aboutsummaryrefslogtreecommitdiff
path: root/odb/lazy-ptr.hxx
blob: e340d942cff418b3e53b5428f6ca905d8cb21f82 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
// file      : odb/lazy-ptr.hxx
// copyright : Copyright (c) 2009-2013 Code Synthesis Tools CC
// license   : GNU GPL v2; see accompanying LICENSE file

#ifndef ODB_LAZY_PTR_HXX
#define ODB_LAZY_PTR_HXX

#include <odb/pre.hxx>

#include <memory>  // std::auto_ptr, std::shared_ptr/weak_ptr
#include <utility> // std::move

#include <odb/forward.hxx>        // odb::core, odb::database
#include <odb/traits.hxx>
#include <odb/lazy-ptr-impl.hxx>
#include <odb/details/config.hxx> // ODB_CXX11

namespace odb
{
  // Raw pointer lazy version.
  //
  template <class T>
  class lazy_ptr
  {
    // Pointer interface.
    //
  public:
    typedef T element_type;

    lazy_ptr ();
    template <class Y> lazy_ptr (Y*);

    lazy_ptr (const lazy_ptr&);
    template <class Y> lazy_ptr (const lazy_ptr<Y>&);

    lazy_ptr& operator= (const lazy_ptr&);
    template <class Y> lazy_ptr& operator= (Y*);
    template <class Y> lazy_ptr& operator= (const lazy_ptr<Y>&);

    void swap (lazy_ptr&);
    void reset ();
    template <class Y> void reset (Y*);

    T& operator* () const;
    T* operator-> () const;
    T* get () const;

    typedef T* lazy_ptr::*unspecified_bool_type;
    operator unspecified_bool_type () const
    {
      return (p_ || i_) ? &lazy_ptr::p_ : 0;
    }

    // Lazy loading interface.
    //
  public:
    typedef odb::database database_type;

    //  NULL      loaded()
    //
    //  true       true      NULL pointer to transient object
    //  false      true      valid pointer to persistent object
    //  true       false     unloaded pointer to persistent object
    //  false      false     valid pointer to transient object
    //
    bool loaded () const;

    T* load () const;

    // Unload the pointer. For transient objects this function is
    // equivalent to reset().
    //
    void unload () const;

    // Get the underlying eager pointer. If this is an unloaded pointer
    // to a persistent object, then the returned pointer will be NULL.
    //
    T* get_eager () const;

    template <class DB, class ID> lazy_ptr (DB&, const ID&);
    template <class DB, class Y> lazy_ptr (DB&, Y*);

    template <class DB, class ID> void reset (DB&, const ID&);
    template <class DB, class Y> void reset (DB&, Y*);

#ifdef ODB_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGUMENT
    template <class O = T>
#else
    template <class O /* = T */>
#endif
    typename object_traits<O>::id_type object_id () const;

    database_type& database () const;

    // Helpers.
    //
  public:
    template <class Y> bool equal (const lazy_ptr<Y>&) const;

  private:
    template <class Y> friend class lazy_ptr;

    mutable T* p_;
    mutable lazy_ptr_impl<T> i_;
  };

  // operator< and operator<< are not provided.
  //
  template <class T, class Y>
  bool operator== (const lazy_ptr<T>&, const lazy_ptr<Y>&);

  template <class T, class Y>
  bool operator!= (const lazy_ptr<T>&, const lazy_ptr<Y>&);

  template <class T> void swap (lazy_ptr<T>&, lazy_ptr<T>&);

  // std::auto_ptr lazy version.
  //
  template <class T>
  struct lazy_auto_ptr_ref
  {
    explicit lazy_auto_ptr_ref (T*, const lazy_ptr_impl_ref&);

    T* p_;
    lazy_ptr_impl_ref i_;
  };

  template <class T>
  class lazy_auto_ptr
  {
    // Standard auto_ptr interface.
    //
  public:
    typedef T element_type;

    explicit lazy_auto_ptr (T* = 0);
    lazy_auto_ptr (lazy_auto_ptr&);
    template <class Y> lazy_auto_ptr (lazy_auto_ptr<Y>&);

    lazy_auto_ptr& operator= (lazy_auto_ptr&);
    template <class Y> lazy_auto_ptr& operator= (lazy_auto_ptr<Y>&);

