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 39namespace 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() = 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>&) { } 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() = 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() 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) 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) 128 : _M_t(__p, __d) { } 129 130 unique_ptr(pointer __p, 131 typename std::remove_reference<deleter_type>::type&& __d) 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) 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) 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) 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) 165 : _M_t(__u.release(), deleter_type()) { } 166#endif 167 168 // Destructor. 169 ~unique_ptr() { reset(); } 170 171 // Assignment. 172 unique_ptr& 173 operator=(unique_ptr&& __u) 174 { 175 reset(__u.release()); 176 get_deleter() = std::forward<deleter_type>(__u.get_deleter()); 177 return *this; 178 } 179 180 template<typename _Up, typename _Ep, typename = typename 181 std::enable_if 182 <std::is_convertible<typename unique_ptr<_Up, _Ep>::pointer, 183 pointer>::value 184 && !std::is_array<_Up>::value>::type> 185 unique_ptr& 186 operator=(unique_ptr<_Up, _Ep>&& __u) 187 { 188 reset(__u.release()); 189 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 190 return *this; 191 } 192 193 unique_ptr& 194 operator=(nullptr_t) 195 { 196 reset(); 197 return *this; 198 } 199 200 // Observers. 201 typename std::add_lvalue_reference<element_type>::type 202 operator*() const 203 { 204 _GLIBCXX_DEBUG_ASSERT(get() != pointer()); 205 return *get(); 206 } 207 208 pointer 209 operator->() const 210 { 211 _GLIBCXX_DEBUG_ASSERT(get() != pointer()); 212 return get(); 213 } 214 215 pointer 216 get() const 217 { return std::get<0>(_M_t); } 218 219 deleter_type& 220 get_deleter() 221 { return std::get<1>(_M_t); } 222 223 const deleter_type& 224 get_deleter() const 225 { return std::get<1>(_M_t); } 226 227 explicit operator bool() const 228 { return get() == pointer() ? false : true; } 229 230 // Modifiers. 231 pointer 232 release() 233 { 234 pointer __p = get(); 235 std::get<0>(_M_t) = pointer(); 236 return __p; 237 } 238 239 void 240 reset(pointer __p = pointer()) 241 { 242 using std::swap; 243 swap(std::get<0>(_M_t), __p); 244 if (__p != pointer()) 245 get_deleter()(__p); 246 } 247 248 void 249 swap(unique_ptr& __u) 250 { 251 using std::swap; 252 swap(_M_t, __u._M_t); 253 } 254 255 // Disable copy from lvalue. 256 unique_ptr(const unique_ptr&) = delete; 257 unique_ptr& operator=(const unique_ptr&) = delete; 258 }; 259 260 /// 20.7.12.3 unique_ptr for array objects with a runtime length 261 // [unique.ptr.runtime] 262 // _GLIBCXX_RESOLVE_LIB_DEFECTS 263 // DR 740 - omit specialization for array objects with a compile time length 264 template<typename _Tp, typename _Dp> 265 class unique_ptr<_Tp[], _Dp> 266 { 267 typedef std::tuple<_Tp*, _Dp> __tuple_type; 268 __tuple_type _M_t; 269 270 public: 271 typedef _Tp* pointer; 272 typedef _Tp element_type; 273 typedef _Dp deleter_type; 274 275 // Constructors. 276 constexpr unique_ptr() 277 : _M_t() 278 { static_assert(!std::is_pointer<deleter_type>::value, 279 "constructed with null function pointer deleter"); } 280 281 explicit 282 unique_ptr(pointer __p) 283 : _M_t(__p, deleter_type()) 284 { static_assert(!std::is_pointer<deleter_type>::value, 285 "constructed with null function pointer deleter"); } 286 287 unique_ptr(pointer __p, 288 typename std::conditional<std::is_reference<deleter_type>::value, 289 deleter_type, const deleter_type&>::type __d) 290 : _M_t(__p, __d) { } 291 292 unique_ptr(pointer __p, 293 typename std::remove_reference<deleter_type>::type && __d) 294 : _M_t(std::move(__p), std::move(__d)) 295 { static_assert(!std::is_reference<deleter_type>::value, 296 "rvalue deleter bound to reference"); } 297 298 constexpr unique_ptr(nullptr_t) 299 : _M_t() 300 { static_assert(!std::is_pointer<deleter_type>::value, 301 "constructed with null function pointer deleter"); } 302 303 // Move constructors. 304 unique_ptr(unique_ptr&& __u) 305 : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { } 306 307 template<typename _Up, typename _Ep> 308 unique_ptr(unique_ptr<_Up, _Ep>&& __u) 309 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter())) 310 { } 311 312 // Destructor. 313 ~unique_ptr() { reset(); } 314 315 // Assignment. 316 unique_ptr& 317 operator=(unique_ptr&& __u) 318 { 319 reset(__u.release()); 320 get_deleter() = std::forward<deleter_type>(__u.get_deleter()); 321 return *this; 322 } 323 324 template<typename _Up, typename _Ep> 325 unique_ptr& 326 operator=(unique_ptr<_Up, _Ep>&& __u) 327 { 328 reset(__u.release()); 329 get_deleter() = std::forward<_Ep>(__u.get_deleter()); 330 return *this; 331 } 332 333 unique_ptr& 334 operator=(nullptr_t) 335 { 336 reset(); 337 return *this; 338 } 339 340 // Observers. 