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

   1 // bit_vector and vector<bool> specialization -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002 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 __GLIBCPP_INTERNAL_BVECTOR_H
  62 #define __GLIBCPP_INTERNAL_BVECTOR_H
  63
  64 namespace std
  65 {
  66   typedef unsigned long _Bit_type;
  67   enum { _M_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   _Bit_reference(_Bit_type * __x, _Bit_type __y)
  74     : _M_p(__x), _M_mask(__y) {}
  75
  76 public:
  77   _Bit_reference() : _M_p(0), _M_mask(0) {}
  78   operator bool() const { return !!(*_M_p & _M_mask); }
  79   _Bit_reference& operator=(bool __x)
  80   {
  81     if (__x)  *_M_p |= _M_mask;
  82     else      *_M_p &= ~_M_mask;
  83     return *this;
  84   }
  85   _Bit_reference& operator=(const _Bit_reference& __x)
  86     { return *this = bool(__x); }
  87   bool operator==(const _Bit_reference& __x) const
  88     { return bool(*this) == bool(__x); }
  89   bool operator<(const _Bit_reference& __x) const
  90     { return !bool(*this) && bool(__x); }
  91   void flip() { *_M_p ^= _M_mask; }
  92 };
  93
  94 struct _Bit_iterator_base : public iterator<random_access_iterator_tag, bool>
  95 {
  96   _Bit_type * _M_p;
  97   unsigned int _M_offset;
  98
  99   _Bit_iterator_base(_Bit_type * __x, unsigned int __y)
 100     : _M_p(__x), _M_offset(__y) {}
 101
 102   void _M_bump_up() {
 103     if (_M_offset++ == _M_word_bit - 1) {
 104       _M_offset = 0;
 105       ++_M_p;
 106     }
 107   }
 108   void _M_bump_down() {
 109     if (_M_offset-- == 0) {
 110       _M_offset = _M_word_bit - 1;
 111       --_M_p;
 112     }
 113   }
 114
 115   void _M_incr(ptrdiff_t __i) {
 116     difference_type __n = __i + _M_offset;
 117     _M_p += __n / _M_word_bit;
 118     __n = __n % _M_word_bit;
 119     if (__n < 0) {
 120       _M_offset = (unsigned int) __n + _M_word_bit;
 121       --_M_p;
 122     } else
 123       _M_offset = (unsigned int) __n;
 124   }
 125
 126   bool operator==(const _Bit_iterator_base& __i) const {
 127     return _M_p == __i._M_p && _M_offset == __i._M_offset;
 128   }
 129   bool operator<(const _Bit_iterator_base& __i) const {
 130     return _M_p < __i._M_p || (_M_p == __i._M_p && _M_offset < __i._M_offset);
 131   }
 132   bool operator!=(const _Bit_iterator_base& __i) const {
 133     return !(*this == __i);
 134   }
 135   bool operator>(const _Bit_iterator_base& __i) const {
 136     return __i < *this;
 137   }
 138   bool operator<=(const _Bit_iterator_base& __i) const {
 139     return !(__i < *this);
 140   }
 141   bool operator>=(const _Bit_iterator_base& __i) const {
 142     return !(*this < __i);
 143   }
 144 };
 145
 146 inline ptrdiff_t
 147 operator-(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y) {
 148   return _M_word_bit * (__x._M_p - __y._M_p) + __x._M_offset - __y._M_offset;
 149 }
 150
 151
 152 struct _Bit_iterator : public _Bit_iterator_base
 153 {
 154   typedef _Bit_reference  reference;
 155   typedef _Bit_reference* pointer;
 156   typedef _Bit_iterator   iterator;
 157
 158   _Bit_iterator() : _Bit_iterator_base(0, 0) {}
 159   _Bit_iterator(_Bit_type * __x, unsigned int __y)
 160     : _Bit_iterator_base(__x, __y) {}
 161
 162   reference operator*() const { return reference(_M_p, 1UL << _M_offset); }
 163   iterator& operator++() {
 164     _M_bump_up();
 165     return *this;
 166   }
 167   iterator operator++(int) {
 168     iterator __tmp = *this;
 169     _M_bump_up();
 170     return __tmp;
 171   }
 172   iterator& operator--() {
 173     _M_bump_down();
 174     return *this;
 175   }
 176   iterator operator--(int) {
 177     iterator __tmp = *this;
 178     _M_bump_down();
 179     return __tmp;
