1// unique_ptr implementation -*- C++ -*-
2
3// Copyright (C) 2008-2019 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 <utility>
37#include <tuple>
38#include <bits/stl_function.h>
39#include <bits/functional_hash.h>
40
41namespace std _GLIBCXX_VISIBILITY(default)
42{
43_GLIBCXX_BEGIN_NAMESPACE_VERSION
44
45 /**
46 * @addtogroup pointer_abstractions
47 * @{
48 */
49
50#if _GLIBCXX_USE_DEPRECATED
51#pragma GCC diagnostic push
52#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
53 template<typename> class auto_ptr;
54#pragma GCC diagnostic pop
55#endif
56
57 /// Primary template of default_delete, used by unique_ptr
58 template<typename _Tp>
59 struct default_delete
60 {
61 /// Default constructor
62 constexpr default_delete() noexcept = default;
63
64 /** @brief Converting constructor.
65 *
66 * Allows conversion from a deleter for arrays of another type, @p _Up,
67 * only if @p _Up* is convertible to @p _Tp*.
68 */
69 template<typename _Up, typename = typename
70 enable_if<is_convertible<_Up*, _Tp*>::value>::type>
71 default_delete(const default_delete<_Up>&) noexcept { }
72
73 /// Calls @c delete @p __ptr
74 void
75 operator()(_Tp* __ptr) const
76 {
77 static_assert(!is_void<_Tp>::value,
78 "can't delete pointer to incomplete type");
79 static_assert(sizeof(_Tp)>0,
80 "can't delete pointer to incomplete type");
81 delete __ptr;
82 }
83 };
84
85 // _GLIBCXX_RESOLVE_LIB_DEFECTS
86 // DR 740 - omit specialization for array objects with a compile time length
87 /// Specialization for arrays, default_delete.
88 template<typename _Tp>
89 struct default_delete<_Tp[]>
90 {
91 public:
92 /// Default constructor
93 constexpr default_delete() noexcept = default;
94
95 /** @brief Converting constructor.
96 *
97 * Allows conversion from a deleter for arrays of another type, such as
98 * a const-qualified version of @p _Tp.
99 *
100 * Conversions from types derived from @c _Tp are not allowed because
101 * it is unsafe to @c delete[] an array of derived types through a
102 * pointer to the base type.
103 */
104 template<typename _Up, typename = typename
105 enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type>
106 default_delete(const default_delete<_Up[]>&) noexcept { }
107
108 /// Calls @c delete[] @p __ptr
109 template<typename _Up>
110 typename enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type
111 operator()(_Up* __ptr) const
112 {
113 static_assert(sizeof(_Tp)>0,
114 "can't delete pointer to incomplete type");
115 delete [] __ptr;
116 }
117 };
118
119 template <typename _Tp, typename _Dp>
120 class __uniq_ptr_impl
121 {
122 template <typename _Up, typename _Ep, typename = void>
123 struct _Ptr
124 {
125 using type = _Up*;
126 };
127
128 template <typename _Up, typename _Ep>
129 struct
130 _Ptr<_Up, _Ep, __void_t<typename remove_reference<_Ep>::type::pointer>>
131 {
132 using type = typename remove_reference<_Ep>::type::pointer;
133 };
134
135 public:
136 using _DeleterConstraint = enable_if<
137 __and_<__not_<is_pointer<_Dp>>,
138 is_default_constructible<_Dp>>::value>;
139
140 using pointer = typename _Ptr<_Tp, _Dp>::type;
141
142 static_assert( !is_rvalue_reference<_Dp>::value,
143 "unique_ptr's deleter type must be a function object type"
144 " or an lvalue reference type" );
145
146 __uniq_ptr_impl() = default;
147 __uniq_ptr_impl(pointer __p) : _M_t() { _M_ptr() = __p; }
148
149 template<typename _Del>
150 __uniq_ptr_impl(pointer __p, _Del&& __d)
151 : _M_t(__p, std::forward<_Del>(__d)) { }
152
153 pointer& _M_ptr() { return std::get<0>(_M_t); }
154 pointer _M_ptr() const { return std::get<0>(_M_t); }
155 _Dp& _M_deleter() { return std::get<1>(_M_t); }
156 const _Dp& _M_deleter() const { return std::get<1>(_M_t); }
157
158 void
159 swap(__uniq_ptr_impl& __rhs) noexcept
160 {
161 using std::swap;
162 swap(this->_M_ptr(), __rhs._M_ptr());
163 swap(this->_M_deleter(), __rhs._M_deleter());
164 }
165
166 private:
167 tuple<pointer, _Dp> _M_t;
168 };
169
170 /// 20.7.1.2 unique_ptr for single objects.
