aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/cxxsupp/libcxx/include/list
blob: e5b524b8835a1112f03b201a7b32bdbc8c5c3e35 (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
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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_LIST
#define _LIBCPP_LIST

/*
    list synopsis

namespace std
{

template <class T, class Alloc = allocator<T> >
class list
{
public:

    // types:
    typedef T value_type;
    typedef Alloc allocator_type;
    typedef typename allocator_type::reference reference;
    typedef typename allocator_type::const_reference const_reference;
    typedef typename allocator_type::pointer pointer;
    typedef typename allocator_type::const_pointer const_pointer;
    typedef implementation-defined iterator;
    typedef implementation-defined const_iterator;
    typedef implementation-defined size_type;
    typedef implementation-defined difference_type;
    typedef reverse_iterator<iterator> reverse_iterator;
    typedef reverse_iterator<const_iterator> const_reverse_iterator;

    list()
        noexcept(is_nothrow_default_constructible<allocator_type>::value);
    explicit list(const allocator_type& a);
    explicit list(size_type n);
    explicit list(size_type n, const allocator_type& a); // C++14
    list(size_type n, const value_type& value);
    list(size_type n, const value_type& value, const allocator_type& a);
    template <class Iter>
        list(Iter first, Iter last);
    template <class Iter>
        list(Iter first, Iter last, const allocator_type& a);
    template<container-compatible-range<T> R>
      list(from_range_t, R&& rg, const Allocator& = Allocator()); // C++23
    list(const list& x);
    list(const list&, const allocator_type& a);
    list(list&& x)
        noexcept(is_nothrow_move_constructible<allocator_type>::value);
    list(list&&, const allocator_type& a);
    list(initializer_list<value_type>);
    list(initializer_list<value_type>, const allocator_type& a);

    ~list();

    list& operator=(const list& x);
    list& operator=(list&& x)
        noexcept(
             allocator_type::propagate_on_container_move_assignment::value &&
             is_nothrow_move_assignable<allocator_type>::value);
    list& operator=(initializer_list<value_type>);
    template <class Iter>
        void assign(Iter first, Iter last);
    template<container-compatible-range<T> R>
      void assign_range(R&& rg); // C++23
    void assign(size_type n, const value_type& t);
    void assign(initializer_list<value_type>);

    allocator_type get_allocator() const noexcept;

    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;

    reference front();
    const_reference front() const;
    reference back();
    const_reference back() const;

    bool empty() const noexcept;
    size_type size() const noexcept;
    size_type max_size() const noexcept;

    template <class... Args>
        reference emplace_front(Args&&... args); // reference in C++17
    void pop_front();
    template <class... Args>
        reference emplace_back(Args&&... args);  // reference in C++17
    void pop_back();
    void push_front(const value_type& x);
    void push_front(value_type&& x);
    template<container-compatible-range<T> R>
      void prepend_range(R&& rg); // C++23
    void push_back(const value_type& x);
    void push_back(value_type&& x);
    template<container-compatible-range<T> R>
      void append_range(R&& rg); // C++23
    template <class... Args>
        iterator emplace(const_iterator position, Args&&... args);
    iterator insert(const_iterator position, const value_type& x);
    iterator insert(const_iterator position, value_type&& x);
    iterator insert(const_iterator position, size_type n, const value_type& x);
    template <class Iter>
        iterator insert(const_iterator position, Iter first, Iter last);
    template<container-compatible-range<T> R>
      iterator insert_range(const_iterator position, R&& rg); // C++23
    iterator insert(const_iterator position, initializer_list<value_type> il);

    iterator erase(const_iterator position);
    iterator erase(const_iterator position, const_iterator last);

    void resize(size_type sz);
    void resize(size_type sz, const value_type& c);

    void swap(list&)
        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
    void clear() noexcept;

    void splice(const_iterator position, list& x);
    void splice(const_iterator position, list&& x);
    void splice(const_iterator position, list& x, const_iterator i);
    void splice(const_iterator position, list&& x, const_iterator i);
    void splice(const_iterator position, list& x, const_iterator first,
                                                  const_iterator last);
    void splice(const_iterator position, list&& x, const_iterator first,
                                                  const_iterator last);

    size_type remove(const value_type& value);       // void before C++20
    template <class Pred>
      size_type remove_if(Pred pred);                // void before C++20
    size_type unique();                              // void before C++20
    template <class BinaryPredicate>
      size_type unique(BinaryPredicate binary_pred); // void before C++20
    void merge(list& x);
    void merge(list&& x);
    template <class Compare>
        void merge(list& x, Compare comp);
    template <class Compare>
        void merge(list&& x, Compare comp);
    void sort();
    template <class Compare>
        void sort(Compare comp);
    void reverse() noexcept;
};


template <class InputIterator, class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
    list(InputIterator, InputIterator, Allocator = Allocator())
    -> list<typename iterator_traits<InputIterator>::value_type, Allocator>;  // C++17

template<ranges::input_range R, class Allocator = allocator<ranges::range_value_t<R>>>
  list(from_range_t, R&&, Allocator = Allocator())
    -> list<ranges::range_value_t<R>, Allocator>; // C++23

template <class T, class Alloc>
    bool operator==(const list<T,Alloc>& x, const list<T,Alloc>& y);
template <class T, class Alloc>
    bool operator< (const list<T,Alloc>& x, const list<T,Alloc>& y);     // removed in C++20
template <class T, class Alloc>
    bool operator!=(const list<T,Alloc>& x, const list<T,Alloc>& y);     // removed in C++20
template <class T, class Alloc>
    bool operator> (const list<T,Alloc>& x, const list<T,Alloc>& y);     // removed in C++20
template <class T, class Alloc>
    bool operator>=(const list<T,Alloc>& x, const list<T,Alloc>& y);     // removed in C++20
template <class T, class Alloc>
    bool operator<=(const list<T,Alloc>& x, const list<T,Alloc>& y);     // removed in C++20
template<class T, class Allocator>
  synth-three-way-result<T> operator<=>(const list<T, Allocator>& x,
                                        const list<T, Allocator>& y);    // since C++20

template <class T, class Alloc>
    void swap(list<T,Alloc>& x, list<T,Alloc>& y)
         noexcept(noexcept(x.swap(y)));

template <class T, class Allocator, class U>
    typename list<T, Allocator>::size_type
    erase(list<T, Allocator>& c, const U& value);       // since C++20
template <class T, class Allocator, class Predicate>
    typename list<T, Allocator>::size_type
    erase_if(list<T, Allocator>& c, Predicate pred);    // since C++20

}  // std

*/

#include <__algorithm/comp.h>
#include <__algorithm/equal.h>
#include <__algorithm/lexicographical_compare.h>
#include <__algorithm/lexicographical_compare_three_way.h>
#include <__algorithm/min.h>
#include <__assert> // all public C++ headers provide the assertion handler
#include <__availability>
#include <__config>
#include <__format/enable_insertable.h>
#include <__iterator/distance.h>
#include <__iterator/iterator_traits.h>
#include <__iterator/move_iterator.h>
#include <__iterator/next.h>
#include <__iterator/prev.h>
#include <__iterator/reverse_iterator.h>
#include <__memory/addressof.h>
#include <__memory/allocation_guard.h>
#include <__memory/allocator.h>
#include <__memory/allocator_traits.h>
#include <__memory/compressed_pair.h>
#include <__memory/construct_at.h>
#include <__memory/pointer_traits.h>
#include <__memory/swap_allocator.h>
#include <__memory_resource/polymorphic_allocator.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__ranges/container_compatible_range.h>
#include <__ranges/from_range.h>
#include <__type_traits/conditional.h>
#include <__type_traits/is_allocator.h>
#include <__type_traits/is_nothrow_default_constructible.h>
#include <__type_traits/is_nothrow_move_assignable.h>
#include <__type_traits/is_nothrow_move_constructible.h>
#include <__type_traits/is_pointer.h>
#include <__type_traits/is_same.h>
#include <__type_traits/type_identity.h>
#include <__utility/forward.h>
#include <__utility/move.h>
#include <__utility/swap.h>
#include <cstring>
#include <limits>
#include <new> // __launder
#include <version>

// standard-mandated includes

// [iterator.range]
#include <__iterator/access.h>
#include <__iterator/data.h>
#include <__iterator/empty.h>
#include <__iterator/reverse_access.h>
#include <__iterator/size.h>

// [list.syn]
#include <compare>
#include <initializer_list>

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

_LIBCPP_PUSH_MACROS
#include <__undef_macros>


_LIBCPP_BEGIN_NAMESPACE_STD

template <class _Tp, class _VoidPtr> struct __list_node;
template <class _Tp, class _VoidPtr> struct __list_node_base;

template <class _Tp, class _VoidPtr>
struct __list_node_pointer_traits {
  typedef __rebind_pointer_t<_VoidPtr, __list_node<_Tp, _VoidPtr> >
        __node_pointer;
  typedef __rebind_pointer_t<_VoidPtr, __list_node_base<_Tp, _VoidPtr> >
        __base_pointer;

