libstdc++-v3/include/bits/stl_bvector.h

   1 // vector<bool> specialization -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 /*
  31  *
  32  * Copyright (c) 1994
  33  * Hewlett-Packard Company
  34  *
  35  * Permission to use, copy, modify, distribute and sell this software
  36  * and its documentation for any purpose is hereby granted without fee,
  37  * provided that the above copyright notice appear in all copies and
  38  * that both that copyright notice and this permission notice appear
  39  * in supporting documentation.  Hewlett-Packard Company makes no
  40  * representations about the suitability of this software for any
  41  * purpose.  It is provided "as is" without express or implied warranty.
  42  *
  43  *
  44  * Copyright (c) 1996-1999
  45  * Silicon Graphics Computer Systems, Inc.
  46  *
  47  * Permission to use, copy, modify, distribute and sell this software
  48  * and its documentation for any purpose is hereby granted without fee,
  49  * provided that the above copyright notice appear in all copies and
  50  * that both that copyright notice and this permission notice appear
  51  * in supporting documentation.  Silicon Graphics makes no
  52  * representations about the suitability of this software for any
  53  * purpose.  It is provided "as is" without express or implied warranty.
  54  */
  55
  56 /** @file stl_bvector.h
  57  *  This is an internal header file, included by other library headers.
  58  *  You should not attempt to use it directly.
  59  */
  60
  61 #ifndef _BVECTOR_H
  62 #define _BVECTOR_H 1
  63
  64 namespace _GLIBCXX_STD
  65 {
  66   typedef unsigned long _Bit_type;
  67   enum { _S_word_bit = int(CHAR_BIT * sizeof(_Bit_type)) };
  68
  69   struct _Bit_reference
  70   {
  71     _Bit_type * _M_p;
  72     _Bit_type _M_mask;
  73
  74     _Bit_reference(_Bit_type * __x, _Bit_type __y)
  75     : _M_p(__x), _M_mask(__y) { }
  76
  77     _Bit_reference() : _M_p(0), _M_mask(0) { }
  78
  79     operator bool() const
  80     { return !!(*_M_p & _M_mask); }
  81
  82     _Bit_reference&
  83     operator=(bool __x)
  84     {
  85       if (__x)
  86         *_M_p |= _M_mask;
  87       else
  88         *_M_p &= ~_M_mask;
  89       return *this;
  90     }
  91
  92     _Bit_reference&
  93     operator=(const _Bit_reference& __x)
  94     { return *this = bool(__x); }
  95
  96     bool
  97     operator==(const _Bit_reference& __x) const
  98     { return bool(*this) == bool(__x); }
  99
 100     bool
 101     operator<(const _Bit_reference& __x) const
 102     { return !bool(*this) && bool(__x); }
 103
 104     void
 105     flip()
 106     { *_M_p ^= _M_mask; }
 107   };
 108
 109   struct _Bit_iterator_base : public iterator<random_access_iterator_tag, bool>
 110   {
 111     _Bit_type * _M_p;
 112     unsigned int _M_offset;
 113
 114     _Bit_iterator_base(_Bit_type * __x, unsigned int __y)
 115     : _M_p(__x), _M_offset(__y) { }
 116
 117     void
 118     _M_bump_up()
 119     {
 120       if (_M_offset++ == _S_word_bit - 1)
 121         {
 122           _M_offset = 0;
 123           ++_M_p;
 124         }
 125     }
 126
 127     void
 128     _M_bump_down()
 129     {
 130       if (_M_offset-- == 0)
 131         {
 132           _M_offset = _S_word_bit - 1;
 133           --_M_p;
 134         }
 135     }
 136
 137     void
 138     _M_incr(ptrdiff_t __i)
 139     {
 140       difference_type __n = __i + _M_offset;
 141       _M_p += __n / _S_word_bit;
 142       __n = __n % _S_word_bit;
 143       if (__n < 0)
 144         {
 145           _M_offset = static_cast<unsigned int>(__n + _S_word_bit);
 146           --_M_p;
 147         }
 148       else