171 template <typename _Tp, typename _Dp = default_delete<_Tp>>
172 class unique_ptr
173 {
174 template <typename _Up>
175 using _DeleterConstraint =
176 typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type;
177
178 __uniq_ptr_impl<_Tp, _Dp> _M_t;
179
180 public:
181 using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer;
182 using element_type = _Tp;
183 using deleter_type = _Dp;
184
185 private:
186 // helper template for detecting a safe conversion from another
187 // unique_ptr
188 template<typename _Up, typename _Ep>
189 using __safe_conversion_up = __and_<
190 is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>,
191 __not_<is_array<_Up>>
192 >;
193
194 public:
195 // Constructors.
196
197 /// Default constructor, creates a unique_ptr that owns nothing.
198 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
199 constexpr unique_ptr() noexcept
200 : _M_t()
201 { }
202
203 /** Takes ownership of a pointer.
204 *
205 * @param __p A pointer to an object of @c element_type
206 *
207 * The deleter will be value-initialized.
208 */
209 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
210 explicit
211 unique_ptr(pointer __p) noexcept
212 : _M_t(__p)
213 { }
214
215 /** Takes ownership of a pointer.
216 *
217 * @param __p A pointer to an object of @c element_type
218 * @param __d A reference to a deleter.
219 *
220 * The deleter will be initialized with @p __d
221 */
222 template<typename _Del = deleter_type,
223 typename = _Require<is_copy_constructible<_Del>>>
224 unique_ptr(pointer __p, const deleter_type& __d) noexcept
225 : _M_t(__p, __d) { }
226
227 /** Takes ownership of a pointer.
228 *
229 * @param __p A pointer to an object of @c element_type
230 * @param __d An rvalue reference to a (non-reference) deleter.
231 *
232 * The deleter will be initialized with @p std::move(__d)
233 */
234 template<typename _Del = deleter_type,
235 typename = _Require<is_move_constructible<_Del>>>
236 unique_ptr(pointer __p,
237 __enable_if_t<!is_lvalue_reference<_Del>::value,
238 _Del&&> __d) noexcept
239 : _M_t(__p, std::move(__d))
240 { }
241
242 template<typename _Del = deleter_type,
243 typename _DelUnref = typename remove_reference<_Del>::type>
244 unique_ptr(pointer,
245 __enable_if_t<is_lvalue_reference<_Del>::value,
246 _DelUnref&&>) = delete;
247
248 /// Creates a unique_ptr that owns nothing.
249 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
250 constexpr unique_ptr(nullptr_t) noexcept
251 : _M_t()
252 { }
253
254 // Move constructors.
255
256 /// Move constructor.
257 unique_ptr(unique_ptr&& __u) noexcept
258 : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
259
260 /** @brief Converting constructor from another type
261 *
262 * Requires that the pointer owned by @p __u is convertible to the
263 * type of pointer owned by this object, @p __u does not own an array,
264 * and @p __u has a compatible deleter type.
265 */
266 template<typename _Up, typename _Ep, typename = _Require<
267 __safe_conversion_up<_Up, _Ep>,
268 typename conditional<is_reference<_Dp>::value,
269 is_same<_Ep, _Dp>,
270 is_convertible<_Ep, _Dp>>::type>>
271 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
272 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
273 { }
274
275#if _GLIBCXX_USE_DEPRECATED
276#pragma GCC diagnostic push
277#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
278 /// Converting constructor from @c auto_ptr
279 template<typename _Up, typename = _Require<
280 is_convertible<_Up*, _Tp*>, is_same<_Dp, default_delete<_Tp>>>>
281 unique_ptr(auto_ptr<_Up>&& __u) noexcept;
282#pragma GCC diagnostic pop
283#endif
284
285 /// Destructor, invokes the deleter if the stored pointer is not null.
