aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/cxxsupp/libcxx/include/__config
blob: 99746b72f56ac51c91b2f9240ce74e00e6916fea (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___CONFIG
#define _LIBCPP___CONFIG
#include <__wrappers_config>

#if defined(_MSC_VER) && !defined(__clang__)
#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#    define _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
#  endif
#endif

#ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
#  pragma GCC system_header
#endif

// Move outside #ifdef __cplusplus because this needs to work in both C and C++ headers.
#if defined(__apple_build_version__)
#  define _LIBCPP_COMPILER_CLANG_BASED
#  define _LIBCPP_APPLE_CLANG_VER (__apple_build_version__ / 10000)
#elif defined(__clang__)
#define _LIBCPP_COMPILER_CLANG
#  define _LIBCPP_COMPILER_CLANG_BASED
#  define _LIBCPP_CLANG_VER (__clang_major__ * 100 + __clang_minor__)
#elif defined(__GNUC__)
#define _LIBCPP_COMPILER_GCC
#elif defined(_MSC_VER)
#define _LIBCPP_COMPILER_MSVC

#if _MSVC_LANG == 201705L
#  define _LIBCPP_STD_VER 20
#elif _MSVC_LANG == 201703L
#  define _LIBCPP_STD_VER 17
#else
#  define _LIBCPP_STD_VER 14
#endif

#define Y_UCRT_INCLUDE_NEXT(x) <Y_UCRT_INCLUDE/x>
#define Y_MSVC_INCLUDE_NEXT(x) <Y_MSVC_INCLUDE/x>
#elif defined(__IBMCPP__)
#define _LIBCPP_COMPILER_IBM
#endif

#ifdef __cplusplus

#define _LIBCPP_VERSION 15000

#if __STDC_HOSTED__ == 0
#  define _LIBCPP_FREESTANDING
#endif

#ifndef _LIBCPP_STD_VER
#  if  __cplusplus <= 201103L
#    define _LIBCPP_STD_VER 11
#  elif __cplusplus <= 201402L
#    define _LIBCPP_STD_VER 14
#  elif __cplusplus <= 201703L
#    define _LIBCPP_STD_VER 17
#  elif __cplusplus <= 202002L
#    define _LIBCPP_STD_VER 20
#  else
#    define _LIBCPP_STD_VER 22  // current year, or date of c++2b ratification
#  endif
#endif // _LIBCPP_STD_VER

#if defined(__ELF__)
#  define _LIBCPP_OBJECT_FORMAT_ELF   1
#elif defined(__MACH__)
#  define _LIBCPP_OBJECT_FORMAT_MACHO 1
#elif defined(_WIN32) || defined(__CYGWIN__)
#  define _LIBCPP_OBJECT_FORMAT_COFF  1
#elif defined(__wasm__)
#  define _LIBCPP_OBJECT_FORMAT_WASM  1
#else
   // ... add new file formats here ...
#endif

#if _LIBCPP_ABI_VERSION >= 2
// Change short string representation so that string data starts at offset 0,
// improving its alignment in some cases.
#  define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
// Fix deque iterator type in order to support incomplete types.
#  define _LIBCPP_ABI_INCOMPLETE_TYPES_IN_DEQUE
// Fix undefined behavior in how std::list stores its linked nodes.
#  define _LIBCPP_ABI_LIST_REMOVE_NODE_POINTER_UB
// Fix undefined behavior in  how __tree stores its end and parent nodes.
#  define _LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB
// Fix undefined behavior in how __hash_table stores its pointer types.
#  define _LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB
#  define _LIBCPP_ABI_FORWARD_LIST_REMOVE_NODE_POINTER_UB
#  define _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE
// Define a key function for `bad_function_call` in the library, to centralize
// its vtable and typeinfo to libc++ rather than having all other libraries
// using that class define their own copies.
#  define _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
// Override the default return value of exception::what() for
// bad_function_call::what() with a string that is specific to
// bad_function_call (see http://wg21.link/LWG2233). This is an ABI break
// because it changes the vtable layout of bad_function_call.
#  define _LIBCPP_ABI_BAD_FUNCTION_CALL_GOOD_WHAT_MESSAGE
// Enable optimized version of __do_get_(un)signed which avoids redundant copies.
#  define _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
// In C++20 and later, don't derive std::plus from std::binary_function,
// nor std::negate from std::unary_function.
#  define _LIBCPP_ABI_NO_BINDER_BASES
// Give reverse_iterator<T> one data member of type T, not two.
// Also, in C++17 and later, don't derive iterator types from std::iterator.
#  define _LIBCPP_ABI_NO_ITERATOR_BASES
// Use the smallest possible integer type to represent the index of the variant.
// Previously libc++ used "unsigned int" exclusively.
#  define _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION
// Unstable attempt to provide a more optimized std::function
#ifdef __EMSCRIPTEN__
// XXX EMSCRIPTEN https://github.com/emscripten-core/emscripten/issues/11022
//#    define _LIBCPP_ABI_OPTIMIZED_FUNCTION
#else
#  define _LIBCPP_ABI_OPTIMIZED_FUNCTION
#endif
// All the regex constants must be distinct and nonzero.
#  define _LIBCPP_ABI_REGEX_CONSTANTS_NONZERO
// Use raw pointers, not wrapped ones, for std::span's iterator type.
#  define _LIBCPP_ABI_SPAN_POINTER_ITERATORS
// Re-worked external template instantiations for std::string with a focus on
// performance and fast-path inlining.
#  define _LIBCPP_ABI_STRING_OPTIMIZED_EXTERNAL_INSTANTIATION
// Enable clang::trivial_abi on std::unique_ptr.
#  define _LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI
// Enable clang::trivial_abi on std::shared_ptr and std::weak_ptr
#  define _LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI
// std::random_device holds some state when it uses an implementation that gets
// entropy from a file (see _LIBCPP_USING_DEV_RANDOM). When switching from this
// implementation to another one on a platform that has already shipped
// std::random_device, one needs to retain the same object layout to remain ABI
// compatible. This switch removes these workarounds for platforms that don't care
// about ABI compatibility.
#  define _LIBCPP_ABI_NO_RANDOM_DEVICE_COMPATIBILITY_LAYOUT
// Remove basic_string common base
#  define _LIBCPP_ABI_DO_NOT_EXPORT_BASIC_STRING_COMMON
// Remove vector base class
#  define _LIBCPP_ABI_DO_NOT_EXPORT_VECTOR_BASE_COMMON
#elif _LIBCPP_ABI_VERSION == 1
#  if !defined(_LIBCPP_OBJECT_FORMAT_COFF)
// Enable compiling copies of now inline methods into the dylib to support
// applications compiled against older libraries. This is unnecessary with
// COFF dllexport semantics, since dllexport forces a non-inline definition
// of inline functions to be emitted anyway. Our own non-inline copy would
// conflict with the dllexport-emitted copy, so we disable it.
#    define _LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS
#  endif
// Feature macros for disabling pre ABI v1 features. All of these options
// are deprecated.
#  if defined(__FreeBSD__)
#    define _LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR
#  endif
#endif

#if defined(_LIBCPP_BUILDING_LIBRARY) || _LIBCPP_ABI_VERSION >= 2
// Enable additional explicit instantiations of iostreams components. This
// reduces the number of weak definitions generated in programs that use
// iostreams by providing a single strong definition in the shared library.
# define _LIBCPP_ABI_ENABLE_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1

// Define a key function for `bad_function_call` in the library, to centralize
// its vtable and typeinfo to libc++ rather than having all other libraries
// using that class define their own copies.
#  define _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
#endif

