aboutsummaryrefslogtreecommitdiffstats
path: root/include/set
blob: ac3fbbe02fc37d391ebc2e084b0d7cb0503a84c7 (plain) (blame)
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
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
// -*- C++ -*-
//===---------------------------- set -------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_SET
#define _LIBCPP_SET

/*

    set synopsis

namespace std
{

template <class Key, class Compare = less<Key>,
          class Allocator = allocator<Key>>
class set
{
public:
    // types:
    typedef Key                                      key_type;
    typedef key_type                                 value_type;
    typedef Compare                                  key_compare;
    typedef key_compare                              value_compare;
    typedef Allocator                                allocator_type;
    typedef typename allocator_type::reference       reference;
    typedef typename allocator_type::const_reference const_reference;
    typedef typename allocator_type::size_type       size_type;
    typedef typename allocator_type::difference_type difference_type;
    typedef typename allocator_type::pointer         pointer;
    typedef typename allocator_type::const_pointer   const_pointer;

    typedef implementation-defined                   iterator;
    typedef implementation-defined                   const_iterator;
    typedef std::reverse_iterator<iterator>          reverse_iterator;
    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
    typedef unspecified                              node_type;               // C++17
    typedef INSERT_RETURN_TYPE<iterator, node_type>  insert_return_type;      // C++17

    // construct/copy/destroy:
    set()
        noexcept(
            is_nothrow_default_constructible<allocator_type>::value &&
            is_nothrow_default_constructible<key_compare>::value &&
            is_nothrow_copy_constructible<key_compare>::value);
    explicit set(const value_compare& comp);
    set(const value_compare& comp, const allocator_type& a);
    template <class InputIterator>
        set(InputIterator first, InputIterator last,
            const value_compare& comp = value_compare());
    template <class InputIterator>
        set(InputIterator first, InputIterator last, const value_compare& comp,
            const allocator_type& a);
    set(const set& s);
    set(set&& s)
        noexcept(
            is_nothrow_move_constructible<allocator_type>::value &&
            is_nothrow_move_constructible<key_compare>::value);
    explicit set(const allocator_type& a);
    set(const set& s, const allocator_type& a);
    set(set&& s, const allocator_type& a);
    set(initializer_list<value_type> il, const value_compare& comp = value_compare());
    set(initializer_list<value_type> il, const value_compare& comp,
        const allocator_type& a);
    template <class InputIterator>
        set(InputIterator first, InputIterator last, const allocator_type& a)
            : set(first, last, Compare(), a) {}  // C++14
    set(initializer_list<value_type> il, const allocator_type& a)
        : set(il, Compare(), a) {}  // C++14
    ~set();

    set& operator=(const set& s);
    set& operator=(set&& s)
        noexcept(
            allocator_type::propagate_on_container_move_assignment::value &&
            is_nothrow_move_assignable<allocator_type>::value &&
            is_nothrow_move_assignable<key_compare>::value);
    set& operator=(initializer_list<value_type> il);

    // iterators:
          iterator begin() noexcept;
    const_iterator begin() const noexcept;
          iterator end() noexcept;
    const_iterator end()   const noexcept;

          reverse_iterator rbegin() noexcept;
    const_reverse_iterator rbegin() const noexcept;
          reverse_iterator rend() noexcept;
    const_reverse_iterator rend()   const noexcept;

    const_iterator         cbegin()  const noexcept;
    const_iterator         cend()    const noexcept;
    const_reverse_iterator crbegin() const noexcept;
    const_reverse_iterator crend()   const noexcept;

    // capacity:
    bool      empty()    const noexcept;
    size_type size()     const noexcept;
    size_type max_size() const noexcept;

    // modifiers:
    template <class... Args>
        pair<iterator, bool> emplace(Args&&... args);
    template <class... Args>
        iterator emplace_hint(const_iterator position, Args&&... args);
    pair<iterator,bool> insert(const value_type& v);
    pair<iterator,bool> insert(value_type&& v);
    iterator insert(const_iterator position, const value_type& v);
    iterator insert(const_iterator position, value_type&& v);
    template <class InputIterator>
        void insert(InputIterator first, InputIterator last);
    void insert(initializer_list<value_type> il);

    node_type extract(const_iterator position);                                       // C++17
    node_type extract(const key_type& x);                                             // C++17
    insert_return_type insert(node_type&& nh);                                        // C++17
    iterator insert(const_iterator hint, node_type&& nh);                             // C++17

    iterator  erase(const_iterator position);
    iterator  erase(iterator position);  // C++14
    size_type erase(const key_type& k);
    iterator  erase(const_iterator first, const_iterator last);
    void clear() noexcept;

    template<class C2>
      void merge(set<Key, C2, Allocator>& source);         // C++17
    template<class C2>
      void merge(set<Key, C2, Allocator>&& source);        // C++17
    template<class C2>
      void merge(multiset<Key, C2, Allocator>& source);    // C++17
    template<class C2>
      void merge(multiset<Key, C2, Allocator>&& source);   // C++17

    void swap(set& s)
        noexcept(
            __is_nothrow_swappable<key_compare>::value &&
            (!allocator_type::propagate_on_container_swap::value ||
             __is_nothrow_swappable<allocator_type>::value));

    // observers:
    allocator_type get_allocator() const noexcept;
    key_compare    key_comp()      const;
    value_compare  value_comp()    const;

    // set operations:
          iterator find(const key_type& k);
    const_iterator find(const key_type& k) const;
    template<typename K>
        iterator find(const K& x);
    template<typename K>
        const_iterator find(const K& x) const;  // C++14
    template<typename K>
        size_type count(const K& x) const;        // C++14
    size_type      count(const key_type& k) const;
        bool contains(const key_type& x) const; // C++20
          iterator lower_bound(const key_type& k);
    const_iterator lower_bound(const key_type& k) const;
    template<typename K>
        iterator lower_bound(const K& x);              // C++14
    template<typename K>
        const_iterator lower_bound(const K& x) const;  // C++14

          iterator upper_bound(const key_type& k);
    const_iterator upper_bound(const key_type& k) const;
    template<typename K>
        iterator upper_bound(const K& x);              // C++14
    template<typename K>
        const_iterator upper_bound(const K& x) const;  // C++14
    pair<iterator,iterator>             equal_range(const key_type& k);
    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
    template<typename K>
        pair<iterator,iterator>             equal_range(const K& x);        // C++14
    template<typename K>
        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
};

template <class Key, class Compare, class Allocator>
bool
operator==(const set<Key, Compare, Allocator>& x,
           const set<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator< (const set<Key, Compare, Allocator>& x,
           const set<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator!=(const set<Key, Compare, Allocator>& x,
           const set<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator> (const set<Key, Compare, Allocator>& x,
           const set<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator>=(const set<Key, Compare, Allocator>& x,
           const set<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator<=(const set<Key, Compare, Allocator>& x,
           const set<Key, Compare, Allocator>& y);