286 ~unique_ptr() noexcept
287 {
288 static_assert(__is_invocable<deleter_type&, pointer>::value,
289 "unique_ptr's deleter must be invocable with a pointer");
290 auto& __ptr = _M_t._M_ptr();
291 if (__ptr != nullptr)
292 get_deleter()(std::move(__ptr));
293 __ptr = pointer();
294 }
295
296 // Assignment.
297
298 /** @brief Move assignment operator.
299 *
300 * @param __u The object to transfer ownership from.
301 *
302 * Invokes the deleter first if this object owns a pointer.
303 */
304 unique_ptr&
305 operator=(unique_ptr&& __u) noexcept
306 {
307 reset(p: __u.release());
308 get_deleter() = std::forward<deleter_type>(__u.get_deleter());
309 return *this;
310 }
311
312 /** @brief Assignment from another type.
313 *
314 * @param __u The object to transfer ownership from, which owns a
315 * convertible pointer to a non-array object.
316 *
317 * Invokes the deleter first if this object owns a pointer.
318 */
319 template<typename _Up, typename _Ep>
320 typename enable_if< __and_<
321 __safe_conversion_up<_Up, _Ep>,
322 is_assignable<deleter_type&, _Ep&&>
323 >::value,
324 unique_ptr&>::type
325 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
326 {
327 reset(p: __u.release());
328 get_deleter() = std::forward<_Ep>(__u.get_deleter());
329 return *this;
330 }
331
332 /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
333 unique_ptr&
334 operator=(nullptr_t) noexcept
335 {
336 reset();
337 return *this;
338 }
339
340 // Observers.
341
342 /// Dereference the stored pointer.
343 typename add_lvalue_reference<element_type>::type
344 operator*() const
345 {
346 __glibcxx_assert(get() != pointer());
347 return *get();
348 }
349
350 /// Return the stored pointer.
351 pointer
352 operator->() const noexcept
353 {
354 _GLIBCXX_DEBUG_PEDASSERT(get() != pointer());
355 return get();
356 }
357
358 /// Return the stored pointer.
359 pointer
360 get() const noexcept
361 { return _M_t._M_ptr(); }
362
363 /// Return a reference to the stored deleter.
364 deleter_type&
365 get_deleter() noexcept
366 { return _M_t._M_deleter(); }
367
368 /// Return a reference to the stored deleter.
369 const deleter_type&
370 get_deleter() const noexcept
371 { return _M_t._M_deleter(); }
372
373 /// Return @c true if the stored pointer is not null.
374 explicit operator bool() const noexcept
375 { return get() == pointer() ? false : true; }
376
377 // Modifiers.
378
379 /// Release ownership of any stored pointer.
380 pointer
381 release() noexcept
382 {
383 pointer __p = get();
384 _M_t._M_ptr() = pointer();
385 return __p;
386 }
387
388 /** @brief Replace the stored pointer.
389 *
390 * @param __p The new pointer to store.
391 *
392 * The deleter will be invoked if a pointer is already owned.
393 */
394 void
395 reset(pointer __p = pointer()) noexcept
396 {
397 static_assert(__is_invocable<deleter_type&, pointer>::value,
398 "unique_ptr's deleter must be invocable with a pointer");
399 using std::swap;
400 swap(_M_t._M_ptr(), __p);
401 if (__p != pointer())
402 get_deleter()(std::move(__p));
403 }
404
405 /// Exchange the pointer and deleter with another object.