    T& operator* () const;
    T* operator-> () const;
    T* get () const;
    T* release ();
    void reset (T* = 0);

    lazy_auto_ptr (const lazy_auto_ptr_ref<T>&);
    lazy_auto_ptr& operator= (const lazy_auto_ptr_ref<T>&);
    template <class Y> operator lazy_auto_ptr_ref<Y> ();
    template <class Y> operator lazy_auto_ptr<Y> ();

    // Extension: conversion to bool.
    //
  public:
    typedef std::auto_ptr<T> lazy_auto_ptr::*unspecified_bool_type;
    operator unspecified_bool_type () const
    {
      return (p_.get () != 0 || i_) ? &lazy_auto_ptr::p_ : 0;
    }

    // Initialization/assignment from auto_ptr.
    //
  public:
    template <class Y> lazy_auto_ptr (std::auto_ptr<Y>&);
    lazy_auto_ptr (std::auto_ptr_ref<T>);

    template <class Y> lazy_auto_ptr& operator= (std::auto_ptr<Y>&);
    lazy_auto_ptr& operator= (std::auto_ptr_ref<T>);

    // Lazy loading interface.
    //
  public:
    typedef odb::database database_type;

    //  NULL      loaded()
    //
    //  true       true      NULL pointer to transient object
    //  false      true      valid pointer to persistent object
    //  true       false     unloaded pointer to persistent object
    //  false      false     valid pointer to transient object
    //
    bool loaded () const;

    std::auto_ptr<T>& load () const;

    // Unload the pointer. For transient objects this function is
    // equivalent to reset().
    //
    void unload () const;

    // Get the underlying eager pointer. If this is an unloaded pointer
    // to a persistent object, then the returned pointer will be NULL.
    //
    std::auto_ptr<T>& get_eager () const;

    template <class DB, class ID> lazy_auto_ptr (DB&, const ID&);
    template <class DB> lazy_auto_ptr (DB&, T*);
    template <class DB, class Y> lazy_auto_ptr (DB&, std::auto_ptr<Y>&);

    template <class DB, class ID> void reset (DB&, const ID&);
    template <class DB> void reset (DB&, T*);
    template <class DB, class Y> void reset (DB&, std::auto_ptr<Y>&);

#ifdef ODB_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGUMENT
    template <class O = T>
#else
    template <class O /* = T */>
#endif
    typename object_traits<O>::id_type object_id () const;

    database_type& database () const;

  private:
    template <class Y> friend class lazy_auto_ptr;

    // Note that it is possible to have a situation where p_ is NULL,
    // i_.id is NULL and i_.db is not NULL. This will happen if the
    // auto_ptr reference returned by load() is transferred to another
    // pointer or reset.
    //
    mutable std::auto_ptr<T> p_;
    mutable lazy_ptr_impl<T> i_;
  };

#ifdef ODB_CXX11

  // C++11 std::unique_ptr lazy version.
  //
  template <class T, class D = std::default_delete<T>>
  class lazy_unique_ptr
  {
    // Standard lazy_unique_ptr interface.
    //
  public:
    typedef T* pointer;     // For now assume it is T*.
    typedef T element_type;
    typedef D deleter_type;

    /*constexpr*/ lazy_unique_ptr () /*noexcept*/;
#ifdef ODB_CXX11_NULLPTR
    /*constexpr*/ lazy_unique_ptr (std::nullptr_t) /*noexcept*/;
#endif
    explicit lazy_unique_ptr (pointer) /*noexcept*/;

    // For now assume D is non-reference.
    //
    lazy_unique_ptr (pointer, const deleter_type&) /*noexcept*/;
    lazy_unique_ptr (pointer, deleter_type&&) /*noexcept*/;

    lazy_unique_ptr (lazy_unique_ptr&&) /*noexcept*/;
    template <class T1, class D1> lazy_unique_ptr (lazy_unique_ptr<T1, D1>&&) /*noexcept*/;
    template <class T1> lazy_unique_ptr (std::auto_ptr<T1>&&) /*noexcept*/;