#define _LIBCPP_TOSTRING2(x) #x
#define _LIBCPP_TOSTRING(x) _LIBCPP_TOSTRING2(x)

#if __cplusplus < 201103L && !defined(_LIBCPP_COMPILER_MSVC)
#define _LIBCPP_CXX03_LANG
#endif

#ifndef __has_attribute
#define __has_attribute(__x) 0
#endif

#ifndef __has_builtin
#define __has_builtin(__x) 0
#endif

#ifndef __has_extension
#define __has_extension(__x) 0
#endif

#ifndef __has_feature
#define __has_feature(__x) 0
#endif

#ifndef __has_cpp_attribute
#define __has_cpp_attribute(__x) 0
#endif

// '__is_identifier' returns '0' if '__x' is a reserved identifier provided by
// the compiler and '1' otherwise.
#ifndef __is_identifier
#define __is_identifier(__x) 1
#endif

#ifndef __has_declspec_attribute
#define __has_declspec_attribute(__x) 0
#endif

#define __has_keyword(__x) !(__is_identifier(__x))

#ifndef __has_include
#define __has_include(...) 0
#endif

#if defined(_LIBCPP_COMPILER_GCC) && __cplusplus < 201103L
#error "libc++ does not support using GCC with C++03. Please enable C++11"
#endif

// FIXME: ABI detection should be done via compiler builtin macros. This
// is just a placeholder until Clang implements such macros. For now assume
// that Windows compilers pretending to be MSVC++ target the Microsoft ABI,
// and allow the user to explicitly specify the ABI to handle cases where this
// heuristic falls short.
#if defined(_LIBCPP_ABI_FORCE_ITANIUM) && defined(_LIBCPP_ABI_FORCE_MICROSOFT)
#  error "Only one of _LIBCPP_ABI_FORCE_ITANIUM and _LIBCPP_ABI_FORCE_MICROSOFT can be defined"
#elif defined(_LIBCPP_ABI_FORCE_ITANIUM)
#  define _LIBCPP_ABI_ITANIUM
#elif defined(_LIBCPP_ABI_FORCE_MICROSOFT)
#  define _LIBCPP_ABI_MICROSOFT
#else
#  if defined(_WIN32) && defined(_MSC_VER)
#    define _LIBCPP_ABI_MICROSOFT
#  else
#    define _LIBCPP_ABI_ITANIUM
#  endif
#endif

#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
# define _LIBCPP_ABI_VCRUNTIME
#endif

// Need to detect which libc we're using if we're on Linux.
#if defined(__linux__)
#  include <features.h>
#  if defined(__GLIBC_PREREQ)
#    define _LIBCPP_GLIBC_PREREQ(a, b) __GLIBC_PREREQ(a, b)
#  else
#    define _LIBCPP_GLIBC_PREREQ(a, b) 0
#  endif // defined(__GLIBC_PREREQ)
#endif // defined(__linux__)

#if defined(__MVS__)
#  include <features.h> // for __NATIVE_ASCII_F
#endif

#ifdef __LITTLE_ENDIAN__
#  if __LITTLE_ENDIAN__
#    define _LIBCPP_LITTLE_ENDIAN
#  endif  // __LITTLE_ENDIAN__
#endif // __LITTLE_ENDIAN__

#ifdef __BIG_ENDIAN__
#  if __BIG_ENDIAN__
#    define _LIBCPP_BIG_ENDIAN
#  endif  // __BIG_ENDIAN__
#endif // __BIG_ENDIAN__

#ifdef __BYTE_ORDER__
#  if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#    define _LIBCPP_LITTLE_ENDIAN
#  elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
#    define _LIBCPP_BIG_ENDIAN
#  endif // __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
#endif // __BYTE_ORDER__

#ifdef __FreeBSD__
#  include <sys/endian.h>
#  include <osreldate.h>
#  if _BYTE_ORDER == _LITTLE_ENDIAN
#    define _LIBCPP_LITTLE_ENDIAN
#  else  // _BYTE_ORDER == _LITTLE_ENDIAN
#    define _LIBCPP_BIG_ENDIAN
#  endif  // _BYTE_ORDER == _LITTLE_ENDIAN
#endif // __FreeBSD__

#if defined(__NetBSD__) || defined(__OpenBSD__)
#  include <sys/endian.h>
#  if _BYTE_ORDER == _LITTLE_ENDIAN
#    define _LIBCPP_LITTLE_ENDIAN
#  else  // _BYTE_ORDER == _LITTLE_ENDIAN
#    define _LIBCPP_BIG_ENDIAN
#  endif  // _BYTE_ORDER == _LITTLE_ENDIAN
#endif // defined(__NetBSD__) || defined(__OpenBSD__)

#if defined(_WIN32)
#  define _LIBCPP_WIN32API
#  define _LIBCPP_LITTLE_ENDIAN
#  define _LIBCPP_SHORT_WCHAR   1
// Both MinGW and native MSVC provide a "MSVC"-like environment
#  define _LIBCPP_MSVCRT_LIKE
// If mingw not explicitly detected, assume using MS C runtime only if
// a MS compatibility version is specified.
#  if defined(_MSC_VER) && !defined(__MINGW32__)
#    define _LIBCPP_MSVCRT // Using Microsoft's C Runtime library
#  endif
#  if (defined(_M_AMD64) || defined(__x86_64__)) || (defined(_M_ARM) || defined(__arm__))
#    define _LIBCPP_HAS_BITSCAN64
#  endif
#  define _LIBCPP_HAS_OPEN_WITH_WCHAR
#endif // defined(_WIN32)

#ifdef __sun__
#  include <sys/isa_defs.h>
#  ifdef _LITTLE_ENDIAN
#    define _LIBCPP_LITTLE_ENDIAN
#  else
#    define _LIBCPP_BIG_ENDIAN
#  endif
#endif // __sun__

#if defined(_AIX) && !defined(__64BIT__)
   // The size of wchar is 2 byte on 32-bit mode on AIX.
#  define _LIBCPP_SHORT_WCHAR   1
#endif

// Libc++ supports various implementations of std::random_device.
//
// _LIBCPP_USING_DEV_RANDOM
//      Read entropy from the given file, by default `/dev/urandom`.
//      If a token is provided, it is assumed to be the path to a file
//      to read entropy from. This is the default behavior if nothing
//      else is specified. This implementation requires storing state
//      inside `std::random_device`.
//
// _LIBCPP_USING_ARC4_RANDOM
//      Use arc4random(). This allows obtaining random data even when
//      using sandboxing mechanisms. On some platforms like Apple, this
//      is the recommended source of entropy for user-space programs.
//      When this option is used, the token passed to `std::random_device`'s
//      constructor *must* be "/dev/urandom" -- anything else is an error.
//
// _LIBCPP_USING_GETENTROPY
//      Use getentropy().
//      When this option is used, the token passed to `std::random_device`'s
//      constructor *must* be "/dev/urandom" -- anything else is an error.
//
// _LIBCPP_USING_FUCHSIA_CPRNG
//      Use Fuchsia's zx_cprng_draw() system call, which is specified to
//      deliver high-quality entropy and cannot fail.
//      When this option is used, the token passed to `std::random_device`'s
//      constructor *must* be "/dev/urandom" -- anything else is an error.
//
// _LIBCPP_USING_NACL_RANDOM
//      NaCl's sandbox (which PNaCl also runs in) doesn't allow filesystem access,
//      including accesses to the special files under `/dev`. This implementation
//      uses the NaCL syscall `nacl_secure_random_init()` to get entropy.
//      When this option is used, the token passed to `std::random_device`'s
//      constructor *must* be "/dev/urandom" -- anything else is an error.
//
// _LIBCPP_USING_WIN32_RANDOM
//      Use rand_s(), for use on Windows.
//      When this option is used, the token passed to `std::random_device`'s
//      constructor *must* be "/dev/urandom" -- anything else is an error.
#if defined(__OpenBSD__) || defined(__APPLE__)
#  define _LIBCPP_USING_ARC4_RANDOM
#elif defined(__wasi__)
#  define _LIBCPP_USING_GETENTROPY
#elif defined(__Fuchsia__)
#  define _LIBCPP_USING_FUCHSIA_CPRNG
#elif defined(__native_client__)
#  define _LIBCPP_USING_NACL_RANDOM
#elif defined(_LIBCPP_WIN32API)
#  define _LIBCPP_USING_WIN32_RANDOM
#else
#  define _LIBCPP_USING_DEV_RANDOM
#endif