// specialized algorithms:
template <class Key, class Compare, class Allocator>
void
swap(set<Key, Compare, Allocator>& x, set<Key, Compare, Allocator>& y)
    noexcept(noexcept(x.swap(y)));

template <class Key, class Compare, class Allocator, class Predicate>
  void erase_if(set<Key, Compare, Allocator>& c, Predicate pred);  // C++20

template <class Key, class Compare = less<Key>,
          class Allocator = allocator<Key>>
class multiset
{
public:
    // types:
    typedef Key                                      key_type;
    typedef key_type                                 value_type;
    typedef Compare                                  key_compare;
    typedef key_compare                              value_compare;
    typedef Allocator                                allocator_type;
    typedef typename allocator_type::reference       reference;
    typedef typename allocator_type::const_reference const_reference;
    typedef typename allocator_type::size_type       size_type;
    typedef typename allocator_type::difference_type difference_type;
    typedef typename allocator_type::pointer         pointer;
    typedef typename allocator_type::const_pointer   const_pointer;

    typedef implementation-defined                   iterator;
    typedef implementation-defined                   const_iterator;
    typedef std::reverse_iterator<iterator>          reverse_iterator;
    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
    typedef unspecified                              node_type;               // C++17

    // construct/copy/destroy:
    multiset()
        noexcept(
            is_nothrow_default_constructible<allocator_type>::value &&
            is_nothrow_default_constructible<key_compare>::value &&
            is_nothrow_copy_constructible<key_compare>::value);
    explicit multiset(const value_compare& comp);
    multiset(const value_compare& comp, const allocator_type& a);
    template <class InputIterator>
        multiset(InputIterator first, InputIterator last,
                 const value_compare& comp = value_compare());
    template <class InputIterator>
        multiset(InputIterator first, InputIterator last,
                 const value_compare& comp, const allocator_type& a);
    multiset(const multiset& s);
    multiset(multiset&& s)
        noexcept(
            is_nothrow_move_constructible<allocator_type>::value &&
            is_nothrow_move_constructible<key_compare>::value);
    explicit multiset(const allocator_type& a);
    multiset(const multiset& s, const allocator_type& a);
    multiset(multiset&& s, const allocator_type& a);
    multiset(initializer_list<value_type> il, const value_compare& comp = value_compare());
    multiset(initializer_list<value_type> il, const value_compare& comp,
             const allocator_type& a);
    template <class InputIterator>
        multiset(InputIterator first, InputIterator last, const allocator_type& a)
            : set(first, last, Compare(), a) {}  // C++14
    multiset(initializer_list<value_type> il, const allocator_type& a)
        : set(il, Compare(), a) {}  // C++14
    ~multiset();

    multiset& operator=(const multiset& s);
    multiset& operator=(multiset&& s)
        noexcept(
            allocator_type::propagate_on_container_move_assignment::value &&
            is_nothrow_move_assignable<allocator_type>::value &&
            is_nothrow_move_assignable<key_compare>::value);
    multiset& operator=(initializer_list<value_type> il);

    // iterators:
          iterator begin() noexcept;
    const_iterator begin() const noexcept;
          iterator end() noexcept;
    const_iterator end()   const noexcept;

          reverse_iterator rbegin() noexcept;
    const_reverse_iterator rbegin() const noexcept;
          reverse_iterator rend() noexcept;
    const_reverse_iterator rend()   const noexcept;

    const_iterator         cbegin()  const noexcept;
    const_iterator         cend()    const noexcept;
    const_reverse_iterator crbegin() const noexcept;
    const_reverse_iterator crend()   const noexcept;

    // capacity:
    bool      empty()    const noexcept;
    size_type size()     const noexcept;
    size_type max_size() const noexcept;

    // modifiers:
    template <class... Args>
        iterator emplace(Args&&... args);
    template <class... Args>
        iterator emplace_hint(const_iterator position, Args&&... args);
    iterator insert(const value_type& v);
    iterator insert(value_type&& v);
    iterator insert(const_iterator position, const value_type& v);
    iterator insert(const_iterator position, value_type&& v);
    template <class InputIterator>
        void insert(InputIterator first, InputIterator last);
    void insert(initializer_list<value_type> il);

    node_type extract(const_iterator position);                                       // C++17
    node_type extract(const key_type& x);                                             // C++17
    iterator insert(node_type&& nh);                                                  // C++17
    iterator insert(const_iterator hint, node_type&& nh);                             // C++17

    iterator  erase(const_iterator position);
    iterator  erase(iterator position);  // C++14
    size_type erase(const key_type& k);
    iterator  erase(const_iterator first, const_iterator last);
    void clear() noexcept;

    template<class C2>
      void merge(multiset<Key, C2, Allocator>& source);    // C++17
    template<class C2>
      void merge(multiset<Key, C2, Allocator>&& source);   // C++17
    template<class C2>
      void merge(set<Key, C2, Allocator>& source);         // C++17
    template<class C2>
      void merge(set<Key, C2, Allocator>&& source);        // C++17

    void swap(multiset& s)
        noexcept(
            __is_nothrow_swappable<key_compare>::value &&
            (!allocator_type::propagate_on_container_swap::value ||
             __is_nothrow_swappable<allocator_type>::value));

    // observers:
    allocator_type get_allocator() const noexcept;
    key_compare    key_comp()      const;
    value_compare  value_comp()    const;

