This file is indexed.

/usr/include/c++/v1/__hash_table is in libc++-dev 6.0-2.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   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
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP__HASH_TABLE
#define _LIBCPP__HASH_TABLE

#include <__config>
#include <initializer_list>
#include <memory>
#include <iterator>
#include <algorithm>
#include <cmath>
#include <utility>
#include <type_traits>

#include <__debug>

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

_LIBCPP_PUSH_MACROS
#include <__undef_macros>


_LIBCPP_BEGIN_NAMESPACE_STD

#ifndef _LIBCPP_CXX03_LANG
template <class _Key, class _Tp>
union __hash_value_type;
#else
template <class _Key, class _Tp>
struct __hash_value_type;
#endif

template <class _Key, class _Cp, class _Hash,
          bool =  is_empty<_Hash>::value && !__libcpp_is_final<_Hash>::value>
class __unordered_map_hasher;

template <class _Key, class _Cp, class _Pred,
          bool = is_empty<_Pred>::value && !__libcpp_is_final<_Pred>::value
         >
class __unordered_map_equal;

#ifndef _LIBCPP_CXX03_LANG
template <class _Tp>
struct __is_hash_value_type_imp : false_type {};

template <class _Key, class _Value>
struct __is_hash_value_type_imp<__hash_value_type<_Key, _Value>> : true_type {};

template <class ..._Args>
struct __is_hash_value_type : false_type {};

template <class _One>
struct __is_hash_value_type<_One> : __is_hash_value_type_imp<typename __uncvref<_One>::type> {};
#endif

_LIBCPP_FUNC_VIS
size_t __next_prime(size_t __n);

template <class _NodePtr>
struct __hash_node_base
{
    typedef typename pointer_traits<_NodePtr>::element_type __node_type;
    typedef __hash_node_base __first_node;
    typedef typename __rebind_pointer<_NodePtr, __first_node>::type __node_base_pointer;
    typedef _NodePtr __node_pointer;

#if defined(_LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB)
  typedef __node_base_pointer __next_pointer;
#else
  typedef typename conditional<
      is_pointer<__node_pointer>::value,
      __node_base_pointer,
      __node_pointer>::type   __next_pointer;
#endif

    __next_pointer    __next_;

    _LIBCPP_INLINE_VISIBILITY
    __next_pointer __ptr() _NOEXCEPT {
        return static_cast<__next_pointer>(
            pointer_traits<__node_base_pointer>::pointer_to(*this));
    }

    _LIBCPP_INLINE_VISIBILITY
    __node_pointer __upcast() _NOEXCEPT {
        return static_cast<__node_pointer>(
            pointer_traits<__node_base_pointer>::pointer_to(*this));
    }

    _LIBCPP_INLINE_VISIBILITY
    size_t __hash() const _NOEXCEPT {
        return static_cast<__node_type const&>(*this).__hash_;
    }

    _LIBCPP_INLINE_VISIBILITY __hash_node_base() _NOEXCEPT : __next_(nullptr) {}
};

template <class _Tp, class _VoidPtr>
struct __hash_node
    : public __hash_node_base
             <
                 typename __rebind_pointer<_VoidPtr, __hash_node<_Tp, _VoidPtr> >::type
             >
{
    typedef _Tp __node_value_type;

    size_t            __hash_;
    __node_value_type __value_;
};

inline _LIBCPP_INLINE_VISIBILITY
bool
__is_hash_power2(size_t __bc)
{
    return __bc > 2 && !(__bc & (__bc - 1));
}

inline _LIBCPP_INLINE_VISIBILITY
size_t
__constrain_hash(size_t __h, size_t __bc)
{
    return !(__bc & (__bc - 1)) ? __h & (__bc - 1) :
        (__h < __bc ? __h : __h % __bc);
}

inline _LIBCPP_INLINE_VISIBILITY
size_t
__next_hash_pow2(size_t __n)
{
    return __n < 2 ? __n : (size_t(1) << (std::numeric_limits<size_t>::digits - __clz(__n-1)));
}


template <class _Tp, class _Hash, class _Equal, class _Alloc> class __hash_table;

template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_iterator;
template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_local_iterator;
template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;

template <class _Tp>
struct __hash_key_value_types {
  static_assert(!is_reference<_Tp>::value && !is_const<_Tp>::value, "");
  typedef _Tp key_type;
  typedef _Tp __node_value_type;
  typedef _Tp __container_value_type;
  static const bool __is_map = false;

  _LIBCPP_INLINE_VISIBILITY
  static key_type const& __get_key(_Tp const& __v) {
    return __v;
  }
  _LIBCPP_INLINE_VISIBILITY
  static __container_value_type const& __get_value(__node_value_type const& __v) {
    return __v;
  }
  _LIBCPP_INLINE_VISIBILITY
  static __container_value_type* __get_ptr(__node_value_type& __n) {
    return _VSTD::addressof(__n);
  }
#ifndef _LIBCPP_CXX03_LANG
  _LIBCPP_INLINE_VISIBILITY
  static  __container_value_type&& __move(__node_value_type& __v) {
    return _VSTD::move(__v);
  }
#endif
};

template <class _Key, class _Tp>
struct __hash_key_value_types<__hash_value_type<_Key, _Tp> > {
  typedef _Key                                         key_type;
  typedef _Tp                                          mapped_type;
  typedef __hash_value_type<_Key, _Tp>                 __node_value_type;
  typedef pair<const _Key, _Tp>                        __container_value_type;
  typedef pair<_Key, _Tp>                              __nc_value_type;
  typedef __container_value_type                       __map_value_type;
  static const bool __is_map = true;

  _LIBCPP_INLINE_VISIBILITY
  static key_type const& __get_key(__container_value_type const& __v) {
    return __v.first;
  }

  template <class _Up>
  _LIBCPP_INLINE_VISIBILITY
  static typename enable_if<__is_same_uncvref<_Up, __node_value_type>::value,
      __container_value_type const&>::type
  __get_value(_Up& __t) {
    return __t.__cc;
  }

  template <class _Up>
  _LIBCPP_INLINE_VISIBILITY
  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value,
      __container_value_type const&>::type
  __get_value(_Up& __t) {
    return __t;
  }

  _LIBCPP_INLINE_VISIBILITY
  static __container_value_type* __get_ptr(__node_value_type& __n) {
    return _VSTD::addressof(__n.__cc);
  }
#ifndef _LIBCPP_CXX03_LANG
  _LIBCPP_INLINE_VISIBILITY
  static __nc_value_type&& __move(__node_value_type& __v) {
    return _VSTD::move(__v.__nc);
  }
#endif

};

template <class _Tp, class _AllocPtr, class _KVTypes = __hash_key_value_types<_Tp>,
          bool = _KVTypes::__is_map>
struct __hash_map_pointer_types {};

template <class _Tp, class _AllocPtr, class _KVTypes>
struct __hash_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> {
  typedef typename _KVTypes::__map_value_type   _Mv;
  typedef typename __rebind_pointer<_AllocPtr, _Mv>::type
                                                       __map_value_type_pointer;
  typedef typename __rebind_pointer<_AllocPtr, const _Mv>::type
                                                 __const_map_value_type_pointer;
};

template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type>
struct __hash_node_types;

template <class _NodePtr, class _Tp, class _VoidPtr>
struct __hash_node_types<_NodePtr, __hash_node<_Tp, _VoidPtr> >
    : public __hash_key_value_types<_Tp>, __hash_map_pointer_types<_Tp, _VoidPtr>

{
  typedef __hash_key_value_types<_Tp>           __base;

public:
  typedef ptrdiff_t difference_type;
  typedef size_t size_type;

  typedef typename __rebind_pointer<_NodePtr, void>::type       __void_pointer;

  typedef typename pointer_traits<_NodePtr>::element_type       __node_type;
  typedef _NodePtr                                              __node_pointer;

  typedef __hash_node_base<__node_pointer>                      __node_base_type;
  typedef typename __rebind_pointer<_NodePtr, __node_base_type>::type
                                                             __node_base_pointer;

  typedef typename __node_base_type::__next_pointer          __next_pointer;

  typedef _Tp                                                 __node_value_type;
  typedef typename __rebind_pointer<_VoidPtr, __node_value_type>::type
                                                      __node_value_type_pointer;
  typedef typename __rebind_pointer<_VoidPtr, const __node_value_type>::type
                                                __const_node_value_type_pointer;

private:
    static_assert(!is_const<__node_type>::value,
                "_NodePtr should never be a pointer to const");
    static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value),
                  "_VoidPtr does not point to unqualified void type");
    static_assert((is_same<typename __rebind_pointer<_VoidPtr, __node_type>::type,
                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr.");
};

template <class _HashIterator>
struct __hash_node_types_from_iterator;
template <class _NodePtr>
struct __hash_node_types_from_iterator<__hash_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
template <class _NodePtr>
struct __hash_node_types_from_iterator<__hash_const_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
template <class _NodePtr>
struct __hash_node_types_from_iterator<__hash_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
template <class _NodePtr>
struct __hash_node_types_from_iterator<__hash_const_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};


template <class _NodeValueTp, class _VoidPtr>
struct __make_hash_node_types {
  typedef __hash_node<_NodeValueTp, _VoidPtr> _NodeTp;
  typedef typename __rebind_pointer<_VoidPtr, _NodeTp>::type _NodePtr;
  typedef __hash_node_types<_NodePtr> type;
};

template <class _NodePtr>
class _LIBCPP_TEMPLATE_VIS __hash_iterator
{
    typedef __hash_node_types<_NodePtr> _NodeTypes;
    typedef _NodePtr                            __node_pointer;
    typedef typename _NodeTypes::__next_pointer __next_pointer;

    __next_pointer            __node_;

public:
    typedef forward_iterator_tag                           iterator_category;
    typedef typename _NodeTypes::__node_value_type         value_type;
    typedef typename _NodeTypes::difference_type           difference_type;
    typedef value_type&                                    reference;
    typedef typename _NodeTypes::__node_value_type_pointer pointer;