#if defined(_LIBCPP_ABI_LIST_REMOVE_NODE_POINTER_UB)
  typedef __base_pointer __link_pointer;
#else
  typedef __conditional_t<is_pointer<_VoidPtr>::value, __base_pointer, __node_pointer> __link_pointer;
#endif

  typedef __conditional_t<is_same<__link_pointer, __node_pointer>::value, __base_pointer, __node_pointer>
      __non_link_pointer;

  static _LIBCPP_INLINE_VISIBILITY
  __link_pointer __unsafe_link_pointer_cast(__link_pointer __p) {
      return __p;
  }

  static _LIBCPP_INLINE_VISIBILITY
  __link_pointer __unsafe_link_pointer_cast(__non_link_pointer __p) {
      return static_cast<__link_pointer>(static_cast<_VoidPtr>(__p));
  }

};

template <class _Tp, class _VoidPtr>
struct __list_node_base
{
    typedef __list_node_pointer_traits<_Tp, _VoidPtr> _NodeTraits;
    typedef typename _NodeTraits::__node_pointer __node_pointer;
    typedef typename _NodeTraits::__base_pointer __base_pointer;
    typedef typename _NodeTraits::__link_pointer __link_pointer;

    __link_pointer __prev_;
    __link_pointer __next_;

    _LIBCPP_INLINE_VISIBILITY
    __list_node_base() : __prev_(_NodeTraits::__unsafe_link_pointer_cast(__self())),
                         __next_(_NodeTraits::__unsafe_link_pointer_cast(__self())) {}

    _LIBCPP_HIDE_FROM_ABI explicit __list_node_base(__link_pointer __prev, __link_pointer __next)
        : __prev_(__prev), __next_(__next) {}

    _LIBCPP_INLINE_VISIBILITY
    __base_pointer __self() {
        return pointer_traits<__base_pointer>::pointer_to(*this);
    }

    _LIBCPP_INLINE_VISIBILITY
    __node_pointer __as_node() {
        return static_cast<__node_pointer>(__self());
    }
};

template <class _Tp, class _VoidPtr>
struct __list_node
    : public __list_node_base<_Tp, _VoidPtr>
{
    // We allow starting the lifetime of nodes without initializing the value held by the node,
    // since that is handled by the list itself in order to be allocator-aware.
#ifndef _LIBCPP_CXX03_LANG
private:
    union {
        _Tp __value_;
    };

public:
    _LIBCPP_HIDE_FROM_ABI _Tp& __get_value() { return __value_; }
#else
private:
    _ALIGNAS_TYPE(_Tp) char __buffer_[sizeof(_Tp)];

public:
    _LIBCPP_HIDE_FROM_ABI _Tp& __get_value() {
        return *std::__launder(reinterpret_cast<_Tp*>(&__buffer_));
    }
#endif

    typedef __list_node_base<_Tp, _VoidPtr> __base;
    typedef typename __base::__link_pointer __link_pointer;

    _LIBCPP_HIDE_FROM_ABI explicit __list_node(__link_pointer __prev, __link_pointer __next) : __base(__prev, __next) {}
    _LIBCPP_HIDE_FROM_ABI ~__list_node() {}

    _LIBCPP_INLINE_VISIBILITY
    __link_pointer __as_link() {
        return static_cast<__link_pointer>(__base::__self());
    }
};

template <class _Tp, class _Alloc = allocator<_Tp> > class _LIBCPP_TEMPLATE_VIS list;
template <class _Tp, class _Alloc> class __list_imp;
template <class _Tp, class _VoidPtr> class _LIBCPP_TEMPLATE_VIS __list_const_iterator;

template <class _Tp, class _VoidPtr>
class _LIBCPP_TEMPLATE_VIS __list_iterator
{
    typedef __list_node_pointer_traits<_Tp, _VoidPtr> _NodeTraits;
    typedef typename _NodeTraits::__link_pointer __link_pointer;

    __link_pointer __ptr_;

    _LIBCPP_INLINE_VISIBILITY
    explicit __list_iterator(__link_pointer __p) _NOEXCEPT
        : __ptr_(__p)
    {
    }

    template<class, class> friend class list;
    template<class, class> friend class __list_imp;
    template<class, class> friend class __list_const_iterator;
public:
    typedef bidirectional_iterator_tag       iterator_category;
    typedef _Tp                              value_type;
    typedef value_type&                      reference;
    typedef __rebind_pointer_t<_VoidPtr, value_type> pointer;
    typedef typename pointer_traits<pointer>::difference_type difference_type;

    _LIBCPP_INLINE_VISIBILITY
    __list_iterator() _NOEXCEPT : __ptr_(nullptr)
    {
    }

    _LIBCPP_INLINE_VISIBILITY
    reference operator*() const
    {
        return __ptr_->__as_node()->__get_value();
    }
    _LIBCPP_INLINE_VISIBILITY
    pointer operator->() const
    {
        return pointer_traits<pointer>::pointer_to(__ptr_->__as_node()->__get_value());
    }

    _LIBCPP_INLINE_VISIBILITY
    __list_iterator& operator++()
    {
        __ptr_ = __ptr_->__next_;
        return *this;
    }
    _LIBCPP_INLINE_VISIBILITY
    __list_iterator operator++(int) {__list_iterator __t(*this); ++(*this); return __t;}

    _LIBCPP_INLINE_VISIBILITY
    __list_iterator& operator--()
    {
        __ptr_ = __ptr_->__prev_;
        return *this;
    }
    _LIBCPP_INLINE_VISIBILITY
    __list_iterator operator--(int) {__list_iterator __t(*this); --(*this); return __t;}

    friend _LIBCPP_INLINE_VISIBILITY
    bool operator==(const __list_iterator& __x, const __list_iterator& __y)
    {
        return __x.__ptr_ == __y.__ptr_;
    }
    friend _LIBCPP_INLINE_VISIBILITY
     bool operator!=(const __list_iterator& __x, const __list_iterator& __y)
        {return !(__x == __y);}
};

template <class _Tp, class _VoidPtr>
class _LIBCPP_TEMPLATE_VIS __list_const_iterator
{
    typedef __list_node_pointer_traits<_Tp, _VoidPtr> _NodeTraits;
    typedef typename _NodeTraits::__link_pointer __link_pointer;

    __link_pointer __ptr_;

    _LIBCPP_INLINE_VISIBILITY
    explicit __list_const_iterator(__link_pointer __p) _NOEXCEPT
        : __ptr_(__p)
    {
    }

    template<class, class> friend class list;
    template<class, class> friend class __list_imp;
public:
    typedef bidirectional_iterator_tag       iterator_category;
    typedef _Tp                              value_type;
    typedef const value_type&                reference;
    typedef __rebind_pointer_t<_VoidPtr, const value_type> pointer;
    typedef typename pointer_traits<pointer>::difference_type difference_type;

    _LIBCPP_INLINE_VISIBILITY
    __list_const_iterator() _NOEXCEPT : __ptr_(nullptr)
    {
    }
    _LIBCPP_INLINE_VISIBILITY
    __list_const_iterator(const __list_iterator<_Tp, _VoidPtr>& __p) _NOEXCEPT
        : __ptr_(__p.__ptr_)
    {
    }

    _LIBCPP_INLINE_VISIBILITY
    reference operator*() const
    {
        return __ptr_->__as_node()->__get_value();
    }
    _LIBCPP_INLINE_VISIBILITY
    pointer operator->() const
    {
        return pointer_traits<pointer>::pointer_to(__ptr_->__as_node()->__get_value());
    }

    _LIBCPP_INLINE_VISIBILITY
    __list_const_iterator& operator++()
    {
        __ptr_ = __ptr_->__next_;
        return *this;
    }
    _LIBCPP_INLINE_VISIBILITY
    __list_const_iterator operator++(int) {__list_const_iterator __t(*this); ++(*this); return __t;}