    // set operations:
          iterator find(const key_type& k);
    const_iterator find(const key_type& k) const;
    template<typename K>
        iterator find(const K& x);
    template<typename K>
        const_iterator find(const K& x) const;  // C++14
    template<typename K>
        size_type count(const K& x) const;      // C++14
    size_type      count(const key_type& k) const;
        bool contains(const key_type& x) const; // C++20
          iterator lower_bound(const key_type& k);
    const_iterator lower_bound(const key_type& k) const;
    template<typename K>
        iterator lower_bound(const K& x);              // C++14
    template<typename K>
        const_iterator lower_bound(const K& x) const;  // C++14

          iterator upper_bound(const key_type& k);
    const_iterator upper_bound(const key_type& k) const;
    template<typename K>
        iterator upper_bound(const K& x);              // C++14
    template<typename K>
        const_iterator upper_bound(const K& x) const;  // C++14

    pair<iterator,iterator>             equal_range(const key_type& k);
    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
    template<typename K>
        pair<iterator,iterator>             equal_range(const K& x);        // C++14
    template<typename K>
        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
};

template <class Key, class Compare, class Allocator>
bool
operator==(const multiset<Key, Compare, Allocator>& x,
           const multiset<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator< (const multiset<Key, Compare, Allocator>& x,
           const multiset<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator!=(const multiset<Key, Compare, Allocator>& x,
           const multiset<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator> (const multiset<Key, Compare, Allocator>& x,
           const multiset<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator>=(const multiset<Key, Compare, Allocator>& x,
           const multiset<Key, Compare, Allocator>& y);

template <class Key, class Compare, class Allocator>
bool
operator<=(const multiset<Key, Compare, Allocator>& x,
           const multiset<Key, Compare, Allocator>& y);

// specialized algorithms:
template <class Key, class Compare, class Allocator>
void
swap(multiset<Key, Compare, Allocator>& x, multiset<Key, Compare, Allocator>& y)
    noexcept(noexcept(x.swap(y)));

template <class Key, class Compare, class Allocator, class Predicate>
  void erase_if(multiset<Key, Compare, Allocator>& c, Predicate pred);  // C++20

}  // std

*/

#include <__config>
#include <__tree>
#include <__node_handle>
#include <functional>
#include <version>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

template <class _Key, class _Compare, class _Allocator>
class multiset;

template <class _Key, class _Compare = less<_Key>,
          class _Allocator = allocator<_Key> >
class _LIBCPP_TEMPLATE_VIS set
{
public:
    // types:
    typedef _Key                                     key_type;
    typedef key_type                                 value_type;
    typedef _Compare                                 key_compare;
    typedef key_compare                              value_compare;
    typedef typename __identity<_Allocator>::type    allocator_type;
    typedef value_type&                              reference;
    typedef const value_type&                        const_reference;

    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
                  "Allocator::value_type must be same type as value_type");

private:
    typedef __tree<value_type, value_compare, allocator_type> __base;
    typedef allocator_traits<allocator_type>                  __alloc_traits;
    typedef typename __base::__node_holder                    __node_holder;

    __base __tree_;

public:
    typedef typename __base::pointer               pointer;
    typedef typename __base::const_pointer         const_pointer;
    typedef typename __base::size_type             size_type;
    typedef typename __base::difference_type       difference_type;
    typedef typename __base::const_iterator        iterator;
    typedef typename __base::const_iterator        const_iterator;
    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;

#if _LIBCPP_STD_VER > 14
    typedef __set_node_handle<typename __base::__node, allocator_type> node_type;
    typedef __insert_return_type<iterator, node_type> insert_return_type;
#endif

    template <class _Key2, class _Compare2, class _Alloc2>
        friend class _LIBCPP_TEMPLATE_VIS set;
    template <class _Key2, class _Compare2, class _Alloc2>
        friend class _LIBCPP_TEMPLATE_VIS multiset;

    _LIBCPP_INLINE_VISIBILITY
    set()
        _NOEXCEPT_(
            is_nothrow_default_constructible<allocator_type>::value &&
            is_nothrow_default_constructible<key_compare>::value &&
            is_nothrow_copy_constructible<key_compare>::value)
        : __tree_(value_compare()) {}

    _LIBCPP_INLINE_VISIBILITY
    explicit set(const value_compare& __comp)
        _NOEXCEPT_(
            is_nothrow_default_constructible<allocator_type>::value &&
            is_nothrow_copy_constructible<key_compare>::value)
        : __tree_(__comp) {}

    _LIBCPP_INLINE_VISIBILITY
    explicit set(const value_compare& __comp, const allocator_type& __a)
        : __tree_(__comp, __a) {}
    template <class _InputIterator>
        _LIBCPP_INLINE_VISIBILITY
        set(_InputIterator __f, _InputIterator __l,
            const value_compare& __comp = value_compare())
        : __tree_(__comp)
        {
            insert(__f, __l);
        }

    template <class _InputIterator>
        _LIBCPP_INLINE_VISIBILITY
        set(_InputIterator __f, _InputIterator __l, const value_compare& __comp,
            const allocator_type& __a)
        : __tree_(__comp, __a)
        {
            insert(__f, __l);
        }

#if _LIBCPP_STD_VER > 11
        template <class _InputIterator>
        _LIBCPP_INLINE_VISIBILITY
        set(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
            : set(__f, __l, key_compare(), __a) {}
#endif

    _LIBCPP_INLINE_VISIBILITY
    set(const set& __s)
        : __tree_(__s.__tree_)
        {
            insert(__s.begin(), __s.end());
        }

    _LIBCPP_INLINE_VISIBILITY
    set& operator=(const set& __s)
        {
            __tree_ = __s.__tree_;
            return *this;
        }

#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    set(set&& __s)
        _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
        : __tree_(_VSTD::move(__s.__tree_)) {}
#endif  // _LIBCPP_CXX03_LANG

    _LIBCPP_INLINE_VISIBILITY
    explicit set(const allocator_type& __a)
        : __tree_(__a) {}

    _LIBCPP_INLINE_VISIBILITY
    set(const set& __s, const allocator_type& __a)
        : __tree_(__s.__tree_.value_comp(), __a)
        {
            insert(__s.begin(), __s.end());
        }

#ifndef _LIBCPP_CXX03_LANG
    set(set&& __s, const allocator_type& __a);

    _LIBCPP_INLINE_VISIBILITY
    set(initializer_list<value_type> __il, const value_compare& __comp = value_compare())
        : __tree_(__comp)
        {
            insert(__il.begin(), __il.end());
        }

    _LIBCPP_INLINE_VISIBILITY
    set(initializer_list<value_type> __il, const value_compare& __comp,
        const allocator_type& __a)
        : __tree_(__comp, __a)
        {
            insert(__il.begin(), __il.end());
        }