 180   }
 181   iterator& operator+=(difference_type __i) {
 182     _M_incr(__i);
 183     return *this;
 184   }
 185   iterator& operator-=(difference_type __i) {
 186     *this += -__i;
 187     return *this;
 188   }
 189   iterator operator+(difference_type __i) const {
 190     iterator __tmp = *this;
 191     return __tmp += __i;
 192   }
 193   iterator operator-(difference_type __i) const {
 194     iterator __tmp = *this;
 195     return __tmp -= __i;
 196   }
 197
 198   reference operator[](difference_type __i) { return *(*this + __i); }
 199 };
 200
 201 inline _Bit_iterator
 202 operator+(ptrdiff_t __n, const _Bit_iterator& __x) { return __x + __n; }
 203
 204
 205 struct _Bit_const_iterator : public _Bit_iterator_base
 206 {
 207   typedef bool                 reference;
 208   typedef bool                 const_reference;
 209   typedef const bool*          pointer;
 210   typedef _Bit_const_iterator  const_iterator;
 211
 212   _Bit_const_iterator() : _Bit_iterator_base(0, 0) {}
 213   _Bit_const_iterator(_Bit_type * __x, unsigned int __y)
 214     : _Bit_iterator_base(__x, __y) {}
 215   _Bit_const_iterator(const _Bit_iterator& __x)
 216     : _Bit_iterator_base(__x._M_p, __x._M_offset) {}
 217
 218   const_reference operator*() const {
 219     return _Bit_reference(_M_p, 1UL << _M_offset);
 220   }
 221   const_iterator& operator++() {
 222     _M_bump_up();
 223     return *this;
 224   }
 225   const_iterator operator++(int) {
 226     const_iterator __tmp = *this;
 227     _M_bump_up();
 228     return __tmp;
 229   }
 230   const_iterator& operator--() {
 231     _M_bump_down();
 232     return *this;
 233   }
 234   const_iterator operator--(int) {
 235     const_iterator __tmp = *this;
 236     _M_bump_down();
 237     return __tmp;
 238   }
 239   const_iterator& operator+=(difference_type __i) {
 240     _M_incr(__i);
 241     return *this;
 242   }
 243   const_iterator& operator-=(difference_type __i) {
 244     *this += -__i;
 245     return *this;
 246   }
 247   const_iterator operator+(difference_type __i) const {
 248     const_iterator __tmp = *this;
 249     return __tmp += __i;
 250   }
 251   const_iterator operator-(difference_type __i) const {
 252     const_iterator __tmp = *this;
 253     return __tmp -= __i;
 254   }
 255   const_reference operator[](difference_type __i) {
 256     return *(*this + __i);
 257   }
 258 };
 259
 260 inline _Bit_const_iterator
 261 operator+(ptrdiff_t __n, const _Bit_const_iterator& __x) { return __x + __n; }
 262
 263
 264 // Bit-vector base class, which encapsulates the difference between
 265 // old SGI-style allocators and standard-conforming allocators.
 266
 267 // Base class for ordinary allocators.
 268 template <class _Allocator, bool __is_static>
 269 class _Bvector_alloc_base {
 270 public:
 271   typedef typename _Alloc_traits<bool, _Allocator>::allocator_type
 272           allocator_type;
 273   allocator_type get_allocator() const { return _M_data_allocator; }
 274
 275   _Bvector_alloc_base(const allocator_type& __a)
 276     : _M_data_allocator(__a), _M_start(), _M_finish(), _M_end_of_storage(0) {}
 277
 278 protected:
 279   _Bit_type * _M_bit_alloc(size_t __n)
 280     { return _M_data_allocator.allocate((__n + _M_word_bit - 1)/_M_word_bit); }
 281   void _M_deallocate() {
 282     if (_M_start._M_p)
 283       _M_data_allocator.deallocate(_M_start._M_p,
 284                                    _M_end_of_storage - _M_start._M_p);
 285   }
 286
 287   typename _Alloc_traits<_Bit_type, _Allocator>::allocator_type
 288           _M_data_allocator;
 289   _Bit_iterator _M_start;
 290   _Bit_iterator _M_finish;
 291   _Bit_type * _M_end_of_storage;
 292 };
 293
 294 // Specialization for instanceless allocators.