#ifdef ODB_CXX11_NULLPTR
    lazy_unique_ptr& operator= (std::nullptr_t) /*noexcept*/;
#endif
    lazy_unique_ptr& operator= (lazy_unique_ptr&&) /*noexcept*/;
    template <class T1, class D1> lazy_unique_ptr& operator= (lazy_unique_ptr<T1, D1>&&) /*noexcept*/;

    T& operator* () const;
    pointer operator-> () const /*noexcept*/;
    pointer get () const /*noexcept*/;
#ifdef ODB_CXX11_EXPLICIT_CONVERSION_OPERATOR
    explicit operator bool() const /*noexcept*/;
#else
    typedef std::unique_ptr<T, D> lazy_unique_ptr::*unspecified_bool_type;
    operator unspecified_bool_type () const
    {
      return (p_ || i_) ? &lazy_unique_ptr::p_ : 0;
    }
#endif

    pointer release () /*noexcept*/;
    void reset (pointer = pointer ()) /*noexcept*/;
    void swap (lazy_unique_ptr&) /*noexcept*/;

    deleter_type& get_deleter () /*noexcept*/;
    const deleter_type& get_deleter () const /*noexcept*/;

#ifdef ODB_CXX11_DELETED_FUNCTION
    lazy_unique_ptr (const lazy_unique_ptr&) = delete;
    lazy_unique_ptr& operator= (const lazy_unique_ptr&) = delete;
#else
  private:
    lazy_unique_ptr (const lazy_unique_ptr&);
    lazy_unique_ptr& operator= (const lazy_unique_ptr&);
#endif

    // Initialization/assignment from unique_ptr.
    //
  public:
    template <class T1, class D1> lazy_unique_ptr (std::unique_ptr<T1, D1>&&) /*noexcept*/;
    template <class T1, class D1> lazy_unique_ptr& operator= (std::unique_ptr<T1, D1>&&) /*noexcept*/;

    // Lazy loading interface.
    //
  public:
    typedef odb::database database_type;

    //  NULL      loaded()
    //
    //  true       true      NULL pointer to transient object
    //  false      true      valid pointer to persistent object
    //  true       false     unloaded pointer to persistent object
    //  false      false     valid pointer to transient object
    //
    bool loaded () const;

    std::unique_ptr<T, D>& load () const;

    // Unload the pointer. For transient objects this function is
    // equivalent to reset().
    //
    void unload () const;

    // Get the underlying eager pointer. If this is an unloaded pointer
    // to a persistent object, then the returned pointer will be NULL.
    //
    std::unique_ptr<T, D>& get_eager () const;

    template <class DB, class ID> lazy_unique_ptr (DB&, const ID&);
    template <class DB> lazy_unique_ptr (DB&, pointer);
    template <class DB> lazy_unique_ptr (DB&, pointer, const deleter_type&);
    template <class DB> lazy_unique_ptr (DB&, pointer, deleter_type&&);
    template <class DB, class T1, class D1> lazy_unique_ptr (DB&, std::unique_ptr<T1, D1>&&);
    template <class DB, class T1> lazy_unique_ptr (DB&, std::auto_ptr<T1>&&);

    template <class DB, class ID> void reset (DB&, const ID&);
    template <class DB> void reset (DB&, pointer);
    template <class DB, class T1, class D1> void reset (DB&, std::unique_ptr<T1, D1>&&);
    template <class DB, class T1> void reset (DB&, std::auto_ptr<T1>&&);

#ifdef ODB_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGUMENT
    template <class O = T>
#else
    template <class O /*= T*/>
#endif
    typename object_traits<O>::id_type object_id () const;

    database_type& database () const;

    // Helpers.
    //
  public:
    template <class T1, class D1> bool equal (const lazy_unique_ptr<T1, D1>&) const;

  private:
    template <class T1, class D1> friend class lazy_unique_ptr;

    // Note that it is possible to have a situation where p_ is NULL,
    // i_.id is NULL and i_.db is not NULL. This will happen if the
    // unique_ptr reference returned by load() is transferred to
    // another pointer or reset.
    //
    mutable std::unique_ptr<T, D> p_;
    mutable lazy_ptr_impl<T> i_;
  };

  template <class T> void swap (lazy_unique_ptr<T>&, lazy_unique_ptr<T>&) /*noexcept*/;

  // operator< and operator<< are not provided.
  //
  template <class T1, class D1, class T2, class D2>
  bool operator== (const lazy_unique_ptr<T1, D1>&, const lazy_unique_ptr<T2, D2>&);

  template <class T1, class D1, class T2, class D2>
  bool operator!= (const lazy_unique_ptr<T1, D1>&, const lazy_unique_ptr<T2, D2>&);

#ifdef ODB_CXX11_NULLPTR
  template <class T, class D>
  bool operator== (const lazy_unique_ptr<T, D>&, std::nullptr_t) /*noexcept*/;

  template <class T, class D>
  bool operator== (std::nullptr_t, const lazy_unique_ptr<T, D>&) /*noexcept*/;

  template <class T, class D>
  bool operator!= (const lazy_unique_ptr<T, D>&, std::nullptr_t) /*noexcept*/;

  template <class T, class D>
  bool operator!= (std::nullptr_t, const lazy_unique_ptr<T, D>&) /*noexcept*/;
#endif

  // C++11 std::shared_ptr lazy version.
  //
  template <class T>
  class lazy_weak_ptr;

  template <class T>
  class lazy_shared_ptr
  {
    // The standard shared_ptr interface.
    //
  public:
    typedef T element_type;

    /*constexpr*/ lazy_shared_ptr () /*noexcept*/;
#ifdef ODB_CXX11_NULLPTR
    /*constexpr*/ lazy_shared_ptr (std::nullptr_t) /*noexcept*/;
#endif
    template <class Y> explicit lazy_shared_ptr (Y*);
    template <class Y, class D> lazy_shared_ptr (Y*, D);
    template <class Y, class D, class A> lazy_shared_ptr (Y*, D, A);
#ifdef ODB_CXX11_NULLPTR
    template <class D> lazy_shared_ptr (std::nullptr_t, D);
    template <class D, class A> lazy_shared_ptr (std::nullptr_t, D, A);
#endif
    template <class Y> lazy_shared_ptr (const lazy_shared_ptr<Y>&, T*) /*noexcept*/;

    lazy_shared_ptr (const lazy_shared_ptr&) /*noexcept*/;
    template <class Y> lazy_shared_ptr (const lazy_shared_ptr<Y>&) /*noexcept*/;
    lazy_shared_ptr (lazy_shared_ptr&&) /*noexcept*/;
    template <class Y> lazy_shared_ptr (lazy_shared_ptr<Y>&&) /*noexcept*/;
    template <class Y> explicit lazy_shared_ptr (const lazy_weak_ptr<Y>&);
    template <class Y> explicit lazy_shared_ptr (std::auto_ptr<Y>&&);
    template <class Y, class D> lazy_shared_ptr (std::unique_ptr<Y, D>&&);

    ~lazy_shared_ptr ();

    lazy_shared_ptr& operator= (const lazy_shared_ptr&) /*noexcept*/;
    template <class Y> lazy_shared_ptr& operator= (const lazy_shared_ptr<Y>&) /*noexcept*/;
    lazy_shared_ptr& operator= (lazy_shared_ptr&&) /*noexcept*/;
    template <class Y> lazy_shared_ptr& operator= (lazy_shared_ptr<Y>&&) /*noexcept*/;
    template <class Y> lazy_shared_ptr& operator= (std::auto_ptr<Y>&&);
    template <class Y, class D> lazy_shared_ptr& operator= (std::unique_ptr<Y, D>&&);

    void swap (lazy_shared_ptr&) /*noexcept*/;
    void reset () /*noexcept*/;
    template <class Y> void reset (Y*);
    template <class Y, class D> void reset (Y*, D);
    template <class Y, class D, class A> void reset (Y*, D, A);

    T* get () const /*noexcept*/;
    T& operator* () const /*noexcept*/;
    T* operator-> () const /*noexcept*/;
    long use_count () const /*noexcept*/;
    bool unique () const /*noexcept*/;
#ifdef ODB_CXX11_EXPLICIT_CONVERSION_OPERATOR
    explicit operator bool () const /*noexcept*/;
#else
    typedef std::shared_ptr<T> lazy_shared_ptr::*unspecified_bool_type;
    operator unspecified_bool_type () const
    {
      return (p_ || i_) ? &lazy_shared_ptr::p_ : 0;
    }
#endif

    // owner_before () is not provded.