    _LIBCPP_INLINE_VISIBILITY __hash_iterator() _NOEXCEPT : __node_(nullptr) {
        _LIBCPP_DEBUG_MODE(__get_db()->__insert_i(this));
    }

#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_INLINE_VISIBILITY
    __hash_iterator(const __hash_iterator& __i)
        : __node_(__i.__node_)
    {
        __get_db()->__iterator_copy(this, &__i);
    }

    _LIBCPP_INLINE_VISIBILITY
    ~__hash_iterator()
    {
        __get_db()->__erase_i(this);
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_iterator& operator=(const __hash_iterator& __i)
    {
        if (this != &__i)
        {
            __get_db()->__iterator_copy(this, &__i);
            __node_ = __i.__node_;
        }
        return *this;
    }
#endif  // _LIBCPP_DEBUG_LEVEL >= 2

    _LIBCPP_INLINE_VISIBILITY
    reference operator*() const {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                             "Attempted to dereference a non-dereferenceable unordered container iterator");
        return __node_->__upcast()->__value_;
    }

    _LIBCPP_INLINE_VISIBILITY
    pointer operator->() const {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                           "Attempted to dereference a non-dereferenceable unordered container iterator");
        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_iterator& operator++() {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                       "Attempted to increment non-incrementable unordered container iterator");
        __node_ = __node_->__next_;
        return *this;
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_iterator operator++(int)
    {
        __hash_iterator __t(*this);
        ++(*this);
        return __t;
    }

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

private:
#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_INLINE_VISIBILITY
    __hash_iterator(__next_pointer __node, const void* __c) _NOEXCEPT
        : __node_(__node)
        {
            __get_db()->__insert_ic(this, __c);
        }
#else
    _LIBCPP_INLINE_VISIBILITY
    __hash_iterator(__next_pointer __node) _NOEXCEPT
        : __node_(__node)
        {}
#endif
    template <class, class, class, class> friend class __hash_table;
    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
};

template <class _NodePtr>
class _LIBCPP_TEMPLATE_VIS __hash_const_iterator
{
    static_assert(!is_const<typename pointer_traits<_NodePtr>::element_type>::value, "");
    typedef __hash_node_types<_NodePtr> _NodeTypes;
    typedef _NodePtr                            __node_pointer;
    typedef typename _NodeTypes::__next_pointer __next_pointer;

    __next_pointer __node_;

public:
    typedef __hash_iterator<_NodePtr> __non_const_iterator;

    typedef forward_iterator_tag                                 iterator_category;
    typedef typename _NodeTypes::__node_value_type               value_type;
    typedef typename _NodeTypes::difference_type                 difference_type;
    typedef const value_type&                                    reference;
    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;


    _LIBCPP_INLINE_VISIBILITY __hash_const_iterator() _NOEXCEPT : __node_(nullptr) {
        _LIBCPP_DEBUG_MODE(__get_db()->__insert_i(this));
    }

    _LIBCPP_INLINE_VISIBILITY 
    __hash_const_iterator(const __non_const_iterator& __x) _NOEXCEPT
        : __node_(__x.__node_)
    {
        _LIBCPP_DEBUG_MODE(__get_db()->__iterator_copy(this, &__x));
    }

#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_INLINE_VISIBILITY
    __hash_const_iterator(const __hash_const_iterator& __i)
        : __node_(__i.__node_)
    {
        __get_db()->__iterator_copy(this, &__i);
    }

    _LIBCPP_INLINE_VISIBILITY
    ~__hash_const_iterator()
    {
        __get_db()->__erase_i(this);
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_const_iterator& operator=(const __hash_const_iterator& __i)
    {
        if (this != &__i)
        {
            __get_db()->__iterator_copy(this, &__i);
            __node_ = __i.__node_;
        }
        return *this;
    }
#endif  // _LIBCPP_DEBUG_LEVEL >= 2

    _LIBCPP_INLINE_VISIBILITY
    reference operator*() const {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
        return __node_->__upcast()->__value_;
    }
    _LIBCPP_INLINE_VISIBILITY
    pointer operator->() const {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_const_iterator& operator++() {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                             "Attempted to increment non-incrementable unordered container const_iterator");
        __node_ = __node_->__next_;
        return *this;
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_const_iterator operator++(int)
    {
        __hash_const_iterator __t(*this);
        ++(*this);
        return __t;
    }

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

private:
#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_INLINE_VISIBILITY
    __hash_const_iterator(__next_pointer __node, const void* __c) _NOEXCEPT
        : __node_(__node)
        {
            __get_db()->__insert_ic(this, __c);
        }
#else
    _LIBCPP_INLINE_VISIBILITY
    __hash_const_iterator(__next_pointer __node) _NOEXCEPT
        : __node_(__node)
        {}
#endif
    template <class, class, class, class> friend class __hash_table;
    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
};

template <class _NodePtr>
class _LIBCPP_TEMPLATE_VIS __hash_local_iterator
{
    typedef __hash_node_types<_NodePtr> _NodeTypes;
    typedef _NodePtr                            __node_pointer;
    typedef typename _NodeTypes::__next_pointer __next_pointer;

    __next_pointer         __node_;
    size_t                 __bucket_;
    size_t                 __bucket_count_;

public:
    typedef forward_iterator_tag                                iterator_category;
    typedef typename _NodeTypes::__node_value_type              value_type;
    typedef typename _NodeTypes::difference_type                difference_type;
    typedef value_type&                                         reference;
    typedef typename _NodeTypes::__node_value_type_pointer      pointer;

    _LIBCPP_INLINE_VISIBILITY __hash_local_iterator() _NOEXCEPT : __node_(nullptr) {
        _LIBCPP_DEBUG_MODE(__get_db()->__insert_i(this));
    }

#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_INLINE_VISIBILITY
    __hash_local_iterator(const __hash_local_iterator& __i)
        : __node_(__i.__node_),
          __bucket_(__i.__bucket_),
          __bucket_count_(__i.__bucket_count_)
    {
        __get_db()->__iterator_copy(this, &__i);
    }

    _LIBCPP_INLINE_VISIBILITY
    ~__hash_local_iterator()
    {
        __get_db()->__erase_i(this);
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_local_iterator& operator=(const __hash_local_iterator& __i)
    {
        if (this != &__i)
        {
            __get_db()->__iterator_copy(this, &__i);
            __node_ = __i.__node_;
            __bucket_ = __i.__bucket_;
            __bucket_count_ = __i.__bucket_count_;
        }
        return *this;
    }
#endif  // _LIBCPP_DEBUG_LEVEL >= 2

    _LIBCPP_INLINE_VISIBILITY
    reference operator*() const {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                           "Attempted to dereference a non-dereferenceable unordered container local_iterator");
        return __node_->__upcast()->__value_;
    }

    _LIBCPP_INLINE_VISIBILITY
    pointer operator->() const {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                             "Attempted to dereference a non-dereferenceable unordered container local_iterator");
        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_local_iterator& operator++() {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                       "Attempted to increment non-incrementable unordered container local_iterator");
        __node_ = __node_->__next_;
        if (__node_ != nullptr && __constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
            __node_ = nullptr;
        return *this;
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_local_iterator operator++(int)
    {
        __hash_local_iterator __t(*this);
        ++(*this);
        return __t;
    }

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

private:
#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_INLINE_VISIBILITY
    __hash_local_iterator(__next_pointer __node, size_t __bucket,
                          size_t __bucket_count, const void* __c) _NOEXCEPT
        : __node_(__node),
          __bucket_(__bucket),
          __bucket_count_(__bucket_count)
        {
            __get_db()->__insert_ic(this, __c);
            if (__node_ != nullptr)
                __node_ = __node_->__next_;
        }
#else
    _LIBCPP_INLINE_VISIBILITY
    __hash_local_iterator(__next_pointer __node, size_t __bucket,
                          size_t __bucket_count) _NOEXCEPT
        : __node_(__node),
          __bucket_(__bucket),
          __bucket_count_(__bucket_count)
        {
            if (__node_ != nullptr)
                __node_ = __node_->__next_;
        }
#endif
    template <class, class, class, class> friend class __hash_table;
    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
};

template <class _ConstNodePtr>
class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator
{
    typedef __hash_node_types<_ConstNodePtr> _NodeTypes;
    typedef _ConstNodePtr                       __node_pointer;
    typedef typename _NodeTypes::__next_pointer __next_pointer;

    __next_pointer         __node_;
    size_t                 __bucket_;
    size_t                 __bucket_count_;

    typedef pointer_traits<__node_pointer>          __pointer_traits;
    typedef typename __pointer_traits::element_type __node;
    typedef typename remove_const<__node>::type     __non_const_node;
    typedef typename __rebind_pointer<__node_pointer, __non_const_node>::type
        __non_const_node_pointer;
public:
    typedef __hash_local_iterator<__non_const_node_pointer>
                                                    __non_const_iterator;

    typedef forward_iterator_tag                                 iterator_category;
    typedef typename _NodeTypes::__node_value_type               value_type;
    typedef typename _NodeTypes::difference_type                 difference_type;
    typedef const value_type&                                    reference;
    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;


    _LIBCPP_INLINE_VISIBILITY __hash_const_local_iterator() _NOEXCEPT : __node_(nullptr) {
        _LIBCPP_DEBUG_MODE(__get_db()->__insert_i(this));
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_const_local_iterator(const __non_const_iterator& __x) _NOEXCEPT
        : __node_(__x.__node_),
          __bucket_(__x.__bucket_),
          __bucket_count_(__x.__bucket_count_)
    {
        _LIBCPP_DEBUG_MODE(__get_db()->__iterator_copy(this, &__x));
    }