 295 template <class _Allocator>
 296 class _Bvector_alloc_base<_Allocator, true> {
 297 public:
 298   typedef typename _Alloc_traits<bool, _Allocator>::allocator_type
 299           allocator_type;
 300   allocator_type get_allocator() const { return allocator_type(); }
 301
 302   _Bvector_alloc_base(const allocator_type&)
 303     : _M_start(), _M_finish(), _M_end_of_storage(0) {}
 304
 305 protected:
 306   typedef typename _Alloc_traits<_Bit_type, _Allocator>::_Alloc_type
 307           _Alloc_type;
 308
 309   _Bit_type * _M_bit_alloc(size_t __n)
 310     { return _Alloc_type::allocate((__n + _M_word_bit - 1)/_M_word_bit); }
 311   void _M_deallocate() {
 312     if (_M_start._M_p)
 313       _Alloc_type::deallocate(_M_start._M_p,
 314                               _M_end_of_storage - _M_start._M_p);
 315   }
 316
 317   _Bit_iterator _M_start;
 318   _Bit_iterator _M_finish;
 319   _Bit_type * _M_end_of_storage;
 320 };
 321
 322 template <class _Alloc>
 323 class _Bvector_base
 324   : public _Bvector_alloc_base<_Alloc,
 325                                _Alloc_traits<bool, _Alloc>::_S_instanceless>
 326 {
 327   typedef _Bvector_alloc_base<_Alloc,
 328                               _Alloc_traits<bool, _Alloc>::_S_instanceless>
 329           _Base;
 330 public:
 331   typedef typename _Base::allocator_type allocator_type;
 332
 333   _Bvector_base(const allocator_type& __a) : _Base(__a) {}
 334   ~_Bvector_base() { _Base::_M_deallocate(); }
 335 };
 336
 337 } // namespace std
 338
 339 // Declare a partial specialization of vector<T, Alloc>.
 340 #include <bits/stl_vector.h>
 341 namespace std
 342 {
 343
 344 template <typename _Alloc>
 345   class vector<bool, _Alloc> : public _Bvector_base<_Alloc>
 346   {
 347   public:
 348     typedef bool value_type;
 349     typedef size_t size_type;
 350     typedef ptrdiff_t difference_type;
 351     typedef _Bit_reference reference;
 352     typedef bool const_reference;
 353     typedef _Bit_reference* pointer;
 354     typedef const bool* const_pointer;
 355
 356     typedef _Bit_iterator                iterator;
 357     typedef _Bit_const_iterator          const_iterator;
 358
 359     typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 360     typedef std::reverse_iterator<iterator> reverse_iterator;
 361
 362     typedef typename _Bvector_base<_Alloc>::allocator_type allocator_type;
 363     allocator_type get_allocator() const {
 364       return _Bvector_base<_Alloc>::get_allocator();
 365     }
 366
 367   protected:
 368     using _Bvector_base<_Alloc>::_M_bit_alloc;
 369     using _Bvector_base<_Alloc>::_M_deallocate;
 370     using _Bvector_base<_Alloc>::_M_start;
 371     using _Bvector_base<_Alloc>::_M_finish;
 372     using _Bvector_base<_Alloc>::_M_end_of_storage;
 373
 374   protected:
 375     void _M_initialize(size_type __n) {
 376       _Bit_type * __q = _M_bit_alloc(__n);
 377       _M_end_of_storage = __q + (__n + _M_word_bit - 1)/_M_word_bit;
 378       _M_start = iterator(__q, 0);
 379       _M_finish = _M_start + difference_type(__n);
 380     }
 381     void _M_insert_aux(iterator __position, bool __x) {
 382       if (_M_finish._M_p != _M_end_of_storage) {
 383         copy_backward(__position, _M_finish, _M_finish + 1);
 384         *__position = __x;
 385         ++_M_finish;
 386       }
 387       else {
 388         size_type __len = size()
 389                           ? 2 * size() : static_cast<size_type>(_M_word_bit);
 390         _Bit_type * __q = _M_bit_alloc(__len);
 391         iterator __i = copy(begin(), __position, iterator(__q, 0));
 392         *__i++ = __x;
 393         _M_finish = copy(__position, end(), __i);
 394         _M_deallocate();
 395         _M_end_of_storage = __q + (__len + _M_word_bit - 1)/_M_word_bit;
 396         _M_start = iterator(__q, 0);
 397       }
 398     }
 399
 400     template <class _InputIterator>
 401     void _M_initialize_range(_InputIterator __first, _InputIterator __last,
 402                              input_iterator_tag) {
 403       _M_start = iterator();
 404       _M_finish = iterator();
 405       _M_end_of_storage = 0;
 406       for ( ; __first != __last; ++__first)