 149         _M_offset = static_cast<unsigned int>(__n);
 150     }
 151
 152     bool
 153     operator==(const _Bit_iterator_base& __i) const
 154     { return _M_p == __i._M_p && _M_offset == __i._M_offset; }
 155
 156     bool
 157     operator<(const _Bit_iterator_base& __i) const
 158     {
 159       return _M_p < __i._M_p
 160              || (_M_p == __i._M_p && _M_offset < __i._M_offset);
 161     }
 162
 163     bool
 164     operator!=(const _Bit_iterator_base& __i) const
 165     { return !(*this == __i); }
 166
 167     bool
 168     operator>(const _Bit_iterator_base& __i) const
 169     { return __i < *this; }
 170
 171     bool
 172     operator<=(const _Bit_iterator_base& __i) const
 173     { return !(__i < *this); }
 174
 175     bool
 176     operator>=(const _Bit_iterator_base& __i) const
 177     { return !(*this < __i); }
 178   };
 179
 180   inline ptrdiff_t
 181   operator-(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y)
 182   {
 183     return _S_word_bit * (__x._M_p - __y._M_p) + __x._M_offset - __y._M_offset;
 184   }
 185
 186   struct _Bit_iterator : public _Bit_iterator_base
 187   {
 188     typedef _Bit_reference  reference;
 189     typedef _Bit_reference* pointer;
 190     typedef _Bit_iterator   iterator;
 191
 192     _Bit_iterator() : _Bit_iterator_base(0, 0) { }
 193
 194     _Bit_iterator(_Bit_type * __x, unsigned int __y)
 195     : _Bit_iterator_base(__x, __y) { }
 196
 197     reference
 198     operator*() const
 199     { return reference(_M_p, 1UL << _M_offset); }
 200
 201     iterator&
 202     operator++()
 203     {
 204       _M_bump_up();
 205       return *this;
 206     }
 207
 208     iterator
 209     operator++(int)
 210     {
 211       iterator __tmp = *this;
 212       _M_bump_up();
 213       return __tmp;
 214     }
 215
 216     iterator&
 217     operator--()
 218     {
 219       _M_bump_down();
 220       return *this;
 221     }
 222
 223     iterator
 224     operator--(int)
 225     {
 226       iterator __tmp = *this;
 227       _M_bump_down();
 228       return __tmp;
 229     }
 230
 231     iterator&
 232     operator+=(difference_type __i)
 233     {
 234       _M_incr(__i);
 235       return *this;
 236     }
 237
 238     iterator&
 239     operator-=(difference_type __i)
 240     {
 241       *this += -__i;
 242       return *this;
 243     }
 244
 245     iterator
 246     operator+(difference_type __i) const
 247     {
 248       iterator __tmp = *this;
 249       return __tmp += __i;
 250     }
 251
 252     iterator
 253     operator-(difference_type __i) const
 254     {
 255       iterator __tmp = *this;
 256       return __tmp -= __i;
 257     }
 258
 259     reference
 260     operator[](difference_type __i)
 261     { return *(*this + __i); }
 262   };
 263
 264   inline _Bit_iterator
 265   operator+(ptrdiff_t __n, const _Bit_iterator& __x)
 266   { return __x + __n; }
 267
 268   struct _Bit_const_iterator : public _Bit_iterator_base
 269   {
 270     typedef bool                 reference;
 271     typedef bool                 const_reference;
 272     typedef const bool*          pointer;
 273     typedef _Bit_const_iterator  const_iterator;
 274
 275     _Bit_const_iterator() : _Bit_iterator_base(0, 0) { }
 276
 277     _Bit_const_iterator(_Bit_type * __x, unsigned int __y)
 278     : _Bit_iterator_base(__x, __y) { }
 279
 280     _Bit_const_iterator(const _Bit_iterator& __x)
 281     : _Bit_iterator_base(__x._M_p, __x._M_offset) { }
 282
 283     const_reference
 284     operator*() const
 285     { return _Bit_reference(_M_p, 1UL << _M_offset); }
 286
 287     const_iterator&
 288     operator++()
 289     {
 290       _M_bump_up();
 291       return *this;
 292     }
 293