#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_INLINE_VISIBILITY
    __hash_const_local_iterator(const __hash_const_local_iterator& __i)
        : __node_(__i.__node_),
          __bucket_(__i.__bucket_),
          __bucket_count_(__i.__bucket_count_)
    {
        __get_db()->__iterator_copy(this, &__i);
    }

    _LIBCPP_INLINE_VISIBILITY
    ~__hash_const_local_iterator()
    {
        __get_db()->__erase_i(this);
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_const_local_iterator& operator=(const __hash_const_local_iterator& __i)
    {
        if (this != &__i)
        {
            __get_db()->__iterator_copy(this, &__i);
            __node_ = __i.__node_;
            __bucket_ = __i.__bucket_;
            __bucket_count_ = __i.__bucket_count_;
        }
        return *this;
    }
#endif  // _LIBCPP_DEBUG_LEVEL >= 2

    _LIBCPP_INLINE_VISIBILITY
    reference operator*() const {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
        return __node_->__upcast()->__value_;
    }

    _LIBCPP_INLINE_VISIBILITY
    pointer operator->() const {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_const_local_iterator& operator++() {
        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                       "Attempted to increment non-incrementable unordered container const_local_iterator");
        __node_ = __node_->__next_;
        if (__node_ != nullptr && __constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
            __node_ = nullptr;
        return *this;
    }

    _LIBCPP_INLINE_VISIBILITY
    __hash_const_local_iterator operator++(int)
    {
        __hash_const_local_iterator __t(*this);
        ++(*this);
        return __t;
    }

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

private:
#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_INLINE_VISIBILITY
    __hash_const_local_iterator(__next_pointer __node, size_t __bucket,
                                size_t __bucket_count, const void* __c) _NOEXCEPT
        : __node_(__node),
          __bucket_(__bucket),
          __bucket_count_(__bucket_count)
        {
            __get_db()->__insert_ic(this, __c);
            if (__node_ != nullptr)
                __node_ = __node_->__next_;
        }
#else
    _LIBCPP_INLINE_VISIBILITY
    __hash_const_local_iterator(__next_pointer __node, size_t __bucket,
                                size_t __bucket_count) _NOEXCEPT
        : __node_(__node),
          __bucket_(__bucket),
          __bucket_count_(__bucket_count)
        {
            if (__node_ != nullptr)
                __node_ = __node_->__next_;
        }
#endif
    template <class, class, class, class> friend class __hash_table;
    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
};

template <class _Alloc>
class __bucket_list_deallocator
{
    typedef _Alloc                                          allocator_type;
    typedef allocator_traits<allocator_type>                __alloc_traits;
    typedef typename __alloc_traits::size_type              size_type;

    __compressed_pair<size_type, allocator_type> __data_;
public:
    typedef typename __alloc_traits::pointer pointer;

    _LIBCPP_INLINE_VISIBILITY
    __bucket_list_deallocator()
        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
        : __data_(0) {}

    _LIBCPP_INLINE_VISIBILITY
    __bucket_list_deallocator(const allocator_type& __a, size_type __size)
        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
        : __data_(__size, __a) {}

#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    __bucket_list_deallocator(__bucket_list_deallocator&& __x)
        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
        : __data_(_VSTD::move(__x.__data_))
    {
        __x.size() = 0;
    }
#endif

    _LIBCPP_INLINE_VISIBILITY
    size_type& size() _NOEXCEPT {return __data_.first();}
    _LIBCPP_INLINE_VISIBILITY
    size_type  size() const _NOEXCEPT {return __data_.first();}

    _LIBCPP_INLINE_VISIBILITY
    allocator_type& __alloc() _NOEXCEPT {return __data_.second();}
    _LIBCPP_INLINE_VISIBILITY
    const allocator_type& __alloc() const _NOEXCEPT {return __data_.second();}

    _LIBCPP_INLINE_VISIBILITY
    void operator()(pointer __p) _NOEXCEPT
    {
        __alloc_traits::deallocate(__alloc(), __p, size());
    }
};

template <class _Alloc> class __hash_map_node_destructor;

template <class _Alloc>
class __hash_node_destructor
{
    typedef _Alloc                                          allocator_type;
    typedef allocator_traits<allocator_type>                __alloc_traits;

public:
    typedef typename __alloc_traits::pointer                pointer;
private:
    typedef __hash_node_types<pointer> _NodeTypes;

    allocator_type& __na_;

    __hash_node_destructor& operator=(const __hash_node_destructor&);

public:
    bool __value_constructed;

    _LIBCPP_INLINE_VISIBILITY
    explicit __hash_node_destructor(allocator_type& __na,
                                    bool __constructed = false) _NOEXCEPT
        : __na_(__na),
          __value_constructed(__constructed)
        {}

    _LIBCPP_INLINE_VISIBILITY
    void operator()(pointer __p) _NOEXCEPT
    {
        if (__value_constructed)
            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_));
        if (__p)
            __alloc_traits::deallocate(__na_, __p, 1);
    }

    template <class> friend class __hash_map_node_destructor;
};


#ifndef _LIBCPP_CXX03_LANG
template <class _Key, class _Hash, class _Equal, class _Alloc>
struct __diagnose_hash_table_helper {
  static constexpr bool __trigger_diagnostics()
    _LIBCPP_DIAGNOSE_WARNING(__check_hash_requirements<_Key, _Hash>::value
                         && !__invokable<_Hash const&, _Key const&>::value,
      "the specified hash functor does not provide a const call operator")
    _LIBCPP_DIAGNOSE_WARNING(is_copy_constructible<_Equal>::value
                          && !__invokable<_Equal const&, _Key const&, _Key const&>::value,
      "the specified comparator type does not provide a const call operator")
  {
    static_assert(__check_hash_requirements<_Key, _Hash>::value,
      "the specified hash does not meet the Hash requirements");
    static_assert(is_copy_constructible<_Equal>::value,
      "the specified comparator is required to be copy constructible");
    return true;
  }
};

template <class _Key, class _Value, class _Hash, class _Equal, class _Alloc>
struct __diagnose_hash_table_helper<
  __hash_value_type<_Key, _Value>,
  __unordered_map_hasher<_Key, __hash_value_type<_Key, _Value>, _Hash>,
  __unordered_map_equal<_Key, __hash_value_type<_Key, _Value>, _Equal>,
  _Alloc>
: __diagnose_hash_table_helper<_Key, _Hash, _Equal, _Alloc>
{
};
#endif // _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
class __hash_table
{
public:
    typedef _Tp    value_type;
    typedef _Hash  hasher;
    typedef _Equal key_equal;
    typedef _Alloc allocator_type;

private:
    typedef allocator_traits<allocator_type> __alloc_traits;
    typedef typename
      __make_hash_node_types<value_type, typename __alloc_traits::void_pointer>::type
                                                                     _NodeTypes;
public:

    typedef typename _NodeTypes::__node_value_type           __node_value_type;
    typedef typename _NodeTypes::__container_value_type      __container_value_type;
    typedef typename _NodeTypes::key_type                    key_type;
    typedef value_type&                              reference;
    typedef const value_type&                        const_reference;
    typedef typename __alloc_traits::pointer         pointer;
    typedef typename __alloc_traits::const_pointer   const_pointer;
#ifndef _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE
    typedef typename __alloc_traits::size_type       size_type;
#else
    typedef typename _NodeTypes::size_type           size_type;
#endif
    typedef typename _NodeTypes::difference_type     difference_type;
public:
    // Create __node

    typedef typename _NodeTypes::__node_type __node;
    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
    typedef allocator_traits<__node_allocator>       __node_traits;
    typedef typename _NodeTypes::__void_pointer      __void_pointer;
    typedef typename _NodeTypes::__node_pointer      __node_pointer;
    typedef typename _NodeTypes::__node_pointer      __node_const_pointer;
    typedef typename _NodeTypes::__node_base_type    __first_node;
    typedef typename _NodeTypes::__node_base_pointer __node_base_pointer;
    typedef typename _NodeTypes::__next_pointer      __next_pointer;

private:
    // check for sane allocator pointer rebinding semantics. Rebinding the
    // allocator for a new pointer type should be exactly the same as rebinding
    // the pointer using 'pointer_traits'.
    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value),
                  "Allocator does not rebind pointers in a sane manner.");
    typedef typename __rebind_alloc_helper<__node_traits, __first_node>::type
        __node_base_allocator;
    typedef allocator_traits<__node_base_allocator> __node_base_traits;
    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value),
                 "Allocator does not rebind pointers in a sane manner.");

private:

    typedef typename __rebind_alloc_helper<__node_traits, __next_pointer>::type __pointer_allocator;
    typedef __bucket_list_deallocator<__pointer_allocator> __bucket_list_deleter;
    typedef unique_ptr<__next_pointer[], __bucket_list_deleter> __bucket_list;
    typedef allocator_traits<__pointer_allocator>          __pointer_alloc_traits;
    typedef typename __bucket_list_deleter::pointer       __node_pointer_pointer;

#ifndef _LIBCPP_CXX03_LANG
    static_assert(__diagnose_hash_table_helper<_Tp, _Hash, _Equal, _Alloc>::__trigger_diagnostics(), "");
#endif

    // --- Member data begin ---
    __bucket_list                                         __bucket_list_;
    __compressed_pair<__first_node, __node_allocator>     __p1_;
    __compressed_pair<size_type, hasher>                  __p2_;
    __compressed_pair<float, key_equal>                   __p3_;
    // --- Member data end ---

    _LIBCPP_INLINE_VISIBILITY
    size_type& size() _NOEXCEPT {return __p2_.first();}
public:
    _LIBCPP_INLINE_VISIBILITY
    size_type  size() const _NOEXCEPT {return __p2_.first();}

    _LIBCPP_INLINE_VISIBILITY
    hasher& hash_function() _NOEXCEPT {return __p2_.second();}
    _LIBCPP_INLINE_VISIBILITY
    const hasher& hash_function() const _NOEXCEPT {return __p2_.second();}

