415 * Invokes the deleter if this object owns a pointer. 416 */ 417 template<typename _Up, typename _Ep> 418 _GLIBCXX23_CONSTEXPR 419 typename enable_if< __and_< 420 __safe_conversion_up<_Up, _Ep>, 421 is_assignable<deleter_type&, _Ep&&> 422 >::value, 423 unique_ptr&>::type 424 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept 425 { 426 reset(__u.release()); 427 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 428 return *this; 429 } 430 431 /// Reset the %unique_ptr to empty, invoking the deleter if necessary. 432 _GLIBCXX23_CONSTEXPR 433 unique_ptr& 434 operator=(nullptr_t) noexcept 435 { 436 reset(); 437 return *this; 438 } 439 440 // Observers. 441 442 /// Dereference the stored pointer. 443 _GLIBCXX23_CONSTEXPR 444 typename add_lvalue_reference<element_type>::type 445 operator*() const noexcept(noexcept(*std::declval<pointer>())) 446 { 447 #if _GLIBCXX_USE_BUILTIN_TRAIT(__reference_converts_from_temporary) 448 // _GLIBCXX_RESOLVE_LIB_DEFECTS 449 // 4148. unique_ptr::operator* should not allow dangling references 450 using _ResT = typename add_lvalue_reference<element_type>::type; 451 using _DerefT = decltype(*get()); 452 static_assert(!__reference_converts_from_temporary(_ResT, _DerefT), 453 "operator* must not return a dangling reference"); 454 #endif 455 __glibcxx_assert(get() != pointer()); 456 return *get(); 457 } 458 459 /// Return the stored pointer. 460 _GLIBCXX23_CONSTEXPR 461 pointer 462 operator->() const noexcept 463 { 464 _GLIBCXX_DEBUG_PEDASSERT(get() != pointer()); 465 return get(); 466 } 467 468 /// Return the stored pointer. 469 _GLIBCXX23_CONSTEXPR 470 pointer 471 get() const noexcept 472 { return _M_t._M_ptr(); } 473 474 /// Return a reference to the stored deleter. 475 _GLIBCXX23_CONSTEXPR 476 deleter_type& 477 get_deleter() noexcept 478 { return _M_t._M_deleter(); } 479 480 /// Return a reference to the stored deleter. 481 _GLIBCXX23_CONSTEXPR 482 const deleter_type& 483 get_deleter() const noexcept 484 { return _M_t._M_deleter(); } 485 486 /// Return @c true if the stored pointer is not null. 487 _GLIBCXX23_CONSTEXPR 488 explicit operator bool() const noexcept 489 { return get() == pointer() ? false : true; } 490 491 // Modifiers. 492 493 /// Release ownership of any stored pointer. 494 _GLIBCXX23_CONSTEXPR 495 pointer 496 release() noexcept 497 { return _M_t.release(); } 498 499 /** @brief Replace the stored pointer. 500 * 501 * @param __p The new pointer to store. 502 * 503 * The deleter will be invoked if a pointer is already owned. 504 */ 505 _GLIBCXX23_CONSTEXPR 506 void 507 reset(pointer __p = pointer()) noexcept 508 { 509 static_assert(__is_invocable<deleter_type&, pointer>::value, 510 "unique_ptr's deleter must be invocable with a pointer"); 511 _M_t.reset(std::move(__p)); 512 } 513 514 /// Exchange the pointer and deleter with another object. 515 _GLIBCXX23_CONSTEXPR 516 void 517 swap(unique_ptr& __u) noexcept 518 { 519 static_assert(__is_swappable<_Dp>::value, "deleter must be swappable"); 520 _M_t.swap(__u._M_t); 521 } 522 523 // Disable copy from lvalue. 524 unique_ptr(const unique_ptr&) = delete; 525 unique_ptr& operator=(const unique_ptr&) = delete; 526 527 private: 528 #ifdef __glibcxx_out_ptr 529 template<typename, typename, typename...> 530 friend class out_ptr_t; 531 template<typename, typename, typename...> 532 friend class inout_ptr_t; 533 #endif 534 }; 535 536 // 20.7.1.3 unique_ptr for array objects with a runtime length 537 // [unique.ptr.runtime] 538 // _GLIBCXX_RESOLVE_LIB_DEFECTS 539 // DR 740 - omit specialization for array objects with a compile time length 540 541 /// A move-only smart pointer that manages unique ownership of an array. 