#if !defined(_LIBCPP_LITTLE_ENDIAN) && !defined(_LIBCPP_BIG_ENDIAN)
#  include <endian.h>
#  if __BYTE_ORDER == __LITTLE_ENDIAN
#    define _LIBCPP_LITTLE_ENDIAN
#  elif __BYTE_ORDER == __BIG_ENDIAN
#    define _LIBCPP_BIG_ENDIAN
#  else  // __BYTE_ORDER == __BIG_ENDIAN
#    error unable to determine endian
#  endif
#endif // !defined(_LIBCPP_LITTLE_ENDIAN) && !defined(_LIBCPP_BIG_ENDIAN)

#if __has_attribute(__no_sanitize__) && !defined(_LIBCPP_COMPILER_GCC)
#  define _LIBCPP_NO_CFI __attribute__((__no_sanitize__("cfi")))
#else
#  define _LIBCPP_NO_CFI
#endif

#ifndef _LIBCPP_CXX03_LANG
# define _LIBCPP_ALIGNOF(_Tp) alignof(_Tp)
#elif defined(_LIBCPP_COMPILER_CLANG_BASED)
# define _LIBCPP_ALIGNOF(_Tp) _Alignof(_Tp)
#else
# error "We don't know a correct way to implement alignof(T) in C++03 outside of Clang"
#endif

#define _LIBCPP_PREFERRED_ALIGNOF(_Tp) __alignof(_Tp)

#if defined(_LIBCPP_COMPILER_CLANG_BASED)

#if defined(__APPLE__) && !defined(__i386__) && !defined(__x86_64__) &&       \
    (!defined(__arm__) || __ARM_ARCH_7K__ >= 2)
#  define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
#endif

#if __has_feature(cxx_alignas)
#  define _ALIGNAS_TYPE(x) alignas(x)
#  define _ALIGNAS(x) alignas(x)
#else
#  define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
#  define _ALIGNAS(x) __attribute__((__aligned__(x)))
#endif

#if __cplusplus < 201103L
typedef __char16_t char16_t;
typedef __char32_t char32_t;
#endif

#if !__has_feature(cxx_exceptions)
#  define _LIBCPP_NO_EXCEPTIONS
#endif

#if __has_feature(cxx_attributes)
#  define _LIBCPP_NORETURN [[noreturn]]
#else
#  define _LIBCPP_NORETURN __attribute__ ((noreturn))
#endif

#ifdef _LIBCPP_CXX03_LANG
# define nullptr __nullptr
#endif

// Objective-C++ features (opt-in)
#if __has_feature(objc_arc)
#define _LIBCPP_HAS_OBJC_ARC
#endif

#if __has_feature(objc_arc_weak)
#define _LIBCPP_HAS_OBJC_ARC_WEAK
#endif

#if __has_extension(blocks)
#  define _LIBCPP_HAS_EXTENSION_BLOCKS
#endif

#if defined(_LIBCPP_HAS_EXTENSION_BLOCKS) && defined(__APPLE__)
#  define _LIBCPP_HAS_BLOCKS_RUNTIME
#endif

#if !(__has_feature(cxx_noexcept))
#define _LIBCPP_HAS_NO_NOEXCEPT
#endif

#if !__has_feature(address_sanitizer)
#define _LIBCPP_HAS_NO_ASAN
#endif

// Allow for build-time disabling of unsigned integer sanitization
#if __has_attribute(no_sanitize)
#define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute__((__no_sanitize__("unsigned-integer-overflow")))
#endif

#define _LIBCPP_ALWAYS_INLINE __attribute__ ((__always_inline__))

#define _LIBCPP_DISABLE_EXTENSION_WARNING __extension__

#elif defined(_LIBCPP_COMPILER_GCC)

#define _ALIGNAS(x) __attribute__((__aligned__(x)))
#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))

#define _LIBCPP_NORETURN __attribute__((noreturn))

#if !defined(__EXCEPTIONS)
#  define _LIBCPP_NO_EXCEPTIONS
#endif

#if !defined(__SANITIZE_ADDRESS__)
#define _LIBCPP_HAS_NO_ASAN
#endif

#define _LIBCPP_ALWAYS_INLINE __attribute__ ((__always_inline__))

#define _LIBCPP_DISABLE_EXTENSION_WARNING __extension__

#elif defined(_LIBCPP_COMPILER_MSVC)

#define _LIBCPP_WARNING(x) __pragma(message(__FILE__ "(" _LIBCPP_TOSTRING(__LINE__) ") : warning note: " x))

#if _MSC_VER < 1900
#error "MSVC versions prior to Visual Studio 2015 are not supported"
#endif

#define _LIBCPP_HAS_IS_FINAL
#define __alignof__ __alignof
#define _LIBCPP_NORETURN __declspec(noreturn)
#define _ALIGNAS(x) __declspec(align(x))
#define _ALIGNAS_TYPE(x) alignas(x)

#define _LIBCPP_UNDERLYING_TYPE(T) __underlying_type(T)
#define _LIBCPP_IS_LITERAL(T) __is_literal_type(T)
#undef __has_feature
#define __has_feature(x) __has_feature_##x
#define __has_feature_is_standard_layout 1
#define __has_feature_is_trivially_copyable 1
#define __has_feature_is_trivial 1
#define __has_feature_is_pod 1
#define __has_feature_cxx_noexcept 1
#define __has_feature_has_nothrow_assign 1
#define __has_feature_is_union 1
#define __has_feature_is_class 1
#define __has_feature_is_enum 1
#define __has_feature_is_convertible_to 1
#define __has_feature_is_empty 1
#define __has_feature_is_polymorphic 1
#define __has_feature_has_virtual_destructor 1
#define __has_feature_cxx_reference_qualified_functions 1
#define __has_feature_is_constructible 1
#define __has_feature_is_trivially_constructible 1
#define __has_feature_is_trivially_assignable 1
#define __has_feature_is_convertible_to 1
#define __has_feature_has_trivial_constructor 1
#define __has_feature_has_trivial_destructor 1
#define __has_feature_has_nothrow_constructor 1
#define __has_feature_has_nothrow_copy 1
#define __has_feature_cxx_explicit_conversions 1

#undef __has_builtin
#define __has_builtin(x) __has_builtin_##x
#define __has_builtin___builtin_addressof 1
#if defined(_MSC_VER) && defined(__CUDACC__)
    // nvcc fails to compile __builtin_is_constant_evaluated() at the time
#   define _LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED 1
#else
#   define __has_builtin___builtin_is_constant_evaluated 1
#endif

#define _LIBCPP_WEAK

#define _LIBCPP_HAS_NO_ASAN

#define _LIBCPP_ALWAYS_INLINE __forceinline

#define _LIBCPP_HAS_NO_VECTOR_EXTENSION

#define _LIBCPP_DISABLE_EXTENSION_WARNING

#elif defined(_LIBCPP_COMPILER_IBM)