    _LIBCPP_INLINE_VISIBILITY
    float& max_load_factor() _NOEXCEPT {return __p3_.first();}
    _LIBCPP_INLINE_VISIBILITY
    float  max_load_factor() const _NOEXCEPT {return __p3_.first();}

    _LIBCPP_INLINE_VISIBILITY
    key_equal& key_eq() _NOEXCEPT {return __p3_.second();}
    _LIBCPP_INLINE_VISIBILITY
    const key_equal& key_eq() const _NOEXCEPT {return __p3_.second();}

    _LIBCPP_INLINE_VISIBILITY
    __node_allocator& __node_alloc() _NOEXCEPT {return __p1_.second();}
    _LIBCPP_INLINE_VISIBILITY
    const __node_allocator& __node_alloc() const _NOEXCEPT
        {return __p1_.second();}

public:
    typedef __hash_iterator<__node_pointer>                   iterator;
    typedef __hash_const_iterator<__node_pointer>             const_iterator;
    typedef __hash_local_iterator<__node_pointer>             local_iterator;
    typedef __hash_const_local_iterator<__node_pointer>       const_local_iterator;

    _LIBCPP_INLINE_VISIBILITY
    __hash_table()
        _NOEXCEPT_(
            is_nothrow_default_constructible<__bucket_list>::value &&
            is_nothrow_default_constructible<__first_node>::value &&
            is_nothrow_default_constructible<__node_allocator>::value &&
            is_nothrow_default_constructible<hasher>::value &&
            is_nothrow_default_constructible<key_equal>::value);
    _LIBCPP_INLINE_VISIBILITY
    __hash_table(const hasher& __hf, const key_equal& __eql);
    __hash_table(const hasher& __hf, const key_equal& __eql,
                 const allocator_type& __a);
    explicit __hash_table(const allocator_type& __a);
    __hash_table(const __hash_table& __u);
    __hash_table(const __hash_table& __u, const allocator_type& __a);
#ifndef _LIBCPP_CXX03_LANG
    __hash_table(__hash_table&& __u)
        _NOEXCEPT_(
            is_nothrow_move_constructible<__bucket_list>::value &&
            is_nothrow_move_constructible<__first_node>::value &&
            is_nothrow_move_constructible<__node_allocator>::value &&
            is_nothrow_move_constructible<hasher>::value &&
            is_nothrow_move_constructible<key_equal>::value);
    __hash_table(__hash_table&& __u, const allocator_type& __a);
#endif  // _LIBCPP_CXX03_LANG
    ~__hash_table();

    __hash_table& operator=(const __hash_table& __u);
#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    __hash_table& operator=(__hash_table&& __u)
        _NOEXCEPT_(
            __node_traits::propagate_on_container_move_assignment::value &&
            is_nothrow_move_assignable<__node_allocator>::value &&
            is_nothrow_move_assignable<hasher>::value &&
            is_nothrow_move_assignable<key_equal>::value);
#endif
    template <class _InputIterator>
        void __assign_unique(_InputIterator __first, _InputIterator __last);
    template <class _InputIterator>
        void __assign_multi(_InputIterator __first, _InputIterator __last);

    _LIBCPP_INLINE_VISIBILITY
    size_type max_size() const _NOEXCEPT
    {
        return std::min<size_type>(
            __node_traits::max_size(__node_alloc()),
            numeric_limits<difference_type >::max()
        );
    }

    pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
    iterator             __node_insert_multi(__node_pointer __nd);
    iterator             __node_insert_multi(const_iterator __p,
                                             __node_pointer __nd);

#ifndef _LIBCPP_CXX03_LANG
    template <class _Key, class ..._Args>
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool> __emplace_unique_key_args(_Key const& __k, _Args&&... __args);

    template <class... _Args>
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);

    template <class _Pp>
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool> __emplace_unique(_Pp&& __x) {
      return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x),
                                          __can_extract_key<_Pp, key_type>());
    }

    template <class _First, class _Second>
    _LIBCPP_INLINE_VISIBILITY
    typename enable_if<
        __can_extract_map_key<_First, key_type, __container_value_type>::value,
        pair<iterator, bool>
    >::type __emplace_unique(_First&& __f, _Second&& __s) {
        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f),
                                              _VSTD::forward<_Second>(__s));
    }

    template <class... _Args>
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool> __emplace_unique(_Args&&... __args) {
      return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...);
    }

    template <class _Pp>
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool>
    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) {
      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x));
    }
    template <class _Pp>
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool>
    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) {
      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x));
    }
    template <class _Pp>
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool>
    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) {
      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x));
    }

    template <class... _Args>
    _LIBCPP_INLINE_VISIBILITY
    iterator __emplace_multi(_Args&&... __args);
    template <class... _Args>
    _LIBCPP_INLINE_VISIBILITY
    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);


    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool>
    __insert_unique(__container_value_type&& __x) {
      return __emplace_unique_key_args(_NodeTypes::__get_key(__x), _VSTD::move(__x));
    }

    template <class _Pp, class = typename enable_if<
            !__is_same_uncvref<_Pp, __container_value_type>::value
        >::type>
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool> __insert_unique(_Pp&& __x) {
      return __emplace_unique(_VSTD::forward<_Pp>(__x));
    }

    template <class _Pp>
    _LIBCPP_INLINE_VISIBILITY
    iterator __insert_multi(_Pp&& __x) {
      return __emplace_multi(_VSTD::forward<_Pp>(__x));
    }

    template <class _Pp>
    _LIBCPP_INLINE_VISIBILITY
    iterator __insert_multi(const_iterator __p, _Pp&& __x) {
        return __emplace_hint_multi(__p, _VSTD::forward<_Pp>(__x));
    }

#else  // !defined(_LIBCPP_CXX03_LANG)
    template <class _Key, class _Args>
    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool> __emplace_unique_key_args(_Key const&, _Args& __args);

    iterator __insert_multi(const __container_value_type& __x);
    iterator __insert_multi(const_iterator __p, const __container_value_type& __x);
#endif

    _LIBCPP_INLINE_VISIBILITY
    pair<iterator, bool> __insert_unique(const __container_value_type& __x) {
        return __emplace_unique_key_args(_NodeTypes::__get_key(__x), __x);
    }

    void clear() _NOEXCEPT;
    void rehash(size_type __n);
    _LIBCPP_INLINE_VISIBILITY void reserve(size_type __n)
        {rehash(static_cast<size_type>(ceil(__n / max_load_factor())));}

    _LIBCPP_INLINE_VISIBILITY
    size_type bucket_count() const _NOEXCEPT
    {
        return __bucket_list_.get_deleter().size();
    }

    _LIBCPP_INLINE_VISIBILITY
    iterator       begin() _NOEXCEPT;
    _LIBCPP_INLINE_VISIBILITY
    iterator       end() _NOEXCEPT;
    _LIBCPP_INLINE_VISIBILITY
    const_iterator begin() const _NOEXCEPT;
    _LIBCPP_INLINE_VISIBILITY
    const_iterator end() const _NOEXCEPT;

    template <class _Key>
        _LIBCPP_INLINE_VISIBILITY
        size_type bucket(const _Key& __k) const
        {
            _LIBCPP_ASSERT(bucket_count() > 0,
                "unordered container::bucket(key) called when bucket_count() == 0");
            return __constrain_hash(hash_function()(__k), bucket_count());
        }

    template <class _Key>
        iterator       find(const _Key& __x);
    template <class _Key>
        const_iterator find(const _Key& __x) const;

    typedef __hash_node_destructor<__node_allocator> _Dp;
    typedef unique_ptr<__node, _Dp> __node_holder;

    iterator erase(const_iterator __p);
    iterator erase(const_iterator __first, const_iterator __last);
    template <class _Key>
        size_type __erase_unique(const _Key& __k);
    template <class _Key>
        size_type __erase_multi(const _Key& __k);
    __node_holder remove(const_iterator __p) _NOEXCEPT;

    template <class _Key>
        _LIBCPP_INLINE_VISIBILITY
        size_type __count_unique(const _Key& __k) const;
    template <class _Key>
        size_type __count_multi(const _Key& __k) const;

    template <class _Key>
        pair<iterator, iterator>
        __equal_range_unique(const _Key& __k);
    template <class _Key>
        pair<const_iterator, const_iterator>
        __equal_range_unique(const _Key& __k) const;

    template <class _Key>
        pair<iterator, iterator>
        __equal_range_multi(const _Key& __k);
    template <class _Key>
        pair<const_iterator, const_iterator>
        __equal_range_multi(const _Key& __k) const;

    void swap(__hash_table& __u)
#if _LIBCPP_STD_VER <= 11
        _NOEXCEPT_DEBUG_(
            __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
            && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
                  || __is_nothrow_swappable<__pointer_allocator>::value)
            && (!__node_traits::propagate_on_container_swap::value
                  || __is_nothrow_swappable<__node_allocator>::value)
            );
#else
     _NOEXCEPT_DEBUG_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value);
#endif

    _LIBCPP_INLINE_VISIBILITY
    size_type max_bucket_count() const _NOEXCEPT
        {return max_size(); }
    size_type bucket_size(size_type __n) const;
    _LIBCPP_INLINE_VISIBILITY float load_factor() const _NOEXCEPT
    {
        size_type __bc = bucket_count();
        return __bc != 0 ? (float)size() / __bc : 0.f;
    }
    _LIBCPP_INLINE_VISIBILITY void max_load_factor(float __mlf) _NOEXCEPT
    {
        _LIBCPP_ASSERT(__mlf > 0,
            "unordered container::max_load_factor(lf) called with lf <= 0");
        max_load_factor() = _VSTD::max(__mlf, load_factor());
    }