 407         push_back(*__first);
 408     }
 409
 410     template <class _ForwardIterator>
 411     void _M_initialize_range(_ForwardIterator __first, _ForwardIterator __last,
 412                              forward_iterator_tag) {
 413       size_type __n = distance(__first, __last);
 414       _M_initialize(__n);
 415       copy(__first, __last, _M_start);
 416     }
 417
 418     template <class _InputIterator>
 419     void _M_insert_range(iterator __pos,
 420                          _InputIterator __first, _InputIterator __last,
 421                          input_iterator_tag) {
 422       for ( ; __first != __last; ++__first) {
 423         __pos = insert(__pos, *__first);
 424         ++__pos;
 425       }
 426     }
 427
 428     template <class _ForwardIterator>
 429     void _M_insert_range(iterator __position,
 430                          _ForwardIterator __first, _ForwardIterator __last,
 431                          forward_iterator_tag) {
 432       if (__first != __last) {
 433         size_type __n = distance(__first, __last);
 434         if (capacity() - size() >= __n) {
 435           copy_backward(__position, end(), _M_finish + difference_type(__n));
 436           copy(__first, __last, __position);
 437           _M_finish += difference_type(__n);
 438         }
 439         else {
 440           size_type __len = size() + max(size(), __n);
 441           _Bit_type * __q = _M_bit_alloc(__len);
 442           iterator __i = copy(begin(), __position, iterator(__q, 0));
 443           __i = copy(__first, __last, __i);
 444           _M_finish = copy(__position, end(), __i);
 445           _M_deallocate();
 446           _M_end_of_storage = __q + (__len + _M_word_bit - 1)/_M_word_bit;
 447           _M_start = iterator(__q, 0);
 448         }
 449       }
 450     }
 451
 452   public:
 453     iterator begin() { return _M_start; }
 454     const_iterator begin() const { return _M_start; }
 455     iterator end() { return _M_finish; }
 456     const_iterator end() const { return _M_finish; }
 457
 458     reverse_iterator rbegin() { return reverse_iterator(end()); }
 459     const_reverse_iterator rbegin() const {
 460       return const_reverse_iterator(end());
 461     }
 462     reverse_iterator rend() { return reverse_iterator(begin()); }
 463     const_reverse_iterator rend() const {
 464       return const_reverse_iterator(begin());
 465     }
 466
 467     size_type size() const { return size_type(end() - begin()); }
 468     size_type max_size() const { return size_type(-1); }
 469     size_type capacity() const {
 470       return size_type(const_iterator(_M_end_of_storage, 0) - begin());
 471     }
 472     bool empty() const { return begin() == end(); }
 473
 474     reference operator[](size_type __n)
 475       { return *(begin() + difference_type(__n)); }
 476     const_reference operator[](size_type __n) const
 477       { return *(begin() + difference_type(__n)); }
 478
 479     void _M_range_check(size_type __n) const {
 480       if (__n >= this->size())
 481         __throw_out_of_range("vector<bool>");
 482     }
 483
 484     reference at(size_type __n)
 485       { _M_range_check(__n); return (*this)[__n]; }
 486     const_reference at(size_type __n) const
 487       { _M_range_check(__n); return (*this)[__n]; }
 488
 489     explicit vector(const allocator_type& __a = allocator_type())
 490       : _Bvector_base<_Alloc>(__a) {}
 491
 492     vector(size_type __n, bool __value,
 493               const allocator_type& __a = allocator_type())
 494       : _Bvector_base<_Alloc>(__a)
 495     {
 496       _M_initialize(__n);
 497       fill(_M_start._M_p, _M_end_of_storage, __value ? ~0 : 0);
 498     }
 499
 500     explicit vector(size_type __n)
 501       : _Bvector_base<_Alloc>(allocator_type())
 502     {
 503       _M_initialize(__n);
 504       fill(_M_start._M_p, _M_end_of_storage, 0);
 505     }
 506
 507     vector(const vector& __x) : _Bvector_base<_Alloc>(__x.get_allocator()) {
 508       _M_initialize(__x.size());
 509       copy(__x.begin(), __x.end(), _M_start);
 510     }
 511
 512     // Check whether it's an integral type.  If so, it's not an iterator.