 294     const_iterator
 295     operator++(int)
 296     {
 297       const_iterator __tmp = *this;
 298       _M_bump_up();
 299       return __tmp;
 300     }
 301
 302     const_iterator&
 303     operator--()
 304     {
 305       _M_bump_down();
 306       return *this;
 307     }
 308
 309     const_iterator
 310     operator--(int)
 311     {
 312       const_iterator __tmp = *this;
 313       _M_bump_down();
 314       return __tmp;
 315     }
 316
 317     const_iterator&
 318     operator+=(difference_type __i)
 319     {
 320       _M_incr(__i);
 321       return *this;
 322     }
 323
 324     const_iterator&
 325     operator-=(difference_type __i)
 326     {
 327       *this += -__i;
 328       return *this;
 329     }
 330
 331     const_iterator
 332     operator+(difference_type __i) const
 333     {
 334       const_iterator __tmp = *this;
 335       return __tmp += __i;
 336     }
 337
 338     const_iterator
 339     operator-(difference_type __i) const
 340     {
 341       const_iterator __tmp = *this;
 342       return __tmp -= __i;
 343     }
 344
 345     const_reference
 346     operator[](difference_type __i)
 347     { return *(*this + __i); }
 348   };
 349
 350   inline _Bit_const_iterator
 351   operator+(ptrdiff_t __n, const _Bit_const_iterator& __x)
 352   { return __x + __n; }
 353
 354   template<class _Alloc>
 355     class _Bvector_base
 356     {
 357       typedef typename _Alloc::template rebind<_Bit_type>::other
 358         _Bit_alloc_type;
 359
 360       struct _Bvector_impl : public _Bit_alloc_type
 361       {
 362         _Bit_iterator   _M_start;
 363         _Bit_iterator   _M_finish;
 364         _Bit_type*      _M_end_of_storage;
 365         _Bvector_impl(const _Bit_alloc_type& __a)
 366         : _Bit_alloc_type(__a), _M_start(), _M_finish(), _M_end_of_storage(0)
 367         { }
 368       };
 369
 370     public:
 371       typedef _Alloc allocator_type;
 372
 373       allocator_type
 374       get_allocator() const
 375       { return *static_cast<const _Bit_alloc_type*>(&this->_M_impl); }
 376
 377       _Bvector_base(const allocator_type& __a) : _M_impl(__a) { }
 378
 379       ~_Bvector_base()
 380       { this->_M_deallocate(); }
 381
 382     protected:
 383       _Bvector_impl _M_impl;
 384
 385       _Bit_type*
 386       _M_allocate(size_t __n)
 387       { return _M_impl.allocate((__n + _S_word_bit - 1) / _S_word_bit); }
 388
 389       void
 390       _M_deallocate()
 391       {
 392         if (_M_impl._M_start._M_p)
 393           _M_impl.deallocate(_M_impl._M_start._M_p,
 394                              _M_impl._M_end_of_storage - _M_impl._M_start._M_p);
 395       }
 396     };
 397 } // namespace std
 398
 399 // Declare a partial specialization of vector<T, Alloc>.
 400 #include <bits/stl_vector.h>
 401
 402 namespace _GLIBCXX_STD
 403 {
 404   /**
 405    *  @brief  A specialization of vector for booleans which offers fixed time
 406    *  access to individual elements in any order.
 407    *
 408    *  Note that vector<bool> does not actually meet the requirements for being
 409    *  a container.  This is because the reference and pointer types are not
 410    *  really references and pointers to bool.  See DR96 for details.  @see
 411    *  vector for function documentation.
 412    *
 413    *  @ingroup Containers
 414    *  @ingroup Sequences
 415    *
 416    *  In some terminology a %vector can be described as a dynamic
 417    *  C-style array, it offers fast and efficient access to individual
 418    *  elements in any order and saves the user from worrying about
 419    *  memory and size allocation.  Subscripting ( @c [] ) access is
 420    *  also provided as with C-style arrays.