    _LIBCPP_INLINE_VISIBILITY
    __list_const_iterator& operator--()
    {
        __ptr_ = __ptr_->__prev_;
        return *this;
    }
    _LIBCPP_INLINE_VISIBILITY
    __list_const_iterator operator--(int) {__list_const_iterator __t(*this); --(*this); return __t;}

    friend _LIBCPP_INLINE_VISIBILITY
    bool operator==(const __list_const_iterator& __x, const __list_const_iterator& __y)
    {
        return __x.__ptr_ == __y.__ptr_;
    }
    friend _LIBCPP_INLINE_VISIBILITY
    bool operator!=(const __list_const_iterator& __x, const __list_const_iterator& __y)
        {return !(__x == __y);}
};

template <class _Tp, class _Alloc>
class __list_imp
{
    __list_imp(const __list_imp&);
    __list_imp& operator=(const __list_imp&);
public:
    typedef _Alloc                                                  allocator_type;
    typedef allocator_traits<allocator_type>                        __alloc_traits;
    typedef typename __alloc_traits::size_type                      size_type;
protected:
    typedef _Tp                                                     value_type;
    typedef typename __alloc_traits::void_pointer                   __void_pointer;
    typedef __list_iterator<value_type, __void_pointer>             iterator;
    typedef __list_const_iterator<value_type, __void_pointer>       const_iterator;
    typedef __list_node_base<value_type, __void_pointer>            __node_base;
    typedef __list_node<value_type, __void_pointer>                 __node_type;
    typedef __rebind_alloc<__alloc_traits, __node_type>             __node_allocator;
    typedef allocator_traits<__node_allocator>                       __node_alloc_traits;
    typedef typename __node_alloc_traits::pointer                    __node_pointer;
    typedef typename __node_alloc_traits::pointer                    __node_const_pointer;
    typedef __list_node_pointer_traits<value_type, __void_pointer> __node_pointer_traits;
    typedef typename __node_pointer_traits::__link_pointer __link_pointer;
    typedef __link_pointer __link_const_pointer;
    typedef typename __alloc_traits::pointer                         pointer;
    typedef typename __alloc_traits::const_pointer                   const_pointer;
    typedef typename __alloc_traits::difference_type                 difference_type;

    typedef __rebind_alloc<__alloc_traits, __node_base>               __node_base_allocator;
    typedef typename allocator_traits<__node_base_allocator>::pointer __node_base_pointer;
    static_assert((!is_same<allocator_type, __node_allocator>::value),
                  "internal allocator type must differ from user-specified "
                  "type; otherwise overload resolution breaks");

    __node_base __end_;
    __compressed_pair<size_type, __node_allocator> __size_alloc_;

    _LIBCPP_INLINE_VISIBILITY
    __link_pointer __end_as_link() const _NOEXCEPT {
        return __node_pointer_traits::__unsafe_link_pointer_cast(
                const_cast<__node_base&>(__end_).__self());
    }

    _LIBCPP_INLINE_VISIBILITY
          size_type& __sz() _NOEXCEPT {return __size_alloc_.first();}
    _LIBCPP_INLINE_VISIBILITY
    const size_type& __sz() const _NOEXCEPT
        {return __size_alloc_.first();}
    _LIBCPP_INLINE_VISIBILITY
          __node_allocator& __node_alloc() _NOEXCEPT
          {return __size_alloc_.second();}
    _LIBCPP_INLINE_VISIBILITY
    const __node_allocator& __node_alloc() const _NOEXCEPT
        {return __size_alloc_.second();}

    _LIBCPP_INLINE_VISIBILITY
    size_type __node_alloc_max_size() const _NOEXCEPT {
        return __node_alloc_traits::max_size(__node_alloc());
    }
    _LIBCPP_INLINE_VISIBILITY
    static void __unlink_nodes(__link_pointer __f, __link_pointer __l) _NOEXCEPT;

    _LIBCPP_INLINE_VISIBILITY
    __list_imp()
        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value);
    _LIBCPP_INLINE_VISIBILITY
    __list_imp(const allocator_type& __a);
    _LIBCPP_INLINE_VISIBILITY
    __list_imp(const __node_allocator& __a);
#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_HIDE_FROM_ABI __list_imp(__node_allocator&& __a) _NOEXCEPT;
#endif
    _LIBCPP_HIDE_FROM_ABI ~__list_imp();
    _LIBCPP_HIDE_FROM_ABI void clear() _NOEXCEPT;
    _LIBCPP_INLINE_VISIBILITY
    bool empty() const _NOEXCEPT {return __sz() == 0;}

    _LIBCPP_INLINE_VISIBILITY
    iterator begin() _NOEXCEPT
    {
        return iterator(__end_.__next_);
    }
    _LIBCPP_INLINE_VISIBILITY
    const_iterator begin() const  _NOEXCEPT
    {
        return const_iterator(__end_.__next_);
    }
    _LIBCPP_INLINE_VISIBILITY
    iterator end() _NOEXCEPT
    {
        return iterator(__end_as_link());
    }
    _LIBCPP_INLINE_VISIBILITY
    const_iterator end() const _NOEXCEPT
    {
        return const_iterator(__end_as_link());
    }

    _LIBCPP_HIDE_FROM_ABI void swap(__list_imp& __c)
#if _LIBCPP_STD_VER >= 14
        _NOEXCEPT;
#else
        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
                    __is_nothrow_swappable<allocator_type>::value);
#endif

    _LIBCPP_INLINE_VISIBILITY
    void __copy_assign_alloc(const __list_imp& __c)
        {__copy_assign_alloc(__c, integral_constant<bool,
                      __node_alloc_traits::propagate_on_container_copy_assignment::value>());}

    _LIBCPP_INLINE_VISIBILITY
    void __move_assign_alloc(__list_imp& __c)
        _NOEXCEPT_(
            !__node_alloc_traits::propagate_on_container_move_assignment::value ||
            is_nothrow_move_assignable<__node_allocator>::value)
        {__move_assign_alloc(__c, integral_constant<bool,
                      __node_alloc_traits::propagate_on_container_move_assignment::value>());}

    template <class ..._Args>
    _LIBCPP_HIDE_FROM_ABI __node_pointer __create_node(__link_pointer __prev, __link_pointer __next, _Args&& ...__args) {
        __node_allocator& __alloc = __node_alloc();
        __allocation_guard<__node_allocator> __guard(__alloc, 1);
        // Begin the lifetime of the node itself. Note that this doesn't begin the lifetime of the value
        // held inside the node, since we need to use the allocator's construct() method for that.
        //
        // We don't use the allocator's construct() method to construct the node itself since the
        // Cpp17FooInsertable named requirements don't require the allocator's construct() method
        // to work on anything other than the value_type.
        std::__construct_at(std::addressof(*__guard.__get()), __prev, __next);

        // Now construct the value_type using the allocator's construct() method.
        __node_alloc_traits::construct(__alloc, std::addressof(__guard.__get()->__get_value()), std::forward<_Args>(__args)...);
        return __guard.__release_ptr();
    }

    template <class ..._Args>
    _LIBCPP_HIDE_FROM_ABI void __delete_node(__node_pointer __node) {
        // For the same reason as above, we use the allocator's destroy() method for the value_type,
        // but not for the node itself.
        __node_allocator& __alloc = __node_alloc();
        __node_alloc_traits::destroy(__alloc, std::addressof(__node->__get_value()));
        std::__destroy_at(std::addressof(*__node));
        __node_alloc_traits::deallocate(__alloc, __node, 1);
    }

private:
    _LIBCPP_INLINE_VISIBILITY
    void __copy_assign_alloc(const __list_imp& __c, true_type)
        {
            if (__node_alloc() != __c.__node_alloc())
                clear();
            __node_alloc() = __c.__node_alloc();
        }

    _LIBCPP_INLINE_VISIBILITY
    void __copy_assign_alloc(const __list_imp&, false_type)
        {}

    _LIBCPP_INLINE_VISIBILITY
    void __move_assign_alloc(__list_imp& __c, true_type)
        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
        {
            __node_alloc() = _VSTD::move(__c.__node_alloc());
        }

    _LIBCPP_INLINE_VISIBILITY
    void __move_assign_alloc(__list_imp&, false_type)
        _NOEXCEPT
        {}
};

// Unlink nodes [__f, __l]
template <class _Tp, class _Alloc>
inline
void
__list_imp<_Tp, _Alloc>::__unlink_nodes(__link_pointer __f, __link_pointer __l)
    _NOEXCEPT
{
    __f->__prev_->__next_ = __l->__next_;
    __l->__next_->__prev_ = __f->__prev_;
}

template <class _Tp, class _Alloc>
inline
__list_imp<_Tp, _Alloc>::__list_imp()
        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
    : __size_alloc_(0, __default_init_tag())
{
}

template <class _Tp, class _Alloc>
inline
__list_imp<_Tp, _Alloc>::__list_imp(const allocator_type& __a)
    : __size_alloc_(0, __node_allocator(__a))
{
}

template <class _Tp, class _Alloc>
inline __list_imp<_Tp, _Alloc>::__list_imp(const __node_allocator& __a)
    : __size_alloc_(0, __a) {}