#if _LIBCPP_STD_VER > 11
    _LIBCPP_INLINE_VISIBILITY
    set(initializer_list<value_type> __il, const allocator_type& __a)
        : set(__il, key_compare(), __a) {}
#endif

    _LIBCPP_INLINE_VISIBILITY
    set& operator=(initializer_list<value_type> __il)
        {
            __tree_.__assign_unique(__il.begin(), __il.end());
            return *this;
        }

    _LIBCPP_INLINE_VISIBILITY
    set& operator=(set&& __s)
        _NOEXCEPT_(is_nothrow_move_assignable<__base>::value)
        {
            __tree_ = _VSTD::move(__s.__tree_);
            return *this;
        }
#endif  // _LIBCPP_CXX03_LANG

    _LIBCPP_INLINE_VISIBILITY
    ~set() {
        static_assert(sizeof(__diagnose_non_const_comparator<_Key, _Compare>()), "");
    }

    _LIBCPP_INLINE_VISIBILITY
          iterator begin() _NOEXCEPT       {return __tree_.begin();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator begin() const _NOEXCEPT {return __tree_.begin();}
    _LIBCPP_INLINE_VISIBILITY
          iterator end() _NOEXCEPT         {return __tree_.end();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator end()   const _NOEXCEPT {return __tree_.end();}

    _LIBCPP_INLINE_VISIBILITY
          reverse_iterator rbegin() _NOEXCEPT
            {return reverse_iterator(end());}
    _LIBCPP_INLINE_VISIBILITY
    const_reverse_iterator rbegin() const _NOEXCEPT
        {return const_reverse_iterator(end());}
    _LIBCPP_INLINE_VISIBILITY
          reverse_iterator rend() _NOEXCEPT
            {return reverse_iterator(begin());}
    _LIBCPP_INLINE_VISIBILITY
    const_reverse_iterator rend() const _NOEXCEPT
        {return const_reverse_iterator(begin());}

    _LIBCPP_INLINE_VISIBILITY
    const_iterator cbegin()  const _NOEXCEPT {return begin();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator cend() const _NOEXCEPT {return end();}
    _LIBCPP_INLINE_VISIBILITY
    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
    _LIBCPP_INLINE_VISIBILITY
    const_reverse_iterator crend() const _NOEXCEPT {return rend();}

    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
    bool empty() const _NOEXCEPT {return __tree_.size() == 0;}
    _LIBCPP_INLINE_VISIBILITY
    size_type size() const _NOEXCEPT {return __tree_.size();}
    _LIBCPP_INLINE_VISIBILITY
    size_type max_size() const _NOEXCEPT {return __tree_.max_size();}

    // modifiers:
#ifndef _LIBCPP_CXX03_LANG
    template <class... _Args>
        _LIBCPP_INLINE_VISIBILITY
        pair<iterator, bool> emplace(_Args&&... __args)
            {return __tree_.__emplace_unique(_VSTD::forward<_Args>(__args)...);}
    template <class... _Args>
        _LIBCPP_INLINE_VISIBILITY
        iterator emplace_hint(const_iterator __p, _Args&&... __args)
            {return __tree_.__emplace_hint_unique(__p, _VSTD::forward<_Args>(__args)...);}
#endif  // _LIBCPP_CXX03_LANG

    _LIBCPP_INLINE_VISIBILITY
    pair<iterator,bool> insert(const value_type& __v)
        {return __tree_.__insert_unique(__v);}
    _LIBCPP_INLINE_VISIBILITY
    iterator insert(const_iterator __p, const value_type& __v)
        {return __tree_.__insert_unique(__p, __v);}

    template <class _InputIterator>
        _LIBCPP_INLINE_VISIBILITY
        void insert(_InputIterator __f, _InputIterator __l)
        {
            for (const_iterator __e = cend(); __f != __l; ++__f)
                __tree_.__insert_unique(__e, *__f);
        }

#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator,bool> insert(value_type&& __v)
        {return __tree_.__insert_unique(_VSTD::move(__v));}

    _LIBCPP_INLINE_VISIBILITY
    iterator insert(const_iterator __p, value_type&& __v)
        {return __tree_.__insert_unique(__p, _VSTD::move(__v));}

    _LIBCPP_INLINE_VISIBILITY
    void insert(initializer_list<value_type> __il)
        {insert(__il.begin(), __il.end());}
#endif  // _LIBCPP_CXX03_LANG

    _LIBCPP_INLINE_VISIBILITY
    iterator  erase(const_iterator __p) {return __tree_.erase(__p);}
    _LIBCPP_INLINE_VISIBILITY
    size_type erase(const key_type& __k)
        {return __tree_.__erase_unique(__k);}
    _LIBCPP_INLINE_VISIBILITY
    iterator  erase(const_iterator __f, const_iterator __l)
        {return __tree_.erase(__f, __l);}
    _LIBCPP_INLINE_VISIBILITY
    void clear() _NOEXCEPT {__tree_.clear();}

#if _LIBCPP_STD_VER > 14
    _LIBCPP_INLINE_VISIBILITY
    insert_return_type insert(node_type&& __nh)
    {
        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
            "node_type with incompatible allocator passed to set::insert()");
        return __tree_.template __node_handle_insert_unique<
            node_type, insert_return_type>(_VSTD::move(__nh));
    }
    _LIBCPP_INLINE_VISIBILITY
    iterator insert(const_iterator __hint, node_type&& __nh)
    {
        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
            "node_type with incompatible allocator passed to set::insert()");
        return __tree_.template __node_handle_insert_unique<node_type>(
            __hint, _VSTD::move(__nh));
    }
    _LIBCPP_INLINE_VISIBILITY
    node_type extract(key_type const& __key)
    {
        return __tree_.template __node_handle_extract<node_type>(__key);
    }
    _LIBCPP_INLINE_VISIBILITY
    node_type extract(const_iterator __it)
    {
        return __tree_.template __node_handle_extract<node_type>(__it);
    }
    template <class _Compare2>
    _LIBCPP_INLINE_VISIBILITY
    void merge(set<key_type, _Compare2, allocator_type>& __source)
    {
        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
                       "merging container with incompatible allocator");
        __tree_.__node_handle_merge_unique(__source.__tree_);
    }
    template <class _Compare2>
    _LIBCPP_INLINE_VISIBILITY
    void merge(set<key_type, _Compare2, allocator_type>&& __source)
    {
        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
                       "merging container with incompatible allocator");
        __tree_.__node_handle_merge_unique(__source.__tree_);
    }
    template <class _Compare2>
    _LIBCPP_INLINE_VISIBILITY
    void merge(multiset<key_type, _Compare2, allocator_type>& __source)
    {
        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
                       "merging container with incompatible allocator");
        __tree_.__node_handle_merge_unique(__source.__tree_);
    }
    template <class _Compare2>
    _LIBCPP_INLINE_VISIBILITY
    void merge(multiset<key_type, _Compare2, allocator_type>&& __source)
    {
        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
                       "merging container with incompatible allocator");
        __tree_.__node_handle_merge_unique(__source.__tree_);
    }
#endif