    // Initialization/assignment from shared_ptr and weak_ptr.
    //
  public:
    template <class Y> lazy_shared_ptr (const std::shared_ptr<Y>&);
    template <class Y> lazy_shared_ptr (std::shared_ptr<Y>&&);
    template <class Y> explicit lazy_shared_ptr (const std::weak_ptr<Y>&);

    template <class Y> lazy_shared_ptr& operator= (const std::shared_ptr<Y>&);
    template <class Y> lazy_shared_ptr& operator= (std::shared_ptr<Y>&&);

    // Lazy loading interface.
    //
  public:
    typedef odb::database database_type;

    //  NULL      loaded()
    //
    //  true       true      NULL pointer to transient object
    //  false      true      valid pointer to persistent object
    //  true       false     unloaded pointer to persistent object
    //  false      false     valid pointer to transient object
    //
    bool loaded () const;

    std::shared_ptr<T> load () const;

    // Unload the pointer. For transient objects this function is
    // equivalent to reset().
    //
    void unload () const;

    // Get the underlying eager pointer. If this is an unloaded pointer
    // to a persistent object, then the returned pointer will be NULL.
    //
    std::shared_ptr<T> get_eager () const;

    template <class DB, class ID> lazy_shared_ptr (DB&, const ID&);
    template <class DB, class Y> lazy_shared_ptr (DB&, Y*);
    template <class DB, class Y, class D> lazy_shared_ptr (DB&, Y*, D);
    template <class DB, class Y, class D, class A> lazy_shared_ptr (DB&, Y*, D, A);
    template <class DB, class Y> lazy_shared_ptr (DB&, std::auto_ptr<Y>&&);
    template <class DB, class Y> lazy_shared_ptr (DB&, const std::shared_ptr<Y>&);
    template <class DB, class Y> lazy_shared_ptr (DB&, std::shared_ptr<Y>&&);
    template <class DB, class Y> lazy_shared_ptr (DB&, const std::weak_ptr<Y>&);

    template <class DB, class ID> void reset (DB&, const ID&);
    template <class DB, class Y> void reset (DB&, Y*);
    template <class DB, class Y, class D> void reset (DB&, Y*, D);
    template <class DB, class Y, class D, class A> void reset (DB&, Y*, D, A);
    template <class DB, class Y> void reset (DB&, std::auto_ptr<Y>&&);
    template <class DB, class Y> void reset (DB&, const std::shared_ptr<Y>&);
    template <class DB, class Y> void reset (DB&, std::shared_ptr<Y>&&);

#ifdef ODB_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGUMENT
    template <class O = T>
#else
    template <class O /*= T*/>
#endif
    typename object_traits<O>::id_type object_id () const;

    database_type& database () const;

    // Helpers.
    //
  public:
    template <class Y> bool equal (const lazy_shared_ptr<Y>&) const;

  private:
    template <class Y> friend class lazy_shared_ptr;
    template <class Y> friend class lazy_weak_ptr;

    mutable std::shared_ptr<T> p_;
    mutable lazy_ptr_impl<T> i_;
  };

  template <class T> void swap (lazy_shared_ptr<T>&, lazy_shared_ptr<T>&) /*noexcept*/;

  template <class D, class T>
  D* get_deleter (const lazy_shared_ptr<T>&) /*noexcept*/;

  // operator< and operator<< are not provided.
  //
  template <class T, class Y>
  bool operator== (const lazy_shared_ptr<T>&, const lazy_shared_ptr<Y>&) /*noexcept*/;

  template <class T, class Y>
  bool operator!= (const lazy_shared_ptr<T>&, const lazy_shared_ptr<Y>&) /*noexcept*/;

#ifdef ODB_CXX11_NULLPTR
  template <class T>
  bool operator== (const lazy_shared_ptr<T>&, std::nullptr_t) /*noexcept*/;

  template <class T>
  bool operator== (std::nullptr_t, const lazy_shared_ptr<T>&) /*noexcept*/;

  template <class T>
  bool operator!= (const lazy_shared_ptr<T>&, std::nullptr_t) /*noexcept*/;

  template <class T>
  bool operator!= (std::nullptr_t, const lazy_shared_ptr<T>&) /*noexcept*/;
#endif

