1 // unique_ptr implementation -*- C++ -*- 2 3 // Copyright (C) 2008, 2009, 2010, 2011 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/debug.h> 35 #include <type_traits> 36 #include <utility> 37 #include <tuple> 38 39 namespace std _GLIBCXX_VISIBILITY(default) 40 { 41 _GLIBCXX_BEGIN_NAMESPACE_VERSION 42 43 /** 44 * @addtogroup pointer_abstractions 45 * @{ 46 */ 47 48 /// Primary template, default_delete. 49 template<typename _Tp> 50 struct default_delete 51 { 52 constexpr default_delete() noexcept = default; 53 54 template<typename _Up, typename = typename 55 std::enable_if<std::is_convertible<_Up*, _Tp*>::value>::type> 56 default_delete(const default_delete<_Up>&) noexcept { } 57 58 void 59 operator()(_Tp* __ptr) const 60 { 61 static_assert(sizeof(_Tp)>0, 62 "can't delete pointer to incomplete type"); 63 delete __ptr; 64 } 65 }; 66 67 // _GLIBCXX_RESOLVE_LIB_DEFECTS 68 // DR 740 - omit specialization for array objects with a compile time length 69 /// Specialization, default_delete. 70 template<typename _Tp> 71 struct default_delete<_Tp[]> 72 { 73 constexpr default_delete() noexcept = default; 74 75 void 76 operator()(_Tp* __ptr) const 77 { 78 static_assert(sizeof(_Tp)>0, 79 "can't delete pointer to incomplete type"); 80 delete [] __ptr; 81 } 82 83 template<typename _Up> void operator()(_Up*) const = delete; 84 }; 85 86 /// 20.7.12.2 unique_ptr for single objects. 87 template <typename _Tp, typename _Dp = default_delete<_Tp> > 88 class unique_ptr 89 { 90 // use SFINAE to determine whether _Del::pointer exists 91 class _Pointer 92 { 93 template<typename _Up> 94 static typename _Up::pointer __test(typename _Up::pointer*); 95 96 template<typename _Up> 97 static _Tp* __test(...); 98 99 typedef typename remove_reference<_Dp>::type _Del; 100 101 public: 102 typedef decltype( __test<_Del>(0)) type; 103 }; 104 105 typedef std::tuple<typename _Pointer::type, _Dp> __tuple_type; 106 __tuple_type _M_t; 107 108 public: 109 typedef typename _Pointer::type pointer; 110 typedef _Tp element_type; 111 typedef _Dp deleter_type; 112 113 // Constructors. 114 constexpr unique_ptr() noexcept 115 : _M_t() 116 { static_assert(!std::is_pointer<deleter_type>::value, 117 "constructed with null function pointer deleter"); } 118 119 explicit 120 unique_ptr(pointer __p) noexcept 121 : _M_t(__p, deleter_type()) 122 { static_assert(!std::is_pointer<deleter_type>::value, 123 "constructed with null function pointer deleter"); } 124 125 unique_ptr(pointer __p, 126 typename std::conditional<std::is_reference<deleter_type>::value, 127 deleter_type, const deleter_type&>::type __d) noexcept 128 : _M_t(__p, __d) { } 129 130 unique_ptr(pointer __p, 131 typename std::remove_reference<deleter_type>::type&& __d) noexcept 132 : _M_t(std::move(__p), std::move(__d)) 133 { static_assert(!std::is_reference<deleter_type>::value, 134 "rvalue deleter bound to reference"); } 135 136 constexpr unique_ptr(nullptr_t) noexcept 137 : _M_t() 138 { static_assert(!std::is_pointer<deleter_type>::value, 139 "constructed with null function pointer deleter"); } 140 141 // Move constructors. 142 unique_ptr(unique_ptr&& __u) noexcept 143 : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { } 144 145 template<typename _Up, typename _Ep, typename = typename 146 std::enable_if 147 <std::is_convertible<typename unique_ptr<_Up, _Ep>::pointer, 148 pointer>::value 149 && !std::is_array<_Up>::value 150 && ((std::is_reference<_Dp>::value 151 && std::is_same<_Ep, _Dp>::value) 152 || (!std::is_reference<_Dp>::value 153 && std::is_convertible<_Ep, _Dp>::value))> 154 ::type> 155 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept 156 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) 157 { } 158 159 #if _GLIBCXX_USE_DEPRECATED 160 template<typename _Up, typename = typename 161 std::enable_if<std::is_convertible<_Up*, _Tp*>::value 162 && std::is_same<_Dp, 163 default_delete<_Tp>>::value>::type> 164 unique_ptr(auto_ptr<_Up>&& __u) noexcept 165 : _M_t(__u.release(), deleter_type()) { } 166 #endif 167 168 // Destructor. 