 513
 514     template <class _Integer>
 515     void _M_initialize_dispatch(_Integer __n, _Integer __x, __true_type) {
 516       _M_initialize(__n);
 517       fill(_M_start._M_p, _M_end_of_storage, __x ? ~0 : 0);
 518     }
 519
 520     template <class _InputIterator>
 521     void _M_initialize_dispatch(_InputIterator __first, _InputIterator __last,
 522                                 __false_type) {
 523       _M_initialize_range(__first, __last, __iterator_category(__first));
 524     }
 525
 526     template <class _InputIterator>
 527     vector(_InputIterator __first, _InputIterator __last,
 528              const allocator_type& __a = allocator_type())
 529       : _Bvector_base<_Alloc>(__a)
 530     {
 531       typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
 532       _M_initialize_dispatch(__first, __last, _Integral());
 533     }
 534
 535     ~vector() { }
 536
 537     vector& operator=(const vector& __x) {
 538       if (&__x == this) return *this;
 539       if (__x.size() > capacity()) {
 540         _M_deallocate();
 541         _M_initialize(__x.size());
 542       }
 543       copy(__x.begin(), __x.end(), begin());
 544       _M_finish = begin() + difference_type(__x.size());
 545       return *this;
 546     }
 547
 548     // assign(), a generalized assignment member function.  Two
 549     // versions: one that takes a count, and one that takes a range.
 550     // The range version is a member template, so we dispatch on whether
 551     // or not the type is an integer.
 552
 553     void _M_fill_assign(size_t __n, bool __x) {
 554       if (__n > size()) {
 555         fill(_M_start._M_p, _M_end_of_storage, __x ? ~0 : 0);
 556         insert(end(), __n - size(), __x);
 557       }
 558       else {
 559         erase(begin() + __n, end());
 560         fill(_M_start._M_p, _M_end_of_storage, __x ? ~0 : 0);
 561       }
 562     }
 563
 564     void assign(size_t __n, bool __x) { _M_fill_assign(__n, __x); }
 565
 566     template <class _InputIterator>
 567     void assign(_InputIterator __first, _InputIterator __last) {
 568       typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
 569       _M_assign_dispatch(__first, __last, _Integral());
 570     }
 571
 572     template <class _Integer>
 573     void _M_assign_dispatch(_Integer __n, _Integer __val, __true_type)
 574       { _M_fill_assign((size_t) __n, (bool) __val); }
 575
 576     template <class _InputIter>
 577     void _M_assign_dispatch(_InputIter __first, _InputIter __last, __false_type)
 578       { _M_assign_aux(__first, __last, __iterator_category(__first)); }
 579
 580     template <class _InputIterator>
 581     void _M_assign_aux(_InputIterator __first, _InputIterator __last,
 582                        input_iterator_tag) {
 583       iterator __cur = begin();
 584       for ( ; __first != __last && __cur != end(); ++__cur, ++__first)
 585         *__cur = *__first;
 586       if (__first == __last)
 587         erase(__cur, end());
 588       else
 589         insert(end(), __first, __last);
 590     }
 591
 592     template <class _ForwardIterator>
 593     void _M_assign_aux(_ForwardIterator __first, _ForwardIterator __last,
 594                        forward_iterator_tag) {
 595       size_type __len = distance(__first, __last);
 596       if (__len < size())
 597         erase(copy(__first, __last, begin()), end());
 598       else {
 599         _ForwardIterator __mid = __first;
 600         advance(__mid, size());
 601         copy(__first, __mid, begin());
 602         insert(end(), __mid, __last);
 603       }
 604     }
 605
 606     void reserve(size_type __n) {
 607       if (capacity() < __n) {
 608         _Bit_type * __q = _M_bit_alloc(__n);
 609         _M_finish = copy(begin(), end(), iterator(__q, 0));
 610         _M_deallocate();
 611         _M_start = iterator(__q, 0);
 612         _M_end_of_storage = __q + (__n + _M_word_bit - 1)/_M_word_bit;
 613       }
 614     }
 615
 616     reference front() { return *begin(); }
 617     const_reference front() const { return *begin(); }
 618     reference back() { return *(end() - 1); }
 619     const_reference back() const { return *(end() - 1); }
 620     void push_back(bool __x) {
 621       if (_M_finish._M_p != _M_end_of_storage)
 622         *_M_finish++ = __x;
 623       else
 624         _M_insert_aux(end(), __x);
 625     }
 626     void swap(vector<bool, _Alloc>& __x) {
 627       std::swap(_M_start, __x._M_start);
 628       std::swap(_M_finish, __x._M_finish);
 629       std::swap(_M_end_of_storage, __x._M_end_of_storage);
 630     }
 631
 632     // [23.2.5]/1, third-to-last entry in synopsis listing
 633     static void swap(reference __x, reference __y) {
 634       bool __tmp = __x;
 635       __x = __y;
 636       __y = __tmp;
 637     }
 638
 639     iterator insert(iterator __position, bool __x = bool()) {
 640       difference_type __n = __position - begin();
 641       if (_M_finish._M_p != _M_end_of_storage && __position == end())
 642         *_M_finish++ = __x;
 643       else
 644         _M_insert_aux(__position, __x);
 645       return begin() + __n;
 646     }
 647
 648     // Check whether it's an integral type.  If so, it's not an iterator.