    _LIBCPP_INLINE_VISIBILITY
    void swap(set& __s) _NOEXCEPT_(__is_nothrow_swappable<__base>::value)
        {__tree_.swap(__s.__tree_);}

    _LIBCPP_INLINE_VISIBILITY
    allocator_type get_allocator() const _NOEXCEPT {return __tree_.__alloc();}
    _LIBCPP_INLINE_VISIBILITY
    key_compare    key_comp()      const {return __tree_.value_comp();}
    _LIBCPP_INLINE_VISIBILITY
    value_compare  value_comp()    const {return __tree_.value_comp();}

    // set operations:
    _LIBCPP_INLINE_VISIBILITY
    iterator find(const key_type& __k)             {return __tree_.find(__k);}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator find(const key_type& __k) const {return __tree_.find(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
    find(const _K2& __k)                           {return __tree_.find(__k);}
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
    find(const _K2& __k) const                     {return __tree_.find(__k);}
#endif

    _LIBCPP_INLINE_VISIBILITY
    size_type      count(const key_type& __k) const
        {return __tree_.__count_unique(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,size_type>::type
    count(const _K2& __k) const                    {return __tree_.__count_multi(__k);}
#endif

#if _LIBCPP_STD_VER > 17
    _LIBCPP_INLINE_VISIBILITY
    bool contains(const key_type& __k) const {return find(__k) != end();}
#endif // _LIBCPP_STD_VER > 17

    _LIBCPP_INLINE_VISIBILITY
    iterator lower_bound(const key_type& __k)
        {return __tree_.lower_bound(__k);}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator lower_bound(const key_type& __k) const
        {return __tree_.lower_bound(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
    lower_bound(const _K2& __k)       {return __tree_.lower_bound(__k);}

    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
    lower_bound(const _K2& __k) const {return __tree_.lower_bound(__k);}
#endif

    _LIBCPP_INLINE_VISIBILITY
    iterator upper_bound(const key_type& __k)
        {return __tree_.upper_bound(__k);}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator upper_bound(const key_type& __k) const
        {return __tree_.upper_bound(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
    upper_bound(const _K2& __k)       {return __tree_.upper_bound(__k);}
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
    upper_bound(const _K2& __k) const {return __tree_.upper_bound(__k);}
#endif

    _LIBCPP_INLINE_VISIBILITY
    pair<iterator,iterator> equal_range(const key_type& __k)
        {return __tree_.__equal_range_unique(__k);}
    _LIBCPP_INLINE_VISIBILITY
    pair<const_iterator,const_iterator> equal_range(const key_type& __k) const
        {return __tree_.__equal_range_unique(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<iterator,iterator>>::type
    equal_range(const _K2& __k)       {return __tree_.__equal_range_multi(__k);}
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<const_iterator,const_iterator>>::type
    equal_range(const _K2& __k) const {return __tree_.__equal_range_multi(__k);}
#endif
};

#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
template<class _InputIterator,
         class _Compare = less<typename iterator_traits<_InputIterator>::value_type>,
         class _Allocator = allocator<typename iterator_traits<_InputIterator>::value_type>,
         class = _EnableIf<__is_allocator<_Allocator>::value, void>,
         class = _EnableIf<!__is_allocator<_Compare>::value, void>>
set(_InputIterator, _InputIterator, _Compare = _Compare(), _Allocator = _Allocator())
  -> set<typename iterator_traits<_InputIterator>::value_type, _Compare, _Allocator>;

template<class _Key, class _Compare = less<_Key>,
         class _Allocator = allocator<_Key>,
         class = _EnableIf<__is_allocator<_Allocator>::value, void>,
         class = _EnableIf<!__is_allocator<_Compare>::value, void>>
set(initializer_list<_Key>, _Compare = _Compare(), _Allocator = _Allocator())
  -> set<_Key, _Compare, _Allocator>;

template<class _InputIterator, class _Allocator,
         class = _EnableIf<__is_allocator<_Allocator>::value, void>>
set(_InputIterator, _InputIterator, _Allocator)
  -> set<typename iterator_traits<_InputIterator>::value_type,
         less<typename iterator_traits<_InputIterator>::value_type>, _Allocator>;

template<class _Key, class _Allocator,
         class = _EnableIf<__is_allocator<_Allocator>::value, void>>
set(initializer_list<_Key>, _Allocator)
  -> set<_Key, less<_Key>, _Allocator>;
#endif

#ifndef _LIBCPP_CXX03_LANG

template <class _Key, class _Compare, class _Allocator>
set<_Key, _Compare, _Allocator>::set(set&& __s, const allocator_type& __a)
    : __tree_(_VSTD::move(__s.__tree_), __a)
{
    if (__a != __s.get_allocator())
    {
        const_iterator __e = cend();
        while (!__s.empty())
            insert(__e, _VSTD::move(__s.__tree_.remove(__s.begin())->__value_));
    }
}

#endif  // _LIBCPP_CXX03_LANG

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const set<_Key, _Compare, _Allocator>& __x,
           const set<_Key, _Compare, _Allocator>& __y)
{
    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator< (const set<_Key, _Compare, _Allocator>& __x,
           const set<_Key, _Compare, _Allocator>& __y)
{
    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const set<_Key, _Compare, _Allocator>& __x,
           const set<_Key, _Compare, _Allocator>& __y)
{
    return !(__x == __y);
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator> (const set<_Key, _Compare, _Allocator>& __x,
           const set<_Key, _Compare, _Allocator>& __y)
{
    return __y < __x;
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(const set<_Key, _Compare, _Allocator>& __x,
           const set<_Key, _Compare, _Allocator>& __y)
{
    return !(__x < __y);
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(const set<_Key, _Compare, _Allocator>& __x,
           const set<_Key, _Compare, _Allocator>& __y)
{
    return !(__y < __x);
}