    _LIBCPP_INLINE_VISIBILITY
    local_iterator
    begin(size_type __n)
    {
        _LIBCPP_ASSERT(__n < bucket_count(),
            "unordered container::begin(n) called with n >= bucket_count()");
#if _LIBCPP_DEBUG_LEVEL >= 2
        return local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
#else
        return local_iterator(__bucket_list_[__n], __n, bucket_count());
#endif
    }

    _LIBCPP_INLINE_VISIBILITY
    local_iterator
    end(size_type __n)
    {
        _LIBCPP_ASSERT(__n < bucket_count(),
            "unordered container::end(n) called with n >= bucket_count()");
#if _LIBCPP_DEBUG_LEVEL >= 2
        return local_iterator(nullptr, __n, bucket_count(), this);
#else
        return local_iterator(nullptr, __n, bucket_count());
#endif
    }

    _LIBCPP_INLINE_VISIBILITY
    const_local_iterator
    cbegin(size_type __n) const
    {
        _LIBCPP_ASSERT(__n < bucket_count(),
            "unordered container::cbegin(n) called with n >= bucket_count()");
#if _LIBCPP_DEBUG_LEVEL >= 2
        return const_local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
#else
        return const_local_iterator(__bucket_list_[__n], __n, bucket_count());
#endif
    }

    _LIBCPP_INLINE_VISIBILITY
    const_local_iterator
    cend(size_type __n) const
    {
        _LIBCPP_ASSERT(__n < bucket_count(),
            "unordered container::cend(n) called with n >= bucket_count()");
#if _LIBCPP_DEBUG_LEVEL >= 2
        return const_local_iterator(nullptr, __n, bucket_count(), this);
#else
        return const_local_iterator(nullptr, __n, bucket_count());
#endif
    }

#if _LIBCPP_DEBUG_LEVEL >= 2

    bool __dereferenceable(const const_iterator* __i) const;
    bool __decrementable(const const_iterator* __i) const;
    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;

#endif  // _LIBCPP_DEBUG_LEVEL >= 2

private:
    void __rehash(size_type __n);

#ifndef _LIBCPP_CXX03_LANG
    template <class ..._Args>
    __node_holder __construct_node(_Args&& ...__args);

    template <class _First, class ..._Rest>
    __node_holder __construct_node_hash(size_t __hash, _First&& __f, _Rest&&... __rest);
#else // _LIBCPP_CXX03_LANG
    __node_holder __construct_node(const __container_value_type& __v);
    __node_holder __construct_node_hash(size_t __hash, const __container_value_type& __v);
#endif


    _LIBCPP_INLINE_VISIBILITY
    void __copy_assign_alloc(const __hash_table& __u)
        {__copy_assign_alloc(__u, integral_constant<bool,
             __node_traits::propagate_on_container_copy_assignment::value>());}
    void __copy_assign_alloc(const __hash_table& __u, true_type);
    _LIBCPP_INLINE_VISIBILITY
        void __copy_assign_alloc(const __hash_table&, false_type) {}

#ifndef _LIBCPP_CXX03_LANG
    void __move_assign(__hash_table& __u, false_type);
    void __move_assign(__hash_table& __u, true_type)
        _NOEXCEPT_(
            is_nothrow_move_assignable<__node_allocator>::value &&
            is_nothrow_move_assignable<hasher>::value &&
            is_nothrow_move_assignable<key_equal>::value);
    _LIBCPP_INLINE_VISIBILITY
    void __move_assign_alloc(__hash_table& __u)
        _NOEXCEPT_(
            !__node_traits::propagate_on_container_move_assignment::value ||
            (is_nothrow_move_assignable<__pointer_allocator>::value &&
             is_nothrow_move_assignable<__node_allocator>::value))
        {__move_assign_alloc(__u, integral_constant<bool,
             __node_traits::propagate_on_container_move_assignment::value>());}
    _LIBCPP_INLINE_VISIBILITY
    void __move_assign_alloc(__hash_table& __u, true_type)
        _NOEXCEPT_(
            is_nothrow_move_assignable<__pointer_allocator>::value &&
            is_nothrow_move_assignable<__node_allocator>::value)
    {
        __bucket_list_.get_deleter().__alloc() =
                _VSTD::move(__u.__bucket_list_.get_deleter().__alloc());
        __node_alloc() = _VSTD::move(__u.__node_alloc());
    }
    _LIBCPP_INLINE_VISIBILITY
        void __move_assign_alloc(__hash_table&, false_type) _NOEXCEPT {}
#endif // _LIBCPP_CXX03_LANG

    void __deallocate_node(__next_pointer __np) _NOEXCEPT;
    __next_pointer __detach() _NOEXCEPT;

    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
};

template <class _Tp, class _Hash, class _Equal, class _Alloc>
inline
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table()
    _NOEXCEPT_(
        is_nothrow_default_constructible<__bucket_list>::value &&
        is_nothrow_default_constructible<__first_node>::value &&
        is_nothrow_default_constructible<__node_allocator>::value &&
        is_nothrow_default_constructible<hasher>::value &&
        is_nothrow_default_constructible<key_equal>::value)
    : __p2_(0),
      __p3_(1.0f)
{
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
inline
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
                                                       const key_equal& __eql)
    : __bucket_list_(nullptr, __bucket_list_deleter()),
      __p1_(),
      __p2_(0, __hf),
      __p3_(1.0f, __eql)
{
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
                                                       const key_equal& __eql,
                                                       const allocator_type& __a)
    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
      __p1_(__second_tag(), __node_allocator(__a)),
      __p2_(0, __hf),
      __p3_(1.0f, __eql)
{
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const allocator_type& __a)
    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
      __p1_(__second_tag(), __node_allocator(__a)),
      __p2_(0),
      __p3_(1.0f)
{
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u)
    : __bucket_list_(nullptr,
          __bucket_list_deleter(allocator_traits<__pointer_allocator>::
              select_on_container_copy_construction(
                  __u.__bucket_list_.get_deleter().__alloc()), 0)),
      __p1_(__second_tag(), allocator_traits<__node_allocator>::
          select_on_container_copy_construction(__u.__node_alloc())),
      __p2_(0, __u.hash_function()),
      __p3_(__u.__p3_)
{
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u,
                                                       const allocator_type& __a)
    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
      __p1_(__second_tag(), __node_allocator(__a)),
      __p2_(0, __u.hash_function()),
      __p3_(__u.__p3_)
{
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u)
        _NOEXCEPT_(
            is_nothrow_move_constructible<__bucket_list>::value &&
            is_nothrow_move_constructible<__first_node>::value &&
            is_nothrow_move_constructible<__node_allocator>::value &&
            is_nothrow_move_constructible<hasher>::value &&
            is_nothrow_move_constructible<key_equal>::value)
    : __bucket_list_(_VSTD::move(__u.__bucket_list_)),
      __p1_(_VSTD::move(__u.__p1_)),
      __p2_(_VSTD::move(__u.__p2_)),
      __p3_(_VSTD::move(__u.__p3_))
{
    if (size() > 0)
    {
        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
            __p1_.first().__ptr();
        __u.__p1_.first().__next_ = nullptr;
        __u.size() = 0;
    }
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u,
                                                       const allocator_type& __a)
    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
      __p1_(__second_tag(), __node_allocator(__a)),
      __p2_(0, _VSTD::move(__u.hash_function())),
      __p3_(_VSTD::move(__u.__p3_))
{
    if (__a == allocator_type(__u.__node_alloc()))
    {
        __bucket_list_.reset(__u.__bucket_list_.release());
        __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
        __u.__bucket_list_.get_deleter().size() = 0;
        if (__u.size() > 0)
        {
            __p1_.first().__next_ = __u.__p1_.first().__next_;
            __u.__p1_.first().__next_ = nullptr;
            __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
                __p1_.first().__ptr();
            size() = __u.size();
            __u.size() = 0;
        }
    }
}

#endif  // _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::~__hash_table()
{
#if defined(_LIBCPP_CXX03_LANG)
    static_assert((is_copy_constructible<key_equal>::value),
                 "Predicate must be copy-constructible.");
    static_assert((is_copy_constructible<hasher>::value),
                 "Hasher must be copy-constructible.");
#endif