169 ~unique_ptr() noexcept 170 { 171 auto& __ptr = std::get<0>(_M_t); 172 if (__ptr != nullptr) 173 get_deleter()(__ptr); 174 __ptr = pointer(); 175 } 176 177 // Assignment. 178 unique_ptr& 179 operator=(unique_ptr&& __u) noexcept 180 { 181 reset(__u.release()); 182 get_deleter() = std::forward<deleter_type>(__u.get_deleter()); 183 return *this; 184 } 185 186 template<typename _Up, typename _Ep, typename = typename 187 std::enable_if 188 <std::is_convertible<typename unique_ptr<_Up, _Ep>::pointer, 189 pointer>::value 190 && !std::is_array<_Up>::value>::type> 191 unique_ptr& 192 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept 193 { 194 reset(__u.release()); 195 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 196 return *this; 197 } 198 199 unique_ptr& 200 operator=(nullptr_t) noexcept 201 { 202 reset(); 203 return *this; 204 } 205 206 // Observers. 207 typename std::add_lvalue_reference<element_type>::type 208 operator*() const 209 { 210 _GLIBCXX_DEBUG_ASSERT(get() != pointer()); 211 return *get(); 212 } 213 214 pointer 215 operator->() const noexcept 216 { 217 _GLIBCXX_DEBUG_ASSERT(get() != pointer()); 218 return get(); 219 } 220 221 pointer 222 get() const noexcept 223 { return std::get<0>(_M_t); } 224 225 deleter_type& 226 get_deleter() noexcept 227 { return std::get<1>(_M_t); } 228 229 const deleter_type& 230 get_deleter() const noexcept 231 { return std::get<1>(_M_t); } 232 233 explicit operator bool() const noexcept 234 { return get() == pointer() ? false : true; } 235 236 // Modifiers. 237 pointer 238 release() noexcept 239 { 240 pointer __p = get(); 241 std::get<0>(_M_t) = pointer(); 242 return __p; 243 } 244 245 void 246 reset(pointer __p = pointer()) noexcept 247 { 248 using std::swap; 249 swap(std::get<0>(_M_t), __p); 250 if (__p != pointer()) 251 get_deleter()(__p); 252 } 253 254 void 255 swap(unique_ptr& __u) noexcept 256 { 257 using std::swap; 258 swap(_M_t, __u._M_t); 259 } 260 261 // Disable copy from lvalue. 262 unique_ptr(const unique_ptr&) = delete; 263 unique_ptr& operator=(const unique_ptr&) = delete; 264 }; 265 266 /// 20.7.12.3 unique_ptr for array objects with a runtime length 267 // [unique.ptr.runtime] 268 // _GLIBCXX_RESOLVE_LIB_DEFECTS 269 // DR 740 - omit specialization for array objects with a compile time length 270 template<typename _Tp, typename _Dp> 271 class unique_ptr<_Tp[], _Dp> 272 { 273 typedef std::tuple<_Tp*, _Dp> __tuple_type; 274 __tuple_type _M_t; 275 276 public: 277 typedef _Tp* pointer; 278 typedef _Tp element_type; 279 typedef _Dp deleter_type; 280 281 // Constructors. 282 constexpr unique_ptr() noexcept 283 : _M_t() 284 { static_assert(!std::is_pointer<deleter_type>::value, 285 "constructed with null function pointer deleter"); } 286 287 explicit 288 unique_ptr(pointer __p) noexcept 289 : _M_t(__p, deleter_type()) 290 { static_assert(!std::is_pointer<deleter_type>::value, 291 "constructed with null function pointer deleter"); } 292 293 unique_ptr(pointer __p, 294 typename std::conditional<std::is_reference<deleter_type>::value, 295 deleter_type, const deleter_type&>::type __d) noexcept 296 : _M_t(__p, __d) { } 297 298 unique_ptr(pointer __p, typename 299 std::remove_reference<deleter_type>::type && __d) noexcept 300 : _M_t(std::move(__p), std::move(__d)) 301 { static_assert(!std::is_reference<deleter_type>::value, 302 "rvalue deleter bound to reference"); } 303 304 constexpr unique_ptr(nullptr_t) noexcept 305 : _M_t() 306 { static_assert(!std::is_pointer<deleter_type>::value, 307 "constructed with null function pointer deleter"); } 308 309 // Move constructors. 