#ifndef _LIBCPP_CXX03_LANG
template <class _Tp, class _Alloc>
inline __list_imp<_Tp, _Alloc>::__list_imp(__node_allocator&& __a) _NOEXCEPT
    : __size_alloc_(0, _VSTD::move(__a)) {}
#endif

template <class _Tp, class _Alloc>
__list_imp<_Tp, _Alloc>::~__list_imp() {
  clear();
}

template <class _Tp, class _Alloc>
void
__list_imp<_Tp, _Alloc>::clear() _NOEXCEPT
{
    if (!empty())
    {
        __link_pointer __f = __end_.__next_;
        __link_pointer __l = __end_as_link();
        __unlink_nodes(__f, __l->__prev_);
        __sz() = 0;
        while (__f != __l)
        {
            __node_pointer __np = __f->__as_node();
            __f = __f->__next_;
            __delete_node(__np);
        }
    }
}

template <class _Tp, class _Alloc>
void
__list_imp<_Tp, _Alloc>::swap(__list_imp& __c)
#if _LIBCPP_STD_VER >= 14
        _NOEXCEPT
#else
        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
                    __is_nothrow_swappable<allocator_type>::value)
#endif
{
    _LIBCPP_ASSERT_COMPATIBLE_ALLOCATOR(__alloc_traits::propagate_on_container_swap::value ||
                                        this->__node_alloc() == __c.__node_alloc(),
                                        "list::swap: Either propagate_on_container_swap must be true"
                                        " or the allocators must compare equal");
    using _VSTD::swap;
    _VSTD::__swap_allocator(__node_alloc(), __c.__node_alloc());
    swap(__sz(), __c.__sz());
    swap(__end_, __c.__end_);
    if (__sz() == 0)
        __end_.__next_ = __end_.__prev_ = __end_as_link();
    else
        __end_.__prev_->__next_ = __end_.__next_->__prev_ = __end_as_link();
    if (__c.__sz() == 0)
        __c.__end_.__next_ = __c.__end_.__prev_ = __c.__end_as_link();
    else
        __c.__end_.__prev_->__next_ = __c.__end_.__next_->__prev_ = __c.__end_as_link();
}

template <class _Tp, class _Alloc /*= allocator<_Tp>*/>
class _LIBCPP_TEMPLATE_VIS list
    : private __list_imp<_Tp, _Alloc>
{
    typedef __list_imp<_Tp, _Alloc> base;
    typedef typename base::__node_type         __node_type;
    typedef typename base::__node_allocator    __node_allocator;
    typedef typename base::__node_pointer      __node_pointer;
    typedef typename base::__node_alloc_traits __node_alloc_traits;
    typedef typename base::__node_base         __node_base;
    typedef typename base::__node_base_pointer __node_base_pointer;
    typedef typename base::__link_pointer __link_pointer;

public:
    typedef _Tp                                            value_type;
    typedef _Alloc                                         allocator_type;
    static_assert((is_same<value_type, typename allocator_type::value_type>::value),
                  "Allocator::value_type must be same type as value_type");
    typedef value_type&                                    reference;
    typedef const value_type&                              const_reference;
    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::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 >= 20
    typedef size_type                                      __remove_return_type;
#else
    typedef void                                           __remove_return_type;
#endif

    static_assert(is_same<allocator_type, __rebind_alloc<allocator_traits<allocator_type>, value_type> >::value,
                  "[allocator.requirements] states that rebinding an allocator to the same type should result in the "
                  "original allocator");

    _LIBCPP_INLINE_VISIBILITY
    list()
        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
    {
    }
    _LIBCPP_INLINE_VISIBILITY
    explicit list(const allocator_type& __a) : base(__a)
    {
    }
    _LIBCPP_HIDE_FROM_ABI explicit list(size_type __n);
#if _LIBCPP_STD_VER >= 14
    _LIBCPP_HIDE_FROM_ABI explicit list(size_type __n, const allocator_type& __a);
#endif
    _LIBCPP_HIDE_FROM_ABI list(size_type __n, const value_type& __x);
    template <class = __enable_if_t<__is_allocator<_Alloc>::value> >
    _LIBCPP_HIDE_FROM_ABI list(size_type __n, const value_type& __x, const allocator_type& __a) : base(__a)
    {
        for (; __n > 0; --__n)
            push_back(__x);
    }

    template <class _InpIter>
    _LIBCPP_HIDE_FROM_ABI list(_InpIter __f, _InpIter __l,
             __enable_if_t<__has_input_iterator_category<_InpIter>::value>* = 0);
    template <class _InpIter>
    _LIBCPP_HIDE_FROM_ABI list(_InpIter __f, _InpIter __l, const allocator_type& __a,
             __enable_if_t<__has_input_iterator_category<_InpIter>::value>* = 0);

#if _LIBCPP_STD_VER >= 23
    template <_ContainerCompatibleRange<_Tp> _Range>
    _LIBCPP_HIDE_FROM_ABI list(from_range_t, _Range&& __range,
        const allocator_type& __a = allocator_type()) : base(__a) {
      prepend_range(std::forward<_Range>(__range));
    }
#endif

    _LIBCPP_HIDE_FROM_ABI list(const list& __c);
    _LIBCPP_HIDE_FROM_ABI list(const list& __c, const __type_identity_t<allocator_type>& __a);
    _LIBCPP_INLINE_VISIBILITY
    list& operator=(const list& __c);
#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_HIDE_FROM_ABI list(initializer_list<value_type> __il);
    _LIBCPP_HIDE_FROM_ABI list(initializer_list<value_type> __il, const allocator_type& __a);

    _LIBCPP_INLINE_VISIBILITY
    list(list&& __c)
        _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value);
    _LIBCPP_INLINE_VISIBILITY
    list(list&& __c, const __type_identity_t<allocator_type>& __a);
    _LIBCPP_INLINE_VISIBILITY
    list& operator=(list&& __c)
        _NOEXCEPT_(
            __node_alloc_traits::propagate_on_container_move_assignment::value &&
            is_nothrow_move_assignable<__node_allocator>::value);

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

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

    template <class _InpIter>
    _LIBCPP_HIDE_FROM_ABI void assign(_InpIter __f, _InpIter __l,
                    __enable_if_t<__has_input_iterator_category<_InpIter>::value>* = 0);

#if _LIBCPP_STD_VER >= 23
    template <_ContainerCompatibleRange<_Tp> _Range>
    _LIBCPP_HIDE_FROM_ABI
    void assign_range(_Range&& __range) {
      __assign_with_sentinel(ranges::begin(__range), ranges::end(__range));
    }
#endif

    _LIBCPP_HIDE_FROM_ABI void assign(size_type __n, const value_type& __x);

    _LIBCPP_INLINE_VISIBILITY
    allocator_type get_allocator() const _NOEXCEPT;

    _LIBCPP_INLINE_VISIBILITY
    size_type size() const _NOEXCEPT     {return base::__sz();}
    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
    bool empty() const _NOEXCEPT         {return base::empty();}
    _LIBCPP_INLINE_VISIBILITY
    size_type max_size() const _NOEXCEPT
        {
            return _VSTD::min<size_type>(
                base::__node_alloc_max_size(),
                numeric_limits<difference_type >::max());
        }

    _LIBCPP_INLINE_VISIBILITY
          iterator begin() _NOEXCEPT        {return base::begin();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator begin()  const _NOEXCEPT {return base::begin();}
    _LIBCPP_INLINE_VISIBILITY
          iterator end() _NOEXCEPT          {return base::end();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator end()    const _NOEXCEPT {return base::end();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator cbegin() const _NOEXCEPT {return base::begin();}
    _LIBCPP_INLINE_VISIBILITY
    const_iterator cend()   const _NOEXCEPT {return base::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_reverse_iterator crbegin() const _NOEXCEPT
        {return const_reverse_iterator(end());}
    _LIBCPP_INLINE_VISIBILITY
    const_reverse_iterator crend()   const _NOEXCEPT
        {return const_reverse_iterator(begin());}

    _LIBCPP_INLINE_VISIBILITY
    reference front()
    {
        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "list::front called on empty list");
        return base::__end_.__next_->__as_node()->__get_value();
    }
    _LIBCPP_INLINE_VISIBILITY
    const_reference front() const
    {
        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "list::front called on empty list");
        return base::__end_.__next_->__as_node()->__get_value();
    }
    _LIBCPP_INLINE_VISIBILITY
    reference back()
    {
        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "list::back called on empty list");
        return base::__end_.__prev_->__as_node()->__get_value();
    }
    _LIBCPP_INLINE_VISIBILITY
    const_reference back() const
    {
        _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "list::back called on empty list");
        return base::__end_.__prev_->__as_node()->__get_value();
    }

#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_HIDE_FROM_ABI void push_front(value_type&& __x);
    _LIBCPP_HIDE_FROM_ABI void push_back(value_type&& __x);

