Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   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
// TR2 <dynamic_bitset> -*- C++ -*-

// Copyright (C) 2009-2017 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file tr2/dynamic_bitset
 *  This is a TR2 C++ Library header.
 */

#ifndef _GLIBCXX_TR2_DYNAMIC_BITSET
#define _GLIBCXX_TR2_DYNAMIC_BITSET 1

#pragma GCC system_header

#include <limits>
#include <vector>
#include <string>
#include <memory> // For std::allocator
#include <bits/functexcept.h>   // For invalid_argument, out_of_range,
				// overflow_error
#include <iosfwd>
#include <bits/cxxabi_forced.h>

namespace std _GLIBCXX_VISIBILITY(default)
{
namespace tr2
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**
   *  @defgroup dynamic_bitset Dynamic Bitset.
   *  @ingroup extensions
   *
   *  @{
   */

  /**
   *  Base class, general case.
   *
   *  See documentation for dynamic_bitset.
   */
  template<typename _WordT = unsigned long long,
	   typename _Alloc = std::allocator<_WordT>>
    struct __dynamic_bitset_base
    {
      static_assert(std::is_unsigned<_WordT>::value, "template argument "
		    "_WordT not an unsigned integral type");

      typedef _WordT block_type;
      typedef _Alloc allocator_type;
      typedef size_t size_type;

      static const size_type _S_bits_per_block = __CHAR_BIT__ * sizeof(block_type);
      static const size_type npos = static_cast<size_type>(-1);

      /// 0 is the least significant word.
      std::vector<block_type, allocator_type> _M_w;

      explicit
      __dynamic_bitset_base(const allocator_type& __alloc = allocator_type())
      : _M_w(__alloc)
      { }

      explicit
      __dynamic_bitset_base(__dynamic_bitset_base&& __b)
      { this->_M_w.swap(__b._M_w); }

      explicit
      __dynamic_bitset_base(size_type __nbits, unsigned long long __val = 0ULL,
			   const allocator_type& __alloc = allocator_type())
      : _M_w(__nbits / _S_bits_per_block
	     + (__nbits % _S_bits_per_block > 0),
	     __val, __alloc)
      {
	unsigned long long __mask = ~static_cast<block_type>(0);
	size_t __n = std::min(this->_M_w.size(),
			      sizeof(unsigned long long) / sizeof(block_type));
	for (size_t __i = 0; __i < __n; ++__i)
	  {
	    this->_M_w[__i] = (__val & __mask) >> (__i * _S_bits_per_block);
	    __mask <<= _S_bits_per_block;
	  }
      }

      void
      _M_assign(const __dynamic_bitset_base& __b)
      { this->_M_w = __b._M_w; }

      void
      _M_swap(__dynamic_bitset_base& __b)
      { this->_M_w.swap(__b._M_w); }

      void
      _M_clear()
      { this->_M_w.clear(); }

      void
      _M_resize(size_t __nbits, bool __value)
      {
	size_t __sz = __nbits / _S_bits_per_block;
	if (__nbits % _S_bits_per_block > 0)
	  ++__sz;
	if (__sz != this->_M_w.size())
	  {
	    block_type __val = 0;
	    if (__value)
	      __val = std::numeric_limits<block_type>::max();
	    this->_M_w.resize(__sz, __val);
	  }
      }

      allocator_type
      _M_get_allocator() const
      { return this->_M_w.get_allocator(); }

      static size_type
      _S_whichword(size_type __pos) noexcept
      { return __pos / _S_bits_per_block; }

      static size_type
      _S_whichbyte(size_type __pos) noexcept
      { return (__pos % _S_bits_per_block) / __CHAR_BIT__; }

      static size_type
      _S_whichbit(size_type __pos) noexcept
      { return __pos % _S_bits_per_block; }

      static block_type
      _S_maskbit(size_type __pos) noexcept
      { return (static_cast<block_type>(1)) << _S_whichbit(__pos); }

      block_type&
      _M_getword(size_type __pos)
      { return this->_M_w[_S_whichword(__pos)]; }

      block_type
      _M_getword(size_type __pos) const
      { return this->_M_w[_S_whichword(__pos)]; }

      block_type&
      _M_hiword()
      { return this->_M_w[_M_w.size() - 1]; }

      block_type
      _M_hiword() const
      { return this->_M_w[_M_w.size() - 1]; }

      void
      _M_do_and(const __dynamic_bitset_base& __x)
      {
	if (__x._M_w.size() == this->_M_w.size())
	  for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	    this->_M_w[__i] &= __x._M_w[__i];
	else
	  return;
      }