341 typename std::add_lvalue_reference<element_type>::type 342 operator[](size_t __i) const 343 { 344 _GLIBCXX_DEBUG_ASSERT(get() != pointer()); 345 return get()[__i]; 346 } 347 348 pointer 349 get() const 350 { return std::get<0>(_M_t); } 351 352 deleter_type& 353 get_deleter() 354 { return std::get<1>(_M_t); } 355 356 const deleter_type& 357 get_deleter() const 358 { return std::get<1>(_M_t); } 359 360 explicit operator bool() const 361 { return get() == pointer() ? false : true; } 362 363 // Modifiers. 364 pointer 365 release() 366 { 367 pointer __p = get(); 368 std::get<0>(_M_t) = pointer(); 369 return __p; 370 } 371 372 void 373 reset(pointer __p = pointer()) 374 { 375 using std::swap; 376 swap(std::get<0>(_M_t), __p); 377 if (__p != nullptr) 378 get_deleter()(__p); 379 } 380 381 void 382 reset(nullptr_t) 383 { 384 pointer __p = get(); 385 std::get<0>(_M_t) = pointer(); 386 if (__p != nullptr) 387 get_deleter()(__p); 388 } 389 390 // DR 821. 391 template<typename _Up> 392 void reset(_Up) = delete; 393 394 void 395 swap(unique_ptr& __u) 396 { 397 using std::swap; 398 swap(_M_t, __u._M_t); 399 } 400 401 // Disable copy from lvalue. 402 unique_ptr(const unique_ptr&) = delete; 403 unique_ptr& operator=(const unique_ptr&) = delete; 404 405 // Disable construction from convertible pointer types. 406 // (N2315 - 20.6.5.3.1) 407 template<typename _Up> 408 unique_ptr(_Up*, typename 409 std::conditional<std::is_reference<deleter_type>::value, 410 deleter_type, const deleter_type&>::type, 411 typename std::enable_if<std::is_convertible<_Up*, 412 pointer>::value>::type* = 0) = delete; 413 414 template<typename _Up> 415 unique_ptr(_Up*, typename std::remove_reference<deleter_type>::type&&, 416 typename std::enable_if<std::is_convertible<_Up*, 417 pointer>::value>::type* = 0) = delete; 418 419 template<typename _Up> 420 explicit 421 unique_ptr(_Up*, typename std::enable_if<std::is_convertible<_Up*, 422 pointer>::value>::type* = 0) = delete; 423 }; 424 425 template<typename _Tp, typename _Dp> 426 inline void 427 swap(unique_ptr<_Tp, _Dp>& __x, 428 unique_ptr<_Tp, _Dp>& __y) 429 { __x.swap(__y); } 430 431 template<typename _Tp, typename _Dp, 432 typename _Up, typename _Ep> 433 inline bool 434 operator==(const unique_ptr<_Tp, _Dp>& __x, 435 const unique_ptr<_Up, _Ep>& __y) 436 { return __x.get() == __y.get(); } 437 438 template<typename _Tp, typename _Dp> 439 inline bool 440 operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 441 { return __x.get() == nullptr; } 442 443 template<typename _Tp, typename _Dp> 444 inline bool 445 operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __y) 446 { return nullptr == __y.get(); } 447 448 template<typename _Tp, typename _Dp, 449 typename _Up, typename _Ep> 450 inline bool 451 operator!=(const unique_ptr<_Tp, _Dp>& __x, 452 const unique_ptr<_Up, _Ep>& __y) 453 { return !(__x.get() == __y.get()); } 454 455 template<typename _Tp, typename _Dp> 456 inline bool 457 operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) 458 { return __x.get() != nullptr; } 459 460 template<typename _Tp, typename _Dp> 461 inline bool 462 operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __y) 463 { return nullptr != __y.get(); } 464 465 template<typename _Tp, typename _Dp, 466 typename _Up, typename _Ep> 467 inline bool 468 operator<(const unique_ptr<_Tp, _Dp>& __x, 469 const unique_ptr<_Up, _Ep>& __y) 470 { return __x.get() < __y.get(); } 471 472 template<typename _Tp, typename _Dp, 473 typename _Up, typename _Ep> 474 inline bool 475 operator<=(const unique_ptr<_Tp, _Dp>& __x, 476 const unique_ptr<_Up, _Ep>& __y) 477 { return !(__y.get() < __x.get()); } 478 479 template<typename _Tp, typename _Dp, 480 typename _Up, typename _Ep> 481 inline bool 482 operator>(const unique_ptr<_Tp, _Dp>& __x, 483 const unique_ptr<_Up, _Ep>& __y) 484 { return __y.get() < __x.get(); } 485 486 template<typename _Tp, typename _Dp, 487 typename _Up, typename _Ep> 488 inline bool 489 operator>=(const unique_ptr<_Tp, _Dp>& __x, 490 const unique_ptr<_Up, _Ep>& __y) 491 { return !(__x.get() < __y.get()); } 492 493 /// std::hash specialization for unique_ptr. 494 template<typename _Tp, typename _Dp> 495 struct hash<unique_ptr<_Tp, _Dp>> 496 : public std::unary_function<unique_ptr<_Tp, _Dp>, size_t> 497 { 498 size_t 499 operator()(const unique_ptr<_Tp, _Dp>& __u) const 500 { 501 typedef unique_ptr<_Tp, _Dp> _UP; 502 return std::hash<typename _UP::pointer>()(__u.get()); 503 } 504 }; 505 506 // @} group pointer_abstractions 507 508_GLIBCXX_END_NAMESPACE_VERSION 509} // namespace 510 511#endif /* _UNIQUE_PTR_H */ 512