406 void
407 swap(unique_ptr& __u) noexcept
408 {
409 static_assert(__is_swappable<_Dp>::value, "deleter must be swappable");
410 _M_t.swap(__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
418 /// 20.7.1.3 unique_ptr for array objects with a runtime length
419 // [unique.ptr.runtime]
420 // _GLIBCXX_RESOLVE_LIB_DEFECTS
421 // DR 740 - omit specialization for array objects with a compile time length
422 template<typename _Tp, typename _Dp>
423 class unique_ptr<_Tp[], _Dp>
424 {
425 template <typename _Up>
426 using _DeleterConstraint =
427 typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type;
428
429 __uniq_ptr_impl<_Tp, _Dp> _M_t;
430
431 template<typename _Up>
432 using __remove_cv = typename remove_cv<_Up>::type;
433
434 // like is_base_of<_Tp, _Up> but false if unqualified types are the same
435 template<typename _Up>
436 using __is_derived_Tp
437 = __and_< is_base_of<_Tp, _Up>,
438 __not_<is_same<__remove_cv<_Tp>, __remove_cv<_Up>>> >;
439
440 public:
441 using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer;
442 using element_type = _Tp;
443 using deleter_type = _Dp;
444
445 // helper template for detecting a safe conversion from another
446 // unique_ptr
447 template<typename _Up, typename _Ep,
448 typename _UPtr = unique_ptr<_Up, _Ep>,
449 typename _UP_pointer = typename _UPtr::pointer,
450 typename _UP_element_type = typename _UPtr::element_type>
451 using __safe_conversion_up = __and_<
452 is_array<_Up>,
453 is_same<pointer, element_type*>,
454 is_same<_UP_pointer, _UP_element_type*>,
455 is_convertible<_UP_element_type(*)[], element_type(*)[]>
456 >;
457
458 // helper template for detecting a safe conversion from a raw pointer
459 template<typename _Up>
460 using __safe_conversion_raw = __and_<
461 __or_<__or_<is_same<_Up, pointer>,
462 is_same<_Up, nullptr_t>>,
463 __and_<is_pointer<_Up>,
464 is_same<pointer, element_type*>,
465 is_convertible<
466 typename remove_pointer<_Up>::type(*)[],
467 element_type(*)[]>
468 >
469 >
470 >;
471
472 // Constructors.
473
474 /// Default constructor, creates a unique_ptr that owns nothing.
475 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
476 constexpr unique_ptr() noexcept
477 : _M_t()
478 { }
479
480 /** Takes ownership of a pointer.
481 *
482 * @param __p A pointer to an array of a type safely convertible
483 * to an array of @c element_type
484 *
485 * The deleter will be value-initialized.
486 */
487 template<typename _Up,
488 typename _Vp = _Dp,
489 typename = _DeleterConstraint<_Vp>,
490 typename = typename enable_if<
491 __safe_conversion_raw<_Up>::value, bool>::type>
492 explicit
493 unique_ptr(_Up __p) noexcept
494 : _M_t(__p)
495 { }
496
497 /** Takes ownership of a pointer.
498 *
499 * @param __p A pointer to an array of a type safely convertible
500 * to an array of @c element_type
501 * @param __d A reference to a deleter.
502 *
503 * The deleter will be initialized with @p __d
504 */
505 template<typename _Up, typename _Del = deleter_type,
506 typename = _Require<__safe_conversion_raw<_Up>,
507 is_copy_constructible<_Del>>>
508 unique_ptr(_Up __p, const deleter_type& __d) noexcept
509 : _M_t(__p, __d) { }
510
511 /** Takes ownership of a pointer.
512 *
513 * @param __p A pointer to an array of a type safely convertible
514 * to an array of @c element_type
515 * @param __d A reference to a deleter.
516 *
517 * The deleter will be initialized with @p std::move(__d)
518 */
519 template<typename _Up, typename _Del = deleter_type,
520 typename = _Require<__safe_conversion_raw<_Up>,
521 is_move_constructible<_Del>>>
522 unique_ptr(_Up __p,
523 __enable_if_t<!is_lvalue_reference<_Del>::value,
524 _Del&&> __d) noexcept
525 : _M_t(std::move(__p), std::move(__d))
526 { }
527
528 template<typename _Up, typename _Del = deleter_type,
529 typename _DelUnref = typename remove_reference<_Del>::type,
530 typename = _Require<__safe_conversion_raw<_Up>>>
531 unique_ptr(_Up,
532 __enable_if_t<is_lvalue_reference<_Del>::value,
533 _DelUnref&&>) = delete;
534
535 /// Move constructor.