310 unique_ptr(unique_ptr&& __u) noexcept 311 : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { } 312 313 template<typename _Up, typename _Ep> 314 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept 315 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) 316 { } 317 318 // Destructor. 319 ~unique_ptr() 320 { 321 auto& __ptr = std::get<0>(_M_t); 322 if (__ptr != nullptr) 323 get_deleter()(__ptr); 324 __ptr = pointer(); 325 } 326 327 // Assignment. 328 unique_ptr& 329 operator=(unique_ptr&& __u) noexcept 330 { 331 reset(__u.release()); 332 get_deleter() = std::forward<deleter_type>(__u.get_deleter()); 333 return *this; 334 } 335 336 template<typename _Up, typename _Ep> 337 unique_ptr& 338 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept 339 { 340 reset(__u.release()); 341 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 342 return *this; 343 } 344 345 unique_ptr& 346 operator=(nullptr_t) noexcept 347 { 348 reset(); 349 return *this; 350 } 351 352 // Observers. 353 typename std::add_lvalue_reference<element_type>::type 354 operator[](size_t __i) const 355 { 356 _GLIBCXX_DEBUG_ASSERT(get() != pointer()); 357 return get()[__i]; 358 } 359 360 pointer 361 get() const noexcept 362 { return std::get<0>(_M_t); } 363 364 deleter_type& 365 get_deleter() noexcept 366 { return std::get<1>(_M_t); } 367 368 const deleter_type& 369 get_deleter() const noexcept 370 { return std::get<1>(_M_t); } 371 372 explicit operator bool() const noexcept 373 { return get() == pointer() ? false : true; } 374 375 // Modifiers. 376 pointer 377 release() noexcept 378 { 379 pointer __p = get(); 380 std::get<0>(_M_t) = pointer(); 381 return __p; 382 } 383 384 void 385 reset(pointer __p = pointer()) noexcept 386 { 387 using std::swap; 388 swap(std::get<0>(_M_t), __p); 389 if (__p != nullptr) 390 get_deleter()(__p); 391 } 392 393 void 394 reset(nullptr_t) noexcept 395 { 396 pointer __p = get(); 397 std::get<0>(_M_t) = pointer(); 398 if (__p != nullptr) 399 get_deleter()(__p); 400 } 401 402 // DR 821. 403 template<typename _Up> 404 void reset(_Up) = delete; 405 406 void 407 swap(unique_ptr& __u) noexcept 408 { 409 using std::swap; 410 swap(_M_t, __u._M_t); 411 } 412 413 // Disable copy from lvalue. 414 unique_ptr(const unique_ptr&) = delete; 415 unique_ptr& operator=(const unique_ptr&) = delete; 416 417 // Disable construction from convertible pointer types. 418 // (N2315 - 20.6.5.3.1) 419 template<typename _Up> 420 unique_ptr(_Up*, typename 421 std::conditional<std::is_reference<deleter_type>::value, 422 deleter_type, const deleter_type&>::type, 423 typename std::enable_if<std::is_convertible<_Up*, 424 pointer>::value>::type* = 0) = delete; 425 426 template<typename _Up> 427 unique_ptr(_Up*, typename std::remove_reference<deleter_type>::type&&, 428 typename std::enable_if<std::is_convertible<_Up*, 429 pointer>::value>::type* = 0) = delete; 430 431 template<typename _Up> 432 explicit 433 unique_ptr(_Up*, typename std::enable_if<std::is_convertible<_Up*, 434 pointer>::value>::type* = 0) = delete; 435 }; 436 437 template<typename _Tp, typename _Dp> 438 inline void 439 swap(unique_ptr<_Tp, _Dp>& __x, 440 unique_ptr<_Tp, _Dp>& __y) noexcept 441 { __x.swap(__y); } 442 443 template<typename _Tp, typename _Dp, 444 typename _Up, typename _Ep> 445 inline bool 446 operator==(const unique_ptr<_Tp, _Dp>& __x, 447 const unique_ptr<_Up, _Ep>& __y) 448 { return __x.get() == __y.get(); } 449 450 template<typename _Tp, typename _Dp> 451 inline bool 452 operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept 453 { return !