 421   */
 422 template<typename _Alloc>
 423   class vector<bool, _Alloc> : public _Bvector_base<_Alloc>
 424   {
 425   public:
 426     typedef bool value_type;
 427     typedef size_t size_type;
 428     typedef ptrdiff_t difference_type;
 429     typedef _Bit_reference reference;
 430     typedef bool const_reference;
 431     typedef _Bit_reference* pointer;
 432     typedef const bool* const_pointer;
 433
 434     typedef _Bit_iterator                iterator;
 435     typedef _Bit_const_iterator          const_iterator;
 436
 437     typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 438     typedef std::reverse_iterator<iterator> reverse_iterator;
 439
 440     typedef typename _Bvector_base<_Alloc>::allocator_type allocator_type;
 441
 442     allocator_type get_allocator() const
 443     { return _Bvector_base<_Alloc>::get_allocator(); }
 444
 445   protected:
 446     using _Bvector_base<_Alloc>::_M_allocate;
 447     using _Bvector_base<_Alloc>::_M_deallocate;
 448
 449   protected:
 450     void
 451     _M_initialize(size_type __n)
 452     {
 453       _Bit_type* __q = this->_M_allocate(__n);
 454       this->_M_impl._M_end_of_storage = (__q
 455                                          + ((__n + _S_word_bit - 1)
 456                                             / _S_word_bit));
 457       this->_M_impl._M_start = iterator(__q, 0);
 458       this->_M_impl._M_finish = this->_M_impl._M_start + difference_type(__n);
 459     }
 460
 461     void
 462     _M_insert_aux(iterator __position, bool __x)
 463     {
 464       if (this->_M_impl._M_finish._M_p != this->_M_impl._M_end_of_storage)
 465         {
 466           std::copy_backward(__position, this->_M_impl._M_finish,
 467                              this->_M_impl._M_finish + 1);
 468           *__position = __x;
 469           ++this->_M_impl._M_finish;
 470         }
 471       else
 472         {
 473           const size_type __len = size() ? 2 * size()
 474                                          : static_cast<size_type>(_S_word_bit);
 475           _Bit_type * __q = this->_M_allocate(__len);
 476           iterator __i = std::copy(begin(), __position, iterator(__q, 0));
 477           *__i++ = __x;
 478           this->_M_impl._M_finish = std::copy(__position, end(), __i);
 479           this->_M_deallocate();
 480           this->_M_impl._M_end_of_storage = (__q + ((__len + _S_word_bit - 1)
 481                                                     / _S_word_bit));
 482           this->_M_impl._M_start = iterator(__q, 0);
 483         }
 484     }
 485
 486     template<class _InputIterator>
 487       void
 488       _M_initialize_range(_InputIterator __first, _InputIterator __last,
 489                           input_iterator_tag)
 490       {
 491         this->_M_impl._M_start = iterator();
 492         this->_M_impl._M_finish = iterator();
 493         this->_M_impl._M_end_of_storage = 0;
 494         for (; __first != __last; ++__first)
 495           push_back(*__first);
 496       }
 497
 498     template<class _ForwardIterator>
 499       void
 500       _M_initialize_range(_ForwardIterator __first, _ForwardIterator __last,
 501                           forward_iterator_tag)
 502       {
 503         const size_type __n = std::distance(__first, __last);
 504         _M_initialize(__n);
 505         std::copy(__first, __last, this->_M_impl._M_start);
 506       }
 507
 508     template<class _InputIterator>
 509       void
 510       _M_insert_range(iterator __pos, _InputIterator __first,
 511                       _InputIterator __last, input_iterator_tag)
 512       {
 513         for (; __first != __last; ++__first)
 514           {
 515             __pos = insert(__pos, *__first);
 516             ++__pos;
 517           }
 518       }
 519
 520     template<class _ForwardIterator>
 521       void
 522       _M_insert_range(iterator __position, _ForwardIterator __first,
 523                       _ForwardIterator __last, forward_iterator_tag)
 524       {
 525         if (__first != __last)
 526           {
 527             size_type __n = std::distance(__first, __last);
 528             if (capacity() - size() >= __n)
 529               {
 530                 std::copy_backward(__position, end(),
 531                                    this->_M_impl._M_finish
 532                                    + difference_type(__n));
 533                 std::copy(__first, __last, __position);
 534                 this->_M_impl._M_finish += difference_type(__n);
 535               }
 536             else
 537               {
 538                 const size_type __len = size() + std::max(size(), __n);
 539                 _Bit_type * __q = this->_M_allocate(__len);
 540                 iterator __i = std::copy(begin(), __position,
 541                                          iterator(__q, 0));
 542                 __i = std::copy(__first, __last, __i);