542 /// @headerfile memory 543 /// @since C++11 544 template<typename _Tp, typename _Dp> 545 class unique_ptr<_Tp[], _Dp> 546 { 547 template <typename _Up> 548 using _DeleterConstraint = 549 typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type; 550 551 __uniq_ptr_data<_Tp, _Dp> _M_t; 552 553 // like is_base_of<_Tp, _Up> but false if unqualified types are the same 554 template<typename _Up> 555 using __is_derived_Tp 556 = __and_< is_base_of<_Tp, _Up>, 557 __not_<is_same<__remove_cv_t<_Tp>, __remove_cv_t<_Up>>> >; 558 559 public: 560 using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer; 561 using element_type = _Tp; 562 using deleter_type = _Dp; 563 564 // helper template for detecting a safe conversion from another 565 // unique_ptr 566 template<typename _Up, typename _Ep, 567 typename _UPtr = unique_ptr<_Up, _Ep>, 568 typename _UP_pointer = typename _UPtr::pointer, 569 typename _UP_element_type = typename _UPtr::element_type> 570 using __safe_conversion_up = __and_< 571 is_array<_Up>, 572 is_same<pointer, element_type*>, 573 is_same<_UP_pointer, _UP_element_type*>, 574 is_convertible<_UP_element_type(*)[], element_type(*)[]> 575 >; 576 577 // helper template for detecting a safe conversion from a raw pointer 578 template<typename _Up> 579 using __safe_conversion_raw = __and_< 580 __or_<__or_<is_same<_Up, pointer>, 581 is_same<_Up, nullptr_t>>, 582 __and_<is_pointer<_Up>, 583 is_same<pointer, element_type*>, 584 is_convertible< 585 typename remove_pointer<_Up>::type(*)[], 586 element_type(*)[]> 587 > 588 > 589 >; 590 591 // Constructors. 592 593 /// Default constructor, creates a unique_ptr that owns nothing. 594 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 595 constexpr unique_ptr() noexcept 596 : _M_t() 597 { } 598 599 /** Takes ownership of a pointer. 600 * 601 * @param __p A pointer to an array of a type safely convertible 602 * to an array of @c element_type 603 * 604 * The deleter will be value-initialized. 605 */ 606 template<typename _Up, 607 typename _Vp = _Dp, 608 typename = _DeleterConstraint<_Vp>, 609 typename = typename enable_if< 610 __safe_conversion_raw<_Up>::value, bool>::type> 611 _GLIBCXX23_CONSTEXPR 612 explicit 613 unique_ptr(_Up __p) noexcept 614 : _M_t(__p) 615 { } 616 617 /** Takes ownership of a pointer. 618 * 619 * @param __p A pointer to an array of a type safely convertible 620 * to an array of @c element_type 621 * @param __d A reference to a deleter. 622 * 623 * The deleter will be initialized with @p __d 624 */ 625 template<typename _Up, typename _Del = deleter_type, 626 typename = _Require<__safe_conversion_raw<_Up>, 627 is_copy_constructible<_Del>>> 628 _GLIBCXX23_CONSTEXPR 629 unique_ptr(_Up __p, const deleter_type& __d) noexcept 630 : _M_t(__p, __d) { } 631 632 /** Takes ownership of a pointer. 633 * 634 * @param __p A pointer to an array of a type safely convertible 635 * to an array of @c element_type 636 * @param __d A reference to a deleter. 637 * 638 * The deleter will be initialized with @p std::move(__d) 639 */ 640 template<typename _Up, typename _Del = deleter_type, 641 typename = _Require<__safe_conversion_raw<_Up>, 642 is_move_constructible<_Del>>> 643 _GLIBCXX23_CONSTEXPR 644 unique_ptr(_Up __p, 645 __enable_if_t<!is_lvalue_reference<_Del>::value, 646 _Del&&> __d) noexcept 647 : _M_t(std::move(__p), std::move(__d)) 648 { } 649 650 template<typename _Up, typename _Del = deleter_type, 651 typename _DelUnref = typename remove_reference<_Del>::type, 652 typename = _Require<__safe_conversion_raw<_Up>>> 653 unique_ptr(_Up, 654 __enable_if_t<is_lvalue_reference<_Del>::value, 655 _DelUnref&&>) = delete; 656 657 /// Move constructor. 