    __deallocate_node(__p1_.first().__next_);
#if _LIBCPP_DEBUG_LEVEL >= 2
    __get_db()->__erase_c(this);
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__copy_assign_alloc(
        const __hash_table& __u, true_type)
{
    if (__node_alloc() != __u.__node_alloc())
    {
        clear();
        __bucket_list_.reset();
        __bucket_list_.get_deleter().size() = 0;
    }
    __bucket_list_.get_deleter().__alloc() = __u.__bucket_list_.get_deleter().__alloc();
    __node_alloc() = __u.__node_alloc();
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
__hash_table<_Tp, _Hash, _Equal, _Alloc>&
__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(const __hash_table& __u)
{
    if (this != &__u)
    {
        __copy_assign_alloc(__u);
        hash_function() = __u.hash_function();
        key_eq() = __u.key_eq();
        max_load_factor() = __u.max_load_factor();
        __assign_multi(__u.begin(), __u.end());
    }
    return *this;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__deallocate_node(__next_pointer __np)
    _NOEXCEPT
{
    __node_allocator& __na = __node_alloc();
    while (__np != nullptr)
    {
        __next_pointer __next = __np->__next_;
#if _LIBCPP_DEBUG_LEVEL >= 2
        __c_node* __c = __get_db()->__find_c_and_lock(this);
        for (__i_node** __p = __c->end_; __p != __c->beg_; )
        {
            --__p;
            iterator* __i = static_cast<iterator*>((*__p)->__i_);
            if (__i->__node_ == __np)
            {
                (*__p)->__c_ = nullptr;
                if (--__c->end_ != __p)
                    memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
            }
        }
        __get_db()->unlock();
#endif
        __node_pointer __real_np = __np->__upcast();
        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__real_np->__value_));
        __node_traits::deallocate(__na, __real_np, 1);
        __np = __next;
    }
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__detach() _NOEXCEPT
{
    size_type __bc = bucket_count();
    for (size_type __i = 0; __i < __bc; ++__i)
        __bucket_list_[__i] = nullptr;
    size() = 0;
    __next_pointer __cache = __p1_.first().__next_;
    __p1_.first().__next_ = nullptr;
    return __cache;
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
        __hash_table& __u, true_type)
    _NOEXCEPT_(
        is_nothrow_move_assignable<__node_allocator>::value &&
        is_nothrow_move_assignable<hasher>::value &&
        is_nothrow_move_assignable<key_equal>::value)
{
    clear();
    __bucket_list_.reset(__u.__bucket_list_.release());
    __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
    __u.__bucket_list_.get_deleter().size() = 0;
    __move_assign_alloc(__u);
    size() = __u.size();
    hash_function() = _VSTD::move(__u.hash_function());
    max_load_factor() = __u.max_load_factor();
    key_eq() = _VSTD::move(__u.key_eq());
    __p1_.first().__next_ = __u.__p1_.first().__next_;
    if (size() > 0)
    {
        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
            __p1_.first().__ptr();
        __u.__p1_.first().__next_ = nullptr;
        __u.size() = 0;
    }
#if _LIBCPP_DEBUG_LEVEL >= 2
    __get_db()->swap(this, &__u);
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
        __hash_table& __u, false_type)
{
    if (__node_alloc() == __u.__node_alloc())
        __move_assign(__u, true_type());
    else
    {
        hash_function() = _VSTD::move(__u.hash_function());
        key_eq() = _VSTD::move(__u.key_eq());
        max_load_factor() = __u.max_load_factor();
        if (bucket_count() != 0)
        {
            __next_pointer __cache = __detach();
#ifndef _LIBCPP_NO_EXCEPTIONS
            try
            {
#endif  // _LIBCPP_NO_EXCEPTIONS
                const_iterator __i = __u.begin();
                while (__cache != nullptr && __u.size() != 0)
                {
                    __cache->__upcast()->__value_ =
                        _VSTD::move(__u.remove(__i++)->__value_);
                    __next_pointer __next = __cache->__next_;
                    __node_insert_multi(__cache->__upcast());
                    __cache = __next;
                }
#ifndef _LIBCPP_NO_EXCEPTIONS
            }
            catch (...)
            {
                __deallocate_node(__cache);
                throw;
            }
#endif  // _LIBCPP_NO_EXCEPTIONS
            __deallocate_node(__cache);
        }
        const_iterator __i = __u.begin();
        while (__u.size() != 0)
        {
            __node_holder __h = __construct_node(_NodeTypes::__move(__u.remove(__i++)->__value_));
            __node_insert_multi(__h.get());
            __h.release();
        }
    }
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
inline
__hash_table<_Tp, _Hash, _Equal, _Alloc>&
__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(__hash_table&& __u)
    _NOEXCEPT_(
        __node_traits::propagate_on_container_move_assignment::value &&
        is_nothrow_move_assignable<__node_allocator>::value &&
        is_nothrow_move_assignable<hasher>::value &&
        is_nothrow_move_assignable<key_equal>::value)
{
    __move_assign(__u, integral_constant<bool,
                  __node_traits::propagate_on_container_move_assignment::value>());
    return *this;
}

#endif  // _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _InputIterator>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_unique(_InputIterator __first,
                                                          _InputIterator __last)
{
    typedef iterator_traits<_InputIterator> _ITraits;
    typedef typename _ITraits::value_type _ItValueType;
    static_assert((is_same<_ItValueType, __container_value_type>::value),
                  "__assign_unique may only be called with the containers value type");

    if (bucket_count() != 0)
    {
        __next_pointer __cache = __detach();
#ifndef _LIBCPP_NO_EXCEPTIONS
        try
        {
#endif  // _LIBCPP_NO_EXCEPTIONS
            for (; __cache != nullptr && __first != __last; ++__first)
            {
                __cache->__upcast()->__value_ = *__first;
                __next_pointer __next = __cache->__next_;
                __node_insert_unique(__cache->__upcast());
                __cache = __next;
            }
#ifndef _LIBCPP_NO_EXCEPTIONS
        }
        catch (...)
        {
            __deallocate_node(__cache);
            throw;
        }
#endif  // _LIBCPP_NO_EXCEPTIONS
        __deallocate_node(__cache);
    }
    for (; __first != __last; ++__first)
        __insert_unique(*__first);
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _InputIterator>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_multi(_InputIterator __first,
                                                         _InputIterator __last)
{
    typedef iterator_traits<_InputIterator> _ITraits;
    typedef typename _ITraits::value_type _ItValueType;
    static_assert((is_same<_ItValueType, __container_value_type>::value ||
                  is_same<_ItValueType, __node_value_type>::value),
                  "__assign_multi may only be called with the containers value type"
                  " or the nodes value type");
    if (bucket_count() != 0)
    {
        __next_pointer __cache = __detach();
#ifndef _LIBCPP_NO_EXCEPTIONS
        try
        {
#endif  // _LIBCPP_NO_EXCEPTIONS
            for (; __cache != nullptr && __first != __last; ++__first)
            {
                __cache->__upcast()->__value_ = *__first;
                __next_pointer __next = __cache->__next_;
                __node_insert_multi(__cache->__upcast());
                __cache = __next;
            }
#ifndef _LIBCPP_NO_EXCEPTIONS
        }
        catch (...)
        {
            __deallocate_node(__cache);
            throw;
        }
#endif  // _LIBCPP_NO_EXCEPTIONS
        __deallocate_node(__cache);
    }
    for (; __first != __last; ++__first)
        __insert_multi(_NodeTypes::__get_value(*__first));
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
inline
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() _NOEXCEPT
{
#if _LIBCPP_DEBUG_LEVEL >= 2
    return iterator(__p1_.first().__next_, this);
#else
    return iterator(__p1_.first().__next_);
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
inline
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() _NOEXCEPT
{
#if _LIBCPP_DEBUG_LEVEL >= 2
    return iterator(nullptr, this);
#else
    return iterator(nullptr);
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
inline
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() const _NOEXCEPT
{
#if _LIBCPP_DEBUG_LEVEL >= 2
    return const_iterator(__p1_.first().__next_, this);
#else
    return const_iterator(__p1_.first().__next_);
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
inline
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() const _NOEXCEPT
{
#if _LIBCPP_DEBUG_LEVEL >= 2
    return const_iterator(nullptr, this);
#else
    return const_iterator(nullptr);
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::clear() _NOEXCEPT
{
    if (size() > 0)
    {
        __deallocate_node(__p1_.first().__next_);
        __p1_.first().__next_ = nullptr;
        size_type __bc = bucket_count();
        for (size_type __i = 0; __i < __bc; ++__i)
            __bucket_list_[__i] = nullptr;
        size() = 0;
    }
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique(__node_pointer __nd)
{
    __nd->__hash_ = hash_function()(__nd->__value_);
    size_type __bc = bucket_count();
    bool __inserted = false;
    __next_pointer __ndptr;
    size_t __chash;
    if (__bc != 0)
    {
        __chash = __constrain_hash(__nd->__hash_, __bc);
        __ndptr = __bucket_list_[__chash];
        if (__ndptr != nullptr)
        {
            for (__ndptr = __ndptr->__next_; __ndptr != nullptr &&
                                             __constrain_hash(__ndptr->__hash(), __bc) == __chash;
                                                     __ndptr = __ndptr->__next_)
            {
                if (key_eq()(__ndptr->__upcast()->__value_, __nd->__value_))
                    goto __done;
            }
        }
    }
    {
        if (size()+1 > __bc * max_load_factor() || __bc == 0)
        {
            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
                           size_type(ceil(float(size() + 1) / max_load_factor()))));
            __bc = bucket_count();
            __chash = __constrain_hash(__nd->__hash_, __bc);
        }
        // insert_after __bucket_list_[__chash], or __first_node if bucket is null
        __next_pointer __pn = __bucket_list_[__chash];
        if (__pn == nullptr)
        {
            __pn =__p1_.first().__ptr();
            __nd->__next_ = __pn->__next_;
            __pn->__next_ = __nd->__ptr();
            // fix up __bucket_list_
            __bucket_list_[__chash] = __pn;
            if (__nd->__next_ != nullptr)
                __bucket_list_[__constrain_hash(__nd->__next_->__hash(), __bc)] = __nd->__ptr();
        }
        else
        {
            __nd->__next_ = __pn->__next_;
            __pn->__next_ = __nd->__ptr();
        }
        __ndptr = __nd->__ptr();
        // increment size
        ++size();
        __inserted = true;
    }
__done:
#if _LIBCPP_DEBUG_LEVEL >= 2
    return pair<iterator, bool>(iterator(__ndptr, this), __inserted);
#else
    return pair<iterator, bool>(iterator(__ndptr), __inserted);
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(__node_pointer __cp)
{
    __cp->__hash_ = hash_function()(__cp->__value_);
    size_type __bc = bucket_count();
    if (size()+1 > __bc * max_load_factor() || __bc == 0)
    {
        rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
                       size_type(ceil(float(size() + 1) / max_load_factor()))));
        __bc = bucket_count();
    }
    size_t __chash = __constrain_hash(__cp->__hash_, __bc);
    __next_pointer __pn = __bucket_list_[__chash];
    if (__pn == nullptr)
    {
        __pn =__p1_.first().__ptr();
        __cp->__next_ = __pn->__next_;
        __pn->__next_ = __cp->__ptr();
        // fix up __bucket_list_
        __bucket_list_[__chash] = __pn;
        if (__cp->__next_ != nullptr)
            __bucket_list_[__constrain_hash(__cp->__next_->__hash(), __bc)]
                = __cp->__ptr();
    }
    else
    {
        for (bool __found = false; __pn->__next_ != nullptr &&
                                   __constrain_hash(__pn->__next_->__hash(), __bc) == __chash;
                                                           __pn = __pn->__next_)
        {
            //      __found    key_eq()     action
            //      false       false       loop
            //      true        true        loop
            //      false       true        set __found to true
            //      true        false       break
            if (__found != (__pn->__next_->__hash() == __cp->__hash_ &&
                            key_eq()(__pn->__next_->__upcast()->__value_, __cp->__value_)))
            {
                if (!__found)
                    __found = true;
                else
                    break;
            }
        }
        __cp->__next_ = __pn->__next_;
        __pn->__next_ = __cp->__ptr();
        if (__cp->__next_ != nullptr)
        {
            size_t __nhash = __constrain_hash(__cp->__next_->__hash(), __bc);
            if (__nhash != __chash)
                __bucket_list_[__nhash] = __cp->__ptr();
        }
    }
    ++size();
#if _LIBCPP_DEBUG_LEVEL >= 2
    return iterator(__cp->__ptr(), this);
#else
    return iterator(__cp->__ptr());
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(
        const_iterator __p, __node_pointer __cp)
{
#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
        " referring to this unordered container");
#endif
    if (__p != end() && key_eq()(*__p, __cp->__value_))
    {
        __next_pointer __np = __p.__node_;
        __cp->__hash_ = __np->__hash();
        size_type __bc = bucket_count();
        if (size()+1 > __bc * max_load_factor() || __bc == 0)
        {
            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
                           size_type(ceil(float(size() + 1) / max_load_factor()))));
            __bc = bucket_count();
        }
        size_t __chash = __constrain_hash(__cp->__hash_, __bc);
        __next_pointer __pp = __bucket_list_[__chash];
        while (__pp->__next_ != __np)
            __pp = __pp->__next_;
        __cp->__next_ = __np;
        __pp->__next_ = static_cast<__next_pointer>(__cp);
        ++size();
#if _LIBCPP_DEBUG_LEVEL >= 2
        return iterator(static_cast<__next_pointer>(__cp), this);
#else
        return iterator(static_cast<__next_pointer>(__cp));
#endif
    }
    return __node_insert_multi(__cp);
}