#if _LIBCPP_STD_VER >= 23
    template <_ContainerCompatibleRange<_Tp> _Range>
    _LIBCPP_HIDE_FROM_ABI
    void prepend_range(_Range&& __range) {
      insert_range(begin(), std::forward<_Range>(__range));
    }

    template <_ContainerCompatibleRange<_Tp> _Range>
    _LIBCPP_HIDE_FROM_ABI
    void append_range(_Range&& __range) {
      insert_range(end(), std::forward<_Range>(__range));
    }
#endif

    template <class... _Args>
#if _LIBCPP_STD_VER >= 17
    _LIBCPP_HIDE_FROM_ABI reference emplace_front(_Args&&... __args);
#else
    _LIBCPP_HIDE_FROM_ABI void      emplace_front(_Args&&... __args);
#endif
    template <class... _Args>
#if _LIBCPP_STD_VER >= 17
    _LIBCPP_HIDE_FROM_ABI reference emplace_back(_Args&&... __args);
#else
    _LIBCPP_HIDE_FROM_ABI void       emplace_back(_Args&&... __args);
#endif
    template <class... _Args>
    _LIBCPP_HIDE_FROM_ABI iterator emplace(const_iterator __p, _Args&&... __args);

    _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, value_type&& __x);

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

    _LIBCPP_HIDE_FROM_ABI void push_front(const value_type& __x);
    _LIBCPP_HIDE_FROM_ABI void push_back(const value_type& __x);

#ifndef _LIBCPP_CXX03_LANG
    template <class _Arg>
    _LIBCPP_INLINE_VISIBILITY
    void __emplace_back(_Arg&& __arg) { emplace_back(_VSTD::forward<_Arg>(__arg)); }
#else
    _LIBCPP_INLINE_VISIBILITY
    void __emplace_back(value_type const& __arg) { push_back(__arg); }
#endif

    _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, const value_type& __x);
    _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, size_type __n, const value_type& __x);
    template <class _InpIter>
    _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator __p, _InpIter __f, _InpIter __l,
                        __enable_if_t<__has_input_iterator_category<_InpIter>::value>* = 0);

#if _LIBCPP_STD_VER >= 23
    template <_ContainerCompatibleRange<_Tp> _Range>
    _LIBCPP_HIDE_FROM_ABI
    iterator insert_range(const_iterator __position, _Range&& __range) {
      return __insert_with_sentinel(__position, ranges::begin(__range), ranges::end(__range));
    }
#endif

    _LIBCPP_INLINE_VISIBILITY
    void swap(list& __c)
#if _LIBCPP_STD_VER >= 14
        _NOEXCEPT
#else
        _NOEXCEPT_(!__node_alloc_traits::propagate_on_container_swap::value ||
                   __is_nothrow_swappable<__node_allocator>::value)
#endif
        {base::swap(__c);}
    _LIBCPP_INLINE_VISIBILITY
    void clear() _NOEXCEPT {base::clear();}

    _LIBCPP_HIDE_FROM_ABI void pop_front();
    _LIBCPP_HIDE_FROM_ABI void pop_back();

    _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __p);
    _LIBCPP_HIDE_FROM_ABI iterator erase(const_iterator __f, const_iterator __l);

    _LIBCPP_HIDE_FROM_ABI void resize(size_type __n);
    _LIBCPP_HIDE_FROM_ABI void resize(size_type __n, const value_type& __x);

    _LIBCPP_HIDE_FROM_ABI void splice(const_iterator __p, list& __c);
#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    void splice(const_iterator __p, list&& __c) {splice(__p, __c);}
    _LIBCPP_INLINE_VISIBILITY
    void splice(const_iterator __p, list&& __c, const_iterator __i)
        {splice(__p, __c, __i);}
    _LIBCPP_INLINE_VISIBILITY
    void splice(const_iterator __p, list&& __c, const_iterator __f, const_iterator __l)
        {splice(__p, __c, __f, __l);}
#endif
    _LIBCPP_HIDE_FROM_ABI void splice(const_iterator __p, list& __c, const_iterator __i);
    _LIBCPP_HIDE_FROM_ABI void splice(const_iterator __p, list& __c, const_iterator __f, const_iterator __l);

    _LIBCPP_HIDE_FROM_ABI __remove_return_type remove(const value_type& __x);
    template <class _Pred>
    _LIBCPP_HIDE_FROM_ABI __remove_return_type remove_if(_Pred __pred);
    _LIBCPP_INLINE_VISIBILITY
    __remove_return_type unique() { return unique(__equal_to()); }
    template <class _BinaryPred>
    _LIBCPP_HIDE_FROM_ABI __remove_return_type unique(_BinaryPred __binary_pred);
    _LIBCPP_INLINE_VISIBILITY
    void merge(list& __c);
#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    void merge(list&& __c) {merge(__c);}

    template <class _Comp>
    _LIBCPP_INLINE_VISIBILITY
        void merge(list&& __c, _Comp __comp) {merge(__c, __comp);}
#endif
    template <class _Comp>
    _LIBCPP_HIDE_FROM_ABI void merge(list& __c, _Comp __comp);

    _LIBCPP_INLINE_VISIBILITY
    void sort();
    template <class _Comp>
        _LIBCPP_INLINE_VISIBILITY
        void sort(_Comp __comp);

    _LIBCPP_HIDE_FROM_ABI void reverse() _NOEXCEPT;

    _LIBCPP_HIDE_FROM_ABI bool __invariants() const;

private:
    template <class _Iterator, class _Sentinel>
    _LIBCPP_HIDE_FROM_ABI
    void __assign_with_sentinel(_Iterator __f, _Sentinel __l);

    template <class _Iterator, class _Sentinel>
    _LIBCPP_HIDE_FROM_ABI
    iterator __insert_with_sentinel(const_iterator __p, _Iterator __f, _Sentinel __l);

    _LIBCPP_INLINE_VISIBILITY
    static void __link_nodes  (__link_pointer __p, __link_pointer __f, __link_pointer __l);
    _LIBCPP_INLINE_VISIBILITY
    void __link_nodes_at_front(__link_pointer __f, __link_pointer __l);
    _LIBCPP_INLINE_VISIBILITY
    void __link_nodes_at_back (__link_pointer __f, __link_pointer __l);
    _LIBCPP_HIDE_FROM_ABI iterator __iterator(size_type __n);
    // TODO: Make this _LIBCPP_HIDE_FROM_ABI
    template <class _Comp>
    _LIBCPP_HIDDEN static iterator __sort(iterator __f1, iterator __e2, size_type __n, _Comp& __comp);

    _LIBCPP_HIDE_FROM_ABI void __move_assign(list& __c, true_type)
        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value);
    _LIBCPP_HIDE_FROM_ABI void __move_assign(list& __c, false_type);
};

#if _LIBCPP_STD_VER >= 17
template<class _InputIterator,
         class _Alloc = allocator<__iter_value_type<_InputIterator>>,
         class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
         class = enable_if_t<__is_allocator<_Alloc>::value>
         >
list(_InputIterator, _InputIterator)
  -> list<__iter_value_type<_InputIterator>, _Alloc>;

template<class _InputIterator,
         class _Alloc,
         class = enable_if_t<__has_input_iterator_category<_InputIterator>::value>,
         class = enable_if_t<__is_allocator<_Alloc>::value>
         >
list(_InputIterator, _InputIterator, _Alloc)
  -> list<__iter_value_type<_InputIterator>, _Alloc>;
#endif

#if _LIBCPP_STD_VER >= 23
template <ranges::input_range _Range,
          class _Alloc = allocator<ranges::range_value_t<_Range>>,
          class = enable_if_t<__is_allocator<_Alloc>::value>
          >
list(from_range_t, _Range&&, _Alloc = _Alloc())
  -> list<ranges::range_value_t<_Range>, _Alloc>;
#endif

// Link in nodes [__f, __l] just prior to __p
template <class _Tp, class _Alloc>
inline
void
list<_Tp, _Alloc>::__link_nodes(__link_pointer __p, __link_pointer __f, __link_pointer __l)
{
    __p->__prev_->__next_ = __f;
    __f->__prev_ = __p->__prev_;
    __p->__prev_ = __l;
    __l->__next_ = __p;
}

// Link in nodes [__f, __l] at the front of the list
template <class _Tp, class _Alloc>
inline
void
list<_Tp, _Alloc>::__link_nodes_at_front(__link_pointer __f, __link_pointer __l)
{
    __f->__prev_ = base::__end_as_link();
    __l->__next_ = base::__end_.__next_;
    __l->__next_->__prev_ = __l;
    base::__end_.__next_ = __f;
}