      void
      _M_do_or(const __dynamic_bitset_base& __x)
      {
	if (__x._M_w.size() == this->_M_w.size())
	  for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	    this->_M_w[__i] |= __x._M_w[__i];
	else
	  return;
      }

      void
      _M_do_xor(const __dynamic_bitset_base& __x)
      {
	if (__x._M_w.size() == this->_M_w.size())
	  for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	    this->_M_w[__i] ^= __x._M_w[__i];
	else
	  return;
      }

      void
      _M_do_dif(const __dynamic_bitset_base& __x)
      {
	if (__x._M_w.size() == this->_M_w.size())
	  for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	    this->_M_w[__i] &= ~__x._M_w[__i];
	else
	  return;
      }

      void
      _M_do_left_shift(size_t __shift);

      void
      _M_do_right_shift(size_t __shift);

      void
      _M_do_flip()
      {
	for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	  this->_M_w[__i] = ~this->_M_w[__i];
      }

      void
      _M_do_set()
      {
	for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	  this->_M_w[__i] = ~static_cast<block_type>(0);
      }

      void
      _M_do_reset()
      {
	for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	  this->_M_w[__i] = static_cast<block_type>(0);
      }

      bool
      _M_is_equal(const __dynamic_bitset_base& __x) const
      {
	if (__x._M_w.size() == this->_M_w.size())
	  {
	    for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	      if (this->_M_w[__i] != __x._M_w[__i])
		return false;
	    return true;
	  }
	else
	  return false;
      }

      bool
      _M_is_less(const __dynamic_bitset_base& __x) const
      {
	if (__x._M_w.size() == this->_M_w.size())
	  {
	    for (size_t __i = this->_M_w.size(); __i > 0; --__i)
	      {
		if (this->_M_w[__i-1] < __x._M_w[__i-1])
		  return true;
		else if (this->_M_w[__i-1] > __x._M_w[__i-1])
		  return false;
	      }
	    return false;
	  }
	else
	  return false;
      }

      size_t
      _M_are_all_aux() const
      {
	for (size_t __i = 0; __i < this->_M_w.size() - 1; ++__i)
	  if (_M_w[__i] != ~static_cast<block_type>(0))
	    return 0;
	return ((this->_M_w.size() - 1) * _S_bits_per_block
		+ __builtin_popcountll(this->_M_hiword()));
      }

      bool
      _M_is_any() const
      {
	for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	  if (this->_M_w[__i] != static_cast<block_type>(0))
	    return true;
	return false;
      }

      bool
      _M_is_subset_of(const __dynamic_bitset_base& __b)
      {
	if (__b._M_w.size() == this->_M_w.size())
	  {
	    for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	      if (this->_M_w[__i] != (this->_M_w[__i] | __b._M_w[__i]))
		return false;
	    return true;
	  }
	else
	  return false;
      }

      bool
      _M_is_proper_subset_of(const __dynamic_bitset_base& __b) const
      {
	if (this->is_subset_of(__b))
	  {
	    if (*this == __b)
	      return false;
	    else
	      return true;
	  }
	else
	  return false;
      }

      size_t
      _M_do_count() const
      {
	size_t __result = 0;
	for (size_t __i = 0; __i < this->_M_w.size(); ++__i)
	  __result += __builtin_popcountll(this->_M_w[__i]);
	return __result;
      }

      size_type
      _M_size() const noexcept
      { return this->_M_w.size(); }

      unsigned long
      _M_do_to_ulong() const;

      unsigned long long
      _M_do_to_ullong() const;

      // find first "on" bit
      size_type
      _M_do_find_first(size_t __not_found) const;

      // find the next "on" bit that follows "prev"
      size_type
      _M_do_find_next(size_t __prev, size_t __not_found) const;

      // do append of block
      void
      _M_do_append_block(block_type __block, size_type __pos)
      {
	size_t __offset = __pos % _S_bits_per_block;
	if (__offset == 0)
	  this->_M_w.push_back(__block);
	else
	  {
	    this->_M_hiword() |= (__block << __offset);
	    this->_M_w.push_back(__block >> (_S_bits_per_block - __offset));
	  }
      }
    };