// specialized algorithms:
template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(set<_Key, _Compare, _Allocator>& __x,
     set<_Key, _Compare, _Allocator>& __y)
    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
{
    __x.swap(__y);
}

#if _LIBCPP_STD_VER > 17
template <class _Key, class _Compare, class _Allocator, class _Predicate>
inline _LIBCPP_INLINE_VISIBILITY
void erase_if(set<_Key, _Compare, _Allocator>& __c, _Predicate __pred)
{ __libcpp_erase_if_container(__c, __pred); }
#endif

template <class _Key, class _Compare = less<_Key>,
          class _Allocator = allocator<_Key> >
class _LIBCPP_TEMPLATE_VIS multiset
{
public:
    // types:
    typedef _Key                                      key_type;
    typedef key_type                                 value_type;
    typedef _Compare                                  key_compare;
    typedef key_compare                              value_compare;
    typedef typename __identity<_Allocator>::type    allocator_type;
    typedef value_type&                              reference;
    typedef const value_type&                        const_reference;

    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
                  "Allocator::value_type must be same type as value_type");

private:
    typedef __tree<value_type, value_compare, allocator_type> __base;
    typedef allocator_traits<allocator_type>                  __alloc_traits;
    typedef typename __base::__node_holder                    __node_holder;

    __base __tree_;

public:
    typedef typename __base::pointer               pointer;
    typedef typename __base::const_pointer         const_pointer;
    typedef typename __base::size_type             size_type;
    typedef typename __base::difference_type       difference_type;
    typedef typename __base::const_iterator        iterator;
    typedef typename __base::const_iterator        const_iterator;
    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;

#if _LIBCPP_STD_VER > 14
    typedef __set_node_handle<typename __base::__node, allocator_type> node_type;
#endif

    template <class _Key2, class _Compare2, class _Alloc2>
        friend class _LIBCPP_TEMPLATE_VIS set;
    template <class _Key2, class _Compare2, class _Alloc2>
        friend class _LIBCPP_TEMPLATE_VIS multiset;

    // construct/copy/destroy:
    _LIBCPP_INLINE_VISIBILITY
    multiset()
        _NOEXCEPT_(
            is_nothrow_default_constructible<allocator_type>::value &&
            is_nothrow_default_constructible<key_compare>::value &&
            is_nothrow_copy_constructible<key_compare>::value)
        : __tree_(value_compare()) {}

    _LIBCPP_INLINE_VISIBILITY
    explicit multiset(const value_compare& __comp)
        _NOEXCEPT_(
            is_nothrow_default_constructible<allocator_type>::value &&
            is_nothrow_copy_constructible<key_compare>::value)
        : __tree_(__comp) {}

    _LIBCPP_INLINE_VISIBILITY
    explicit multiset(const value_compare& __comp, const allocator_type& __a)
        : __tree_(__comp, __a) {}
    template <class _InputIterator>
        _LIBCPP_INLINE_VISIBILITY
        multiset(_InputIterator __f, _InputIterator __l,
                 const value_compare& __comp = value_compare())
        : __tree_(__comp)
        {
            insert(__f, __l);
        }

#if _LIBCPP_STD_VER > 11
        template <class _InputIterator>
        _LIBCPP_INLINE_VISIBILITY
        multiset(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
            : multiset(__f, __l, key_compare(), __a) {}
#endif

    template <class _InputIterator>
        _LIBCPP_INLINE_VISIBILITY
        multiset(_InputIterator __f, _InputIterator __l,
                 const value_compare& __comp, const allocator_type& __a)
        : __tree_(__comp, __a)
        {
            insert(__f, __l);
        }

    _LIBCPP_INLINE_VISIBILITY
    multiset(const multiset& __s)
        : __tree_(__s.__tree_.value_comp(),
          __alloc_traits::select_on_container_copy_construction(__s.__tree_.__alloc()))
        {
            insert(__s.begin(), __s.end());
        }

    _LIBCPP_INLINE_VISIBILITY
    multiset& operator=(const multiset& __s)
        {
            __tree_ = __s.__tree_;
            return *this;
        }

#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    multiset(multiset&& __s)
        _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
        : __tree_(_VSTD::move(__s.__tree_)) {}

    multiset(multiset&& __s, const allocator_type& __a);
#endif  // _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    explicit multiset(const allocator_type& __a)
        : __tree_(__a) {}
    _LIBCPP_INLINE_VISIBILITY
    multiset(const multiset& __s, const allocator_type& __a)
        : __tree_(__s.__tree_.value_comp(), __a)
        {
            insert(__s.begin(), __s.end());
        }

#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    multiset(initializer_list<value_type> __il, const value_compare& __comp = value_compare())
        : __tree_(__comp)
        {
            insert(__il.begin(), __il.end());
        }

    _LIBCPP_INLINE_VISIBILITY
    multiset(initializer_list<value_type> __il, const value_compare& __comp,
        const allocator_type& __a)
        : __tree_(__comp, __a)
        {
            insert(__il.begin(), __il.end());
        }

#if _LIBCPP_STD_VER > 11
    _LIBCPP_INLINE_VISIBILITY
    multiset(initializer_list<value_type> __il, const allocator_type& __a)
        : multiset(__il, key_compare(), __a) {}
#endif

    _LIBCPP_INLINE_VISIBILITY
    multiset& operator=(initializer_list<value_type> __il)
        {
            __tree_.__assign_multi(__il.begin(), __il.end());
            return *this;
        }

    _LIBCPP_INLINE_VISIBILITY
    multiset& operator=(multiset&& __s)
        _NOEXCEPT_(is_nothrow_move_assignable<__base>::value)
        {
            __tree_ = _VSTD::move(__s.__tree_);
            return *this;
        }
#endif  // _LIBCPP_CXX03_LANG

    _LIBCPP_INLINE_VISIBILITY
    ~multiset() {
        static_assert(sizeof(__diagnose_non_const_comparator<_Key, _Compare>()), "");
    }

    _LIBCPP_INLINE_VISIBILITY
          iterator begin() _NOEXCEPT       {return __tree_.begin();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator begin() const _NOEXCEPT {return __tree_.begin();}
    _LIBCPP_INLINE_VISIBILITY
          iterator end() _NOEXCEPT         {return __tree_.end();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator end()   const _NOEXCEPT {return __tree_.end();}