658 unique_ptr(unique_ptr&&) = default; 659 660 /// Creates a unique_ptr that owns nothing. 661 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>> 662 constexpr unique_ptr(nullptr_t) noexcept 663 : _M_t() 664 { } 665 666 template<typename _Up, typename _Ep, typename = _Require< 667 __safe_conversion_up<_Up, _Ep>, 668 __conditional_t<is_reference<_Dp>::value, 669 is_same<_Ep, _Dp>, 670 is_convertible<_Ep, _Dp>>>> 671 _GLIBCXX23_CONSTEXPR 672 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept 673 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) 674 { } 675 676 /// Destructor, invokes the deleter if the stored pointer is not null. 677 #if __cplusplus > 202002L && __cpp_constexpr_dynamic_alloc 678 constexpr 679 #endif 680 ~unique_ptr() 681 { 682 auto& __ptr = _M_t._M_ptr(); 683 if (__ptr != nullptr) 684 get_deleter()(__ptr); 685 __ptr = pointer(); 686 } 687 688 // Assignment. 689 690 /** @brief Move assignment operator. 691 * 692 * Invokes the deleter if this object owns a pointer. 693 */ 694 unique_ptr& 695 operator=(unique_ptr&&) = default; 696 697 /** @brief Assignment from another type. 698 * 699 * @param __u The object to transfer ownership from, which owns a 700 * convertible pointer to an array object. 701 * 702 * Invokes the deleter if this object owns a pointer. 703 */ 704 template<typename _Up, typename _Ep> 705 _GLIBCXX23_CONSTEXPR 706 typename 707 enable_if<__and_<__safe_conversion_up<_Up, _Ep>, 708 is_assignable<deleter_type&, _Ep&&> 709 >::value, 710 unique_ptr&>::type 711 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept 712 { 713 reset(__u.release()); 714 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 715 return *this; 716 } 717 718 /// Reset the %unique_ptr to empty, invoking the deleter if necessary. 719 _GLIBCXX23_CONSTEXPR 720 unique_ptr& 721 operator=(nullptr_t) noexcept 722 { 723 reset(); 724 return *this; 725 } 726 727 // Observers. 728 729 /// Access an element of owned array. 730 _GLIBCXX23_CONSTEXPR 731 typename std::add_lvalue_reference<element_type>::type 732 operator[](size_t __i) const 733 { 734 __glibcxx_assert(get() != pointer()); 735 return get()[__i]; 736 } 737 738 /// Return the stored pointer. 739 _GLIBCXX23_CONSTEXPR 740 pointer 741 get() const noexcept 742 { return _M_t._M_ptr(); } 743 744 /// Return a reference to the stored deleter. 745 _GLIBCXX23_CONSTEXPR 746 deleter_type& 747 get_deleter() noexcept 748 { return _M_t._M_deleter(); } 749 750 /// Return a reference to the stored deleter. 751 _GLIBCXX23_CONSTEXPR 752 const deleter_type& 753 get_deleter() const noexcept 754 { return _M_t._M_deleter(); } 755 756 /// Return @c true if the stored pointer is not null. 757 _GLIBCXX23_CONSTEXPR 758 explicit operator bool() const noexcept 759 { return get() == pointer() ? false : true; } 760 761 // Modifiers. 762 763 /// Release ownership of any stored pointer. 764 _GLIBCXX23_CONSTEXPR 765 pointer 766 release() noexcept 767 { return _M_t.release(); } 768 769 /** @brief Replace the stored pointer. 770 * 771 * @param __p The new pointer to store. 772 * 773 * The deleter will be invoked if a pointer is already owned. 