  /**
   *  @brief  The %dynamic_bitset class represents a sequence of bits.
   *
   *  See N2050,
   *  Proposal to Add a Dynamically Sizeable Bitset to the Standard Library.
   *
   *  In the general unoptimized case, storage is allocated in
   *  word-sized blocks.  Let B be the number of bits in a word, then
   *  (Nb+(B-1))/B words will be used for storage.  B - Nb%B bits are
   *  unused.  (They are the high-order bits in the highest word.)  It
   *  is a class invariant that those unused bits are always zero.
   *
   *  If you think of %dynamic_bitset as "a simple array of bits," be
   *  aware that your mental picture is reversed: a %dynamic_bitset
   *  behaves the same way as bits in integers do, with the bit at
   *  index 0 in the "least significant / right-hand" position, and
   *  the bit at index Nb-1 in the "most significant / left-hand"
   *  position.  Thus, unlike other containers, a %dynamic_bitset's
   *  index "counts from right to left," to put it very loosely.
   *
   *  This behavior is preserved when translating to and from strings.
   *  For example, the first line of the following program probably
   *  prints "b('a') is 0001100001" on a modern ASCII system.
   *
   *  @code
   *     #include <dynamic_bitset>
   *     #include <iostream>
   *     #include <sstream>
   *
   *     using namespace std;
   *
   *     int main()
   *     {
   *         long         a = 'a';
   *         dynamic_bitset<> b(a);
   *
   *         cout << "b('a') is " << b << endl;
   *
   *         ostringstream s;
   *         s << b;
   *         string  str = s.str();
   *         cout << "index 3 in the string is " << str[3] << " but\n"
   *              << "index 3 in the bitset is " << b[3] << endl;
   *     }
   *  @endcode
   *
   *  Most of the actual code isn't contained in %dynamic_bitset<>
   *  itself, but in the base class __dynamic_bitset_base.  The base
   *  class works with whole words, not with individual bits.  This
   *  allows us to specialize __dynamic_bitset_base for the important
   *  special case where the %dynamic_bitset is only a single word.
   *
   *  Extra confusion can result due to the fact that the storage for
   *  __dynamic_bitset_base @e is a vector, and is indexed as such.  This is
   *  carefully encapsulated.
   */
  template<typename _WordT = unsigned long long,
	   typename _Alloc = std::allocator<_WordT>>
    class dynamic_bitset
    : private __dynamic_bitset_base<_WordT, _Alloc>
    {
      static_assert(std::is_unsigned<_WordT>::value, "template argument "
		    "_WordT not an unsigned integral type");

    public:

      typedef __dynamic_bitset_base<_WordT, _Alloc> _Base;
      typedef _WordT block_type;
      typedef _Alloc allocator_type;
      typedef size_t size_type;

      static const size_type bits_per_block = __CHAR_BIT__ * sizeof(block_type);
      // Use this: constexpr size_type std::numeric_limits<size_type>::max().
      static const size_type npos = static_cast<size_type>(-1);

    private:

      //  Clear the unused bits in the uppermost word.
      void
      _M_do_sanitize()
      {
	size_type __shift = this->_M_Nb % bits_per_block;
	if (__shift > 0)
	  this->_M_hiword() &= ~((~static_cast<block_type>(0)) << __shift);
      }

      //  Set the unused bits in the uppermost word.
      void
      _M_do_fill()
      {
	size_type __shift = this->_M_Nb % bits_per_block;
	if (__shift > 0)
	  this->_M_hiword() |= ((~static_cast<block_type>(0)) << __shift);
      }

      /**
       *  These versions of single-bit set, reset, flip, and test
       *  do no range checking.
       */
      dynamic_bitset<_WordT, _Alloc>&
      _M_unchecked_set(size_type __pos)
      {
	this->_M_getword(__pos) |= _Base::_S_maskbit(__pos);
	return *this;
      }

      dynamic_bitset<_WordT, _Alloc>&
      _M_unchecked_set(size_type __pos, int __val)
      {
	if (__val)
	  this->_M_getword(__pos) |= _Base::_S_maskbit(__pos);
	else
	  this->_M_getword(__pos) &= ~_Base::_S_maskbit(__pos);
	return *this;
      }

      dynamic_bitset<_WordT, _Alloc>&
      _M_unchecked_reset(size_type __pos)
      {
	this->_M_getword(__pos) &= ~_Base::_S_maskbit(__pos);
	return *this;
      }

      dynamic_bitset<_WordT, _Alloc>&
      _M_unchecked_flip(size_type __pos)
      {
	this->_M_getword(__pos) ^= _Base::_S_maskbit(__pos);
	return *this;
      }

      bool
      _M_unchecked_test(size_type __pos) const
      { return ((this->_M_getword(__pos) & _Base::_S_maskbit(__pos))
		!= static_cast<_WordT>(0)); }

      size_type _M_Nb;

    public:
      /**
       *  This encapsulates the concept of a single bit.  An instance
       *  of this class is a proxy for an actual bit; this way the
       *  individual bit operations are done as faster word-size
       *  bitwise instructions.
       *
       *  Most users will never need to use this class directly;
       *  conversions to and from bool are automatic and should be
       *  transparent.  Overloaded operators help to preserve the
       *  illusion.
       *
       *  (On a typical system, this "bit %reference" is 64 times the
       *  size of an actual bit.  Ha.)
       */
      class reference
      {
	friend class dynamic_bitset;

	block_type *_M_wp;
	size_type _M_bpos;