    _LIBCPP_INLINE_VISIBILITY
          reverse_iterator rbegin() _NOEXCEPT
            {return reverse_iterator(end());}
    _LIBCPP_INLINE_VISIBILITY
    const_reverse_iterator rbegin() const _NOEXCEPT
        {return const_reverse_iterator(end());}
    _LIBCPP_INLINE_VISIBILITY
          reverse_iterator rend() _NOEXCEPT
            {return       reverse_iterator(begin());}
    _LIBCPP_INLINE_VISIBILITY
    const_reverse_iterator rend() const _NOEXCEPT
        {return const_reverse_iterator(begin());}

    _LIBCPP_INLINE_VISIBILITY
    const_iterator cbegin()  const _NOEXCEPT {return begin();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator cend() const _NOEXCEPT {return end();}
    _LIBCPP_INLINE_VISIBILITY
    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
    _LIBCPP_INLINE_VISIBILITY
    const_reverse_iterator crend() const _NOEXCEPT {return rend();}

    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
    bool empty() const _NOEXCEPT {return __tree_.size() == 0;}
    _LIBCPP_INLINE_VISIBILITY
    size_type size() const _NOEXCEPT {return __tree_.size();}
    _LIBCPP_INLINE_VISIBILITY
    size_type max_size() const _NOEXCEPT {return __tree_.max_size();}

    // modifiers:
#ifndef _LIBCPP_CXX03_LANG
    template <class... _Args>
        _LIBCPP_INLINE_VISIBILITY
        iterator emplace(_Args&&... __args)
            {return __tree_.__emplace_multi(_VSTD::forward<_Args>(__args)...);}
    template <class... _Args>
        _LIBCPP_INLINE_VISIBILITY
        iterator emplace_hint(const_iterator __p, _Args&&... __args)
            {return __tree_.__emplace_hint_multi(__p, _VSTD::forward<_Args>(__args)...);}
#endif  // _LIBCPP_CXX03_LANG

    _LIBCPP_INLINE_VISIBILITY
    iterator insert(const value_type& __v)
        {return __tree_.__insert_multi(__v);}
    _LIBCPP_INLINE_VISIBILITY
    iterator insert(const_iterator __p, const value_type& __v)
        {return __tree_.__insert_multi(__p, __v);}

    template <class _InputIterator>
        _LIBCPP_INLINE_VISIBILITY
        void insert(_InputIterator __f, _InputIterator __l)
        {
            for (const_iterator __e = cend(); __f != __l; ++__f)
                __tree_.__insert_multi(__e, *__f);
        }

#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    iterator insert(value_type&& __v)
        {return __tree_.__insert_multi(_VSTD::move(__v));}

    _LIBCPP_INLINE_VISIBILITY
    iterator insert(const_iterator __p, value_type&& __v)
        {return __tree_.__insert_multi(__p, _VSTD::move(__v));}

    _LIBCPP_INLINE_VISIBILITY
    void insert(initializer_list<value_type> __il)
        {insert(__il.begin(), __il.end());}
#endif  // _LIBCPP_CXX03_LANG

    _LIBCPP_INLINE_VISIBILITY
    iterator  erase(const_iterator __p) {return __tree_.erase(__p);}
    _LIBCPP_INLINE_VISIBILITY
    size_type erase(const key_type& __k) {return __tree_.__erase_multi(__k);}
    _LIBCPP_INLINE_VISIBILITY
    iterator  erase(const_iterator __f, const_iterator __l)
        {return __tree_.erase(__f, __l);}
    _LIBCPP_INLINE_VISIBILITY
    void clear() _NOEXCEPT {__tree_.clear();}

#if _LIBCPP_STD_VER > 14
    _LIBCPP_INLINE_VISIBILITY
    iterator insert(node_type&& __nh)
    {
        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
            "node_type with incompatible allocator passed to multiset::insert()");
        return __tree_.template __node_handle_insert_multi<node_type>(
            _VSTD::move(__nh));
    }
    _LIBCPP_INLINE_VISIBILITY
    iterator insert(const_iterator __hint, node_type&& __nh)
    {
        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
            "node_type with incompatible allocator passed to multiset::insert()");
        return __tree_.template __node_handle_insert_multi<node_type>(
            __hint, _VSTD::move(__nh));
    }
    _LIBCPP_INLINE_VISIBILITY
    node_type extract(key_type const& __key)
    {
        return __tree_.template __node_handle_extract<node_type>(__key);
    }
    _LIBCPP_INLINE_VISIBILITY
    node_type extract(const_iterator __it)
    {
        return __tree_.template __node_handle_extract<node_type>(__it);
    }
    template <class _Compare2>
    _LIBCPP_INLINE_VISIBILITY
    void merge(multiset<key_type, _Compare2, allocator_type>& __source)
    {
        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
                       "merging container with incompatible allocator");
        __tree_.__node_handle_merge_multi(__source.__tree_);
    }
    template <class _Compare2>
    _LIBCPP_INLINE_VISIBILITY
    void merge(multiset<key_type, _Compare2, allocator_type>&& __source)
    {
        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
                       "merging container with incompatible allocator");
        __tree_.__node_handle_merge_multi(__source.__tree_);
    }
    template <class _Compare2>
    _LIBCPP_INLINE_VISIBILITY
    void merge(set<key_type, _Compare2, allocator_type>& __source)
    {
        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
                       "merging container with incompatible allocator");
        __tree_.__node_handle_merge_multi(__source.__tree_);
    }
    template <class _Compare2>
    _LIBCPP_INLINE_VISIBILITY
    void merge(set<key_type, _Compare2, allocator_type>&& __source)
    {
        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
                       "merging container with incompatible allocator");
        __tree_.__node_handle_merge_multi(__source.__tree_);
    }
#endif

    _LIBCPP_INLINE_VISIBILITY
    void swap(multiset& __s)
        _NOEXCEPT_(__is_nothrow_swappable<__base>::value)
        {__tree_.swap(__s.__tree_);}

    _LIBCPP_INLINE_VISIBILITY
    allocator_type get_allocator() const _NOEXCEPT {return __tree_.__alloc();}
    _LIBCPP_INLINE_VISIBILITY
    key_compare    key_comp()      const {return __tree_.value_comp();}
    _LIBCPP_INLINE_VISIBILITY
    value_compare  value_comp()    const {return __tree_.value_comp();}