__x; } 454 455 template<typename _Tp, typename _Dp> 456 inline bool 457 operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept 458 { return !__x; } 459 460 template<typename _Tp, typename _Dp, 461 typename _Up, typename _Ep> 462 inline bool 463 operator!=(const unique_ptr<_Tp, _Dp>& __x, 464 const unique_ptr<_Up, _Ep>& __y) 465 { return __x.get() != __y.get(); } 466 467 template<typename _Tp, typename _Dp> 468 inline bool 469 operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept 470 { return (bool)__x; } 471 472 template<typename _Tp, typename _Dp> 473 inline bool 474 operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept 475 { return (bool)__x; } 476 477 template<typename _Tp, typename _Dp, 478 typename _Up, typename _Ep> 479 inline bool 480 operator<(const unique_ptr<_Tp, _Dp>& __x, 481 const unique_ptr<_Up, _Ep>& __y) 482 { 483 typedef typename 484 std::common_type<typename unique_ptr<_Tp, _Dp>::pointer, 485 typename unique_ptr<_Up, _Ep>::pointer>::type _CT; 486 return std::less<_CT>()(__x.get(), __y.get()); 487 } 488 489 template<typename _Tp, typename _Dp> 490 inline bool 491 operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 492 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), 493 nullptr); } 494 495 template<typename _Tp, typename _Dp> 496 inline bool 497 operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 498 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, 499 __x.get()); } 500 501 template<typename _Tp, typename _Dp, 502 typename _Up, typename _Ep> 503 inline bool 504 operator<=(const unique_ptr<_Tp, _Dp>& __x, 505 const unique_ptr<_Up, _Ep>& __y) 506 { return !(__y < __x); } 507 508 template<typename _Tp, typename _Dp> 509 inline bool 510 operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 511 { return !(nullptr < __x); } 512 513 template<typename _Tp, typename _Dp> 514 inline bool 515 operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 516 { return !(__x < nullptr); } 517 518 template<typename _Tp, typename _Dp, 519 typename _Up, typename _Ep> 520 inline bool 521 operator>(const unique_ptr<_Tp, _Dp>& __x, 522 const unique_ptr<_Up, _Ep>& __y) 523 { return (__y < __x); } 524 525 template<typename _Tp, typename _Dp> 526 inline bool 527 operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 528 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr, 529 __x.get()); } 530 531 template<typename _Tp, typename _Dp> 532 inline bool 533 operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 534 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(), 535 nullptr); } 536 537 template<typename _Tp, typename _Dp, 538 typename _Up, typename _Ep> 539 inline bool 540 operator>=(const unique_ptr<_Tp, _Dp>& __x, 541 const unique_ptr<_Up, _Ep>& __y) 542 { return !(__x < __y); } 543 544 template<typename _Tp, typename _Dp> 545 inline bool 546 operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 547 { return !(__x < nullptr); } 548 549 template<typename _Tp, typename _Dp> 550 inline bool 551 operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) 552 { return !(nullptr < __x); } 553 554 /// std::hash specialization for unique_ptr. 555 template<typename _Tp, typename _Dp> 556 struct hash<unique_ptr<_Tp, _Dp>> 557 : public __hash_base<size_t, unique_ptr<_Tp, _Dp>> 558 { 559 size_t 560 operator()(const unique_ptr<_Tp, _Dp>& __u) const noexcept 561 { 562 typedef unique_ptr<_Tp, _Dp> _UP; 563 return std::hash<typename _UP::pointer>()(__u.get()); 564 } 565 }; 566 567 // @} group pointer_abstractions 568 569 _GLIBCXX_END_NAMESPACE_VERSION 570 } // namespace 571 572 #endif /* _UNIQUE_PTR_H */ 573