// Link in nodes [__f, __l] at the back of the list
template <class _Tp, class _Alloc>
inline
void
list<_Tp, _Alloc>::__link_nodes_at_back(__link_pointer __f, __link_pointer __l)
{
    __l->__next_ = base::__end_as_link();
    __f->__prev_ = base::__end_.__prev_;
    __f->__prev_->__next_ = __f;
    base::__end_.__prev_ = __l;
}


template <class _Tp, class _Alloc>
inline
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::__iterator(size_type __n)
{
    return __n <= base::__sz() / 2 ? _VSTD::next(begin(), __n)
                                   : _VSTD::prev(end(), base::__sz() - __n);
}

template <class _Tp, class _Alloc>
list<_Tp, _Alloc>::list(size_type __n)
{
    for (; __n > 0; --__n)
#ifndef _LIBCPP_CXX03_LANG
        emplace_back();
#else
        push_back(value_type());
#endif
}

#if _LIBCPP_STD_VER >= 14
template <class _Tp, class _Alloc>
list<_Tp, _Alloc>::list(size_type __n, const allocator_type& __a) : base(__a)
{
    for (; __n > 0; --__n)
        emplace_back();
}
#endif

template <class _Tp, class _Alloc>
list<_Tp, _Alloc>::list(size_type __n, const value_type& __x)
{
    for (; __n > 0; --__n)
        push_back(__x);
}

template <class _Tp, class _Alloc>
template <class _InpIter>
list<_Tp, _Alloc>::list(_InpIter __f, _InpIter __l,
                        __enable_if_t<__has_input_iterator_category<_InpIter>::value>*)
{
    for (; __f != __l; ++__f)
        __emplace_back(*__f);
}

template <class _Tp, class _Alloc>
template <class _InpIter>
list<_Tp, _Alloc>::list(_InpIter __f, _InpIter __l, const allocator_type& __a,
                        __enable_if_t<__has_input_iterator_category<_InpIter>::value>*)
    : base(__a)
{
    for (; __f != __l; ++__f)
        __emplace_back(*__f);
}

template <class _Tp, class _Alloc>
list<_Tp, _Alloc>::list(const list& __c)
    : base(__node_alloc_traits::select_on_container_copy_construction(
          __c.__node_alloc())) {
    for (const_iterator __i = __c.begin(), __e = __c.end(); __i != __e; ++__i)
        push_back(*__i);
}

template <class _Tp, class _Alloc>
list<_Tp, _Alloc>::list(const list& __c, const __type_identity_t<allocator_type>& __a)
    : base(__a)
{
    for (const_iterator __i = __c.begin(), __e = __c.end(); __i != __e; ++__i)
        push_back(*__i);
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Alloc>
list<_Tp, _Alloc>::list(initializer_list<value_type> __il, const allocator_type& __a)
    : base(__a)
{
    for (typename initializer_list<value_type>::const_iterator __i = __il.begin(),
            __e = __il.end(); __i != __e; ++__i)
        push_back(*__i);
}

template <class _Tp, class _Alloc>
list<_Tp, _Alloc>::list(initializer_list<value_type> __il)
{
    for (typename initializer_list<value_type>::const_iterator __i = __il.begin(),
            __e = __il.end(); __i != __e; ++__i)
        push_back(*__i);
}

template <class _Tp, class _Alloc>
inline list<_Tp, _Alloc>::list(list&& __c)
        _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value)
        : base(_VSTD::move(__c.__node_alloc())) {
    splice(end(), __c);
}

template <class _Tp, class _Alloc>
inline
list<_Tp, _Alloc>::list(list&& __c, const __type_identity_t<allocator_type>& __a)
    : base(__a)
{
    if (__a == __c.get_allocator())
        splice(end(), __c);
    else
    {
        typedef move_iterator<iterator> _Ip;
        assign(_Ip(__c.begin()), _Ip(__c.end()));
    }
}

template <class _Tp, class _Alloc>
inline
list<_Tp, _Alloc>&
list<_Tp, _Alloc>::operator=(list&& __c)
        _NOEXCEPT_(
            __node_alloc_traits::propagate_on_container_move_assignment::value &&
            is_nothrow_move_assignable<__node_allocator>::value)
{
    __move_assign(__c, integral_constant<bool,
          __node_alloc_traits::propagate_on_container_move_assignment::value>());
    return *this;
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::__move_assign(list& __c, false_type)
{
    if (base::__node_alloc() != __c.__node_alloc())
    {
        typedef move_iterator<iterator> _Ip;
        assign(_Ip(__c.begin()), _Ip(__c.end()));
    }
    else
        __move_assign(__c, true_type());
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::__move_assign(list& __c, true_type)
        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
{
    clear();
    base::__move_assign_alloc(__c);
    splice(end(), __c);
}

#endif // _LIBCPP_CXX03_LANG

template <class _Tp, class _Alloc>
inline
list<_Tp, _Alloc>&
list<_Tp, _Alloc>::operator=(const list& __c)
{
    if (this != _VSTD::addressof(__c))
    {
        base::__copy_assign_alloc(__c);
        assign(__c.begin(), __c.end());
    }
    return *this;
}

template <class _Tp, class _Alloc>
template <class _InpIter>
void
list<_Tp, _Alloc>::assign(_InpIter __f, _InpIter __l,
                          __enable_if_t<__has_input_iterator_category<_InpIter>::value>*)
{
  __assign_with_sentinel(__f, __l);
}

template <class _Tp, class _Alloc>
template <class _Iterator, class _Sentinel>
_LIBCPP_HIDE_FROM_ABI
void list<_Tp, _Alloc>::__assign_with_sentinel(_Iterator __f, _Sentinel __l) {
    iterator __i = begin();
    iterator __e = end();
    for (; __f != __l && __i != __e; ++__f, (void) ++__i)
        *__i = *__f;
    if (__i == __e)
        __insert_with_sentinel(__e, std::move(__f), std::move(__l));
    else
        erase(__i, __e);
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::assign(size_type __n, const value_type& __x)
{
    iterator __i = begin();
    iterator __e = end();
    for (; __n > 0 && __i != __e; --__n, (void) ++__i)
        *__i = __x;
    if (__i == __e)
        insert(__e, __n, __x);
    else
        erase(__i, __e);
}

template <class _Tp, class _Alloc>
inline
_Alloc
list<_Tp, _Alloc>::get_allocator() const _NOEXCEPT
{
    return allocator_type(base::__node_alloc());
}

template <class _Tp, class _Alloc>
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::insert(const_iterator __p, const value_type& __x)
{
    __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, __x);
    __link_nodes(__p.__ptr_, __node->__as_link(), __node->__as_link());
    ++base::__sz();
    return iterator(__node->__as_link());
}

template <class _Tp, class _Alloc>
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::insert(const_iterator __p, size_type __n, const value_type& __x)
{
    iterator __r(__p.__ptr_);
    if (__n > 0)
    {
        size_type __ds = 0;
        __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, __x);
        ++__ds;
        __r = iterator(__node->__as_link());
        iterator __e = __r;
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
        try
        {
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
            for (--__n; __n != 0; --__n, (void) ++__e, ++__ds)
            {
                __e.__ptr_->__next_ = this->__create_node(/* prev = */__e.__ptr_, /* next = */nullptr, __x)->__as_link();
            }
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
        }
        catch (...)
        {
            while (true)
            {
                __link_pointer __prev = __e.__ptr_->__prev_;
                __node_pointer __current = __e.__ptr_->__as_node();
                this->__delete_node(__current);
                if (__prev == 0)
                    break;
                __e = iterator(__prev);
            }
            throw;
        }
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
        __link_nodes(__p.__ptr_, __r.__ptr_, __e.__ptr_);
        base::__sz() += __ds;
    }
    return __r;
}

template <class _Tp, class _Alloc>
template <class _InpIter>
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::insert(const_iterator __p, _InpIter __f, _InpIter __l,
                          __enable_if_t<__has_input_iterator_category<_InpIter>::value>*)
{
    return __insert_with_sentinel(__p, __f, __l);
}