 543                 this->_M_impl._M_finish = std::copy(__position, end(), __i);
 544                 this->_M_deallocate();
 545                 this->_M_impl._M_end_of_storage = (__q
 546                                                    + ((__len + _S_word_bit - 1)
 547                                                       / _S_word_bit));
 548                 this->_M_impl._M_start = iterator(__q, 0);
 549               }
 550           }
 551       }
 552
 553   public:
 554     iterator
 555     begin()
 556     { return this->_M_impl._M_start; }
 557
 558     const_iterator
 559     begin() const
 560     { return this->_M_impl._M_start; }
 561
 562     iterator
 563     end()
 564     { return this->_M_impl._M_finish; }
 565
 566     const_iterator
 567     end() const
 568     { return this->_M_impl._M_finish; }
 569
 570     reverse_iterator
 571     rbegin()
 572     { return reverse_iterator(end()); }
 573
 574     const_reverse_iterator
 575     rbegin() const
 576     { return const_reverse_iterator(end()); }
 577
 578     reverse_iterator
 579     rend()
 580     { return reverse_iterator(begin()); }
 581
 582     const_reverse_iterator
 583     rend() const
 584     { return const_reverse_iterator(begin()); }
 585
 586     size_type
 587     size() const
 588     { return size_type(end() - begin()); }
 589
 590     size_type
 591     max_size() const
 592     { return size_type(-1); }
 593
 594     size_type
 595     capacity() const
 596     { return size_type(const_iterator(this->_M_impl._M_end_of_storage, 0)
 597                        - begin()); }
 598     bool
 599     empty() const
 600     { return begin() == end(); }
 601
 602     reference
 603     operator[](size_type __n)
 604     { return *(begin() + difference_type(__n)); }
 605
 606     const_reference
 607     operator[](size_type __n) const
 608     { return *(begin() + difference_type(__n)); }
 609
 610     void
 611     _M_range_check(size_type __n) const
 612     {
 613       if (__n >= this->size())
 614         __throw_out_of_range(__N("vector<bool>::_M_range_check"));
 615     }
 616
 617     reference
 618     at(size_type __n)
 619     { _M_range_check(__n); return (*this)[__n]; }
 620
 621     const_reference
 622     at(size_type __n) const
 623     { _M_range_check(__n); return (*this)[__n]; }
 624
 625     explicit
 626     vector(const allocator_type& __a = allocator_type())
 627     : _Bvector_base<_Alloc>(__a) { }
 628
 629     vector(size_type __n, bool __value,
 630            const allocator_type& __a = allocator_type())
 631     : _Bvector_base<_Alloc>(__a)
 632     {
 633       _M_initialize(__n);
 634       std::fill(this->_M_impl._M_start._M_p, this->_M_impl._M_end_of_storage,
 635                 __value ? ~0 : 0);
 636     }
 637
 638     explicit
 639     vector(size_type __n)
 640     : _Bvector_base<_Alloc>(allocator_type())
 641     {
 642       _M_initialize(__n);
 643       std::fill(this->_M_impl._M_start._M_p,
 644                 this->_M_impl._M_end_of_storage, 0);
 645     }
 646
 647     vector(const vector& __x)
 648     : _Bvector_base<_Alloc>(__x.get_allocator())
 649     {
 650       _M_initialize(__x.size());
 651       std::copy(__x.begin(), __x.end(), this->_M_impl._M_start);
 652     }
 653
 654     // Check whether it's an integral type.  If so, it's not an iterator.
 655     template<class _Integer>
 656       void
 657       _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type)
 658       {
 659         _M_initialize(__n);
 660         std::fill(this->_M_impl._M_start._M_p,
 661                   this->_M_impl._M_end_of_storage, __x ? ~0 : 0);
 662       }
 663
 664     template<class _InputIterator>
 665       void
 666       _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
 667                              __false_type)
 668       { _M_initialize_range(__first, __last,
 669                             std::__iterator_category(__first)); }
 670
 671     template<class _InputIterator>
 672       vector(_InputIterator __first, _InputIterator __last,
 673              const allocator_type& __a = allocator_type())
 674       : _Bvector_base<_Alloc>(__a)
 675       {
 676         typedef typename std::__is_integer<_InputIterator>::__type _Integral;
 677         _M_initialize_dispatch(__first, __last, _Integral());
 678       }
 679
 680     ~vector() { }
 681
 682     vector&
 683     operator=(const vector& __x)
 684     {
 685       if (&__x == this)
 686         return *this;
 687       if (__x.size() > capacity())
 688         {
 689           this->_M_deallocate();
 690           _M_initialize(__x.size());
 691         }
 692       std::copy(__x.begin(), __x.end(), begin());
 693       this->_M_impl._M_finish = begin() + difference_type(__x.size());
 694       return *this;
 695     }
 696
 697     // assign(), a generalized assignment member function.  Two
 698     // versions: one that takes a count, and one that takes a range.