536 unique_ptr(unique_ptr&& __u) noexcept
537 : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
538
539 /// Creates a unique_ptr that owns nothing.
540 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
541 constexpr unique_ptr(nullptr_t) noexcept
542 : _M_t()
543 { }
544
545 template<typename _Up, typename _Ep, typename = _Require<
546 __safe_conversion_up<_Up, _Ep>,
547 typename conditional<is_reference<_Dp>::value,
548 is_same<_Ep, _Dp>,
549 is_convertible<_Ep, _Dp>>::type>>
550 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
551 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
552 { }
553
554 /// Destructor, invokes the deleter if the stored pointer is not null.
555 ~unique_ptr()
556 {
557 auto& __ptr = _M_t._M_ptr();
558 if (__ptr != nullptr)
559 get_deleter()(__ptr);
560 __ptr = pointer();
561 }
562
563 // Assignment.
564
565 /** @brief Move assignment operator.
566 *
567 * @param __u The object to transfer ownership from.
568 *
569 * Invokes the deleter first if this object owns a pointer.
570 */
571 unique_ptr&
572 operator=(unique_ptr&& __u) noexcept
573 {
574 reset(__u.release());
575 get_deleter() = std::forward<deleter_type>(__u.get_deleter());
576 return *this;
577 }
578
579 /** @brief Assignment from another type.
580 *
581 * @param __u The object to transfer ownership from, which owns a
582 * convertible pointer to an array object.
583 *
584 * Invokes the deleter first if this object owns a pointer.
585 */
586 template<typename _Up, typename _Ep>
587 typename
588 enable_if<__and_<__safe_conversion_up<_Up, _Ep>,
589 is_assignable<deleter_type&, _Ep&&>
590 >::value,
591 unique_ptr&>::type
592 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
593 {
594 reset(__u.release());
595 get_deleter() = std::forward<_Ep>(__u.get_deleter());
596 return *this;
597 }
598
599 /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
600 unique_ptr&
601 operator=(nullptr_t) noexcept
602 {
603 reset();
604 return *this;
605 }
606
607 // Observers.
608
609 /// Access an element of owned array.
610 typename std::add_lvalue_reference<element_type>::type
611 operator[](size_t __i) const
612 {
613 __glibcxx_assert(get() != pointer());
614 return get()[__i];
615 }
616
617 /// Return the stored pointer.
618 pointer
619 get() const noexcept
620 { return _M_t._M_ptr(); }
621
622 /// Return a reference to the stored deleter.
623 deleter_type&
624 get_deleter() noexcept
625 { return _M_t._M_deleter(); }
626
627 /// Return a reference to the stored deleter.
628 const deleter_type&
629 get_deleter() const noexcept
630 { return _M_t._M_deleter(); }
631
632 /// Return @c true if the stored pointer is not null.
633 explicit operator bool() const noexcept
634 { return get() == pointer() ? false : true; }
635
636 // Modifiers.
637
638 /// Release ownership of any stored pointer.
639 pointer
640 release() noexcept
641 {
642 pointer __p = get();
643 _M_t._M_ptr() = pointer();
644 return __p;
645 }
646
647 /** @brief Replace the stored pointer.
648 *
649 * @param __p The new pointer to store.
650 *
651 * The deleter will be invoked if a pointer is already owned.
652 */
653 template <typename _Up,
654 typename = _Require<
655 __or_<is_same<_Up, pointer>,
656 __and_<is_same<pointer, element_type*>,
657 is_pointer<_Up>,
658 is_convertible<
659 typename remove_pointer<_Up>::type(*)[],
660 element_type(*)[]
661 >
662 >
663 >
664 >>
665 void
666 reset(_Up __p) noexcept
667 {
668 pointer __ptr = __p;
669 using std::swap;
670 swap(_M_t._M_ptr(), __ptr);
671 if (__ptr != nullptr)
672 get_deleter()(__ptr);
673 }
674
675 void reset(nullptr_t = nullptr) noexcept
676 {
677 reset(pointer());
678 }
679
680 /// Exchange the pointer and deleter with another object.