template <class _Tp, class _Alloc>
template <class _Iterator, class _Sentinel>
_LIBCPP_HIDE_FROM_ABI
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::__insert_with_sentinel(const_iterator __p, _Iterator __f, _Sentinel __l) {
    iterator __r(__p.__ptr_);
    if (__f != __l)
    {
        size_type __ds = 0;
        __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, *__f);
        ++__ds;
        __r = iterator(__node->__as_link());
        iterator __e = __r;
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
        try
        {
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
            for (++__f; __f != __l; ++__f, (void) ++__e, ++__ds)
            {
                __e.__ptr_->__next_ = this->__create_node(/* prev = */__e.__ptr_, /* next = */nullptr, *__f)->__as_link();
            }
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
        }
        catch (...)
        {
            while (true)
            {
                __link_pointer __prev = __e.__ptr_->__prev_;
                __node_pointer __current = __e.__ptr_->__as_node();
                this->__delete_node(__current);
                if (__prev == 0)
                    break;
                __e = iterator(__prev);
            }
            throw;
        }
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
        __link_nodes(__p.__ptr_, __r.__ptr_, __e.__ptr_);
        base::__sz() += __ds;
    }
    return __r;
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::push_front(const value_type& __x)
{
    __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, __x);
    __link_pointer __nl = __node->__as_link();
    __link_nodes_at_front(__nl, __nl);
    ++base::__sz();
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::push_back(const value_type& __x)
{
    __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, __x);
    __link_pointer __nl = __node->__as_link();
    __link_nodes_at_back(__nl, __nl);
    ++base::__sz();
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::push_front(value_type&& __x)
{
    __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, std::move(__x));
    __link_pointer __nl = __node->__as_link();
    __link_nodes_at_front(__nl, __nl);
    ++base::__sz();
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::push_back(value_type&& __x)
{
    __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, std::move(__x));
    __link_pointer __nl = __node->__as_link();
    __link_nodes_at_back(__nl, __nl);
    ++base::__sz();
}

template <class _Tp, class _Alloc>
template <class... _Args>
#if _LIBCPP_STD_VER >= 17
typename list<_Tp, _Alloc>::reference
#else
void
#endif
list<_Tp, _Alloc>::emplace_front(_Args&&... __args)
{
    __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, std::forward<_Args>(__args)...);
    __link_pointer __nl = __node->__as_link();
    __link_nodes_at_front(__nl, __nl);
    ++base::__sz();
#if _LIBCPP_STD_VER >= 17
    return __node->__get_value();
#endif
}

template <class _Tp, class _Alloc>
template <class... _Args>
#if _LIBCPP_STD_VER >= 17
typename list<_Tp, _Alloc>::reference
#else
void
#endif
list<_Tp, _Alloc>::emplace_back(_Args&&... __args)
{
    __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, std::forward<_Args>(__args)...);
    __link_pointer __nl = __node->__as_link();
    __link_nodes_at_back(__nl, __nl);
    ++base::__sz();
#if _LIBCPP_STD_VER >= 17
    return __node->__get_value();
#endif
}

template <class _Tp, class _Alloc>
template <class... _Args>
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::emplace(const_iterator __p, _Args&&... __args)
{
    __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, std::forward<_Args>(__args)...);
    __link_pointer __nl = __node->__as_link();
    __link_nodes(__p.__ptr_, __nl, __nl);
    ++base::__sz();
    return iterator(__nl);
}

template <class _Tp, class _Alloc>
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::insert(const_iterator __p, value_type&& __x)
{
    __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, std::move(__x));
    __link_pointer __nl = __node->__as_link();
    __link_nodes(__p.__ptr_, __nl, __nl);
    ++base::__sz();
    return iterator(__nl);
}

#endif // _LIBCPP_CXX03_LANG

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::pop_front()
{
    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "list::pop_front() called with empty list");
    __link_pointer __n = base::__end_.__next_;
    base::__unlink_nodes(__n, __n);
    --base::__sz();
    this->__delete_node(__n->__as_node());
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::pop_back()
{
    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "list::pop_back() called on an empty list");
    __link_pointer __n = base::__end_.__prev_;
    base::__unlink_nodes(__n, __n);
    --base::__sz();
    this->__delete_node(__n->__as_node());
}

template <class _Tp, class _Alloc>
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::erase(const_iterator __p)
{
    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__p != end(),
        "list::erase(iterator) called with a non-dereferenceable iterator");
    __link_pointer __n = __p.__ptr_;
    __link_pointer __r = __n->__next_;
    base::__unlink_nodes(__n, __n);
    --base::__sz();
    this->__delete_node(__n->__as_node());
    return iterator(__r);
}

template <class _Tp, class _Alloc>
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::erase(const_iterator __f, const_iterator __l)
{
    if (__f != __l)
    {
        base::__unlink_nodes(__f.__ptr_, __l.__ptr_->__prev_);
        while (__f != __l)
        {
            __link_pointer __n = __f.__ptr_;
            ++__f;
            --base::__sz();
            this->__delete_node(__n->__as_node());
        }
    }
    return iterator(__l.__ptr_);
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::resize(size_type __n)
{
    if (__n < base::__sz())
        erase(__iterator(__n), end());
    else if (__n > base::__sz())
    {
        __n -= base::__sz();
        size_type __ds = 0;
        __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr);
        ++__ds;
        iterator __r = iterator(__node->__as_link());
        iterator __e = __r;
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
        try
        {
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
            for (--__n; __n != 0; --__n, (void) ++__e, ++__ds)
            {
                __e.__ptr_->__next_ = this->__create_node(/* prev = */__e.__ptr_, /* next = */nullptr)->__as_link();
            }
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
        }
        catch (...)
        {
            while (true)
            {
                __link_pointer __prev = __e.__ptr_->__prev_;
                __node_pointer __current = __e.__ptr_->__as_node();
                this->__delete_node(__current);
                if (__prev == 0)
                    break;
                __e = iterator(__prev);
            }
            throw;
        }
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
        __link_nodes_at_back(__r.__ptr_, __e.__ptr_);
        base::__sz() += __ds;
    }
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::resize(size_type __n, const value_type& __x)
{
    if (__n < base::__sz())
        erase(__iterator(__n), end());
    else if (__n > base::__sz())
    {
        __n -= base::__sz();
        size_type __ds = 0;
        __node_pointer __node = this->__create_node(/* prev = */nullptr, /* next = */nullptr, __x);
        ++__ds;
        __link_pointer __nl = __node->__as_link();
        iterator __r = iterator(__nl);
        iterator __e = __r;
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
        try
        {
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
            for (--__n; __n != 0; --__n, (void) ++__e, ++__ds)
            {
                __e.__ptr_->__next_ = this->__create_node(/* prev = */__e.__ptr_, /* next = */nullptr, __x)->__as_link();
            }
#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
        }
        catch (...)
        {
            while (true)
            {
                __link_pointer __prev = __e.__ptr_->__prev_;
                __node_pointer __current = __e.__ptr_->__as_node();
                this->__delete_node(__current);
                if (__prev == 0)
                    break;
                __e = iterator(__prev);
            }
            throw;
        }
#endif // _LIBCPP_HAS_NO_EXCEPTIONS
        __link_nodes(base::__end_as_link(), __r.__ptr_, __e.__ptr_);
        base::__sz() += __ds;
    }
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::splice(const_iterator __p, list& __c)
{
    _LIBCPP_ASSERT_VALID_INPUT_RANGE(this != _VSTD::addressof(__c),
                                     "list::splice(iterator, list) called with this == &list");
    if (!__c.empty())
    {
        __link_pointer __f = __c.__end_.__next_;
        __link_pointer __l = __c.__end_.__prev_;
        base::__unlink_nodes(__f, __l);
        __link_nodes(__p.__ptr_, __f, __l);
        base::__sz() += __c.__sz();
        __c.__sz() = 0;
    }
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::splice(const_iterator __p, list& __c, const_iterator __i)
{
    if (__p.__ptr_ != __i.__ptr_ && __p.__ptr_ != __i.__ptr_->__next_)
    {
        __link_pointer __f = __i.__ptr_;
        base::__unlink_nodes(__f, __f);
        __link_nodes(__p.__ptr_, __f, __f);
        --__c.__sz();
        ++base::__sz();
    }
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::splice(const_iterator __p, list& __c, const_iterator __f, const_iterator __l)
{
    if (__f != __l)
    {
        __link_pointer __first = __f.__ptr_;
        --__l;
        __link_pointer __last = __l.__ptr_;
        if (this != _VSTD::addressof(__c))
        {
            size_type __s = _VSTD::distance(__f, __l) + 1;
            __c.__sz() -= __s;
            base::__sz() += __s;
        }
        base::__unlink_nodes(__first, __last);
        __link_nodes(__p.__ptr_, __first, __last);
    }
}

template <class _Tp, class _Alloc>
typename list<_Tp, _Alloc>::__remove_return_type
list<_Tp, _Alloc>::remove(const value_type& __x)
{
    list<_Tp, _Alloc> __deleted_nodes(get_allocator()); // collect the nodes we're removing
    for (const_iterator __i = begin(), __e = end(); __i != __e;)
    {
        if (*__i == __x)
        {
            const_iterator __j = _VSTD::next(__i);
            for (; __j != __e && *__j == __x; ++__j)
                ;
            __deleted_nodes.splice(__deleted_nodes.end(), *this, __i, __j);
            __i = __j;
            if (__i != __e)
                ++__i;
        }
        else
            ++__i;
    }