 649
 650     template <class _Integer>
 651     void _M_insert_dispatch(iterator __pos, _Integer __n, _Integer __x,
 652                             __true_type) {
 653       _M_fill_insert(__pos, __n, __x);
 654     }
 655
 656     template <class _InputIterator>
 657     void _M_insert_dispatch(iterator __pos,
 658                             _InputIterator __first, _InputIterator __last,
 659                             __false_type) {
 660       _M_insert_range(__pos, __first, __last, __iterator_category(__first));
 661     }
 662
 663     template <class _InputIterator>
 664     void insert(iterator __position,
 665                 _InputIterator __first, _InputIterator __last) {
 666       typedef typename _Is_integer<_InputIterator>::_Integral _Integral;
 667       _M_insert_dispatch(__position, __first, __last, _Integral());
 668     }
 669
 670     void _M_fill_insert(iterator __position, size_type __n, bool __x) {
 671       if (__n == 0) return;
 672       if (capacity() - size() >= __n) {
 673         copy_backward(__position, end(), _M_finish + difference_type(__n));
 674         fill(__position, __position + difference_type(__n), __x);
 675         _M_finish += difference_type(__n);
 676       }
 677       else {
 678         size_type __len = size() + max(size(), __n);
 679         _Bit_type * __q = _M_bit_alloc(__len);
 680         iterator __i = copy(begin(), __position, iterator(__q, 0));
 681         fill_n(__i, __n, __x);
 682         _M_finish = copy(__position, end(), __i + difference_type(__n));
 683         _M_deallocate();
 684         _M_end_of_storage = __q + (__len + _M_word_bit - 1)/_M_word_bit;
 685         _M_start = iterator(__q, 0);
 686       }
 687     }
 688
 689     void insert(iterator __position, size_type __n, bool __x) {
 690       _M_fill_insert(__position, __n, __x);
 691     }
 692
 693     void pop_back() { --_M_finish; }
 694     iterator erase(iterator __position) {
 695       if (__position + 1 != end())
 696         copy(__position + 1, end(), __position);
 697         --_M_finish;
 698       return __position;
 699     }
 700     iterator erase(iterator __first, iterator __last) {
 701       _M_finish = copy(__last, end(), __first);
 702       return __first;
 703     }
 704     void resize(size_type __new_size, bool __x = bool()) {
 705       if (__new_size < size())
 706         erase(begin() + difference_type(__new_size), end());
 707       else
 708         insert(end(), __new_size - size(), __x);
 709     }
 710     void flip() {
 711       for (_Bit_type * __p = _M_start._M_p; __p != _M_end_of_storage; ++__p)
 712         *__p = ~*__p;
 713     }
 714
 715     void clear() { erase(begin(), end()); }
 716   };
 717
 718 // This typedef is non-standard.  It is provided for backward compatibility.
 719 typedef vector<bool, __alloc> bit_vector;
 720
 721 } // namespace std
 722
 723 #endif /* __GLIBCPP_INTERNAL_BVECTOR_H */
 724
 725 // Local Variables:
 726 // mode:C++
 727 // End: