1// unique_ptr implementation -*- C++ -*-
2
3// Copyright (C) 2008, 2009 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 unique_ptr.h
26 *  This is an internal header file, included by other library headers.
27 *  You should not attempt to use it directly.
28 */
29
30#ifndef _UNIQUE_PTR_H
31#define _UNIQUE_PTR_H 1
32
33#ifndef __GXX_EXPERIMENTAL_CXX0X__
34# include <c++0x_warning.h>
35#endif
36
37#include <bits/c++config.h>
38#include <debug/debug.h>
39#include <type_traits>
40#include <utility>
41#include <tuple>
42
43_GLIBCXX_BEGIN_NAMESPACE(std)
44
45  /**
46   * @addtogroup pointer_abstractions
47   * @{
48   */
49
50  /// Primary template, default_delete.
51  template<typename _Tp>
52    struct default_delete
53      {
54	default_delete() { }
55
56	template<typename _Up>
57	  default_delete(const default_delete<_Up>&) { }
58
59	void
60	operator()(_Tp* __ptr) const
61	{
62	  static_assert(sizeof(_Tp)>0,
63			"can't delete pointer to incomplete type");
64	  delete __ptr;
65	}
66    };
67
68  // _GLIBCXX_RESOLVE_LIB_DEFECTS
69  // DR 740 - omit specialization for array objects with a compile time length
70  /// Specialization, default_delete.
71  template<typename _Tp>
72    struct default_delete<_Tp[]>
73    {
74      void
75      operator()(_Tp* __ptr) const
76      {
77	static_assert(sizeof(_Tp)>0,
78		      "can't delete pointer to incomplete type");
79	delete [] __ptr;
80      }
81    };
82
83  /// 20.7.12.2 unique_ptr for single objects.
84  template <typename _Tp, typename _Tp_Deleter = default_delete<_Tp> >
85    class unique_ptr
86    {
87      typedef std::tuple<_Tp*, _Tp_Deleter>  __tuple_type;
88      typedef __tuple_type unique_ptr::*     __unspecified_bool_type;
89      typedef _Tp* unique_ptr::*             __unspecified_pointer_type;
90
91    public:
92      typedef _Tp*               pointer;
93      typedef _Tp                element_type;
94      typedef _Tp_Deleter        deleter_type;
95
96      // Constructors.
97      unique_ptr()
98      : _M_t(pointer(), deleter_type())
99      { static_assert(!std::is_pointer<deleter_type>::value,
100		      "constructed with null function pointer deleter"); }
101
102      explicit
103      unique_ptr(pointer __p)
104      : _M_t(__p, deleter_type())
105      { static_assert(!std::is_pointer<deleter_type>::value,
106		     "constructed with null function pointer deleter"); }
107
108      unique_ptr(pointer __p,
109          typename std::conditional<std::is_reference<deleter_type>::value,
110            deleter_type, const deleter_type&>::type __d)
111      : _M_t(__p, __d) { }
112
113      unique_ptr(pointer __p,
114          typename std::remove_reference<deleter_type>::type&& __d)
115      : _M_t(std::move(__p), std::move(__d))
116      { static_assert(!std::is_reference<deleter_type>::value,
117		      "rvalue deleter bound to reference"); }
118
119      // Move constructors.
120      unique_ptr(unique_ptr&& __u)
121      : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
122
123      template<typename _Up, typename _Up_Deleter>
124        unique_ptr(unique_ptr<_Up, _Up_Deleter>&& __u)
125        : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter()))
126	{ }
127
128      // Destructor.
129      ~unique_ptr() { reset(); }
130
131      // Assignment.
132      unique_ptr&
133      operator=(unique_ptr&& __u)
134      {
135        reset(__u.release());
136        get_deleter() = std::move(__u.get_deleter());
137        return *this;
138      }
139
140      template<typename _Up, typename _Up_Deleter>
141        unique_ptr&
142        operator=(unique_ptr<_Up, _Up_Deleter>&& __u)
143	{
144          reset(__u.release());
145          get_deleter() = std::move(__u.get_deleter());
146          return *this;
147        }
148
149      unique_ptr&
150      operator=(__unspecified_pointer_type)
151      {
152	reset();
153	return *this;
154      }
155
156      // Observers.
157      typename std::add_lvalue_reference<element_type>::type operator*() const
158      {
159	_GLIBCXX_DEBUG_ASSERT(get() != 0);
160	return *get();
161      }
162
163      pointer
164      operator->() const
165      {
166	_GLIBCXX_DEBUG_ASSERT(get() != 0);
167	return get();
168      }
169
170      pointer
171      get() const
172      { return std::get<0>(_M_t); }
173
174      typename std::add_lvalue_reference<deleter_type>::type
175      get_deleter()
176      { return std::get<1>(_M_t); }
177
178      typename std::add_lvalue_reference<
179          typename std::add_const<deleter_type>::type
180              >::type
181      get_deleter() const
182      { return std::get<1>(_M_t); }
183
184      operator __unspecified_bool_type () const
185      { return get() == 0 ? 0 : &unique_ptr::_M_t; }
186
187      // Modifiers.
188      pointer
189      release()
190      {
191	pointer __p = get();
192	std::get<0>(_M_t) = 0;
193	return __p;
194      }
195
196      void
197      reset(pointer __p = pointer())
198      {
199	if (__p != get())
200	  {
201	    get_deleter()(get());
202	    std::get<0>(_M_t) = __p;
203	  }
204      }
205
206      void
207      swap(unique_ptr&& __u)
208      {
209	using std::swap;
210	swap(_M_t, __u._M_t);
211      }
212
213      // Disable copy from lvalue.
214      unique_ptr(const unique_ptr&) = delete;
215
216      template<typename _Up, typename _Up_Deleter>
217        unique_ptr(const unique_ptr<_Up, _Up_Deleter>&) = delete;
218
219      unique_ptr& operator=(const unique_ptr&) = delete;
220
221      template<typename _Up, typename _Up_Deleter>
222        unique_ptr& operator=(const unique_ptr<_Up, _Up_Deleter>&) = delete;
223
224    private:
225      __tuple_type _M_t;
226  };
227
228  /// 20.7.12.3 unique_ptr for array objects with a runtime length
229  // [unique.ptr.runtime]
230  // _GLIBCXX_RESOLVE_LIB_DEFECTS
231  // DR 740 - omit specialization for array objects with a compile time length
232  template<typename _Tp, typename _Tp_Deleter>
233    class unique_ptr<_Tp[], _Tp_Deleter>
234    {
235      typedef std::tuple<_Tp*, _Tp_Deleter>  __tuple_type;
236      typedef __tuple_type unique_ptr::*     __unspecified_bool_type;
237      typedef _Tp* unique_ptr::*             __unspecified_pointer_type;
238
239    public:
240      typedef _Tp*               pointer;
241      typedef _Tp                element_type;
242      typedef _Tp_Deleter        deleter_type;
243
244      // Constructors.
245      unique_ptr()
246      : _M_t(pointer(), deleter_type())
247      { static_assert(!std::is_pointer<deleter_type>::value,
248		      "constructed with null function pointer deleter"); }
249
250      explicit
251      unique_ptr(pointer __p)
252      : _M_t(__p, deleter_type())
253      { static_assert(!std::is_pointer<deleter_type>::value,
254		      "constructed with null function pointer deleter"); }
255
256      unique_ptr(pointer __p,
257          typename std::conditional<std::is_reference<deleter_type>::value,
258              deleter_type, const deleter_type&>::type __d)
259      : _M_t(__p, __d) { }
260
261      unique_ptr(pointer __p,
262		 typename std::remove_reference<deleter_type>::type && __d)
263      : _M_t(std::move(__p), std::move(__d))
264      { static_assert(!std::is_reference<deleter_type>::value,
265		      "rvalue deleter bound to reference"); }
266
267      // Move constructors.
268      unique_ptr(unique_ptr&& __u)
269      : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
270
271      template<typename _Up, typename _Up_Deleter>
272        unique_ptr(unique_ptr<_Up, _Up_Deleter>&& __u)
273	: _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter()))
274	{ }
275
276      // Destructor.
277      ~unique_ptr() { reset(); }
278
279      // Assignment.
280      unique_ptr&
281      operator=(unique_ptr&& __u)
282      {
283	reset(__u.release());
284	get_deleter() = std::move(__u.get_deleter());
285	return *this;
286      }
287
288      template<typename _Up, typename _Up_Deleter>
289        unique_ptr&
290        operator=(unique_ptr<_Up, _Up_Deleter>&& __u)
291	{
292          reset(__u.release());
293          get_deleter() = std::move(__u.get_deleter());
294          return *this;
295        }
296
297      unique_ptr&
298      operator=(__unspecified_pointer_type)
299      {
300	reset();
301	return *this;
302      }
303
304      // Observers.
305      typename std::add_lvalue_reference<element_type>::type
306      operator[](size_t __i) const
307      {
308	_GLIBCXX_DEBUG_ASSERT(get() != 0);
309	return get()[__i];
310      }
311
312      pointer
313      get() const
314      { return std::get<0>(_M_t); }
315
316      typename std::add_lvalue_reference<deleter_type>::type
317      get_deleter()
318      { return std::get<1>(_M_t); }
319
320      typename std::add_lvalue_reference<
321          typename std::add_const<deleter_type>::type
322              >::type
323      get_deleter() const
324      { return std::get<1>(_M_t); }
325
326      operator __unspecified_bool_type () const
327      { return get() == 0 ? 0 : &unique_ptr::_M_t; }
328
329      // Modifiers.
330      pointer
331      release()
332      {
333	pointer __p = get();
334	std::get<0>(_M_t) = 0;
335	return __p;
336      }
337
338      void
339      reset(pointer __p = pointer())
340      {
341	if (__p != get())
342	{
343	  get_deleter()(get());
344	  std::get<0>(_M_t) = __p;
345	}
346      }
347
348      // DR 821.
349      template<typename _Up>
350        void reset(_Up) = delete;
351
352      void
353      swap(unique_ptr&& __u)
354      {
355	using std::swap;
356	swap(_M_t, __u._M_t);
357      }
358
359      // Disable copy from lvalue.
360      unique_ptr(const unique_ptr&) = delete;
361      unique_ptr& operator=(const unique_ptr&) = delete;
362
363      // Disable construction from convertible pointer types.
364      // (N2315 - 20.6.5.3.1)
365      template<typename _Up>
366        unique_ptr(_Up*, typename
367		   std::conditional<std::is_reference<deleter_type>::value,
368		   deleter_type, const deleter_type&>::type,
369		   typename std::enable_if<std::is_convertible<_Up*,
370		   pointer>::value>::type* = 0) = delete;
371
372      template<typename _Up>
373        unique_ptr(_Up*, typename std::remove_reference<deleter_type>::type&&,
374		   typename std::enable_if<std::is_convertible<_Up*,
375		   pointer>::value>::type* = 0) = delete;
376
377      template<typename _Up>
378        explicit
379        unique_ptr(_Up*, typename std::enable_if<std::is_convertible<_Up*,
380		   pointer>::value>::type* = 0) = delete;
381
382    private:
383      __tuple_type _M_t;
384  };
385
386  template<typename _Tp, typename _Tp_Deleter>
387    inline void
388    swap(unique_ptr<_Tp, _Tp_Deleter>& __x,
389	 unique_ptr<_Tp, _Tp_Deleter>& __y)
390    { __x.swap(__y); }
391
392  template<typename _Tp, typename _Tp_Deleter>
393    inline void
394    swap(unique_ptr<_Tp, _Tp_Deleter>&& __x,
395	 unique_ptr<_Tp, _Tp_Deleter>& __y)
396    { __x.swap(__y); }
397
398  template<typename _Tp, typename _Tp_Deleter>
399    inline void
400    swap(unique_ptr<_Tp, _Tp_Deleter>& __x,
401	 unique_ptr<_Tp, _Tp_Deleter>&& __y)
402    { __x.swap(__y); }
403
404  template<typename _Tp, typename _Tp_Deleter,
405	   typename _Up, typename _Up_Deleter>
406    inline bool
407    operator==(const unique_ptr<_Tp, _Tp_Deleter>& __x,
408	       const unique_ptr<_Up, _Up_Deleter>& __y)
409    { return __x.get() == __y.get(); }
410
411  template<typename _Tp, typename _Tp_Deleter,
412	   typename _Up, typename _Up_Deleter>
413    inline bool
414    operator!=(const unique_ptr<_Tp, _Tp_Deleter>& __x,
415	       const unique_ptr<_Up, _Up_Deleter>& __y)
416    { return !(__x.get() == __y.get()); }
417
418  template<typename _Tp, typename _Tp_Deleter,
419	   typename _Up, typename _Up_Deleter>
420    inline bool
421    operator<(const unique_ptr<_Tp, _Tp_Deleter>& __x,
422	      const unique_ptr<_Up, _Up_Deleter>& __y)
423    { return __x.get() < __y.get(); }
424
425  template<typename _Tp, typename _Tp_Deleter,
426	   typename _Up, typename _Up_Deleter>
427    inline bool
428    operator<=(const unique_ptr<_Tp, _Tp_Deleter>& __x,
429	       const unique_ptr<_Up, _Up_Deleter>& __y)
430    { return !(__y.get() < __x.get()); }
431
432  template<typename _Tp, typename _Tp_Deleter,
433	   typename _Up, typename _Up_Deleter>
434    inline bool
435    operator>(const unique_ptr<_Tp, _Tp_Deleter>& __x,
436	      const unique_ptr<_Up, _Up_Deleter>& __y)
437    { return __y.get() < __x.get(); }
438
439  template<typename _Tp, typename _Tp_Deleter,
440	   typename _Up, typename _Up_Deleter>
441    inline bool
442    operator>=(const unique_ptr<_Tp, _Tp_Deleter>& __x,
443	       const unique_ptr<_Up, _Up_Deleter>& __y)
444    { return !(__x.get() < __y.get()); }
445
446  // @} group pointer_abstractions
447
448_GLIBCXX_END_NAMESPACE
449
450#endif /* _UNIQUE_PTR_H */
451