xref: /netbsd-src/external/gpl3/gcc/dist/libstdc++-v3/include/bits/unique_ptr.h (revision a3e9eb183fc82afd2c22c9f48bcba8e00d943a4f)
1 // unique_ptr implementation -*- C++ -*-
2 
3 // Copyright (C) 2008-2018 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 
41 namespace 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       __uniq_ptr_impl() = default;
143       __uniq_ptr_impl(pointer __p) : _M_t() { _M_ptr() = __p; }
144 
145       template<typename _Del>
146       __uniq_ptr_impl(pointer __p, _Del&& __d)
147 	: _M_t(__p, std::forward<_Del>(__d)) { }
148 
149       pointer&   _M_ptr() { return std::get<0>(_M_t); }
150       pointer    _M_ptr() const { return std::get<0>(_M_t); }
151       _Dp&       _M_deleter() { return std::get<1>(_M_t); }
152       const _Dp& _M_deleter() const { return std::get<1>(_M_t); }
153 
154       void
155       swap(__uniq_ptr_impl& __rhs) noexcept
156       {
157 	using std::swap;
158 	swap(this->_M_ptr(), __rhs._M_ptr());
159 	swap(this->_M_deleter(), __rhs._M_deleter());
160       }
161 
162     private:
163       tuple<pointer, _Dp> _M_t;
164     };
165 
166   /// 20.7.1.2 unique_ptr for single objects.
167   template <typename _Tp, typename _Dp = default_delete<_Tp>>
168     class unique_ptr
169     {
170       template <class _Up>
171       using _DeleterConstraint =
172 	typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type;
173 
174       __uniq_ptr_impl<_Tp, _Dp> _M_t;
175 
176     public:
177       using pointer	  = typename __uniq_ptr_impl<_Tp, _Dp>::pointer;
178       using element_type  = _Tp;
179       using deleter_type  = _Dp;
180 
181       // helper template for detecting a safe conversion from another
182       // unique_ptr
183       template<typename _Up, typename _Ep>
184 	using __safe_conversion_up = __and_<
185 	  is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>,
186 	  __not_<is_array<_Up>>
187         >;
188 
189       // Constructors.
190 
191       /// Default constructor, creates a unique_ptr that owns nothing.
192       template <typename _Up = _Dp,
193 		typename = _DeleterConstraint<_Up>>
194 	constexpr unique_ptr() noexcept
195 	: _M_t()
196 	{ }
197 
198       /** Takes ownership of a pointer.
199        *
200        * @param __p  A pointer to an object of @c element_type
201        *
202        * The deleter will be value-initialized.
203        */
204       template <typename _Up = _Dp,
205 		typename = _DeleterConstraint<_Up>>
206 	explicit
207 	unique_ptr(pointer __p) noexcept
208 	: _M_t(__p)
209         { }
210 
211       /** Takes ownership of a pointer.
212        *
213        * @param __p  A pointer to an object of @c element_type
214        * @param __d  A reference to a deleter.
215        *
216        * The deleter will be initialized with @p __d
217        */
218       unique_ptr(pointer __p,
219 	  typename conditional<is_reference<deleter_type>::value,
220 	    deleter_type, const deleter_type&>::type __d) noexcept
221       : _M_t(__p, __d) { }
222 
223       /** Takes ownership of a pointer.
224        *
225        * @param __p  A pointer to an object of @c element_type
226        * @param __d  An rvalue reference to a deleter.
227        *
228        * The deleter will be initialized with @p std::move(__d)
229        */
230       unique_ptr(pointer __p,
231 	  typename remove_reference<deleter_type>::type&& __d) noexcept
232       : _M_t(std::move(__p), std::move(__d))
233       { static_assert(!std::is_reference<deleter_type>::value,
234 		      "rvalue deleter bound to reference"); }
235 
236       /// Creates a unique_ptr that owns nothing.
237       template <typename _Up = _Dp,
238 		typename = _DeleterConstraint<_Up>>
239 	constexpr unique_ptr(nullptr_t) noexcept : _M_t() { }
240 
241       // Move constructors.