681 void
682 swap(unique_ptr& __u) noexcept
683 {
684 static_assert(__is_swappable<_Dp>::value, "deleter must be swappable");
685 _M_t.swap(__u._M_t);
686 }
687
688 // Disable copy from lvalue.
689 unique_ptr(const unique_ptr&) = delete;
690 unique_ptr& operator=(const unique_ptr&) = delete;
691 };
692
693 template<typename _Tp, typename _Dp>
694 inline
695#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
696 // Constrained free swap overload, see p0185r1
697 typename enable_if<__is_swappable<_Dp>::value>::type
698#else
699 void
700#endif
701 swap(unique_ptr<_Tp, _Dp>& __x,
702 unique_ptr<_Tp, _Dp>& __y) noexcept
703 { __x.swap(__y); }
704
705#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
706 template<typename _Tp, typename _Dp>
707 typename enable_if<!__is_swappable<_Dp>::value>::type
708 swap(unique_ptr<_Tp, _Dp>&,
709 unique_ptr<_Tp, _Dp>&) = delete;
710#endif
711
712 template<typename _Tp, typename _Dp,
713 typename _Up, typename _Ep>
714 _GLIBCXX_NODISCARD inline bool
715 operator==(const unique_ptr<_Tp, _Dp>& __x,
716 const unique_ptr<_Up, _Ep>& __y)
717 { return __x.get() == __y.get(); }
718
719 template<typename _Tp, typename _Dp>
720 _GLIBCXX_NODISCARD inline bool
721 operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
722 { return !__x; }
723
724 template<typename _Tp, typename _Dp>
725 _GLIBCXX_NODISCARD inline bool
726 operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
727 { return !__x; }
728
729 template<typename _Tp, typename _Dp,
730 typename _Up, typename _Ep>
731 _GLIBCXX_NODISCARD inline bool
732 operator!=(const unique_ptr<_Tp, _Dp>& __x,
733 const unique_ptr<_Up, _Ep>& __y)
734 { return __x.get() != __y.get(); }
735
736 template<typename _Tp, typename _Dp>
737 _GLIBCXX_NODISCARD inline bool
738 operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
739 { return (bool)__x; }
740
741 template<typename _Tp, typename _Dp>
742 _GLIBCXX_NODISCARD inline bool
743 operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
744 { return (bool)__x; }
745
746 template<typename _Tp, typename _Dp,
747 typename _Up, typename _Ep>
748 _GLIBCXX_NODISCARD inline bool
749 operator<(const unique_ptr<_Tp, _Dp>& __x,
750 const unique_ptr<_Up, _Ep>& __y)
751 {
752 typedef typename
753 std::common_type<typename unique_ptr<_Tp, _Dp>::pointer,
754 typename unique_ptr<_Up, _Ep>::pointer>::type _CT;
755 return std::less<_CT>()(__x.get(), __y.get());
756 }
757
758 template<typename _Tp, typename _Dp>
759 _GLIBCXX_NODISCARD inline bool
760 operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
761 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
762 nullptr); }
763
764 template<typename _Tp, typename _Dp>
765 _GLIBCXX_NODISCARD inline bool
766 operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
767 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
768 __x.get()); }
769
770 template<typename _Tp, typename _Dp,
771 typename _Up, typename _Ep>
772 _GLIBCXX_NODISCARD inline bool
773 operator<=(const unique_ptr<_Tp, _Dp>& __x,
774 const unique_ptr<_Up, _Ep>& __y)
775 { return !(__y < __x); }
776
777 template<typename _Tp, typename _Dp>
778 _GLIBCXX_NODISCARD inline bool
779 operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
780 { return !(nullptr < __x); }
781
782 template<typename _Tp, typename _Dp>
783 _GLIBCXX_NODISCARD inline bool
784 operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