	// left undefined
	reference();

      public:
	reference(dynamic_bitset& __b, size_type __pos)
	{
	  this->_M_wp = &__b._M_getword(__pos);
	  this->_M_bpos = _Base::_S_whichbit(__pos);
	}

	~reference()
	{ }

	// For b[i] = __x;
	reference&
	operator=(bool __x)
	{
	  if (__x)
	    *this->_M_wp |= _Base::_S_maskbit(this->_M_bpos);
	  else
	    *this->_M_wp &= ~_Base::_S_maskbit(this->_M_bpos);
	  return *this;
	}

	// For b[i] = b[__j];
	reference&
	operator=(const reference& __j)
	{
	  if ((*(__j._M_wp) & _Base::_S_maskbit(__j._M_bpos)))
	    *this->_M_wp |= _Base::_S_maskbit(this->_M_bpos);
	  else
	    *this->_M_wp &= ~_Base::_S_maskbit(this->_M_bpos);
	  return *this;
	}

	// Flips the bit
	bool
	operator~() const
	{ return (*(_M_wp) & _Base::_S_maskbit(this->_M_bpos)) == 0; }

	// For __x = b[i];
	operator bool() const
	{ return (*(this->_M_wp) & _Base::_S_maskbit(this->_M_bpos)) != 0; }

	// For b[i].flip();
	reference&
	flip()
	{
	  *this->_M_wp ^= _Base::_S_maskbit(this->_M_bpos);
	  return *this;
	}
      };

      friend class reference;

      typedef bool const_reference;

      // 23.3.5.1 constructors:
      /// All bits set to zero.
      explicit
      dynamic_bitset(const allocator_type& __alloc = allocator_type())
      : _Base(__alloc), _M_Nb(0)
      { }

      /// Initial bits bitwise-copied from a single word (others set to zero).
      explicit
      dynamic_bitset(size_type __nbits, unsigned long long __val = 0ULL,
		     const allocator_type& __alloc = allocator_type())
      : _Base(__nbits, __val, __alloc),
	_M_Nb(__nbits)
      { }

      dynamic_bitset(initializer_list<block_type> __il,
		     const allocator_type& __alloc = allocator_type())
      : _Base(__alloc), _M_Nb(0)
      { this->append(__il); }

      /**
       *  @brief  Use a subset of a string.
       *  @param  __str  A string of '0' and '1' characters.
       *  @param  __pos  Index of the first character in @p __str to use.
       *  @param  __n    The number of characters to copy.
       *  @param  __zero The character to use for unset bits.
       *  @param  __one  The character to use for set bits.
       *  @param  __alloc An allocator.
       *  @throw  std::out_of_range  If @p __pos is bigger the size of @p __str.
       *  @throw  std::invalid_argument  If a character appears in the string
       *                                 which is neither '0' nor '1'.
       */
      template<typename _CharT, typename _Traits, typename _Alloc1>
	explicit
	dynamic_bitset(const std::basic_string<_CharT, _Traits, _Alloc1>& __str,
		       typename basic_string<_CharT,_Traits,_Alloc1>::size_type
		       __pos = 0,
		       typename basic_string<_CharT,_Traits,_Alloc1>::size_type
		       __n = std::basic_string<_CharT, _Traits, _Alloc1>::npos,
		       _CharT __zero = _CharT('0'), _CharT __one = _CharT('1'),
		       const allocator_type& __alloc = allocator_type())
	: _Base(__alloc),
	  _M_Nb(0) // Watch for npos.
	{
	  if (__pos > __str.size())
	    __throw_out_of_range(__N("dynamic_bitset::bitset initial position "
				     "not valid"));

	  // Watch for npos.
	  this->_M_Nb = (__n > __str.size() ? __str.size() - __pos : __n);
	  this->resize(this->_M_Nb);
	  this->_M_copy_from_string(__str, __pos, __n,
				    _CharT('0'), _CharT('1'));
	}