242 
243       /// Move constructor.
244       unique_ptr(unique_ptr&& __u) noexcept
245       : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
246 
247       /** @brief Converting constructor from another type
248        *
249        * Requires that the pointer owned by @p __u is convertible to the
250        * type of pointer owned by this object, @p __u does not own an array,
251        * and @p __u has a compatible deleter type.
252        */
253       template<typename _Up, typename _Ep, typename = _Require<
254                __safe_conversion_up<_Up, _Ep>,
255 	       typename conditional<is_reference<_Dp>::value,
256 				    is_same<_Ep, _Dp>,
257 				    is_convertible<_Ep, _Dp>>::type>>
258 	unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
259 	: _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
260 	{ }
261 
262 #if _GLIBCXX_USE_DEPRECATED
263 #pragma GCC diagnostic push
264 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
265       /// Converting constructor from @c auto_ptr
266       template<typename _Up, typename = _Require<
267 	       is_convertible<_Up*, _Tp*>, is_same<_Dp, default_delete<_Tp>>>>
268 	unique_ptr(auto_ptr<_Up>&& __u) noexcept;
269 #pragma GCC diagnostic pop
270 #endif
271 
272       /// Destructor, invokes the deleter if the stored pointer is not null.
273       ~unique_ptr() noexcept
274       {
275 	auto& __ptr = _M_t._M_ptr();
276 	if (__ptr != nullptr)
277 	  get_deleter()(__ptr);
278 	__ptr = pointer();
279       }
280 
281       // Assignment.
282 
283       /** @brief Move assignment operator.
284        *
285        * @param __u  The object to transfer ownership from.
286        *
287        * Invokes the deleter first if this object owns a pointer.
288        */
289       unique_ptr&
290       operator=(unique_ptr&& __u) noexcept
291       {
292 	reset(__u.release());
293 	get_deleter() = std::forward<deleter_type>(__u.get_deleter());
294 	return *this;
295       }
296 
297       /** @brief Assignment from another type.
298        *
299        * @param __u  The object to transfer ownership from, which owns a
300        *             convertible pointer to a non-array object.
301        *
302        * Invokes the deleter first if this object owns a pointer.
303        */
304       template<typename _Up, typename _Ep>
305         typename enable_if< __and_<
306           __safe_conversion_up<_Up, _Ep>,
307           is_assignable<deleter_type&, _Ep&&>
308           >::value,
309           unique_ptr&>::type
310 	operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
311 	{
312 	  reset(__u.release());
313 	  get_deleter() = std::forward<_Ep>(__u.get_deleter());
314 	  return *this;
315 	}
316 
317       /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
318       unique_ptr&
319       operator=(nullptr_t) noexcept
320       {
321 	reset();
322 	return *this;
323       }
324 
325       // Observers.
326 
327       /// Dereference the stored pointer.
328       typename add_lvalue_reference<element_type>::type
329       operator*() const
330       {
331 	__glibcxx_assert(get() != pointer());
332 	return *get();
333       }
334 
335       /// Return the stored pointer.
336       pointer
337       operator->() const noexcept
338       {
339 	_GLIBCXX_DEBUG_PEDASSERT(get() != pointer());
340 	return get();
341       }
342 
343       /// Return the stored pointer.
344       pointer
345       get() const noexcept
346       { return _M_t._M_ptr(); }
347 
348       /// Return a reference to the stored deleter.
349       deleter_type&
350       get_deleter() noexcept
351       { return _M_t._M_deleter(); }
352 
353       /// Return a reference to the stored deleter.
354       const deleter_type&
355       get_deleter() const noexcept
356       { return _M_t._M_deleter(); }
357 
358       /// Return @c true if the stored pointer is not null.
359       explicit operator bool() const noexcept
360       { return get() == pointer() ? false : true; }
361 
362       // Modifiers.
363 
364       /// Release ownership of any stored pointer.
365       pointer
366       release() noexcept
367       {
368 	pointer __p = get();
369 	_M_t._M_ptr() = pointer();
370 	return __p;
371       }
372 
373       /** @brief Replace the stored pointer.
374        *
375        * @param __p  The new pointer to store.
376        *
377        * The deleter will be invoked if a pointer is already owned.
378        */
379       void
380       reset(pointer __p = pointer()) noexcept
381       {
382 	using std::swap;
383 	swap(_M_t._M_ptr(), __p);
384 	if (__p != pointer())
385 	  get_deleter()(__p);
386       }
387 
388       /// Exchange the pointer and deleter with another object.
389       void
390       swap(unique_ptr& __u) noexcept
391       {
392 	static_assert(__is_swappable<_Dp>::value, "deleter must be swappable");
393 	_M_t.swap(__u._M_t);
394       }
395 
396       // Disable copy from lvalue.
397       unique_ptr(const unique_ptr&) = delete;
398       unique_ptr& operator=(const unique_ptr&) = delete;
399   };
400 
401   /// 20.7.1.3 unique_ptr for array objects with a runtime length
402   // [unique.ptr.runtime]
403   // _GLIBCXX_RESOLVE_LIB_DEFECTS
404   // DR 740 - omit specialization for array objects with a compile time length
405   template<typename _Tp, typename _Dp>
406     class unique_ptr<_Tp[], _Dp>
407     {
408       template <typename _Up>
409       using _DeleterConstraint =
410 	typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type;
411 
412       __uniq_ptr_impl<_Tp, _Dp> _M_t;
413 
414       template<typename _Up>
415 	using __remove_cv = typename remove_cv<_Up>::type;
416 
417       // like is_base_of<_Tp, _Up> but false if unqualified types are the same
418       template<typename _Up>
419 	using __is_derived_Tp
420 	  = __and_< is_base_of<_Tp, _Up>,
421 		    __not_<is_same<__remove_cv<_Tp>, __remove_cv<_Up>>> >;
422 
423     public:
424       using pointer	  = typename __uniq_ptr_impl<_Tp, _Dp>::pointer;
425       using element_type  = _Tp;
426       using deleter_type  = _Dp;
427 
428       // helper template for detecting a safe conversion from another
429       // unique_ptr
430       template<typename _Up, typename _Ep,
431                typename _UPtr = unique_ptr<_Up, _Ep>,
432 	       typename _UP_pointer = typename _UPtr::pointer,
433 	       typename _UP_element_type = typename _UPtr::element_type>
434 	using __safe_conversion_up = __and_<
435           is_array<_Up>,
436           is_same<pointer, element_type*>,
437           is_same<_UP_pointer, _UP_element_type*>,
438           is_convertible<_UP_element_type(*)[], element_type(*)[]>
439         >;
440 
441       // helper template for detecting a safe conversion from a raw pointer
442       template<typename _Up>
443         using __safe_conversion_raw = __and_<
444           __or_<__or_<is_same<_Up, pointer>,
445                       is_same<_Up, nullptr_t>>,
446                 __and_<is_pointer<_Up>,
447                        is_same<pointer, element_type*>,
448                        is_convertible<
449                          typename remove_pointer<_Up>::type(*)[],
450                          element_type(*)[]>
451                 >
452           >
453         >;
454 
455       // Constructors.
456 
457       /// Default constructor, creates a unique_ptr that owns nothing.
458       template <typename _Up = _Dp,
459 		typename = _DeleterConstraint<_Up>>
460 	constexpr unique_ptr() noexcept
461 	: _M_t()
462 	{ }
463 
464       /** Takes ownership of a pointer.
465        *
466        * @param __p  A pointer to an array of a type safely convertible
467        * to an array of @c element_type
468        *
469        * The deleter will be value-initialized.
470        */
471       template<typename _Up,
472 	       typename _Vp = _Dp,
473 	       typename = _DeleterConstraint<_Vp>,
474 	       typename = typename enable_if<
475                  __safe_conversion_raw<_Up>::value, bool>::type>
476 	explicit
477 	unique_ptr(_Up __p) noexcept
478 	: _M_t(__p)
479         { }
480 
481       /** Takes ownership of a pointer.
482        *
483        * @param __p  A pointer to an array of a type safely convertible
484        * to an array of @c element_type
485        * @param __d  A reference to a deleter.
486        *
487        * The deleter will be initialized with @p __d
488        */
489       template<typename _Up,
490                typename = typename enable_if<
491                  __safe_conversion_raw<_Up>::value, bool>::type>
492       unique_ptr(_Up __p,
493                  typename conditional<is_reference<deleter_type>::value,
494                  deleter_type, const deleter_type&>::type __d) noexcept
495       : _M_t(__p, __d) { }
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 std::move(__d)
504        */
505       template<typename _Up,
506                typename = typename enable_if<
507                  __safe_conversion_raw<_Up>::value, bool>::type>
508       unique_ptr(_Up __p, typename
509 		 remove_reference<deleter_type>::type&& __d) noexcept
510       : _M_t(std::move(__p), std::move(__d))
511       { static_assert(!is_reference<deleter_type>::value,
512 		      "rvalue deleter bound to reference"); }
513 
514       /// Move constructor.
515       unique_ptr(unique_ptr&& __u) noexcept
516       : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
517 
518       /// Creates a unique_ptr that owns nothing.
519       template <typename _Up = _Dp,
520 		typename = _DeleterConstraint<_Up>>
521 	constexpr unique_ptr(nullptr_t) noexcept : _M_t() { }
522 
523       template<typename _Up, typename _Ep, typename = _Require<
524 	       __safe_conversion_up<_Up, _Ep>,
525 	       typename conditional<is_reference<_Dp>::value,
526 				    is_same<_Ep, _Dp>,
527 				    is_convertible<_Ep, _Dp>>::type>>
528 	unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
529 	: _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
530 	{ }
531 
532       /// Destructor, invokes the deleter if the stored pointer is not null.
533       ~unique_ptr()
534       {
535 	auto& __ptr = _M_t._M_ptr();
536 	if (__ptr != nullptr)
537 	  get_deleter()(__ptr);
538 	__ptr = pointer();
539       }
540 
541       // Assignment.
542 
543       /** @brief Move assignment operator.
544        *
545        * @param __u  The object to transfer ownership from.
546        *
547        * Invokes the deleter first if this object owns a pointer.
548        */
549       unique_ptr&
550       operator=(unique_ptr&& __u) noexcept
551       {
552 	reset(__u.release());
553 	get_deleter() = std::forward<deleter_type>(__u.get_deleter());
554 	return *this;
555       }
556 
557       /** @brief Assignment from another type.
558        *
559        * @param __u  The object to transfer ownership from, which owns a
560        *             convertible pointer to an array object.
561        *
562        * Invokes the deleter first if this object owns a pointer.
563        */
564       template<typename _Up, typename _Ep>
565 	typename
566 	enable_if<__and_<__safe_conversion_up<_Up, _Ep>,
567                          is_assignable<deleter_type&, _Ep&&>
568                   >::value,
569                   unique_ptr&>::type
570 	operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
571 	{
572 	  reset(__u.release());
573 	  get_deleter() = std::forward<_Ep>(__u.get_deleter());
574 	  return *this;
575 	}
576 
577       /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
578       unique_ptr&
579       operator=(nullptr_t) noexcept
580       {
581 	reset();
582 	return *this;
583       }
584 
585       // Observers.
586 
587       /// Access an element of owned array.
588       typename std::add_lvalue_reference<element_type>::type
589       operator[](size_t __i) const
590       {
591 	__glibcxx_assert(get() != pointer());
592 	return get()[__i];
593       }
594 
595       /// Return the stored pointer.
596       pointer
597       get() const noexcept
598       { return _M_t._M_ptr(); }
599 
600       /// Return a reference to the stored deleter.
601       deleter_type&
602       get_deleter() noexcept
603       { return _M_t._M_deleter(); }
604 
605       /// Return a reference to the stored deleter.
606       const deleter_type&
607       get_deleter() const noexcept
608       { return _M_t._M_deleter(); }
609 
610       /// Return @c true if the stored pointer is not null.
