| blob | 0263162718231e616c1d3a2321ef632e25b6b55e |
1 // <bitset> -*- C++ -*-
3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 // Free Software Foundation, Inc.
5 //
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 2, or (at your option)
10 // any later version.
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this library; see the file COPYING. If not, write to
19 // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
20 // Boston, MA 02110-1301, USA.
22 // As a special exception, you may use this file as part of a free software
23 // library without restriction. Specifically, if other files instantiate
24 // templates or use macros or inline functions from this file, or you compile
25 // this file and link it with other files to produce an executable, this
26 // file does not by itself cause the resulting executable to be covered by
27 // the GNU General Public License. This exception does not however
28 // invalidate any other reasons why the executable file might be covered by
29 // the GNU General Public License.
31 /*
32 * Copyright (c) 1998
33 * Silicon Graphics Computer Systems, Inc.
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. Silicon Graphics 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 */
44 /** @file include/bitset
45 * This is a Standard C++ Library header.
46 */
48 #ifndef _GLIBCXX_BITSET
49 #define _GLIBCXX_BITSET 1
51 #pragma GCC system_header
53 #include <cstddef> // For size_t
54 #include <string>
55 #include <bits/functexcept.h> // For invalid_argument, out_of_range,
56 // overflow_error
57 #include <iosfwd>
58 #include <cxxabi-forced.h>
60 #define _GLIBCXX_BITSET_BITS_PER_WORD (__CHAR_BIT__ * sizeof(unsigned long))
61 #define _GLIBCXX_BITSET_WORDS(__n) \
62 ((__n) < 1 ? 0 : ((__n) + _GLIBCXX_BITSET_BITS_PER_WORD - 1) \
63 / _GLIBCXX_BITSET_BITS_PER_WORD)
65 _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
67 /**
68 * Base class, general case. It is a class invariant that _Nw will be
69 * nonnegative.
70 *
71 * See documentation for bitset.
72 */
73 template<size_t _Nw>
74 struct _Base_bitset
75 {
76 typedef unsigned long _WordT;
78 /// 0 is the least significant word.
79 _WordT _M_w[_Nw];
81 _Base_bitset()
82 { _M_do_reset(); }
84 _Base_bitset(unsigned long __val)
85 {
86 _M_do_reset();
87 _M_w[0] = __val;
88 }
90 static size_t
91 _S_whichword(size_t __pos )
92 { return __pos / _GLIBCXX_BITSET_BITS_PER_WORD; }
94 static size_t
95 _S_whichbyte(size_t __pos )
96 { return (__pos % _GLIBCXX_BITSET_BITS_PER_WORD) / __CHAR_BIT__; }
98 static size_t
99 _S_whichbit(size_t __pos )
100 { return __pos % _GLIBCXX_BITSET_BITS_PER_WORD; }
102 static _WordT
103 _S_maskbit(size_t __pos )
104 { return (static_cast<_WordT>(1)) << _S_whichbit(__pos); }
106 _WordT&
107 _M_getword(size_t __pos)
108 { return _M_w[_S_whichword(__pos)]; }
110 _WordT
111 _M_getword(size_t __pos) const
112 { return _M_w[_S_whichword(__pos)]; }
114 _WordT&
115 _M_hiword()
116 { return _M_w[_Nw - 1]; }
118 _WordT
119 _M_hiword() const
120 { return _M_w[_Nw - 1]; }
122 void
123 _M_do_and(const _Base_bitset<_Nw>& __x)
124 {
125 for (size_t __i = 0; __i < _Nw; __i++)
126 _M_w[__i] &= __x._M_w[__i];
127 }
129 void
130 _M_do_or(const _Base_bitset<_Nw>& __x)
131 {
132 for (size_t __i = 0; __i < _Nw; __i++)
133 _M_w[__i] |= __x._M_w[__i];
134 }
136 void
137 _M_do_xor(const _Base_bitset<_Nw>& __x)
138 {
139 for (size_t __i = 0; __i < _Nw; __i++)
140 _M_w[__i] ^= __x._M_w[__i];
141 }
143 void
144 _M_do_left_shift(size_t __shift);
146 void
147 _M_do_right_shift(size_t __shift);
149 void
150 _M_do_flip()
151 {