 699     // The range version is a member template, so we dispatch on whether
 700     // or not the type is an integer.
 701
 702     void
 703     _M_fill_assign(size_t __n, bool __x)
 704     {
 705       if (__n > size())
 706         {
 707           std::fill(this->_M_impl._M_start._M_p,
 708                     this->_M_impl._M_end_of_storage, __x ? ~0 : 0);
 709           insert(end(), __n - size(), __x);
 710         }
 711       else
 712         {
 713           erase(begin() + __n, end());
 714           std::fill(this->_M_impl._M_start._M_p,
 715                     this->_M_impl._M_end_of_storage, __x ? ~0 : 0);
 716         }
 717     }
 718
 719     void
 720     assign(size_t __n, bool __x)
 721     { _M_fill_assign(__n, __x); }
 722
 723     template<class _InputIterator>
 724       void
 725       assign(_InputIterator __first, _InputIterator __last)
 726       {
 727         typedef typename std::__is_integer<_InputIterator>::__type _Integral;
 728         _M_assign_dispatch(__first, __last, _Integral());
 729       }
 730
 731     template<class _Integer>
 732       void
 733       _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
 734       { _M_fill_assign((size_t) __n, (bool) __val); }
 735
 736     template<class _InputIterator>
 737       void
 738       _M_assign_dispatch(_InputIterator __first, _InputIterator __last,
 739                          __false_type)
 740       { _M_assign_aux(__first, __last, std::__iterator_category(__first)); }
 741
 742     template<class _InputIterator>
 743       void
 744       _M_assign_aux(_InputIterator __first, _InputIterator __last,
 745                     input_iterator_tag)
 746       {
 747         iterator __cur = begin();
 748         for (; __first != __last && __cur != end(); ++__cur, ++__first)
 749           *__cur = *__first;
 750         if (__first == __last)
 751           erase(__cur, end());
 752         else
 753           insert(end(), __first, __last);
 754       }
 755
 756     template<class _ForwardIterator>
 757       void
 758       _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
 759                     forward_iterator_tag)
 760       {
 761         const size_type __len = std::distance(__first, __last);
 762         if (__len < size())
 763           erase(std::copy(__first, __last, begin()), end());
 764         else
 765           {
 766             _ForwardIterator __mid = __first;
 767             std::advance(__mid, size());
 768             std::copy(__first, __mid, begin());
 769             insert(end(), __mid, __last);
 770           }
 771       }
 772
 773     void
 774     reserve(size_type __n)
 775     {
 776       if (__n > this->max_size())
 777         __throw_length_error(__N("vector::reserve"));
 778       if (this->capacity() < __n)
 779         {
 780           _Bit_type* __q = this->_M_allocate(__n);
 781           this->_M_impl._M_finish = std::copy(begin(), end(),
 782                                               iterator(__q, 0));
 783           this->_M_deallocate();
 784           this->_M_impl._M_start = iterator(__q, 0);
 785           this->_M_impl._M_end_of_storage = (__q + (__n + _S_word_bit - 1)
 786                                              / _S_word_bit);
 787         }
 788     }
 789
 790     reference
 791     front()
 792     { return *begin(); }
 793
 794     const_reference
 795     front() const
 796     { return *begin(); }
 797
 798     reference
 799     back()
 800     { return *(end() - 1); }
 801
 802     const_reference
 803     back() const
 804     { return *(end() - 1); }
 805
 806     void
 807     push_back(bool __x)
 808     {
 809       if (this->_M_impl._M_finish._M_p != this->_M_impl._M_end_of_storage)
 810         *this->_M_impl._M_finish++ = __x;
 811       else
 812         _M_insert_aux(end(), __x);
 813     }
 814
 815     void
 816     swap(vector<bool, _Alloc>& __x)
 817     {
 818       std::swap(this->_M_impl._M_start, __x._M_impl._M_start);
 819       std::swap(this->_M_impl._M_finish, __x._M_impl._M_finish);
 820       std::swap(this->_M_impl._M_end_of_storage,
 821                 __x._M_impl._M_end_of_storage);
 822     }
 823
 824     // [23.2.5]/1, third-to-last entry in synopsis listing
 825     static void
 826     swap(reference __x, reference __y)
 827     {
 828       bool __tmp = __x;
 829       __x = __y;
 830       __y = __tmp;
 831     }
 832
 833     iterator
 834     insert(iterator __position, bool __x = bool())
 835     {
 836       const difference_type __n = __position - begin();
 837       if (this->_M_impl._M_finish._M_p != this->_M_impl._M_end_of_storage
 838           && __position == end())
 839         *this->_M_impl._M_finish++ = __x;
 840       else
 841         _M_insert_aux(__position, __x);
 842       return begin() + __n;
 843     }
 844
 845     // Check whether it's an integral type.  If so, it's not an iterator.