611       explicit operator bool() const noexcept
612       { return get() == pointer() ? false : true; }
613 
614       // Modifiers.
615 
616       /// Release ownership of any stored pointer.
617       pointer
618       release() noexcept
619       {
620 	pointer __p = get();
621 	_M_t._M_ptr() = pointer();
622 	return __p;
623       }
624 
625       /** @brief Replace the stored pointer.
626        *
627        * @param __p  The new pointer to store.
628        *
629        * The deleter will be invoked if a pointer is already owned.
630        */
631       template <typename _Up,
632                 typename = _Require<
633                   __or_<is_same<_Up, pointer>,
634                         __and_<is_same<pointer, element_type*>,
635                                is_pointer<_Up>,
636                                is_convertible<
637                                  typename remove_pointer<_Up>::type(*)[],
638                                  element_type(*)[]
639                                >
640                         >
641                   >
642                >>
643       void
644       reset(_Up __p) noexcept
645       {
646 	pointer __ptr = __p;
647 	using std::swap;
648 	swap(_M_t._M_ptr(), __ptr);
649 	if (__ptr != nullptr)
650 	  get_deleter()(__ptr);
651       }
652 
653       void reset(nullptr_t = nullptr) noexcept
654       {
655         reset(pointer());
656       }
657 
658       /// Exchange the pointer and deleter with another object.
659       void
660       swap(unique_ptr& __u) noexcept
661       {
662 	static_assert(__is_swappable<_Dp>::value, "deleter must be swappable");
663 	_M_t.swap(__u._M_t);
664       }
665 
666       // Disable copy from lvalue.
667       unique_ptr(const unique_ptr&) = delete;
668       unique_ptr& operator=(const unique_ptr&) = delete;
669     };
670 
671   template<typename _Tp, typename _Dp>
672     inline
673 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
674     // Constrained free swap overload, see p0185r1
675     typename enable_if<__is_swappable<_Dp>::value>::type
676 #else
677     void
678 #endif
679     swap(unique_ptr<_Tp, _Dp>& __x,
680 	 unique_ptr<_Tp, _Dp>& __y) noexcept
681     { __x.swap(__y); }
682 
683 #if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
684   template<typename _Tp, typename _Dp>
685     typename enable_if<!__is_swappable<_Dp>::value>::type
686     swap(unique_ptr<_Tp, _Dp>&,
687 	 unique_ptr<_Tp, _Dp>&) = delete;
688 #endif
689 
690   template<typename _Tp, typename _Dp,
691 	   typename _Up, typename _Ep>
692     inline bool
693     operator==(const unique_ptr<_Tp, _Dp>& __x,
694 	       const unique_ptr<_Up, _Ep>& __y)
695     { return __x.get() == __y.get(); }
696 
697   template<typename _Tp, typename _Dp>
698     inline bool
699     operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
700     { return !__x; }
701 
702   template<typename _Tp, typename _Dp>
703     inline bool
704     operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
705     { return !__x; }
706 
707   template<typename _Tp, typename _Dp,
708 	   typename _Up, typename _Ep>
709     inline bool
710     operator!=(const unique_ptr<_Tp, _Dp>& __x,
711 	       const unique_ptr<_Up, _Ep>& __y)
712     { return __x.get() != __y.get(); }
713 
714   template<typename _Tp, typename _Dp>
715     inline bool
716     operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
717     { return (bool)__x; }
718 
719   template<typename _Tp, typename _Dp>
720     inline bool
721     operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
722     { return (bool)__x; }
723 
724   template<typename _Tp, typename _Dp,
725 	   typename _Up, typename _Ep>
726     inline bool
727     operator<(const unique_ptr<_Tp, _Dp>& __x,
728 	      const unique_ptr<_Up, _Ep>& __y)
729     {
730       typedef typename
731 	std::common_type<typename unique_ptr<_Tp, _Dp>::pointer,
732 	                 typename unique_ptr<_Up, _Ep>::pointer>::type _CT;
733       return std::less<_CT>()(__x.get(), __y.get());
734     }
735 
736   template<typename _Tp, typename _Dp>
737     inline bool
738     operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
739     { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
740 								 nullptr); }
741 
742   template<typename _Tp, typename _Dp>
743     inline bool
744     operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
745     { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
746 								 __x.get()); }
747 
748   template<typename _Tp, typename _Dp,
749 	   typename _Up, typename _Ep>
750     inline bool
751     operator<=(const unique_ptr<_Tp, _Dp>& __x,
752 	       const unique_ptr<_Up, _Ep>& __y)
753     { return !(__y < __x); }
754 
755   template<typename _Tp, typename _Dp>
756     inline bool
757     operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
758     { return !(nullptr < __x); }
759 
760   template<typename _Tp, typename _Dp>
761     inline bool
762     operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
763     { return !(__x < nullptr); }
764 
765   template<typename _Tp, typename _Dp,
766 	   typename _Up, typename _Ep>
767     inline bool
768     operator>(const unique_ptr<_Tp, _Dp>& __x,
769 	      const unique_ptr<_Up, _Ep>& __y)
770     { return (__y < __x); }
771 
772   template<typename _Tp, typename _Dp>
773     inline bool
774     operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
775     { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
776 								 __x.get()); }
777 
778   template<typename _Tp, typename _Dp>
779     inline bool
780     operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
781     { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
782 								 nullptr); }
783 
784   template<typename _Tp, typename _Dp,
785 	   typename _Up, typename _Ep>
786     inline bool
787     operator>=(const unique_ptr<_Tp, _Dp>& __x,
788 	       const unique_ptr<_Up, _Ep>& __y)
789     { return !(__x < __y); }
790 
791   template<typename _Tp, typename _Dp>
792     inline bool
793     operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
794     { return !(__x < nullptr); }
795 
796   template<typename _Tp, typename _Dp>
797     inline bool
798     operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
799     { return !(nullptr < __x); }
800 
801   /// std::hash specialization for unique_ptr.
802   template<typename _Tp, typename _Dp>
803     struct hash<unique_ptr<_Tp, _Dp>>
804     : public __hash_base<size_t, unique_ptr<_Tp, _Dp>>,
805     private __poison_hash<typename unique_ptr<_Tp, _Dp>::pointer>
806     {
807       size_t
808       operator()(const unique_ptr<_Tp, _Dp>& __u) const noexcept
809       {
810 	typedef unique_ptr<_Tp, _Dp> _UP;
811 	return std::hash<typename _UP::pointer>()(__u.get());
812       }
813     };
814 
815 #if __cplusplus > 201103L
816 
817 #define __cpp_lib_make_unique 201304
818 
819   template<typename _Tp>
820     struct _MakeUniq
821     { typedef unique_ptr<_Tp> __single_object; };
822 
823   template<typename _Tp>
824     struct _MakeUniq<_Tp[]>
825     { typedef unique_ptr<_Tp[]> __array; };
826 
827   template<typename _Tp, size_t _Bound>
828     struct _MakeUniq<_Tp[_Bound]>
829     { struct __invalid_type { }; };
830 
831   /// std::make_unique for single objects
832   template<typename _Tp, typename... _Args>
833     inline typename _MakeUniq<_Tp>::__single_object
834     make_unique(_Args&&... __args)
835     { return unique_ptr<_Tp>(new _Tp(std::forward<_Args>(__args)...)); }
836 
837   /// std::make_unique for arrays of unknown bound
838   template<typename _Tp>
839     inline typename _MakeUniq<_Tp>::__array
840     make_unique(size_t __num)
841     { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]()); }
842 
843   /// Disable std::make_unique for arrays of known bound
844   template<typename _Tp, typename... _Args>
845     inline typename _MakeUniq<_Tp>::__invalid_type
846     make_unique(_Args&&...) = delete;
847 #endif
848 
849   // @} group pointer_abstractions
850 
851 _GLIBCXX_END_NAMESPACE_VERSION
852 } // namespace
853 
854 #endif /* _UNIQUE_PTR_H */
855