  // C++11 std::weak_ptr lazy version.
  //
  template <class T>
  class lazy_weak_ptr
  {
    // The standard weak_ptr interface.
    //
  public:
    typedef T element_type;

    /*constexpr*/ lazy_weak_ptr () /*noexcept*/;
    template <class Y> lazy_weak_ptr (const lazy_shared_ptr<Y>&) /*noexcept*/;
    lazy_weak_ptr (const lazy_weak_ptr&) /*noexcept*/;
    template <class Y> lazy_weak_ptr (const lazy_weak_ptr<Y>&) /*noexcept*/;

    ~lazy_weak_ptr ();

    lazy_weak_ptr& operator= (const lazy_weak_ptr&) /*noexcept*/;
    template <class Y> lazy_weak_ptr& operator= (const lazy_weak_ptr<Y>&) /*noexcept*/;
    template <class Y> lazy_weak_ptr& operator= (const lazy_shared_ptr<Y>&) /*noexcept*/;

    void swap (lazy_weak_ptr<T>&) /*noexcept*/;
    void reset () /*noexcept*/;

    long use_count () const /*noexcept*/;
    bool expired () const /*noexcept*/;

    lazy_shared_ptr<T> lock () const /*noexcept*/;

    // owner_before () is not provded.

    // Initialization/assignment from shared_ptr and weak_ptr.
    //
  public:
    template <class Y> lazy_weak_ptr (const std::weak_ptr<Y>&);
    template <class Y> lazy_weak_ptr (const std::shared_ptr<Y>&);

    template <class Y> lazy_weak_ptr& operator= (const std::weak_ptr<Y>&);
    template <class Y> lazy_weak_ptr& operator= (const std::shared_ptr<Y>&);

    // Lazy loading interface.
    //
  public:
    typedef odb::database database_type;

    // expired()  loaded()
    //
    //  true       true      expired pointer to transient object
    //  false      true      valid pointer to persistent object
    //  true       false     expired pointer to persistent object
    //  false      false     valid pointer to transient object
    //
    bool loaded () const;

    // Performs both lock and load.
    //
    std::shared_ptr<T> load () const;

    // Unload the pointer. For transient objects this function is
    // equivalent to reset().
    //
    void unload () const;

    // Get the underlying eager pointer. If this is an unloaded pointer
    // to a persistent object, then the returned pointer will be NULL.
    //
    std::weak_ptr<T> get_eager () const;

    template <class DB, class ID> lazy_weak_ptr (DB&, const ID&);
    template <class DB, class Y> lazy_weak_ptr (DB&, const std::shared_ptr<Y>&);
    template <class DB, class Y> lazy_weak_ptr (DB&, const std::weak_ptr<Y>&);

    template <class DB, class ID> void reset (DB&, const ID&);
    template <class DB, class Y> void reset (DB&, const std::shared_ptr<Y>&);
    template <class DB, class Y> void reset (DB&, const std::weak_ptr<Y>&);

    // The object_id() function can only be called when the object is
    // persistent, or: expired() XOR loaded() (can use != for XOR).
    //
#ifdef ODB_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGUMENT
    template <class O = T>
#else
    template <class O /*= T*/>
#endif
    typename object_traits<O>::id_type object_id () const;

    database_type& database () const;

  private:
    template <class Y> friend class lazy_shared_ptr;
    template <class Y> friend class lazy_weak_ptr;

    mutable std::weak_ptr<T> p_;
    mutable lazy_ptr_impl<T> i_;
  };

  // operator< is not provided.
  //
  template <class T> void swap (lazy_weak_ptr<T>&, lazy_weak_ptr<T>&);

#endif // ODB_CXX11

  namespace common
  {
    using odb::lazy_ptr;
    using odb::lazy_auto_ptr;

#ifdef ODB_CXX11
    using odb::lazy_unique_ptr;
    using odb::lazy_shared_ptr;
    using odb::lazy_weak_ptr;
#endif
  }
}

#include <odb/lazy-ptr.ixx>
#include <odb/lazy-ptr.txx>

#include <odb/lazy-pointer-traits.hxx>

#include <odb/post.hxx>

#endif // ODB_LAZY_PTR_HXX