152 for (size_t __i = 0; __i < _Nw; __i++)
153 _M_w[__i] = ~_M_w[__i];
154 }
156 void
157 _M_do_set()
158 {
159 for (size_t __i = 0; __i < _Nw; __i++)
160 _M_w[__i] = ~static_cast<_WordT>(0);
161 }
163 void
164 _M_do_reset()
165 { __builtin_memset(_M_w, 0, _Nw * sizeof(_WordT)); }
167 bool
168 _M_is_equal(const _Base_bitset<_Nw>& __x) const
169 {
170 for (size_t __i = 0; __i < _Nw; ++__i)
171 if (_M_w[__i] != __x._M_w[__i])
172 return false;
173 return true;
174 }
176 size_t
177 _M_are_all_aux() const
178 {
179 for (size_t __i = 0; __i < _Nw - 1; __i++)
180 if (_M_w[__i] != ~static_cast<_WordT>(0))
181 return 0;
182 return ((_Nw - 1) * _GLIBCXX_BITSET_BITS_PER_WORD
183 + __builtin_popcountl(_M_hiword()));
184 }
186 bool
187 _M_is_any() const
188 {
189 for (size_t __i = 0; __i < _Nw; __i++)
190 if (_M_w[__i] != static_cast<_WordT>(0))
191 return true;
192 return false;
193 }
195 size_t
196 _M_do_count() const
197 {
198 size_t __result = 0;
199 for (size_t __i = 0; __i < _Nw; __i++)
200 __result += __builtin_popcountl(_M_w[__i]);
201 return __result;
202 }
204 unsigned long
205 _M_do_to_ulong() const;
207 // find first "on" bit
208 size_t
209 _M_do_find_first(size_t __not_found) const;
211 // find the next "on" bit that follows "prev"
212 size_t
213 _M_do_find_next(size_t __prev, size_t __not_found) const;
214 };
216 // Definitions of non-inline functions from _Base_bitset.
217 template<size_t _Nw>
218 void
219 _Base_bitset<_Nw>::_M_do_left_shift(size_t __shift)
220 {
221 if (__builtin_expect(__shift != 0, 1))
222 {
223 const size_t __wshift = __shift / _GLIBCXX_BITSET_BITS_PER_WORD;
224 const size_t __offset = __shift % _GLIBCXX_BITSET_BITS_PER_WORD;
226 if (__offset == 0)
227 for (size_t __n = _Nw - 1; __n >= __wshift; --__n)
228 _M_w[__n] = _M_w[__n - __wshift];
229 else
230 {
231 const size_t __sub_offset = (_GLIBCXX_BITSET_BITS_PER_WORD
232 - __offset);
233 for (size_t __n = _Nw - 1; __n > __wshift; --__n)
234 _M_w[__n] = ((_M_w[__n - __wshift] << __offset)
235 | (_M_w[__n - __wshift - 1] >> __sub_offset));
236 _M_w[__wshift] = _M_w[0] << __offset;
237 }
239 std::fill(_M_w + 0, _M_w + __wshift, static_cast<_WordT>(0));
240 }
241 }
243 template<size_t _Nw>
244 void
245 _Base_bitset<_Nw>::_M_do_right_shift(size_t __shift)
246 {
247 if (__builtin_expect(__shift != 0, 1))
248 {
249 const size_t __wshift = __shift / _GLIBCXX_BITSET_BITS_PER_WORD;
250 const size_t __offset = __shift % _GLIBCXX_BITSET_BITS_PER_WORD;
251 const size_t __limit = _Nw - __wshift - 1;
253 if (__offset == 0)
254 for (size_t __n = 0; __n <= __limit; ++__n)
255 _M_w[__n] = _M_w[__n + __wshift];
256 else
257 {
258 const size_t __sub_offset = (_GLIBCXX_BITSET_BITS_PER_WORD
259 - __offset);
260 for (size_t __n = 0; __n < __limit; ++__n)
261 _M_w[__n] = ((_M_w[__n + __wshift] >> __offset)
262 | (_M_w[__n + __wshift + 1] << __sub_offset));
263 _M_w[__limit] = _M_w[_Nw-1] >> __offset;
264 }
266 std::fill(_M_w + __limit + 1, _M_w + _Nw, static_cast<_WordT>(0));
267 }
268 }
270 template<size_t _Nw>
271 unsigned long
272 _Base_bitset<_Nw>::_M_do_to_ulong() const
273 {
274 for (size_t __i = 1; __i < _Nw; ++__i)
275 if (_M_w[__i])
276 __throw_overflow_error(__N("_Base_bitset::_M_do_to_ulong"));
277 return _M_w[0];
278 }
280 template<size_t _Nw>
281 size_t
282 _Base_bitset<_Nw>::_M_do_find_first(size_t __not_found) const
283 {
284 for (size_t __i = 0; __i < _Nw; __i++)
285 {
286 _WordT __thisword = _M_w[__i];
287 if (__thisword != static_cast<_WordT>(0))
288 return (__i * _GLIBCXX_BITSET_BITS_PER_WORD
289 + __builtin_ctzl(__thisword));
290 }
291 // not found, so return an indication of failure.