#ifndef _LIBCPP_CXX03_LANG
template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key, class ..._Args>
pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args)
#else
template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key, class _Args>
pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_key_args(_Key const& __k, _Args& __args)
#endif
{

    size_t __hash = hash_function()(__k);
    size_type __bc = bucket_count();
    bool __inserted = false;
    __next_pointer __nd;
    size_t __chash;
    if (__bc != 0)
    {
        __chash = __constrain_hash(__hash, __bc);
        __nd = __bucket_list_[__chash];
        if (__nd != nullptr)
        {
            for (__nd = __nd->__next_; __nd != nullptr &&
                (__nd->__hash() == __hash || __constrain_hash(__nd->__hash(), __bc) == __chash);
                                                           __nd = __nd->__next_)
            {
                if (key_eq()(__nd->__upcast()->__value_, __k))
                    goto __done;
            }
        }
    }
    {
#ifndef _LIBCPP_CXX03_LANG
        __node_holder __h = __construct_node_hash(__hash, _VSTD::forward<_Args>(__args)...);
#else
        __node_holder __h = __construct_node_hash(__hash, __args);
#endif
        if (size()+1 > __bc * max_load_factor() || __bc == 0)
        {
            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
                           size_type(ceil(float(size() + 1) / max_load_factor()))));
            __bc = bucket_count();
            __chash = __constrain_hash(__hash, __bc);
        }
        // insert_after __bucket_list_[__chash], or __first_node if bucket is null
        __next_pointer __pn = __bucket_list_[__chash];
        if (__pn == nullptr)
        {
            __pn = __p1_.first().__ptr();
            __h->__next_ = __pn->__next_;
            __pn->__next_ = __h.get()->__ptr();
            // fix up __bucket_list_
            __bucket_list_[__chash] = __pn;
            if (__h->__next_ != nullptr)
                __bucket_list_[__constrain_hash(__h->__next_->__hash(), __bc)]
                    = __h.get()->__ptr();
        }
        else
        {
            __h->__next_ = __pn->__next_;
            __pn->__next_ = static_cast<__next_pointer>(__h.get());
        }
        __nd = static_cast<__next_pointer>(__h.release());
        // increment size
        ++size();
        __inserted = true;
    }
__done:
#if _LIBCPP_DEBUG_LEVEL >= 2
    return pair<iterator, bool>(iterator(__nd, this), __inserted);
#else
    return pair<iterator, bool>(iterator(__nd), __inserted);
#endif
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class... _Args>
pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_impl(_Args&&... __args)
{
    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
    pair<iterator, bool> __r = __node_insert_unique(__h.get());
    if (__r.second)
        __h.release();
    return __r;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class... _Args>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_multi(_Args&&... __args)
{
    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
    iterator __r = __node_insert_multi(__h.get());
    __h.release();
    return __r;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class... _Args>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_hint_multi(
        const_iterator __p, _Args&&... __args)
{
#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
        " referring to this unordered container");
#endif
    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
    iterator __r = __node_insert_multi(__p, __h.get());
    __h.release();
    return __r;
}

#else // _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(const __container_value_type& __x)
{
    __node_holder __h = __construct_node(__x);
    iterator __r = __node_insert_multi(__h.get());
    __h.release();
    return __r;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(const_iterator __p,
                                                         const __container_value_type& __x)
{
#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
        "unordered container::insert(const_iterator, lvalue) called with an iterator not"
        " referring to this unordered container");
#endif
    __node_holder __h = __construct_node(__x);
    iterator __r = __node_insert_multi(__p, __h.get());
    __h.release();
    return __r;
}

#endif  // _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::rehash(size_type __n)
{
    if (__n == 1)
        __n = 2;
    else if (__n & (__n - 1))
        __n = __next_prime(__n);
    size_type __bc = bucket_count();
    if (__n > __bc)
        __rehash(__n);
    else if (__n < __bc)
    {
        __n = _VSTD::max<size_type>
              (
                  __n,
                  __is_hash_power2(__bc) ? __next_hash_pow2(size_t(ceil(float(size()) / max_load_factor()))) :
                                           __next_prime(size_t(ceil(float(size()) / max_load_factor())))
              );
        if (__n < __bc)
            __rehash(__n);
    }
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__rehash(size_type __nbc)
{
#if _LIBCPP_DEBUG_LEVEL >= 2
    __get_db()->__invalidate_all(this);
#endif  // _LIBCPP_DEBUG_LEVEL >= 2
    __pointer_allocator& __npa = __bucket_list_.get_deleter().__alloc();
    __bucket_list_.reset(__nbc > 0 ?
                      __pointer_alloc_traits::allocate(__npa, __nbc) : nullptr);
    __bucket_list_.get_deleter().size() = __nbc;
    if (__nbc > 0)
    {
        for (size_type __i = 0; __i < __nbc; ++__i)
            __bucket_list_[__i] = nullptr;
        __next_pointer __pp = __p1_.first().__ptr();
        __next_pointer __cp = __pp->__next_;
        if (__cp != nullptr)
        {
            size_type __chash = __constrain_hash(__cp->__hash(), __nbc);
            __bucket_list_[__chash] = __pp;
            size_type __phash = __chash;
            for (__pp = __cp, __cp = __cp->__next_; __cp != nullptr;
                                                           __cp = __pp->__next_)
            {
                __chash = __constrain_hash(__cp->__hash(), __nbc);
                if (__chash == __phash)
                    __pp = __cp;
                else
                {
                    if (__bucket_list_[__chash] == nullptr)
                    {
                        __bucket_list_[__chash] = __pp;
                        __pp = __cp;
                        __phash = __chash;
                    }
                    else
                    {
                        __next_pointer __np = __cp;
                        for (; __np->__next_ != nullptr &&
                               key_eq()(__cp->__upcast()->__value_,
                                        __np->__next_->__upcast()->__value_);
                                                           __np = __np->__next_)
                            ;
                        __pp->__next_ = __np->__next_;
                        __np->__next_ = __bucket_list_[__chash]->__next_;
                        __bucket_list_[__chash]->__next_ = __cp;

                    }
                }
            }
        }
    }
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k)
{
    size_t __hash = hash_function()(__k);
    size_type __bc = bucket_count();
    if (__bc != 0)
    {
        size_t __chash = __constrain_hash(__hash, __bc);
        __next_pointer __nd = __bucket_list_[__chash];
        if (__nd != nullptr)
        {
            for (__nd = __nd->__next_; __nd != nullptr &&
                (__nd->__hash() == __hash
                  || __constrain_hash(__nd->__hash(), __bc) == __chash);
                                                           __nd = __nd->__next_)
            {
                if ((__nd->__hash() == __hash)
                    && key_eq()(__nd->__upcast()->__value_, __k))
#if _LIBCPP_DEBUG_LEVEL >= 2
                    return iterator(__nd, this);
#else
                    return iterator(__nd);
#endif
            }
        }
    }
    return end();
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k) const
{
    size_t __hash = hash_function()(__k);
    size_type __bc = bucket_count();
    if (__bc != 0)
    {
        size_t __chash = __constrain_hash(__hash, __bc);
        __next_pointer __nd = __bucket_list_[__chash];
        if (__nd != nullptr)
        {
            for (__nd = __nd->__next_; __nd != nullptr &&
                (__hash == __nd->__hash()
                    || __constrain_hash(__nd->__hash(), __bc) == __chash);
                                                           __nd = __nd->__next_)
            {
                if ((__nd->__hash() == __hash)
                    && key_eq()(__nd->__upcast()->__value_, __k))
#if _LIBCPP_DEBUG_LEVEL >= 2
                    return const_iterator(__nd, this);
#else
                    return const_iterator(__nd);
#endif
            }
        }