#define _ALIGNAS(x) __attribute__((__aligned__(x)))
#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
#define _ATTRIBUTE(x) __attribute__((x))
#define _LIBCPP_NORETURN __attribute__((noreturn))

#define _LIBCPP_HAS_NO_UNICODE_CHARS

#if defined(_AIX)
#define __MULTILOCALE_API
#endif

#define _LIBCPP_HAS_NO_ASAN

#define _LIBCPP_ALWAYS_INLINE __attribute__ ((__always_inline__))

#define _LIBCPP_HAS_NO_VECTOR_EXTENSION

#define _LIBCPP_DISABLE_EXTENSION_WARNING

#endif // _LIBCPP_COMPILER_[CLANG|GCC|MSVC|IBM]

#if defined(_LIBCPP_OBJECT_FORMAT_COFF)

#ifdef _DLL
#  define _LIBCPP_CRT_FUNC __declspec(dllimport)
#else
#  define _LIBCPP_CRT_FUNC
#endif

#if defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#  define _LIBCPP_DLL_VIS
#  define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
#  define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
#  define _LIBCPP_OVERRIDABLE_FUNC_VIS
#  define _LIBCPP_EXPORTED_FROM_ABI
#elif defined(_LIBCPP_BUILDING_LIBRARY)
#  define _LIBCPP_DLL_VIS __declspec(dllexport)
#  if defined(__MINGW32__)
#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
#    define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
#  else
#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
#    define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS
#  endif
#  define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_DLL_VIS
#  define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllexport)
#else
#  define _LIBCPP_DLL_VIS __declspec(dllimport)
#  define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
#  define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
#  define _LIBCPP_OVERRIDABLE_FUNC_VIS
#  define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllimport)
#endif

#define _LIBCPP_TYPE_VIS            _LIBCPP_DLL_VIS
#define _LIBCPP_FUNC_VIS            _LIBCPP_DLL_VIS
#define _LIBCPP_EXCEPTION_ABI       _LIBCPP_DLL_VIS
#define _LIBCPP_HIDDEN
#define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
#define _LIBCPP_TEMPLATE_VIS
#define _LIBCPP_TEMPLATE_DATA_VIS
#define _LIBCPP_ENUM_VIS

#endif // defined(_LIBCPP_OBJECT_FORMAT_COFF)

#ifndef _LIBCPP_HIDDEN
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#    define _LIBCPP_HIDDEN __attribute__ ((__visibility__("hidden")))
#  else
#    define _LIBCPP_HIDDEN
#  endif
#endif

#ifndef _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
// The inline should be removed once PR32114 is resolved
#    define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS inline _LIBCPP_HIDDEN
#  else
#    define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
#  endif
#endif

#ifndef _LIBCPP_FUNC_VIS
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#    define _LIBCPP_FUNC_VIS __attribute__ ((__visibility__("default")))
#  else
#    define _LIBCPP_FUNC_VIS
#  endif
#endif

#ifndef _LIBCPP_TYPE_VIS
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#    define _LIBCPP_TYPE_VIS __attribute__ ((__visibility__("default")))
#  else
#    define _LIBCPP_TYPE_VIS
#  endif
#endif

#ifndef _LIBCPP_TEMPLATE_VIS
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#    if __has_attribute(__type_visibility__)
#      define _LIBCPP_TEMPLATE_VIS __attribute__ ((__type_visibility__("default")))
#    else
#      define _LIBCPP_TEMPLATE_VIS __attribute__ ((__visibility__("default")))
#    endif
#  else
#    define _LIBCPP_TEMPLATE_VIS
#  endif
#endif

#ifndef _LIBCPP_TEMPLATE_DATA_VIS
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#    define _LIBCPP_TEMPLATE_DATA_VIS __attribute__ ((__visibility__("default")))
#  else
#    define _LIBCPP_TEMPLATE_DATA_VIS
#  endif
#endif

#ifndef _LIBCPP_EXPORTED_FROM_ABI
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#    define _LIBCPP_EXPORTED_FROM_ABI __attribute__((__visibility__("default")))
#  else
#    define _LIBCPP_EXPORTED_FROM_ABI
#  endif
#endif

#ifndef _LIBCPP_OVERRIDABLE_FUNC_VIS
#define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_FUNC_VIS
#endif

#ifndef _LIBCPP_EXCEPTION_ABI
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#    define _LIBCPP_EXCEPTION_ABI __attribute__ ((__visibility__("default")))
#  else
#    define _LIBCPP_EXCEPTION_ABI
#  endif
#endif

#ifndef _LIBCPP_ENUM_VIS
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && __has_attribute(__type_visibility__)
#    define _LIBCPP_ENUM_VIS __attribute__ ((__type_visibility__("default")))
#  else
#    define _LIBCPP_ENUM_VIS
#  endif
#endif

#ifndef _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __attribute__ ((__visibility__("default")))
#  else
#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
#  endif
#endif

#ifndef _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
#define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
#endif

#if __has_attribute(internal_linkage)
#  define _LIBCPP_INTERNAL_LINKAGE __attribute__ ((internal_linkage))
#else
#  define _LIBCPP_INTERNAL_LINKAGE _LIBCPP_ALWAYS_INLINE
#endif

#if __has_attribute(exclude_from_explicit_instantiation)
#  define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION __attribute__ ((__exclude_from_explicit_instantiation__))
#else
   // Try to approximate the effect of exclude_from_explicit_instantiation
   // (which is that entities are not assumed to be provided by explicit
   // template instantiations in the dylib) by always inlining those entities.
#ifdef _LIBCPP_COMPILER_MSVC
#  define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
#else
#  define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE
#endif
#endif

#ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU
#  ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT
#    define _LIBCPP_HIDE_FROM_ABI_PER_TU 0
#  else
#    define _LIBCPP_HIDE_FROM_ABI_PER_TU 1
#  endif
#endif

#ifndef _LIBCPP_HIDE_FROM_ABI
#  if _LIBCPP_HIDE_FROM_ABI_PER_TU
#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_INTERNAL_LINKAGE
#  else
#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
#  endif
#endif

#ifdef _LIBCPP_BUILDING_LIBRARY
#  if _LIBCPP_ABI_VERSION > 1
#    define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
#  else
#    define _LIBCPP_HIDE_FROM_ABI_AFTER_V1
#  endif
#else
#  define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
#endif

// Just so we can migrate to the new macros gradually.
#define _LIBCPP_INLINE_VISIBILITY _LIBCPP_HIDE_FROM_ABI

// Inline namespaces are available in Clang/GCC/MSVC regardless of C++ dialect.
#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std { inline namespace _LIBCPP_ABI_NAMESPACE {
#define _LIBCPP_END_NAMESPACE_STD  } }
#define _VSTD std
_LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_END_NAMESPACE_STD

#if _LIBCPP_STD_VER > 14
#define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM \
  _LIBCPP_BEGIN_NAMESPACE_STD inline namespace __fs { namespace filesystem {
#else
#define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM \
  _LIBCPP_BEGIN_NAMESPACE_STD namespace __fs { namespace filesystem {
#endif

#define _LIBCPP_END_NAMESPACE_FILESYSTEM \
  _LIBCPP_END_NAMESPACE_STD } }

#define _VSTD_FS std::__fs::filesystem

#if __has_attribute(__enable_if__)
#   define _LIBCPP_PREFERRED_OVERLOAD __attribute__ ((__enable_if__(true, "")))
#endif

#ifndef _LIBCPP_HAS_NO_NOEXCEPT
#  define _NOEXCEPT noexcept
#  define _NOEXCEPT_(x) noexcept(x)
#else
#  define _NOEXCEPT throw()
#  define _NOEXCEPT_(x)
#endif

#ifdef _LIBCPP_HAS_NO_UNICODE_CHARS
typedef unsigned short char16_t;
typedef unsigned int   char32_t;
#endif

#ifndef __SIZEOF_INT128__
#define _LIBCPP_HAS_NO_INT128
#endif

#ifdef _LIBCPP_CXX03_LANG
# define static_assert(...) _Static_assert(__VA_ARGS__)
# define decltype(...) __decltype(__VA_ARGS__)
#endif // _LIBCPP_CXX03_LANG

#ifdef _LIBCPP_CXX03_LANG
#  define _LIBCPP_CONSTEXPR
#else
#  define _LIBCPP_CONSTEXPR constexpr
#endif

#ifndef __cpp_consteval
#  define _LIBCPP_CONSTEVAL _LIBCPP_CONSTEXPR
#else
#  define _LIBCPP_CONSTEVAL consteval
#endif

#ifdef __GNUC__
#  define _LIBCPP_NOALIAS __attribute__((__malloc__))
#else
#  define _LIBCPP_NOALIAS
#endif

#if __has_attribute(using_if_exists)
# define _LIBCPP_USING_IF_EXISTS __attribute__((using_if_exists))
#else
# define _LIBCPP_USING_IF_EXISTS
#endif

#ifdef _LIBCPP_CXX03_LANG
#  define _LIBCPP_DECLARE_STRONG_ENUM(x) struct _LIBCPP_TYPE_VIS x { enum __lx
#  define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x) \
     __lx __v_; \
     _LIBCPP_INLINE_VISIBILITY x(__lx __v) : __v_(__v) {} \
     _LIBCPP_INLINE_VISIBILITY explicit x(int __v) : __v_(static_cast<__lx>(__v)) {} \
     _LIBCPP_INLINE_VISIBILITY operator int() const {return __v_;} \
     };
#else  // _LIBCPP_CXX03_LANG
#  define _LIBCPP_DECLARE_STRONG_ENUM(x) enum class _LIBCPP_ENUM_VIS x
#  define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)
#endif // _LIBCPP_CXX03_LANG

// _LIBCPP_DEBUG potential values:
//  - undefined: No assertions. This is the default.
//  - 0:         Basic assertions
//  - 1:         Basic assertions + iterator validity checks + unspecified behavior randomization.
#  if !defined(_LIBCPP_DEBUG)
#    define _LIBCPP_DEBUG_LEVEL 0
#  elif _LIBCPP_DEBUG == 0
#    define _LIBCPP_DEBUG_LEVEL 1
#  elif _LIBCPP_DEBUG == 1
#    define _LIBCPP_DEBUG_LEVEL 2
#  else
#    error Supported values for _LIBCPP_DEBUG are 0 and 1
#  endif

#  if _LIBCPP_DEBUG_LEVEL >= 2 && !defined(_LIBCPP_CXX03_LANG)
#    define _LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY
#  endif

#  if defined(_LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY)
#    if defined(_LIBCPP_CXX03_LANG)
#      error Support for unspecified stability is only for C++11 and higher
#    endif
#    define _LIBCPP_DEBUG_RANDOMIZE_RANGE(__first, __last)                                                             \
      do {                                                                                                             \
        if (!__builtin_is_constant_evaluated())                                                                        \
          _VSTD::shuffle(__first, __last, __libcpp_debug_randomizer());                                                \
      } while (false)
#  else
#    define _LIBCPP_DEBUG_RANDOMIZE_RANGE(__first, __last)                                                             \
      do {                                                                                                             \
      } while (false)
#  endif

// Libc++ allows disabling extern template instantiation declarations by
// means of users defining _LIBCPP_DISABLE_EXTERN_TEMPLATE.
//
// Furthermore, when the Debug mode is enabled, we disable extern declarations
// when building user code because we don't want to use the functions compiled
// in the library, which might not have had the debug mode enabled when built.
// However, some extern declarations need to be used, because code correctness
// depends on it (several instances in <locale>). Those special declarations
// are declared with _LIBCPP_EXTERN_TEMPLATE_EVEN_IN_DEBUG_MODE, which is enabled
// even when the debug mode is enabled.
#if defined(_LIBCPP_DISABLE_EXTERN_TEMPLATE)
#   define _LIBCPP_EXTERN_TEMPLATE(...) /* nothing */
#   define _LIBCPP_EXTERN_TEMPLATE_EVEN_IN_DEBUG_MODE(...) /* nothing */
#elif _LIBCPP_DEBUG_LEVEL >= 1 && !defined(_LIBCPP_BUILDING_LIBRARY)
#   define _LIBCPP_EXTERN_TEMPLATE(...) /* nothing */
#   define _LIBCPP_EXTERN_TEMPLATE_EVEN_IN_DEBUG_MODE(...) extern template __VA_ARGS__;
#else
#   define _LIBCPP_EXTERN_TEMPLATE(...) extern template __VA_ARGS__;
#   define _LIBCPP_EXTERN_TEMPLATE_EVEN_IN_DEBUG_MODE(...) extern template __VA_ARGS__;
#endif

#if defined(__APPLE__) || defined(__FreeBSD__) || defined(_LIBCPP_MSVCRT_LIKE) || \
    defined(__sun__) || defined(__NetBSD__)
#define _LIBCPP_LOCALE__L_EXTENSIONS 1
#endif

#ifdef __FreeBSD__
#define _DECLARE_C99_LDBL_MATH 1
#endif

// If we are getting operator new from the MSVC CRT, then allocation overloads
// for align_val_t were added in 19.12, aka VS 2017 version 15.3.
#if defined(_LIBCPP_MSVCRT) && defined(_MSC_VER) && _MSC_VER < 1912
#  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
#elif defined(_LIBCPP_ABI_VCRUNTIME) && !defined(__cpp_aligned_new)
   // We're deferring to Microsoft's STL to provide aligned new et al. We don't
   // have it unless the language feature test macro is defined.
#  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
#elif defined(__MVS__)
#  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
#endif

#if defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION) || \
    (!defined(__cpp_aligned_new) || __cpp_aligned_new < 201606)
#  define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
#endif

#if defined(__APPLE__) || defined(__FreeBSD__)
#define _LIBCPP_HAS_DEFAULTRUNELOCALE
#endif

#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__sun__)
#define _LIBCPP_WCTYPE_IS_MASK
#endif

#if _LIBCPP_STD_VER <= 17 || !defined(__cpp_char8_t)
#define _LIBCPP_HAS_NO_CHAR8_T
#endif

// Deprecation macros.
//
// Deprecations warnings are always enabled, except when users explicitly opt-out
// by defining _LIBCPP_DISABLE_DEPRECATION_WARNINGS.
#if !defined(_LIBCPP_DISABLE_DEPRECATION_WARNINGS)
#  if __has_attribute(deprecated)
#    define _LIBCPP_DEPRECATED __attribute__ ((deprecated))
#  elif _LIBCPP_STD_VER > 11
#    define _LIBCPP_DEPRECATED [[deprecated]]
#  else
#    define _LIBCPP_DEPRECATED
#  endif
#else
#  define _LIBCPP_DEPRECATED
#endif

#if !defined(_LIBCPP_CXX03_LANG)
#  define _LIBCPP_DEPRECATED_IN_CXX11 _LIBCPP_DEPRECATED
#else
#  define _LIBCPP_DEPRECATED_IN_CXX11
#endif

#if _LIBCPP_STD_VER > 11
#  define _LIBCPP_DEPRECATED_IN_CXX14 _LIBCPP_DEPRECATED
#else
#  define _LIBCPP_DEPRECATED_IN_CXX14
#endif

#if _LIBCPP_STD_VER > 14
#  define _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_DEPRECATED
#else
#  define _LIBCPP_DEPRECATED_IN_CXX17
#endif

#if _LIBCPP_STD_VER > 17
#  define _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_DEPRECATED
#else
#  define _LIBCPP_DEPRECATED_IN_CXX20
#endif

#if !defined(_LIBCPP_HAS_NO_CHAR8_T)
#  define _LIBCPP_DEPRECATED_WITH_CHAR8_T _LIBCPP_DEPRECATED
#else
#  define _LIBCPP_DEPRECATED_WITH_CHAR8_T
#endif

#if defined(_LIBCPP_COMPILER_CLANG_BASED) || defined(_LIBCPP_COMPILER_GCC)
#   define _LIBCPP_SUPPRESS_DEPRECATED_PUSH \
        _Pragma("GCC diagnostic push") \
        _Pragma("GCC diagnostic ignored \"-Wdeprecated\"") \
        _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
#   define _LIBCPP_SUPPRESS_DEPRECATED_POP \
        _Pragma("GCC diagnostic pop")
#else
#   define _LIBCPP_SUPPRESS_DEPRECATED_PUSH
#   define _LIBCPP_SUPPRESS_DEPRECATED_POP
#endif

#if _LIBCPP_STD_VER <= 11
#  define _LIBCPP_EXPLICIT_AFTER_CXX11
#else
#  define _LIBCPP_EXPLICIT_AFTER_CXX11 explicit
#endif

#if _LIBCPP_STD_VER > 11
#  define _LIBCPP_CONSTEXPR_AFTER_CXX11 constexpr
#else
#  define _LIBCPP_CONSTEXPR_AFTER_CXX11
#endif

#if _LIBCPP_STD_VER > 14
#  define _LIBCPP_CONSTEXPR_AFTER_CXX14 constexpr
#else
#  define _LIBCPP_CONSTEXPR_AFTER_CXX14
#endif

#if _LIBCPP_STD_VER > 17
#  define _LIBCPP_CONSTEXPR_AFTER_CXX17 constexpr
#else
#  define _LIBCPP_CONSTEXPR_AFTER_CXX17
#endif

#if __has_cpp_attribute(nodiscard) || defined(_LIBCPP_COMPILER_MSVC)
#  define _LIBCPP_NODISCARD [[nodiscard]]
#elif defined(_LIBCPP_COMPILER_CLANG_BASED) && !defined(_LIBCPP_CXX03_LANG)
#  define _LIBCPP_NODISCARD [[clang::warn_unused_result]]
#else
// We can't use GCC's [[gnu::warn_unused_result]] and
// __attribute__((warn_unused_result)), because GCC does not silence them via
// (void) cast.
#  define _LIBCPP_NODISCARD
#endif

// _LIBCPP_NODISCARD_EXT may be used to apply [[nodiscard]] to entities not
// specified as such as an extension.
#if defined(_LIBCPP_ENABLE_NODISCARD) && !defined(_LIBCPP_DISABLE_NODISCARD_EXT)
#  define _LIBCPP_NODISCARD_EXT _LIBCPP_NODISCARD
#else
#  define _LIBCPP_NODISCARD_EXT
#endif

#if !defined(_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17) && \
    (_LIBCPP_STD_VER > 17 || defined(_LIBCPP_ENABLE_NODISCARD))
#  define _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_NODISCARD
#else
#  define _LIBCPP_NODISCARD_AFTER_CXX17
#endif

#if __has_attribute(no_destroy)
#  define _LIBCPP_NO_DESTROY __attribute__((__no_destroy__))
#else
#  define _LIBCPP_NO_DESTROY
#endif

#ifndef _LIBCPP_HAS_NO_ASAN
extern "C" _LIBCPP_FUNC_VIS void __sanitizer_annotate_contiguous_container(
  const void *, const void *, const void *, const void *);
#endif

// Try to find out if RTTI is disabled.
#if defined(_LIBCPP_COMPILER_CLANG_BASED) && !__has_feature(cxx_rtti)
#  define _LIBCPP_NO_RTTI
#elif defined(__GNUC__) && !defined(__GXX_RTTI)
#  define _LIBCPP_NO_RTTI
#elif defined(_LIBCPP_COMPILER_MSVC) && !defined(_CPPRTTI)
#  define _LIBCPP_NO_RTTI
#endif

#ifndef _LIBCPP_WEAK
#define _LIBCPP_WEAK __attribute__((__weak__))
#endif

// Thread API
#if !defined(_LIBCPP_HAS_NO_THREADS) && \
    !defined(_LIBCPP_HAS_THREAD_API_PTHREAD) && \
    !defined(_LIBCPP_HAS_THREAD_API_WIN32) && \
    !defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
#  if defined(__FreeBSD__) || \
      defined(__wasi__) || \
      defined(__NetBSD__) || \
      defined(__OpenBSD__) || \
      defined(__NuttX__) || \
      defined(__linux__) || \
      defined(__GNU__) || \
      defined(__APPLE__) || \
      defined(__sun__) || \
      defined(__MVS__) || \
      defined(_AIX) || \
      defined(__CYGWIN__)
#    define _LIBCPP_HAS_THREAD_API_PTHREAD
#  elif defined(__Fuchsia__)
     // TODO(44575): Switch to C11 thread API when possible.
#    define _LIBCPP_HAS_THREAD_API_PTHREAD
#  elif defined(_LIBCPP_WIN32API)
#    define _LIBCPP_HAS_THREAD_API_WIN32
#  else
#    error "No thread API"
#  endif // _LIBCPP_HAS_THREAD_API
#endif // _LIBCPP_HAS_NO_THREADS

#if defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
#if defined(__ANDROID__) && __ANDROID_API__ >= 30
#define _LIBCPP_HAS_COND_CLOCKWAIT
#elif defined(_LIBCPP_GLIBC_PREREQ)
#if _LIBCPP_GLIBC_PREREQ(2, 30)
#define _LIBCPP_HAS_COND_CLOCKWAIT
#endif
#endif
#endif

#if defined(_LIBCPP_HAS_NO_THREADS) && defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
#error _LIBCPP_HAS_THREAD_API_PTHREAD may only be defined when \
       _LIBCPP_HAS_NO_THREADS is not defined.
#endif

#if defined(_LIBCPP_HAS_NO_THREADS) && defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
#error _LIBCPP_HAS_THREAD_API_EXTERNAL may not be defined when \
       _LIBCPP_HAS_NO_THREADS is defined.
#endif

#if defined(_LIBCPP_HAS_NO_MONOTONIC_CLOCK) && !defined(_LIBCPP_HAS_NO_THREADS)
#error _LIBCPP_HAS_NO_MONOTONIC_CLOCK may only be defined when \
       _LIBCPP_HAS_NO_THREADS is defined.
#endif

#if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(__STDCPP_THREADS__)
#define __STDCPP_THREADS__ 1
#endif

// The glibc and Bionic implementation of pthreads implements
// pthread_mutex_destroy as nop for regular mutexes. Additionally, Win32
// mutexes have no destroy mechanism.
//
// This optimization can't be performed on Apple platforms, where
// pthread_mutex_destroy can allow the kernel to release resources.
// See https://llvm.org/D64298 for details.
//
// TODO(EricWF): Enable this optimization on Bionic after speaking to their
//               respective stakeholders.
#if (defined(_LIBCPP_HAS_THREAD_API_PTHREAD) && defined(__GLIBC__)) \
  || (defined(_LIBCPP_HAS_THREAD_API_C11) && defined(__Fuchsia__)) \
  || defined(_LIBCPP_HAS_THREAD_API_WIN32)
# define _LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION
#endif

// Destroying a condvar is a nop on Windows.
//
// This optimization can't be performed on Apple platforms, where
// pthread_cond_destroy can allow the kernel to release resources.
// See https://llvm.org/D64298 for details.
//
// TODO(EricWF): This is potentially true for some pthread implementations
// as well.
#if (defined(_LIBCPP_HAS_THREAD_API_C11) && defined(__Fuchsia__)) || \
     defined(_LIBCPP_HAS_THREAD_API_WIN32)
# define _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION
#endif

// Some systems do not provide gets() in their C library, for security reasons.
#if defined(_LIBCPP_MSVCRT) || \
    (defined(__FreeBSD_version) && __FreeBSD_version >= 1300043) || \
    defined(__OpenBSD__)
#   define _LIBCPP_C_HAS_NO_GETS
#endif

#if defined(__BIONIC__) || defined(__NuttX__) ||           \
    defined(__Fuchsia__) || defined(__wasi__) ||           \
    defined(_LIBCPP_HAS_MUSL_LIBC) || defined(__OpenBSD__)
#define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
#endif

#if __has_feature(cxx_atomic) || __has_extension(c_atomic) || __has_keyword(_Atomic)
#  define _LIBCPP_HAS_C_ATOMIC_IMP
#elif defined(_LIBCPP_COMPILER_GCC)
#  define _LIBCPP_HAS_GCC_ATOMIC_IMP
#endif

#if !defined(_LIBCPP_HAS_C_ATOMIC_IMP) && \
    !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP) && \
    !defined(_LIBCPP_COMPILER_MSVC) && \
    !defined(_LIBCPP_HAS_EXTERNAL_ATOMIC_IMP)
#  define _LIBCPP_HAS_NO_ATOMIC_HEADER
#else
#  ifndef _LIBCPP_ATOMIC_FLAG_TYPE
#    define _LIBCPP_ATOMIC_FLAG_TYPE bool
#  endif
#  ifdef _LIBCPP_FREESTANDING
#    define _LIBCPP_ATOMIC_ONLY_USE_BUILTINS
#  endif
#endif

#ifndef _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
#define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
#endif

#if defined(_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS)
#  if defined(__clang__) && __has_attribute(acquire_capability)
// Work around the attribute handling in clang.  When both __declspec and
// __attribute__ are present, the processing goes awry preventing the definition
// of the types. In MinGW mode, __declspec evaluates to __attribute__, and thus
// combining the two does work.
#    if !defined(_MSC_VER)
#      define _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
#    endif
#  endif
#endif

#ifdef _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
#   define _LIBCPP_THREAD_SAFETY_ANNOTATION(x) __attribute__((x))
#else
#   define _LIBCPP_THREAD_SAFETY_ANNOTATION(x)
#endif

#if _LIBCPP_STD_VER > 17 && (!defined(_MSC_VER) || _MSC_VER >= 1929)
#  define _LIBCPP_CONSTINIT constinit
#elif __has_attribute(require_constant_initialization)
#  define _LIBCPP_CONSTINIT __attribute__((__require_constant_initialization__))
#else
#  define _LIBCPP_CONSTINIT
#endif

#if !__has_builtin(__builtin_is_constant_evaluated) || (defined(_LIBCPP_COMPILER_GCC) && _GNUC_VER < 900) || __CUDACC_VER_MAJOR__ == 10
#define _LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED
#endif

#if __has_attribute(diagnose_if) && !defined(_LIBCPP_DISABLE_ADDITIONAL_DIAGNOSTICS)
#  define _LIBCPP_DIAGNOSE_WARNING(...) \
     __attribute__((diagnose_if(__VA_ARGS__, "warning")))
#  define _LIBCPP_DIAGNOSE_ERROR(...) \
     __attribute__((diagnose_if(__VA_ARGS__, "error")))
#else
#  define _LIBCPP_DIAGNOSE_WARNING(...)
#  define _LIBCPP_DIAGNOSE_ERROR(...)
#endif

// Use a function like macro to imply that it must be followed by a semicolon
#if _LIBCPP_STD_VER > 14 && __has_cpp_attribute(fallthrough)
#  define _LIBCPP_FALLTHROUGH() [[fallthrough]]
#elif __has_cpp_attribute(clang::fallthrough)
#  define _LIBCPP_FALLTHROUGH() [[clang::fallthrough]]
#elif __has_attribute(__fallthrough__)
#  define _LIBCPP_FALLTHROUGH() __attribute__((__fallthrough__))
#else
#  define _LIBCPP_FALLTHROUGH() ((void)0)
#endif

#if defined(_LIBCPP_COMPILER_CLANG_BASED)
# define _LIBCPP_REINITIALIZES_OBJECT [[clang::reinitializes]]
#else
# define _LIBCPP_REINITIALIZES_OBJECT
#endif

#if __has_attribute(__nodebug__) && !defined(__CUDACC__)
#define _LIBCPP_NODEBUG __attribute__((__nodebug__))
#else
#define _LIBCPP_NODEBUG
#endif

#if __has_attribute(__standalone_debug__)
#define _LIBCPP_STANDALONE_DEBUG __attribute__((__standalone_debug__))
#else
#define _LIBCPP_STANDALONE_DEBUG
#endif

#if __has_attribute(__preferred_name__)
#define _LIBCPP_PREFERRED_NAME(x) __attribute__((__preferred_name__(x)))
#else
#define _LIBCPP_PREFERRED_NAME(x)
#endif

// We often repeat things just for handling wide characters in the library.
// When wide characters are disabled, it can be useful to have a quick way of
// disabling it without having to resort to #if-#endif, which has a larger
// impact on readability.
#if defined(_LIBCPP_HAS_NO_WIDE_CHARACTERS)
# define _LIBCPP_IF_WIDE_CHARACTERS(...)
#else
# define _LIBCPP_IF_WIDE_CHARACTERS(...) __VA_ARGS__
#endif

#if defined(_LIBCPP_ABI_MICROSOFT) && \
   (defined(_LIBCPP_COMPILER_MSVC) || __has_declspec_attribute(empty_bases)) && \
    !defined(__CUDACC__)
#  define _LIBCPP_DECLSPEC_EMPTY_BASES __declspec(empty_bases)
#else
#  define _LIBCPP_DECLSPEC_EMPTY_BASES
#endif

#if defined(_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES)
#define _LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR
#define _LIBCPP_ENABLE_CXX17_REMOVED_BINDERS
#define _LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE
#define _LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS
#endif // _LIBCPP_ENABLE_CXX17_REMOVED_FEATURES

#if defined(_LIBCPP_ENABLE_CXX20_REMOVED_FEATURES)
#define _LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS
#define _LIBCPP_ENABLE_CXX20_REMOVED_BINDER_TYPEDEFS
#define _LIBCPP_ENABLE_CXX20_REMOVED_NEGATORS
#define _LIBCPP_ENABLE_CXX20_REMOVED_RAW_STORAGE_ITERATOR
#define _LIBCPP_ENABLE_CXX20_REMOVED_TYPE_TRAITS
#endif // _LIBCPP_ENABLE_CXX20_REMOVED_FEATURES

#if !defined(__cpp_impl_coroutine) || __cpp_impl_coroutine < 201902L
#define _LIBCPP_HAS_NO_CXX20_COROUTINES
#endif

// Yandex-specific: We build our own libc++, so it has everything available
#define _LIBCPP_DISABLE_AVAILABILITY
// End of Yandex-specific

#if defined(_LIBCPP_COMPILER_IBM) || defined(__CUDACC__)
#define _LIBCPP_HAS_NO_PRAGMA_PUSH_POP_MACRO
#endif

#if defined(_LIBCPP_HAS_NO_PRAGMA_PUSH_POP_MACRO)
#  define _LIBCPP_PUSH_MACROS
#  define _LIBCPP_POP_MACROS
#else
  // Don't warn about macro conflicts when we can restore them at the
  // end of the header.
#  ifndef _LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS
#    define _LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS
#  endif
#  if defined(_LIBCPP_COMPILER_MSVC)
#    define _LIBCPP_PUSH_MACROS    \
       __pragma(push_macro("min")) \
       __pragma(push_macro("max"))
#    define _LIBCPP_POP_MACROS     \
       __pragma(pop_macro("min"))  \
       __pragma(pop_macro("max"))
#  else
#    define _LIBCPP_PUSH_MACROS        \
       _Pragma("push_macro(\"min\")")  \
       _Pragma("push_macro(\"max\")")
#    define _LIBCPP_POP_MACROS         \
       _Pragma("pop_macro(\"min\")")   \
       _Pragma("pop_macro(\"max\")")
#  endif
#endif // defined(_LIBCPP_HAS_NO_PRAGMA_PUSH_POP_MACRO)

#ifndef _LIBCPP_NO_AUTO_LINK
#  if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
#    if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
#      pragma comment(lib, "c++.lib")
#    else
#      pragma comment(lib, "libc++.lib")
#    endif
#  endif // defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
#endif // _LIBCPP_NO_AUTO_LINK

// Configures the fopen close-on-exec mode character, if any. This string will
// be appended to any mode string used by fstream for fopen/fdopen.
//
// Not all platforms support this, but it helps avoid fd-leaks on platforms that
// do.
#if defined(__BIONIC__)
#  define _LIBCPP_FOPEN_CLOEXEC_MODE "e"
#else
#  define _LIBCPP_FOPEN_CLOEXEC_MODE
#endif

#ifdef _LIBCPP_COMPILER_MSVC
#define _LIBCPP_BUILTIN_CONSTANT_P(x) false
#else
#define _LIBCPP_BUILTIN_CONSTANT_P(x) __builtin_constant_p(x)
#endif

// Support for _FILE_OFFSET_BITS=64 landed gradually in Android, so the full set
// of functions used in cstdio may not be available for low API levels when
// using 64-bit file offsets on LP32.
#if defined(__BIONIC__) && defined(__USE_FILE_OFFSET64) && __ANDROID_API__ < 24
#define _LIBCPP_HAS_NO_FGETPOS_FSETPOS
#endif

#if __has_attribute(init_priority)
    // TODO: Remove this once we drop support for building libc++ with old Clangs
#   if (defined(_LIBCPP_CLANG_VER) && _LIBCPP_CLANG_VER < 1200) || \
       (defined(__apple_build_version__) && __apple_build_version__ < 13000000)
#     define _LIBCPP_INIT_PRIORITY_MAX __attribute__((init_priority(101)))
#   else
#     define _LIBCPP_INIT_PRIORITY_MAX __attribute__((init_priority(100)))
#   endif
#else
# define _LIBCPP_INIT_PRIORITY_MAX
#endif

#if defined(__GNUC__) || defined(__clang__)
  // The attribute uses 1-based indices for ordinary and static member functions.
  // The attribute uses 2-based indices for non-static member functions.
# define _LIBCPP_ATTRIBUTE_FORMAT(archetype, format_string_index, first_format_arg_index) \
    __attribute__((__format__(archetype, format_string_index, first_format_arg_index)))
#else
# define _LIBCPP_ATTRIBUTE_FORMAT(archetype, format_string_index, first_format_arg_index) /* nothing */
#endif

#if __has_cpp_attribute(msvc::no_unique_address)
   // MSVC implements [[no_unique_address]] as a silent no-op currently.
   // (If/when MSVC breaks its C++ ABI, it will be changed to work as intended.)
   // However, MSVC implements [[msvc::no_unique_address]] which does what
   // [[no_unique_address]] is supposed to do, in general.

   // Clang-cl does not yet (14.0) implement either [[no_unique_address]] or
   // [[msvc::no_unique_address]] though. If/when it does implement
   // [[msvc::no_unique_address]], this should be preferred though.
#  define _LIBCPP_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
#elif __has_cpp_attribute(no_unique_address)
#  define _LIBCPP_NO_UNIQUE_ADDRESS [[no_unique_address]]
#else
#  define _LIBCPP_NO_UNIQUE_ADDRESS /* nothing */
   // Note that this can be replaced by #error as soon as clang-cl
   // implements msvc::no_unique_address, since there should be no C++20
   // compiler that doesn't support one of the two attributes at that point.
   // We geenrally don't want to use this macro outside of C++20-only code,
   // because using it conditionally in one language version only would make
   // the ABI inconsistent.
#endif

#if __has_cpp_attribute(msvc::no_unique_address)
   // MSVC implements [[no_unique_address]] as a silent no-op currently.
   // (If/when MSVC breaks its C++ ABI, it will be changed to work as intended.)
   // However, MSVC implements [[msvc::no_unique_address]] which does what
   // [[no_unique_address]] is supposed to do, in general.

   // Clang-cl does not yet (14.0) implement either [[no_unique_address]] or
   // [[msvc::no_unique_address]] though. If/when it does implement
   // [[msvc::no_unique_address]], this should be preferred though.
#  define _LIBCPP_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
#elif __has_cpp_attribute(no_unique_address)
#  define _LIBCPP_NO_UNIQUE_ADDRESS [[no_unique_address]]
#else
#  define _LIBCPP_NO_UNIQUE_ADDRESS /* nothing */
   // Note that this can be replaced by #error as soon as clang-cl
   // implements msvc::no_unique_address, since there should be no C++20
   // compiler that doesn't support one of the two attributes at that point.
   // We generally don't want to use this macro outside of C++20-only code,
   // because using it conditionally in one language version only would make
   // the ABI inconsistent.
#endif

#ifdef _LIBCPP_COMPILER_CLANG_BASED
#  define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("clang diagnostic push")
#  define _LIBCPP_DIAGNOSTIC_POP _Pragma("clang diagnostic pop")
#  define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(clang diagnostic ignored str))
#  define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
#elif defined(_LIBCPP_COMPILER_GCC)
#  define _LIBCPP_DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push")
#  define _LIBCPP_DIAGNOSTIC_POP _Pragma("GCC diagnostic pop")
#  define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
#  define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str) _Pragma(_LIBCPP_TOSTRING(GCC diagnostic ignored str))
#else
#  define _LIBCPP_DIAGNOSTIC_PUSH
#  define _LIBCPP_DIAGNOSTIC_POP
#  define _LIBCPP_CLANG_DIAGNOSTIC_IGNORED(str)
#  define _LIBCPP_GCC_DIAGNOSTIC_IGNORED(str)
#endif

#if defined(_AIX) && !defined(_LIBCPP_COMPILER_GCC)
#  define _LIBCPP_PACKED_BYTE_FOR_AIX _Pragma("pack(1)")
#  define _LIBCPP_PACKED_BYTE_FOR_AIX_END _Pragma("pack(pop)")
#else
#  define _LIBCPP_PACKED_BYTE_FOR_AIX      /* empty */
#  define _LIBCPP_PACKED_BYTE_FOR_AIX_END  /* empty */
#endif

#endif // __cplusplus

#endif // _LIBCPP___CONFIG