    return (__remove_return_type) __deleted_nodes.size();
}

template <class _Tp, class _Alloc>
template <class _Pred>
typename list<_Tp, _Alloc>::__remove_return_type
list<_Tp, _Alloc>::remove_if(_Pred __pred)
{
    list<_Tp, _Alloc> __deleted_nodes(get_allocator()); // collect the nodes we're removing
    for (iterator __i = begin(), __e = end(); __i != __e;)
    {
        if (__pred(*__i))
        {
            iterator __j = _VSTD::next(__i);
            for (; __j != __e && __pred(*__j); ++__j)
                ;
            __deleted_nodes.splice(__deleted_nodes.end(), *this, __i, __j);
            __i = __j;
            if (__i != __e)
                ++__i;
        }
        else
            ++__i;
    }

    return (__remove_return_type) __deleted_nodes.size();
}

template <class _Tp, class _Alloc>
template <class _BinaryPred>
typename list<_Tp, _Alloc>::__remove_return_type
list<_Tp, _Alloc>::unique(_BinaryPred __binary_pred)
{
    list<_Tp, _Alloc> __deleted_nodes(get_allocator()); // collect the nodes we're removing
    for (iterator __i = begin(), __e = end(); __i != __e;)
    {
        iterator __j = _VSTD::next(__i);
        for (; __j != __e && __binary_pred(*__i, *__j); ++__j)
            ;
        if (++__i != __j) {
            __deleted_nodes.splice(__deleted_nodes.end(), *this, __i, __j);
            __i = __j;
            }
    }

    return (__remove_return_type) __deleted_nodes.size();
}

template <class _Tp, class _Alloc>
inline
void
list<_Tp, _Alloc>::merge(list& __c)
{
    merge(__c, __less<>());
}

template <class _Tp, class _Alloc>
template <class _Comp>
void
list<_Tp, _Alloc>::merge(list& __c, _Comp __comp)
{
    if (this != _VSTD::addressof(__c))
    {
        iterator __f1 = begin();
        iterator __e1 = end();
        iterator __f2 = __c.begin();
        iterator __e2 = __c.end();
        while (__f1 != __e1 && __f2 != __e2)
        {
            if (__comp(*__f2, *__f1))
            {
                size_type __ds = 1;
                iterator __m2 = _VSTD::next(__f2);
                for (; __m2 != __e2 && __comp(*__m2, *__f1); ++__m2, (void) ++__ds)
                    ;
                base::__sz() += __ds;
                __c.__sz() -= __ds;
                __link_pointer __f = __f2.__ptr_;
                __link_pointer __l = __m2.__ptr_->__prev_;
                __f2 = __m2;
                base::__unlink_nodes(__f, __l);
                __m2 = _VSTD::next(__f1);
                __link_nodes(__f1.__ptr_, __f, __l);
                __f1 = __m2;
            }
            else
                ++__f1;
        }
        splice(__e1, __c);
    }
}

template <class _Tp, class _Alloc>
inline
void
list<_Tp, _Alloc>::sort()
{
    sort(__less<>());
}

template <class _Tp, class _Alloc>
template <class _Comp>
inline
void
list<_Tp, _Alloc>::sort(_Comp __comp)
{
    __sort(begin(), end(), base::__sz(), __comp);
}

template <class _Tp, class _Alloc>
template <class _Comp>
typename list<_Tp, _Alloc>::iterator
list<_Tp, _Alloc>::__sort(iterator __f1, iterator __e2, size_type __n, _Comp& __comp)
{
    switch (__n)
    {
    case 0:
    case 1:
        return __f1;
    case 2:
        if (__comp(*--__e2, *__f1))
        {
            __link_pointer __f = __e2.__ptr_;
            base::__unlink_nodes(__f, __f);
            __link_nodes(__f1.__ptr_, __f, __f);
            return __e2;
        }
        return __f1;
    }
    size_type __n2 = __n / 2;
    iterator __e1 = _VSTD::next(__f1, __n2);
    iterator  __r = __f1 = __sort(__f1, __e1, __n2, __comp);
    iterator __f2 = __e1 = __sort(__e1, __e2, __n - __n2, __comp);
    if (__comp(*__f2, *__f1))
    {
        iterator __m2 = _VSTD::next(__f2);
        for (; __m2 != __e2 && __comp(*__m2, *__f1); ++__m2)
            ;
        __link_pointer __f = __f2.__ptr_;
        __link_pointer __l = __m2.__ptr_->__prev_;
        __r = __f2;
        __e1 = __f2 = __m2;
        base::__unlink_nodes(__f, __l);
        __m2 = _VSTD::next(__f1);
        __link_nodes(__f1.__ptr_, __f, __l);
        __f1 = __m2;
    }
    else
        ++__f1;
    while (__f1 != __e1 && __f2 != __e2)
    {
        if (__comp(*__f2, *__f1))
        {
            iterator __m2 = _VSTD::next(__f2);
            for (; __m2 != __e2 && __comp(*__m2, *__f1); ++__m2)
                ;
            __link_pointer __f = __f2.__ptr_;
            __link_pointer __l = __m2.__ptr_->__prev_;
            if (__e1 == __f2)
                __e1 = __m2;
            __f2 = __m2;
            base::__unlink_nodes(__f, __l);
            __m2 = _VSTD::next(__f1);
            __link_nodes(__f1.__ptr_, __f, __l);
            __f1 = __m2;
        }
        else
            ++__f1;
    }
    return __r;
}

template <class _Tp, class _Alloc>
void
list<_Tp, _Alloc>::reverse() _NOEXCEPT
{
    if (base::__sz() > 1)
    {
        iterator __e = end();
        for (iterator __i = begin(); __i.__ptr_ != __e.__ptr_;)
        {
            _VSTD::swap(__i.__ptr_->__prev_, __i.__ptr_->__next_);
            __i.__ptr_ = __i.__ptr_->__prev_;
        }
        _VSTD::swap(__e.__ptr_->__prev_, __e.__ptr_->__next_);
    }
}

template <class _Tp, class _Alloc>
bool
list<_Tp, _Alloc>::__invariants() const
{
    return size() == _VSTD::distance(begin(), end());
}

template <class _Tp, class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
{
    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
}

#if _LIBCPP_STD_VER <= 17

template <class _Tp, class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator< (const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
{
    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
}

template <class _Tp, class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
{
    return !(__x == __y);
}

template <class _Tp, class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator> (const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
{
    return __y < __x;
}

template <class _Tp, class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
{
    return !(__x < __y);
}

template <class _Tp, class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
{
    return !(__y < __x);
}

#else // _LIBCPP_STD_VER <= 17

template <class _Tp, class _Allocator>
_LIBCPP_HIDE_FROM_ABI __synth_three_way_result<_Tp>
operator<=>(const list<_Tp, _Allocator>& __x, const list<_Tp, _Allocator>& __y) {
    return std::lexicographical_compare_three_way(
        __x.begin(), __x.end(), __y.begin(), __y.end(), std::__synth_three_way<_Tp, _Tp>);
}

#endif // _LIBCPP_STD_VER <= 17

template <class _Tp, class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(list<_Tp, _Alloc>& __x, list<_Tp, _Alloc>& __y)
    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
{
    __x.swap(__y);
}

#if _LIBCPP_STD_VER >= 20
template <class _Tp, class _Allocator, class _Predicate>
inline _LIBCPP_INLINE_VISIBILITY typename list<_Tp, _Allocator>::size_type
erase_if(list<_Tp, _Allocator>& __c, _Predicate __pred) {
  return __c.remove_if(__pred);
}

template <class _Tp, class _Allocator, class _Up>
inline _LIBCPP_INLINE_VISIBILITY typename list<_Tp, _Allocator>::size_type
erase(list<_Tp, _Allocator>& __c, const _Up& __v) {
  return _VSTD::erase_if(__c, [&](auto& __elem) { return __elem == __v; });
}

template <>
inline constexpr bool __format::__enable_insertable<std::list<char>> = true;
#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <>
inline constexpr bool __format::__enable_insertable<std::list<wchar_t>> = true;
#endif

#endif // _LIBCPP_STD_VER >= 20

_LIBCPP_END_NAMESPACE_STD

#if _LIBCPP_STD_VER >= 17
_LIBCPP_BEGIN_NAMESPACE_STD
namespace pmr {
template <class _ValueT>
using list _LIBCPP_AVAILABILITY_PMR = std::list<_ValueT, polymorphic_allocator<_ValueT>>;
} // namespace pmr
_LIBCPP_END_NAMESPACE_STD
#endif

_LIBCPP_POP_MACROS

#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
#  include <algorithm>
#  include <atomic>
#  include <concepts>
#  include <cstdint>
#  include <cstdlib>
#  include <functional>
#  include <iosfwd>
#  include <iterator>
#  include <type_traits>
#  include <typeinfo>
#endif

#endif // _LIBCPP_LIST