    // set operations:
    _LIBCPP_INLINE_VISIBILITY
    iterator find(const key_type& __k)             {return __tree_.find(__k);}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator find(const key_type& __k) const {return __tree_.find(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,iterator>::type
    find(const _K2& __k)                           {return __tree_.find(__k);}
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,const_iterator>::type
    find(const _K2& __k) const                     {return __tree_.find(__k);}
#endif

    _LIBCPP_INLINE_VISIBILITY
    size_type      count(const key_type& __k) const
        {return __tree_.__count_multi(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<__is_transparent<_Compare, _K2>::value,size_type>::type
    count(const _K2& __k) const            {return __tree_.__count_multi(__k);}
#endif

#if _LIBCPP_STD_VER > 17
    _LIBCPP_INLINE_VISIBILITY
    bool contains(const key_type& __k) const {return find(__k) != end();}
#endif // _LIBCPP_STD_VER > 17

    _LIBCPP_INLINE_VISIBILITY
    iterator lower_bound(const key_type& __k)
        {return __tree_.lower_bound(__k);}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator lower_bound(const key_type& __k) const
            {return __tree_.lower_bound(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,iterator>::type
    lower_bound(const _K2& __k)       {return __tree_.lower_bound(__k);}

    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,const_iterator>::type
    lower_bound(const _K2& __k) const {return __tree_.lower_bound(__k);}
#endif

    _LIBCPP_INLINE_VISIBILITY
    iterator upper_bound(const key_type& __k)
            {return __tree_.upper_bound(__k);}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator upper_bound(const key_type& __k) const
            {return __tree_.upper_bound(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,iterator>::type
    upper_bound(const _K2& __k)       {return __tree_.upper_bound(__k);}
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,const_iterator>::type
    upper_bound(const _K2& __k) const {return __tree_.upper_bound(__k);}
#endif

    _LIBCPP_INLINE_VISIBILITY
    pair<iterator,iterator>             equal_range(const key_type& __k)
            {return __tree_.__equal_range_multi(__k);}
    _LIBCPP_INLINE_VISIBILITY
    pair<const_iterator,const_iterator> equal_range(const key_type& __k) const
            {return __tree_.__equal_range_multi(__k);}
#if _LIBCPP_STD_VER > 11
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,pair<iterator,iterator>>::type
    equal_range(const _K2& __k)       {return __tree_.__equal_range_multi(__k);}
    template <typename _K2>
    _LIBCPP_INLINE_VISIBILITY
    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,pair<const_iterator,const_iterator>>::type
    equal_range(const _K2& __k) const {return __tree_.__equal_range_multi(__k);}
#endif
};

#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
template<class _InputIterator,
         class _Compare = less<typename iterator_traits<_InputIterator>::value_type>,
         class _Allocator = allocator<typename iterator_traits<_InputIterator>::value_type>,
         class = _EnableIf<__is_allocator<_Allocator>::value, void>,
         class = _EnableIf<!__is_allocator<_Compare>::value, void>>
multiset(_InputIterator, _InputIterator, _Compare = _Compare(), _Allocator = _Allocator())
  -> multiset<typename iterator_traits<_InputIterator>::value_type, _Compare, _Allocator>;

template<class _Key, class _Compare = less<_Key>,
         class _Allocator = allocator<_Key>,
         class = _EnableIf<__is_allocator<_Allocator>::value, void>,
         class = _EnableIf<!__is_allocator<_Compare>::value, void>>
multiset(initializer_list<_Key>, _Compare = _Compare(), _Allocator = _Allocator())
  -> multiset<_Key, _Compare, _Allocator>;

template<class _InputIterator, class _Allocator,
         class = _EnableIf<__is_allocator<_Allocator>::value, void>>
multiset(_InputIterator, _InputIterator, _Allocator)
  -> multiset<typename iterator_traits<_InputIterator>::value_type,
         less<typename iterator_traits<_InputIterator>::value_type>, _Allocator>;

template<class _Key, class _Allocator,
         class = _EnableIf<__is_allocator<_Allocator>::value, void>>
multiset(initializer_list<_Key>, _Allocator)
  -> multiset<_Key, less<_Key>, _Allocator>;
#endif

#ifndef _LIBCPP_CXX03_LANG

template <class _Key, class _Compare, class _Allocator>
multiset<_Key, _Compare, _Allocator>::multiset(multiset&& __s, const allocator_type& __a)
    : __tree_(_VSTD::move(__s.__tree_), __a)
{
    if (__a != __s.get_allocator())
    {
        const_iterator __e = cend();
        while (!__s.empty())
            insert(__e, _VSTD::move(__s.__tree_.remove(__s.begin())->__value_));
    }
}

#endif  // _LIBCPP_CXX03_LANG

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const multiset<_Key, _Compare, _Allocator>& __x,
           const multiset<_Key, _Compare, _Allocator>& __y)
{
    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator< (const multiset<_Key, _Compare, _Allocator>& __x,
           const multiset<_Key, _Compare, _Allocator>& __y)
{
    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const multiset<_Key, _Compare, _Allocator>& __x,
           const multiset<_Key, _Compare, _Allocator>& __y)
{
    return !(__x == __y);
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator> (const multiset<_Key, _Compare, _Allocator>& __x,
           const multiset<_Key, _Compare, _Allocator>& __y)
{
    return __y < __x;
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(const multiset<_Key, _Compare, _Allocator>& __x,
           const multiset<_Key, _Compare, _Allocator>& __y)
{
    return !(__x < __y);
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(const multiset<_Key, _Compare, _Allocator>& __x,
           const multiset<_Key, _Compare, _Allocator>& __y)
{
    return !(__y < __x);
}

template <class _Key, class _Compare, class _Allocator>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(multiset<_Key, _Compare, _Allocator>& __x,
     multiset<_Key, _Compare, _Allocator>& __y)
    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
{
    __x.swap(__y);
}

#if _LIBCPP_STD_VER > 17
template <class _Key, class _Compare, class _Allocator, class _Predicate>
inline _LIBCPP_INLINE_VISIBILITY
void erase_if(multiset<_Key, _Compare, _Allocator>& __c, _Predicate __pred)
{ __libcpp_erase_if_container(__c, __pred); }
#endif

_LIBCPP_END_NAMESPACE_STD

#endif  // _LIBCPP_SET