      /**
       *  @brief  Construct from a string.
       *  @param  __str  A string of '0' and '1' characters.
       *  @param  __alloc An allocator.
       *  @throw  std::invalid_argument  If a character appears in the string
       *                                 which is neither '0' nor '1'.
       */
      explicit
      dynamic_bitset(const char* __str,
		     const allocator_type& __alloc = allocator_type())
      : _Base(__alloc)
      {
	size_t __len = 0;
	if (__str)
	  while (__str[__len] != '\0')
	    ++__len;
	this->resize(__len);
	this->_M_copy_from_ptr<char,std::char_traits<char>>
		   (__str, __len, 0, __len, '0', '1');
      }

      /**
       *  @brief  Copy constructor.
       */
      dynamic_bitset(const dynamic_bitset& __b)
      : _Base(__b), _M_Nb(__b.size())
      { }

      /**
       *  @brief  Move constructor.
       */
      dynamic_bitset(dynamic_bitset&& __b)
      : _Base(std::forward<_Base>(__b)), _M_Nb(__b.size())
      { }

      /**
       *  @brief  Swap with another bitset.
       */
      void
      swap(dynamic_bitset& __b)
      {
	this->_M_swap(__b);
	std::swap(this->_M_Nb, __b._M_Nb);
      }

      /**
       *  @brief  Assignment.
       */
      dynamic_bitset&
      operator=(const dynamic_bitset& __b)
      {
	if (&__b != this)
	  {
	    this->_M_assign(__b);
	    this->_M_Nb = __b._M_Nb;
	  }
      }

      /**
       *  @brief  Move assignment.
       */
      dynamic_bitset&
      operator=(dynamic_bitset&& __b)
      {
	this->swap(__b);
	return *this;
      }

      /**
       *  @brief  Return the allocator for the bitset.
       */
      allocator_type
      get_allocator() const
      { return this->_M_get_allocator(); }

      /**
       *  @brief  Resize the bitset.
       */
      void
      resize(size_type __nbits, bool __value = false)
      {
	if (__value)
	  this->_M_do_fill();
	this->_M_resize(__nbits, __value);
	this->_M_Nb = __nbits;
	this->_M_do_sanitize();
      }

      /**
       *  @brief  Clear the bitset.
       */
      void
      clear()
      {
	this->_M_clear();
	this->_M_Nb = 0;
      }

      /**
       *  @brief  Push a bit onto the high end of the bitset.
       */
      void
      push_back(bool __bit)
      {
	if (size_t __offset = this->size() % bits_per_block == 0)
	  this->_M_do_append_block(block_type(0), this->_M_Nb);
	++this->_M_Nb;
	this->_M_unchecked_set(this->_M_Nb, __bit);
      }

      /**
       *  @brief  Append a block.
       */
      void
      append(block_type __block)
      {
	this->_M_do_append_block(__block, this->_M_Nb);
	this->_M_Nb += bits_per_block;
      }

      /**
       *  @brief
       */
      void
      append(initializer_list<block_type> __il)
      { this->append(__il.begin(), __il.end()); }

      /**
       *  @brief  Append an iterator range of blocks.
       */
      template <typename _BlockInputIterator>
	void
	append(_BlockInputIterator __first, _BlockInputIterator __last)
	{
	  for (; __first != __last; ++__first)
	    this->append(*__first);
	}

      // 23.3.5.2 dynamic_bitset operations:
      //@{
      /**
       *  @brief  Operations on dynamic_bitsets.
       *  @param  __rhs  A same-sized dynamic_bitset.
       *
       *  These should be self-explanatory.
       */
      dynamic_bitset<_WordT, _Alloc>&
      operator&=(const dynamic_bitset<_WordT, _Alloc>& __rhs)
      {
	this->_M_do_and(__rhs);
	return *this;
      }

      dynamic_bitset<_WordT, _Alloc>&
      operator&=(dynamic_bitset<_WordT, _Alloc>&& __rhs)
      {
	this->_M_do_and(std::move(__rhs));
	return *this;
      }

      dynamic_bitset<_WordT, _Alloc>&
      operator|=(const dynamic_bitset<_WordT, _Alloc>& __rhs)
      {
	this->_M_do_or(__rhs);
	return *this;
      }

      dynamic_bitset<_WordT, _Alloc>&
      operator^=(const dynamic_bitset<_WordT, _Alloc>& __rhs)
      {
	this->_M_do_xor(__rhs);
	return *this;
      }

      dynamic_bitset<_WordT, _Alloc>&
      operator-=(const dynamic_bitset<_WordT, _Alloc>& __rhs)
      {
	this->_M_do_dif(__rhs);
	return *this;
      }
      //@}

      //@{
      /**
       *  @brief  Operations on dynamic_bitsets.
       *  @param  __pos The number of places to shift.
       *
       *  These should be self-explanatory.
       */
      dynamic_bitset<_WordT, _Alloc>&
      operator<<=(size_type __pos)
      {
	if (__builtin_expect(__pos < this->_M_Nb, 1))
	  {
	    this->_M_do_left_shift(__pos);
	    this->_M_do_sanitize();
	  }
	else
	  this->_M_do_reset();
	return *this;
      }

      dynamic_bitset<_WordT, _Alloc>&
      operator>>=(size_type __pos)
      {
	if (__builtin_expect(__pos < this->_M_Nb, 1))
	  {
	    this->_M_do_right_shift(__pos);
	    this->_M_do_sanitize();
	  }
	else
	  this->_M_do_reset();
	return *this;
      }
      //@}

      // Set, reset, and flip.
      /**
       *  @brief Sets every bit to true.
       */
      dynamic_bitset<_WordT, _Alloc>&
      set()
      {
	this->_M_do_set();
	this->_M_do_sanitize();
	return *this;
      }

      /**
       *  @brief Sets a given bit to a particular value.
       *  @param  __pos  The index of the bit.
       *  @param  __val  Either true or false, defaults to true.
       *  @throw  std::out_of_range  If @a __pos is bigger the size of the %set.
       */
      dynamic_bitset<_WordT, _Alloc>&
      set(size_type __pos, bool __val = true)
      {
	if (__pos >= _M_Nb)
	  __throw_out_of_range(__N("dynamic_bitset::set"));
	return this->_M_unchecked_set(__pos, __val);
      }

      /**
       *  @brief Sets every bit to false.
       */
      dynamic_bitset<_WordT, _Alloc>&
      reset()
      {
	this->_M_do_reset();
	return *this;
      }

      /**
       *  @brief Sets a given bit to false.
       *  @param  __pos  The index of the bit.
       *  @throw  std::out_of_range  If @a __pos is bigger the size of the %set.
       *
       *  Same as writing @c set(__pos, false).
       */
      dynamic_bitset<_WordT, _Alloc>&
      reset(size_type __pos)
      {
	if (__pos >= _M_Nb)
	  __throw_out_of_range(__N("dynamic_bitset::reset"));
	return this->_M_unchecked_reset(__pos);
      }

      /**
       *  @brief Toggles every bit to its opposite value.
       */
      dynamic_bitset<_WordT, _Alloc>&
      flip()
      {
	this->_M_do_flip();
	this->_M_do_sanitize();
	return *this;
      }

      /**
       *  @brief Toggles a given bit to its opposite value.
       *  @param  __pos  The index of the bit.
       *  @throw  std::out_of_range  If @a __pos is bigger the size of the %set.
       */
      dynamic_bitset<_WordT, _Alloc>&
      flip(size_type __pos)
      {
	if (__pos >= _M_Nb)
	  __throw_out_of_range(__N("dynamic_bitset::flip"));
	return this->_M_unchecked_flip(__pos);
      }

      /// See the no-argument flip().
      dynamic_bitset<_WordT, _Alloc>
      operator~() const
      { return dynamic_bitset<_WordT, _Alloc>(*this).flip(); }

      //@{
      /**
       *  @brief  Array-indexing support.
       *  @param  __pos  Index into the %dynamic_bitset.
       *  @return A bool for a 'const %dynamic_bitset'.  For non-const
       *           bitsets, an instance of the reference proxy class.
       *  @note These operators do no range checking and throw no
       *         exceptions, as required by DR 11 to the standard.
       */
      reference
      operator[](size_type __pos)
      { return reference(*this,__pos); }

      const_reference
      operator[](size_type __pos) const
      { return _M_unchecked_test(__pos); }
      //@}

      /**
       *  @brief Returns a numerical interpretation of the %dynamic_bitset.
       *  @return  The integral equivalent of the bits.
       *  @throw  std::overflow_error  If there are too many bits to be
       *                               represented in an @c unsigned @c long.
       */
      unsigned long
      to_ulong() const
      { return this->_M_do_to_ulong(); }

      /**
       *  @brief Returns a numerical interpretation of the %dynamic_bitset.
       *  @return  The integral equivalent of the bits.
       *  @throw  std::overflow_error  If there are too many bits to be
       *                               represented in an @c unsigned @c long.
       */
      unsigned long long
      to_ullong() const
      { return this->_M_do_to_ullong(); }

      /**
       *  @brief Returns a character interpretation of the %dynamic_bitset.
       *  @return  The string equivalent of the bits.
       *
       *  Note the ordering of the bits:  decreasing character positions
       *  correspond to increasing bit positions (see the main class notes for
       *  an example).
       */
      template<typename _CharT = char,
	       typename _Traits = std::char_traits<_CharT>,
	       typename _Alloc1 = std::allocator<_CharT>>
	std::basic_string<_CharT, _Traits, _Alloc1>
	to_string(_CharT __zero = _CharT('0'), _CharT __one = _CharT('1')) const
	{
	  std::basic_string<_CharT, _Traits, _Alloc1> __result;
	  _M_copy_to_string(__result, __zero, __one);
	  return __result;
	}

      // Helper functions for string operations.
      template<typename _CharT, typename _Traits>
	void
	_M_copy_from_ptr(const _CharT*, size_t, size_t, size_t,
			 _CharT, _CharT);

      template<typename _CharT, typename _Traits, typename _Alloc1>
	void
	_M_copy_from_string(const std::basic_string<_CharT,
			    _Traits, _Alloc1>& __str, size_t __pos, size_t __n,
			    _CharT __zero = _CharT('0'),
			    _CharT __one = _CharT('1'))
	{ _M_copy_from_ptr<_CharT, _Traits>(__str.data(), __str.size(),
					    __pos, __n, __zero, __one); }

      template<typename _CharT, typename _Traits, typename _Alloc1>
	void
	_M_copy_to_string(std::basic_string<_CharT, _Traits, _Alloc1>& __str,
			  _CharT __zero = _CharT('0'),
			  _CharT __one = _CharT('1')) const;

      /// Returns the number of bits which are set.
      size_type
      count() const noexcept
      { return this->_M_do_count(); }

      /// Returns the total number of bits.
      size_type
      size() const noexcept
      { return this->_M_Nb; }

      /// Returns the total number of blocks.
      size_type
      num_blocks() const noexcept
      { return this->_M_size(); }

      /// Returns true if the dynamic_bitset is empty.
      bool
      empty() const noexcept
      { return (this->_M_Nb == 0); }

      /// Returns the maximum size of a dynamic_bitset object having the same
      /// type as *this.
      /// The real answer is max() * bits_per_block but is likely to overflow.
      constexpr size_type
      max_size() noexcept
      { return std::numeric_limits<block_type>::max(); }

      /**
       *  @brief Tests the value of a bit.
       *  @param  __pos  The index of a bit.
       *  @return  The value at @a __pos.
       *  @throw  std::out_of_range  If @a __pos is bigger the size of the %set.
       */
      bool
      test(size_type __pos) const
      {
	if (__pos >= _M_Nb)
	  __throw_out_of_range(__N("dynamic_bitset::test"));
	return _M_unchecked_test(__pos);
      }

      /**
       *  @brief Tests whether all the bits are on.
       *  @return  True if all the bits are set.
       */
      bool
      all() const
      { return this->_M_are_all_aux() == _M_Nb; }

      /**
       *  @brief Tests whether any of the bits are on.
       *  @return  True if at least one bit is set.
       */
      bool
      any() const
      { return this->_M_is_any(); }

      /**
       *  @brief Tests whether any of the bits are on.
       *  @return  True if none of the bits are set.
       */
      bool
      none() const
      { return !this->_M_is_any(); }

      //@{
      /// Self-explanatory.
      dynamic_bitset<_WordT, _Alloc>
      operator<<(size_type __pos) const
      { return dynamic_bitset<_WordT, _Alloc>(*this) <<= __pos; }

      dynamic_bitset<_WordT, _Alloc>
      operator>>(size_type __pos) const
      { return dynamic_bitset<_WordT, _Alloc>(*this) >>= __pos; }
      //@}

      /**
       *  @brief  Finds the index of the first "on" bit.
       *  @return  The index of the first bit set, or size() if not found.
       *  @sa  find_next
       */
      size_type
      find_first() const
      { return this->_M_do_find_first(this->_M_Nb); }

      /**
       *  @brief  Finds the index of the next "on" bit after prev.
       *  @return  The index of the next bit set, or size() if not found.
       *  @param  __prev  Where to start searching.
       *  @sa  find_first
       */
      size_type
      find_next(size_t __prev) const
      { return this->_M_do_find_next(__prev, this->_M_Nb); }

      bool
      is_subset_of(const dynamic_bitset& __b) const
      { return this->_M_is_subset_of(__b); }

      bool
      is_proper_subset_of(const dynamic_bitset& __b) const
      { return this->_M_is_proper_subset_of(__b); }

      friend bool
      operator==(const dynamic_bitset<_WordT, _Alloc>& __lhs,
		 const dynamic_bitset<_WordT, _Alloc>& __rhs)
      { return __lhs._M_is_equal(__rhs); }