 846
 847     template<class _Integer>
 848       void
 849       _M_insert_dispatch(iterator __pos, _Integer __n, _Integer __x,
 850                          __true_type)
 851       { _M_fill_insert(__pos, __n, __x); }
 852
 853     template<class _InputIterator>
 854       void
 855       _M_insert_dispatch(iterator __pos,
 856                          _InputIterator __first, _InputIterator __last,
 857                          __false_type)
 858       { _M_insert_range(__pos, __first, __last,
 859                         std::__iterator_category(__first)); }
 860
 861     template<class _InputIterator>
 862       void
 863       insert(iterator __position,
 864              _InputIterator __first, _InputIterator __last)
 865       {
 866         typedef typename std::__is_integer<_InputIterator>::__type _Integral;
 867         _M_insert_dispatch(__position, __first, __last, _Integral());
 868       }
 869
 870     void
 871     _M_fill_insert(iterator __position, size_type __n, bool __x)
 872     {
 873       if (__n == 0)
 874         return;
 875       if (capacity() - size() >= __n)
 876         {
 877           std::copy_backward(__position, end(),
 878                              this->_M_impl._M_finish + difference_type(__n));
 879           std::fill(__position, __position + difference_type(__n), __x);
 880           this->_M_impl._M_finish += difference_type(__n);
 881         }
 882       else
 883         {
 884           const size_type __len = size() + std::max(size(), __n);
 885           _Bit_type * __q = this->_M_allocate(__len);
 886           iterator __i = std::copy(begin(), __position, iterator(__q, 0));
 887           std::fill_n(__i, __n, __x);
 888           this->_M_impl._M_finish = std::copy(__position, end(),
 889                                               __i + difference_type(__n));
 890           this->_M_deallocate();
 891           this->_M_impl._M_end_of_storage = (__q + ((__len + _S_word_bit - 1)
 892                                                     / _S_word_bit));
 893           this->_M_impl._M_start = iterator(__q, 0);
 894         }
 895     }
 896
 897     void
 898     insert(iterator __position, size_type __n, bool __x)
 899     { _M_fill_insert(__position, __n, __x); }
 900
 901     void
 902     pop_back()
 903     { --this->_M_impl._M_finish; }
 904
 905     iterator
 906     erase(iterator __position)
 907     {
 908       if (__position + 1 != end())
 909         std::copy(__position + 1, end(), __position);
 910       --this->_M_impl._M_finish;
 911       return __position;
 912     }
 913
 914     iterator
 915     erase(iterator __first, iterator __last)
 916     {
 917       this->_M_impl._M_finish = std::copy(__last, end(), __first);
 918       return __first;
 919     }
 920
 921     void
 922     resize(size_type __new_size, bool __x = bool())
 923     {
 924       if (__new_size < size())
 925         erase(begin() + difference_type(__new_size), end());
 926       else
 927         insert(end(), __new_size - size(), __x);
 928     }
 929
 930     void
 931     flip()
 932     {
 933       for (_Bit_type * __p = this->_M_impl._M_start._M_p;
 934            __p != this->_M_impl._M_end_of_storage; ++__p)
 935         *__p = ~*__p;
 936     }
 937
 938     void
 939     clear()
 940     { erase(begin(), end()); }
 941   };
 942 } // namespace std
 943
 944 #endif