774 */ 775 template <typename _Up, 776 typename = _Require< 777 __or_<is_same<_Up, pointer>, 778 __and_<is_same<pointer, element_type*>, 779 is_pointer<_Up>, 780 is_convertible< 781 typename remove_pointer<_Up>::type(*)[], 782 element_type(*)[] 783 > 784 > 785 > 786 >> 787 _GLIBCXX23_CONSTEXPR 788 void 789 reset(_Up __p) noexcept 790 { _M_t.reset(std::move(__p)); } 791 792 _GLIBCXX23_CONSTEXPR 793 void reset(nullptr_t = nullptr) noexcept 794 { reset(pointer()); } 795 796 /// Exchange the pointer and deleter with another object. 797 _GLIBCXX23_CONSTEXPR 798 void 799 swap(unique_ptr& __u) noexcept 800 { 801 static_assert(__is_swappable<_Dp>::value, "deleter must be swappable"); 802 _M_t.swap(__u._M_t); 803 } 804 805 // Disable copy from lvalue. 806 unique_ptr(const unique_ptr&) = delete; 807 unique_ptr& operator=(const unique_ptr&) = delete; 808 809 private: 810 #ifdef __glibcxx_out_ptr 811 template<typename, typename, typename...> friend class out_ptr_t; 812 template<typename, typename, typename...> friend class inout_ptr_t; 813 #endif 814 }; 815 816 /// @{ 817 /// @relates unique_ptr 818 819 /// Swap overload for unique_ptr 820 template<typename _Tp, typename _Dp> 821 inline 822 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 823 // Constrained free swap overload, see p0185r1 824 _GLIBCXX23_CONSTEXPR 825 typename enable_if<__is_swappable<_Dp>::value>::type 826 #else 827 void 828 #endif 829 swap(unique_ptr<_Tp, _Dp>& __x, 830 unique_ptr<_Tp, _Dp>& __y) noexcept 831 { __x.swap(__y); } 832 833 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11 834 template<typename _Tp, typename _Dp> 835 typename enable_if<!__is_swappable<_Dp>::value>::type 836 swap(unique_ptr<_Tp, _Dp>&, 837 unique_ptr<_Tp, _Dp>&) = delete; 838 #endif 839 840 /// Equality operator for unique_ptr objects, compares the owned pointers 841 template<typename _Tp, typename _Dp, 842 typename _Up, typename _Ep> 843 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 844 inline bool 845 operator==(const unique_ptr<_Tp, _Dp>& __x, 846 const unique_ptr<_Up, _Ep>& __y) 847 { return __x.get() == __y.get(); } 848 849 /// unique_ptr comparison with nullptr 850 template<typename _Tp, typename _Dp> 851 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 852 inline bool 853 operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept 854 { return !__x; } 855 856 #ifndef __cpp_lib_three_way_comparison 857 /// unique_ptr comparison with nullptr 858 template<typename _Tp, typename _Dp> 859 _GLIBCXX_NODISCARD 860 inline bool 861 operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept 862 { return !__x; } 863 864 /// Inequality operator for unique_ptr objects, compares the owned pointers 865 template<typename _Tp, typename _Dp, 866 typename _Up, typename _Ep> 867 _GLIBCXX_NODISCARD 868 inline bool 869 operator!=(const unique_ptr<_Tp, _Dp>& __x, 870 const unique_ptr<_Up, _Ep>& __y) 871 { return __x.get() != __y.get(); } 872 873 /// unique_ptr comparison with nullptr 874 template<typename _Tp, typename _Dp> 875 _GLIBCXX_NODISCARD 876 inline bool 877 operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept 878 { return (bool)__x; } 879 880 /// unique_ptr comparison with nullptr 881 template<typename _Tp, typename _Dp> 882 _GLIBCXX_NODISCARD 883 inline bool 884 operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept 885 { return (bool)__x; } 886 #endif // three way comparison 887 888 /// Relational operator for unique_ptr objects, compares the owned pointers 889 template<typename _Tp, typename _Dp, 890 typename _Up, typename _Ep> 891 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 892 inline bool 893 operator<(const unique_ptr<_Tp, _Dp>& __x, 894 const unique_ptr<_Up, _Ep>& __y) 895 { 896 typedef typename 897 std::common_type<typename unique_ptr<_Tp, _Dp>::pointer, 898 typename unique_ptr<_Up, _Ep>::pointer>::type _CT; 899 return std::less<_CT>()(__x.get(), __y.get()); 900 } 901 902 /// unique_ptr comparison with nullptr 903 template<typename _Tp, typename _Dp> 904 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 905 inline bool 906 operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 907 { 908 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), 909 nullptr); 910 } 911 912 /// unique_ptr comparison with nullptr 913 template<typename _Tp, typename _Dp> 914 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 915 inline bool 916 operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 917 { 918 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, 919 __x.get()); 920 } 921 922 /// Relational operator for unique_ptr objects, compares the owned pointers 923 template<typename _Tp, typename _Dp, 924 typename _Up, typename _Ep> 925 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 926 inline bool 927 operator<=(const unique_ptr<_Tp, _Dp>& __x, 928 const unique_ptr<_Up, _Ep>& __y) 929 { return !(__y < __x); } 930 931 /// unique_ptr comparison with nullptr 932 template<typename _Tp, typename _Dp> 933 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 934 inline bool 935 operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 936 { return !(nullptr < __x); } 937 938 /// unique_ptr comparison with nullptr 939 template<typename _Tp, typename _Dp> 940 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 941 inline bool 942 operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 943 { return !(__x < nullptr); } 944 945 /// Relational operator for unique_ptr objects, compares the owned pointers 946 template<typename _Tp, typename _Dp, 947 typename _Up, typename _Ep> 948 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 949 inline bool 950 operator>(const unique_ptr<_Tp, _Dp>& __x, 951 const unique_ptr<_Up, _Ep>& __y) 952 { return (__y < __x); } 953 954 /// unique_ptr comparison with nullptr 955 template<typename _Tp, typename _Dp> 956 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 957 inline bool 958 operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 959 { 960 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, 961 __x.get()); 962 } 963 964 /// unique_ptr comparison with nullptr 965 template<typename _Tp, typename _Dp> 966 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 967 inline bool 968 operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 969 { 970 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), 971 nullptr); 972 } 973 974 /// Relational operator for unique_ptr objects, compares the owned pointers 975 template<typename _Tp, typename _Dp, 976 typename _Up, typename _Ep> 977 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 978 inline bool 979 operator>=(const unique_ptr<_Tp, _Dp>& __x, 980 const unique_ptr<_Up, _Ep>& __y) 981 { return !(__x < __y); } 982 983 /// unique_ptr comparison with nullptr 984 template<typename _Tp, typename _Dp> 985 _GLIBCXX_NODISCARD _GLIBCXX23_CONSTEXPR 986 inline bool 987 operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 988 { return !(__x < nullptr); } 989 990 /// unique_ptr comparison with nullptr 991 template<typename _Tp, typename _Dp> 992 _GLIBCXX_NODISCARD inline bool 993 operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 994 { return !(nullptr < __x); } 995 996 #ifdef __cpp_lib_three_way_comparison 997 template<typename _Tp, typename _Dp, typename _Up, typename _Ep> 998 requires three_way_comparable_with<typename unique_ptr<_Tp, _Dp>::pointer, 999 typename unique_ptr<_Up, _Ep>::pointer> 1000 _GLIBCXX23_CONSTEXPR 1001 inline 1002 compare_three_way_result_t<typename unique_ptr<_Tp, _Dp>::pointer, 1003 typename unique_ptr<_Up, _Ep>::pointer> 1004 operator<=>(const unique_ptr<_Tp, _Dp>& __x, 1005 const unique_ptr<_Up, _Ep>& __y) 1006 { return compare_three_way()(__x.get(), __y.get()); } 1007 1008 template<typename _Tp, typename _Dp> 1009 requires three_way_comparable<typename unique_ptr<_Tp, _Dp>::pointer> 1010 _GLIBCXX23_CONSTEXPR 1011 inline 1012 compare_three_way_result_t<typename unique_ptr<_Tp, _Dp>::pointer> 1013 operator<=>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 1014 { 1015 using pointer = typename unique_ptr<_Tp, _Dp>::pointer; 1016 return compare_three_way()(__x.get(), static_cast<pointer>(nullptr)); 1017 } 1018 #endif 1019 /// @} relates unique_ptr 1020 1021 /// @cond undocumented 1022 template<typename _Up, typename _Ptr = typename _Up::pointer> 1023 struct __uniq_ptr_hash 1024 : public __hash_base<size_t, _Up> 1025 #if ! _GLIBCXX_INLINE_VERSION 1026 , private __hash_empty_base<_Ptr> 1027 #endif 1028 { 1029 size_t 1030 operator()(const _Up& __u) const 1031 noexcept(noexcept(std::declval<hash<_Ptr>>()(std::declval<_Ptr>()))) 1032 { return hash<_Ptr>()(__u.get()); } 1033 }; 1034 1035 template<typename _Up> 1036 using __uniq_ptr_hash_base 1037 = __conditional_t<__is_hash_enabled_for<typename _Up::pointer>, 1038 __uniq_ptr_hash<_Up>, 1039 __hash_not_enabled<typename _Up::pointer>>; 1040 /// @endcond 1041 1042 /// std::hash specialization for unique_ptr. 1043 template<typename _Tp, typename _Dp> 1044 struct hash<unique_ptr<_Tp, _Dp>> 1045 : public __uniq_ptr_hash_base<unique_ptr<_Tp, _Dp>> 1046 { }; 1047 1048 #ifdef __glibcxx_make_unique // C++ >= 14 && HOSTED 1049 /// @cond undocumented 1050 namespace __detail 1051 { 1052 template<typename _Tp> 1053 struct _MakeUniq 1054 { typedef unique_ptr<_Tp> __single_object; }; 1055 1056 template<typename _Tp> 1057 struct _MakeUniq<_Tp[]> 1058 { typedef unique_ptr<_Tp[]> __array; }; 1059 1060 template<typename _Tp, size_t _Bound> 1061 struct _MakeUniq<_Tp[_Bound]> 1062 { struct __invalid_type { }; }; 1063 1064 template<typename _Tp> 1065 using __unique_ptr_t = typename _MakeUniq<_Tp>::__single_object; 1066 template<typename _Tp> 1067 using __unique_ptr_array_t = typename _MakeUniq<_Tp>::__array; 1068 template<typename _Tp> 1069 using __invalid_make_unique_t = typename _MakeUniq<_Tp>::__invalid_type; 1070 } 1071 /// @endcond 1072 1073 /** Create an object owned by a `unique_ptr`. 1074 * @tparam _Tp A non-array object type. 1075 * @param __args Constructor arguments for the new object. 1076 * @returns A `unique_ptr<_Tp>` that owns the new object. 1077 * @since C++14 1078 * @relates unique_ptr 1079 */ 1080 template<typename _Tp, typename... _Args> 1081 _GLIBCXX23_CONSTEXPR 1082 inline __detail::__unique_ptr_t<_Tp> 1083 make_unique(_Args&&... __args) 1084 { return unique_ptr<_Tp>(new _Tp(std::forward<_Args>(__args)...)); } 1085 1086 /** Create an array owned by a `unique_ptr`. 1087 * @tparam _Tp An array type of unknown bound, such as `U[]`. 1088 * @param __num The number of elements of type `U` in the new array. 1089 * @returns A `unique_ptr<U[]>` that owns the new array. 1090 * @since C++14 1091 * @relates unique_ptr 1092 * 1093 * The array elements are value-initialized. 1094 */ 1095 template<typename _Tp> 1096 _GLIBCXX23_CONSTEXPR 1097 inline __detail::__unique_ptr_array_t<_Tp> 1098 make_unique(size_t __num) 1099 { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]()); } 1100 1101 /** Disable std::make_unique for arrays of known bound. 1102 * @tparam _Tp An array type of known bound, such as `U[N]`. 1103 * @since C++14 1104 * @relates unique_ptr 1105 */ 1106 template<typename _Tp, typename... _Args> 1107 __detail::__invalid_make_unique_t<_Tp> 1108 make_unique(_Args&&...) = delete; 1109 1110 #if __cplusplus > 201703L 1111 /** Create a default-initialied object owned by a `unique_ptr`. 1112 * @tparam _Tp A non-array object type. 1113 * @returns A `unique_ptr<_Tp>` that owns the new object. 1114 * @since C++20 1115 * @relates unique_ptr 1116 */ 1117 template<typename _Tp> 1118 _GLIBCXX23_CONSTEXPR 1119 inline __detail::__unique_ptr_t<_Tp> 1120 make_unique_for_overwrite() 1121 { return unique_ptr<_Tp>(new _Tp); } 1122 1123 /** Create a default-initialized array owned by a `unique_ptr`. 1124 * @tparam _Tp An array type of unknown bound, such as `U[]`. 1125 * @param __num The number of elements of type `U` in the new array. 1126 * @returns A `unique_ptr<U[]>` that owns the new array. 1127 * @since C++20 1128 * @relates unique_ptr 1129 */ 1130 template<typename _Tp> 1131 _GLIBCXX23_CONSTEXPR 1132 inline __detail::__unique_ptr_array_t<_Tp> 1133 make_unique_for_overwrite(size_t __num) 1134 { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]); } 1135 1136 /** Disable std::make_unique_for_overwrite for arrays of known bound. 1137 * @tparam _Tp An array type of known bound, such as `U[N]`. 1138 * @since C++20 1139 * @relates unique_ptr 1140 */ 1141 template<typename _Tp, typename... _Args> 1142 __detail::__invalid_make_unique_t<_Tp> 1143 make_unique_for_overwrite(_Args&&...) = delete; 1144 #endif // C++20 1145 1146 #endif // C++14 && HOSTED 1147 1148 #if __cplusplus > 201703L && __cpp_concepts && _GLIBCXX_HOSTED 1149 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1150 // 2948. unique_ptr does not define operator<< for stream output 1151 /// Stream output operator for unique_ptr 1152 /// @relates unique_ptr 1153 /// @since C++20 1154 template<typename _CharT, typename _Traits, typename _Tp, typename _Dp> 1155 inline basic_ostream<_CharT, _Traits>& 1156 operator<<(basic_ostream<_CharT, _Traits>& __os, 1157 const unique_ptr<_Tp, _Dp>& __p) 1158 requires requires { __os << __p.get(); } 1159 { 1160 __os << __p.get(); 1161 return __os; 1162 } 1163 #endif // C++20 && HOSTED 1164 1165 #if __cpp_variable_templates 1166 template<typename _Tp> 1167 constexpr bool __is_unique_ptr = false; 1168 template<typename _Tp, typename _Del> 1169 constexpr bool __is_unique_ptr<unique_ptr<_Tp, _Del>> = true; 1170 #endif 1171 1172 /// @} group pointer_abstractions 1173 1174 #if __cplusplus >= 201703L 1175 namespace __detail::__variant 1176 { 1177 template<typename> struct _Never_valueless_alt; // see <variant> 1178 1179 // Provide the strong exception-safety guarantee when emplacing a 1180 // unique_ptr into a variant. 1181 template<typename _Tp, typename _Del> 1182 struct _Never_valueless_alt<std::unique_ptr<_Tp, _Del>> 1183 : std::true_type 1184 { }; 1185 } // namespace __detail::__variant 1186 #endif // C++17 1187 1188 _GLIBCXX_END_NAMESPACE_VERSION 1189 } // namespace 1190 1191 #endif /* _UNIQUE_PTR_H */