      friend bool
      operator<(const dynamic_bitset<_WordT, _Alloc>& __lhs,
		const dynamic_bitset<_WordT, _Alloc>& __rhs)
      { return __lhs._M_is_less(__rhs); }
    };

  template<typename _WordT, typename _Alloc>
    template<typename _CharT, typename _Traits, typename _Alloc1>
      inline void
      dynamic_bitset<_WordT, _Alloc>::
      _M_copy_to_string(std::basic_string<_CharT, _Traits, _Alloc1>& __str,
			_CharT __zero, _CharT __one) const
      {
	__str.assign(_M_Nb, __zero);
	for (size_t __i = _M_Nb; __i > 0; --__i)
	  if (_M_unchecked_test(__i - 1))
	    _Traits::assign(__str[_M_Nb - __i], __one);
      }


  //@{
  /// These comparisons for equality/inequality are, well, @e bitwise.

  template<typename _WordT, typename _Alloc>
    inline bool
    operator!=(const dynamic_bitset<_WordT, _Alloc>& __lhs,
	       const dynamic_bitset<_WordT, _Alloc>& __rhs)
    { return !(__lhs == __rhs); }

  template<typename _WordT, typename _Alloc>
    inline bool
    operator<=(const dynamic_bitset<_WordT, _Alloc>& __lhs,
	       const dynamic_bitset<_WordT, _Alloc>& __rhs)
    { return !(__lhs > __rhs); }

  template<typename _WordT, typename _Alloc>
    inline bool
    operator>(const dynamic_bitset<_WordT, _Alloc>& __lhs,
	      const dynamic_bitset<_WordT, _Alloc>& __rhs)
    { return __rhs < __lhs; }

  template<typename _WordT, typename _Alloc>
    inline bool
    operator>=(const dynamic_bitset<_WordT, _Alloc>& __lhs,
	       const dynamic_bitset<_WordT, _Alloc>& __rhs)
    { return !(__lhs < __rhs); }
  //@}

  // 23.3.5.3 bitset operations:
  //@{
  /**
   *  @brief  Global bitwise operations on bitsets.
   *  @param  __x  A bitset.
   *  @param  __y  A bitset of the same size as @a __x.
   *  @return  A new bitset.
   *
   *  These should be self-explanatory.
   */
  template<typename _WordT, typename _Alloc>
    inline dynamic_bitset<_WordT, _Alloc>
    operator&(const dynamic_bitset<_WordT, _Alloc>& __x,
	      const dynamic_bitset<_WordT, _Alloc>& __y)
    {
      dynamic_bitset<_WordT, _Alloc> __result(__x);
      __result &= __y;
      return __result;
    }

  template<typename _WordT, typename _Alloc>
    inline dynamic_bitset<_WordT, _Alloc>
    operator|(const dynamic_bitset<_WordT, _Alloc>& __x,
	      const dynamic_bitset<_WordT, _Alloc>& __y)
    {
      dynamic_bitset<_WordT, _Alloc> __result(__x);
      __result |= __y;
      return __result;
    }

  template <typename _WordT, typename _Alloc>
    inline dynamic_bitset<_WordT, _Alloc>
    operator^(const dynamic_bitset<_WordT, _Alloc>& __x,
	      const dynamic_bitset<_WordT, _Alloc>& __y)
    {
      dynamic_bitset<_WordT, _Alloc> __result(__x);
      __result ^= __y;
      return __result;
    }

  template <typename _WordT, typename _Alloc>
    inline dynamic_bitset<_WordT, _Alloc>
    operator-(const dynamic_bitset<_WordT, _Alloc>& __x,
	      const dynamic_bitset<_WordT, _Alloc>& __y)
    {
      dynamic_bitset<_WordT, _Alloc> __result(__x);
      __result -= __y;
      return __result;
    }
  //@}

  /// Stream output operator for dynamic_bitset.
  template <typename _CharT, typename _Traits,
	    typename _WordT, typename _Alloc>
    inline std::basic_ostream<_CharT, _Traits>&
    operator<<(std::basic_ostream<_CharT, _Traits>& __os,
	       const dynamic_bitset<_WordT, _Alloc>& __x)
    {
      std::basic_string<_CharT, _Traits> __tmp;

      const ctype<_CharT>& __ct = use_facet<ctype<_CharT>>(__os.getloc());
      __x._M_copy_to_string(__tmp, __ct.widen('0'), __ct.widen('1'));
      return __os << __tmp;
    }
  /**
   *  @}
   */

_GLIBCXX_END_NAMESPACE_VERSION
} // tr2
} // std

#include <tr2/dynamic_bitset.tcc>

#endif /* _GLIBCXX_TR2_DYNAMIC_BITSET */