    }
    return end();
}

#ifndef _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class ..._Args>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(_Args&& ...__args)
{
    static_assert(!__is_hash_value_type<_Args...>::value,
                  "Construct cannot be called with a hash value type");
    __node_allocator& __na = __node_alloc();
    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...);
    __h.get_deleter().__value_constructed = true;
    __h->__hash_ = hash_function()(__h->__value_);
    __h->__next_ = nullptr;
    return __h;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _First, class ..._Rest>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node_hash(
    size_t __hash, _First&& __f, _Rest&& ...__rest)
{
    static_assert(!__is_hash_value_type<_First, _Rest...>::value,
                  "Construct cannot be called with a hash value type");
    __node_allocator& __na = __node_alloc();
    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_),
                             _VSTD::forward<_First>(__f),
                             _VSTD::forward<_Rest>(__rest)...);
    __h.get_deleter().__value_constructed = true;
    __h->__hash_ = __hash;
    __h->__next_ = nullptr;
    return __h;
}

#else  // _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(const __container_value_type& __v)
{
    __node_allocator& __na = __node_alloc();
    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), __v);
    __h.get_deleter().__value_constructed = true;
    __h->__hash_ = hash_function()(__h->__value_);
    __h->__next_ = nullptr;
    return _LIBCPP_EXPLICIT_MOVE(__h);  // explicitly moved for C++03
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node_hash(size_t __hash,
                                                                const __container_value_type& __v)
{
    __node_allocator& __na = __node_alloc();
    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), __v);
    __h.get_deleter().__value_constructed = true;
    __h->__hash_ = __hash;
    __h->__next_ = nullptr;
    return _LIBCPP_EXPLICIT_MOVE(__h);  // explicitly moved for C++03
}

#endif  // _LIBCPP_CXX03_LANG

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __p)
{
    __next_pointer __np = __p.__node_;
#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
        "unordered container erase(iterator) called with an iterator not"
        " referring to this container");
    _LIBCPP_ASSERT(__p != end(),
        "unordered container erase(iterator) called with a non-dereferenceable iterator");
    iterator __r(__np, this);
#else
    iterator __r(__np);
#endif
    ++__r;
    remove(__p);
    return __r;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __first,
                                                const_iterator __last)
{
#if _LIBCPP_DEBUG_LEVEL >= 2
    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
        "unodered container::erase(iterator, iterator) called with an iterator not"
        " referring to this unodered container");
    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__last) == this,
        "unodered container::erase(iterator, iterator) called with an iterator not"
        " referring to this unodered container");
#endif
    for (const_iterator __p = __first; __first != __last; __p = __first)
    {
        ++__first;
        erase(__p);
    }
    __next_pointer __np = __last.__node_;
#if _LIBCPP_DEBUG_LEVEL >= 2
    return iterator (__np, this);
#else
    return iterator (__np);
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_unique(const _Key& __k)
{
    iterator __i = find(__k);
    if (__i == end())
        return 0;
    erase(__i);
    return 1;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_multi(const _Key& __k)
{
    size_type __r = 0;
    iterator __i = find(__k);
    if (__i != end())
    {
        iterator __e = end();
        do
        {
            erase(__i++);
            ++__r;
        } while (__i != __e && key_eq()(*__i, __k));
    }
    return __r;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
__hash_table<_Tp, _Hash, _Equal, _Alloc>::remove(const_iterator __p) _NOEXCEPT
{
    // current node
    __next_pointer __cn = __p.__node_;
    size_type __bc = bucket_count();
    size_t __chash = __constrain_hash(__cn->__hash(), __bc);
    // find previous node
    __next_pointer __pn = __bucket_list_[__chash];
    for (; __pn->__next_ != __cn; __pn = __pn->__next_)
        ;
    // Fix up __bucket_list_
        // if __pn is not in same bucket (before begin is not in same bucket) &&
        //    if __cn->__next_ is not in same bucket (nullptr is not in same bucket)
    if (__pn == __p1_.first().__ptr()
            || __constrain_hash(__pn->__hash(), __bc) != __chash)
    {
        if (__cn->__next_ == nullptr
            || __constrain_hash(__cn->__next_->__hash(), __bc) != __chash)
            __bucket_list_[__chash] = nullptr;
    }
        // if __cn->__next_ is not in same bucket (nullptr is in same bucket)
    if (__cn->__next_ != nullptr)
    {
        size_t __nhash = __constrain_hash(__cn->__next_->__hash(), __bc);
        if (__nhash != __chash)
            __bucket_list_[__nhash] = __pn;
    }
    // remove __cn
    __pn->__next_ = __cn->__next_;
    __cn->__next_ = nullptr;
    --size();
#if _LIBCPP_DEBUG_LEVEL >= 2
    __c_node* __c = __get_db()->__find_c_and_lock(this);
    for (__i_node** __dp = __c->end_; __dp != __c->beg_; )
    {
        --__dp;
        iterator* __i = static_cast<iterator*>((*__dp)->__i_);
        if (__i->__node_ == __cn)
        {
            (*__dp)->__c_ = nullptr;
            if (--__c->end_ != __dp)
                memmove(__dp, __dp+1, (__c->end_ - __dp)*sizeof(__i_node*));
        }
    }
    __get_db()->unlock();
#endif
    return __node_holder(__cn->__upcast(), _Dp(__node_alloc(), true));
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
inline
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_unique(const _Key& __k) const
{
    return static_cast<size_type>(find(__k) != end());
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_multi(const _Key& __k) const
{
    size_type __r = 0;
    const_iterator __i = find(__k);
    if (__i != end())
    {
        const_iterator __e = end();
        do
        {
            ++__i;
            ++__r;
        } while (__i != __e && key_eq()(*__i, __k));
    }
    return __r;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
        const _Key& __k)
{
    iterator __i = find(__k);
    iterator __j = __i;
    if (__i != end())
        ++__j;
    return pair<iterator, iterator>(__i, __j);
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
        const _Key& __k) const
{
    const_iterator __i = find(__k);
    const_iterator __j = __i;
    if (__i != end())
        ++__j;
    return pair<const_iterator, const_iterator>(__i, __j);
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
        const _Key& __k)
{
    iterator __i = find(__k);
    iterator __j = __i;
    if (__i != end())
    {
        iterator __e = end();
        do
        {
            ++__j;
        } while (__j != __e && key_eq()(*__j, __k));
    }
    return pair<iterator, iterator>(__i, __j);
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
template <class _Key>
pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
        const _Key& __k) const
{
    const_iterator __i = find(__k);
    const_iterator __j = __i;
    if (__i != end())
    {
        const_iterator __e = end();
        do
        {
            ++__j;
        } while (__j != __e && key_eq()(*__j, __k));
    }
    return pair<const_iterator, const_iterator>(__i, __j);
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
void
__hash_table<_Tp, _Hash, _Equal, _Alloc>::swap(__hash_table& __u)
#if _LIBCPP_STD_VER <= 11
    _NOEXCEPT_DEBUG_(
        __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
        && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
              || __is_nothrow_swappable<__pointer_allocator>::value)
        && (!__node_traits::propagate_on_container_swap::value
              || __is_nothrow_swappable<__node_allocator>::value)
            )
#else
  _NOEXCEPT_DEBUG_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value)
#endif
{
    _LIBCPP_ASSERT(__node_traits::propagate_on_container_swap::value ||
                   this->__node_alloc() == __u.__node_alloc(),
                   "list::swap: Either propagate_on_container_swap must be true"
                   " or the allocators must compare equal");
    {
    __node_pointer_pointer __npp = __bucket_list_.release();
    __bucket_list_.reset(__u.__bucket_list_.release());
    __u.__bucket_list_.reset(__npp);
    }
    _VSTD::swap(__bucket_list_.get_deleter().size(), __u.__bucket_list_.get_deleter().size());
    __swap_allocator(__bucket_list_.get_deleter().__alloc(),
             __u.__bucket_list_.get_deleter().__alloc());
    __swap_allocator(__node_alloc(), __u.__node_alloc());
    _VSTD::swap(__p1_.first().__next_, __u.__p1_.first().__next_);
    __p2_.swap(__u.__p2_);
    __p3_.swap(__u.__p3_);
    if (size() > 0)
        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
            __p1_.first().__ptr();
    if (__u.size() > 0)
        __u.__bucket_list_[__constrain_hash(__u.__p1_.first().__next_->__hash(), __u.bucket_count())] =
            __u.__p1_.first().__ptr();
#if _LIBCPP_DEBUG_LEVEL >= 2
    __get_db()->swap(this, &__u);
#endif
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
__hash_table<_Tp, _Hash, _Equal, _Alloc>::bucket_size(size_type __n) const
{
    _LIBCPP_ASSERT(__n < bucket_count(),
        "unordered container::bucket_size(n) called with n >= bucket_count()");
    __next_pointer __np = __bucket_list_[__n];
    size_type __bc = bucket_count();
    size_type __r = 0;
    if (__np != nullptr)
    {
        for (__np = __np->__next_; __np != nullptr &&
                                   __constrain_hash(__np->__hash(), __bc) == __n;
                                                    __np = __np->__next_, ++__r)
            ;
    }
    return __r;
}

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

#if _LIBCPP_DEBUG_LEVEL >= 2

template <class _Tp, class _Hash, class _Equal, class _Alloc>
bool
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__dereferenceable(const const_iterator* __i) const
{
    return __i->__node_ != nullptr;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
bool
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__decrementable(const const_iterator*) const
{
    return false;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
bool
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__addable(const const_iterator*, ptrdiff_t) const
{
    return false;
}

template <class _Tp, class _Hash, class _Equal, class _Alloc>
bool
__hash_table<_Tp, _Hash, _Equal, _Alloc>::__subscriptable(const const_iterator*, ptrdiff_t) const
{
    return false;
}

#endif  // _LIBCPP_DEBUG_LEVEL >= 2

_LIBCPP_END_NAMESPACE_STD

_LIBCPP_POP_MACROS

#endif  // _LIBCPP__HASH_TABLE