785 { return !(__x < nullptr); }
786
787 template<typename _Tp, typename _Dp,
788 typename _Up, typename _Ep>
789 _GLIBCXX_NODISCARD inline bool
790 operator>(const unique_ptr<_Tp, _Dp>& __x,
791 const unique_ptr<_Up, _Ep>& __y)
792 { return (__y < __x); }
793
794 template<typename _Tp, typename _Dp>
795 _GLIBCXX_NODISCARD inline bool
796 operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
797 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
798 __x.get()); }
799
800 template<typename _Tp, typename _Dp>
801 _GLIBCXX_NODISCARD inline bool
802 operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
803 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
804 nullptr); }
805
806 template<typename _Tp, typename _Dp,
807 typename _Up, typename _Ep>
808 _GLIBCXX_NODISCARD inline bool
809 operator>=(const unique_ptr<_Tp, _Dp>& __x,
810 const unique_ptr<_Up, _Ep>& __y)
811 { return !(__x < __y); }
812
813 template<typename _Tp, typename _Dp>
814 _GLIBCXX_NODISCARD inline bool
815 operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
816 { return !(__x < nullptr); }
817
818 template<typename _Tp, typename _Dp>
819 _GLIBCXX_NODISCARD inline bool
820 operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
821 { return !(nullptr < __x); }
822
823 /// std::hash specialization for unique_ptr.
824 template<typename _Tp, typename _Dp>
825 struct hash<unique_ptr<_Tp, _Dp>>
826 : public __hash_base<size_t, unique_ptr<_Tp, _Dp>>,
827 private __poison_hash<typename unique_ptr<_Tp, _Dp>::pointer>
828 {
829 size_t
830 operator()(const unique_ptr<_Tp, _Dp>& __u) const noexcept
831 {
832 typedef unique_ptr<_Tp, _Dp> _UP;
833 return std::hash<typename _UP::pointer>()(__u.get());
834 }
835 };
836
837#if __cplusplus > 201103L
838
839#define __cpp_lib_make_unique 201304
840
841 template<typename _Tp>
842 struct _MakeUniq
843 { typedef unique_ptr<_Tp> __single_object; };
844
845 template<typename _Tp>
846 struct _MakeUniq<_Tp[]>
847 { typedef unique_ptr<_Tp[]> __array; };
848
849 template<typename _Tp, size_t _Bound>
850 struct _MakeUniq<_Tp[_Bound]>
851 { struct __invalid_type { }; };
852
853 /// std::make_unique for single objects
854 template<typename _Tp, typename... _Args>
855 inline typename _MakeUniq<_Tp>::__single_object
856 make_unique(_Args&&... __args)
857 { return unique_ptr<_Tp>(new _Tp(std::forward<_Args>(__args)...)); }
858
859 /// std::make_unique for arrays of unknown bound
860 template<typename _Tp>
861 inline typename _MakeUniq<_Tp>::__array
862 make_unique(size_t __num)
863 { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]()); }
864
865 /// Disable std::make_unique for arrays of known bound
866 template<typename _Tp, typename... _Args>
867 inline typename _MakeUniq<_Tp>::__invalid_type
868 make_unique(_Args&&...) = delete;
869#endif
870
871 /// @} group pointer_abstractions
872
873#if __cplusplus >= 201703L
874 namespace __detail::__variant
875 {
876 template<typename> struct _Never_valueless_alt; // see <variant>
877
878 // Provide the strong exception-safety guarantee when emplacing a
879 // unique_ptr into a variant.
880 template<typename _Tp, typename _Del>
881 struct _Never_valueless_alt<std::unique_ptr<_Tp, _Del>>
882 : std::true_type
883 { };
884 } // namespace __detail::__variant
885#endif // C++17
886
887_GLIBCXX_END_NAMESPACE_VERSION
888} // namespace
889
890#endif /* _UNIQUE_PTR_H */
891

source code of include/c++/9/bits/unique_ptr.h