292 return __not_found;
293 }
295 template<size_t _Nw>
296 size_t
297 _Base_bitset<_Nw>::_M_do_find_next(size_t __prev, size_t __not_found) const
298 {
299 // make bound inclusive
300 ++__prev;
302 // check out of bounds
303 if (__prev >= _Nw * _GLIBCXX_BITSET_BITS_PER_WORD)
304 return __not_found;
306 // search first word
307 size_t __i = _S_whichword(__prev);
308 _WordT __thisword = _M_w[__i];
310 // mask off bits below bound
311 __thisword &= (~static_cast<_WordT>(0)) << _S_whichbit(__prev);
313 if (__thisword != static_cast<_WordT>(0))
314 return (__i * _GLIBCXX_BITSET_BITS_PER_WORD
315 + __builtin_ctzl(__thisword));
317 // check subsequent words
318 __i++;
319 for (; __i < _Nw; __i++)
320 {
321 __thisword = _M_w[__i];
322 if (__thisword != static_cast<_WordT>(0))
323 return (__i * _GLIBCXX_BITSET_BITS_PER_WORD
324 + __builtin_ctzl(__thisword));
325 }
326 // not found, so return an indication of failure.
327 return __not_found;
328 } // end _M_do_find_next
330 /**
331 * Base class, specialization for a single word.
332 *
333 * See documentation for bitset.
334 */
335 template<>
336 struct _Base_bitset<1>
337 {
338 typedef unsigned long _WordT;
339 _WordT _M_w;
341 _Base_bitset(void)
342 : _M_w(0)
343 { }
345 _Base_bitset(unsigned long __val)
346 : _M_w(__val)
347 { }
349 static size_t
350 _S_whichword(size_t __pos )
351 { return __pos / _GLIBCXX_BITSET_BITS_PER_WORD; }
353 static size_t
354 _S_whichbyte(size_t __pos )
355 { return (__pos % _GLIBCXX_BITSET_BITS_PER_WORD) / __CHAR_BIT__; }
357 static size_t
358 _S_whichbit(size_t __pos )
359 { return __pos % _GLIBCXX_BITSET_BITS_PER_WORD; }
361 static _WordT
362 _S_maskbit(size_t __pos )
363 { return (static_cast<_WordT>(1)) << _S_whichbit(__pos); }
365 _WordT&
366 _M_getword(size_t)
367 { return _M_w; }
369 _WordT
370 _M_getword(size_t) const
371 { return _M_w; }
373 _WordT&
374 _M_hiword()
375 { return _M_w; }
377 _WordT
378 _M_hiword() const
379 { return _M_w; }
381 void
382 _M_do_and(const _Base_bitset<1>& __x)
383 { _M_w &= __x._M_w; }
385 void
386 _M_do_or(const _Base_bitset<1>& __x)
387 { _M_w |= __x._M_w; }
389 void
390 _M_do_xor(const _Base_bitset<1>& __x)
391 { _M_w ^= __x._M_w; }
393 void
394 _M_do_left_shift(size_t __shift)
395 { _M_w <<= __shift; }
397 void
398 _M_do_right_shift(size_t __shift)
399 { _M_w >>= __shift; }
401 void
402 _M_do_flip()
403 { _M_w = ~_M_w; }
405 void
406 _M_do_set()
407 { _M_w = ~static_cast<_WordT>(0); }
409 void
410 _M_do_reset()
411 { _M_w = 0; }
413 bool
414 _M_is_equal(const _Base_bitset<1>& __x) const
415 { return _M_w == __x._M_w; }
417 size_t
418 _M_are_all_aux() const
419 { return __builtin_popcountl(_M_w); }
421 bool
422 _M_is_any() const
423 { return _M_w != 0; }
425 size_t
426 _M_do_count() const
427 { return __builtin_popcountl(_M_w); }
429 unsigned long
430 _M_do_to_ulong() const
431 { return _M_w; }
433 size_t
434 _M_do_find_first(size_t __not_found) const
435 {
436 if (_M_w != 0)
437 return __builtin_ctzl(_M_w);
438 else
439 return __not_found;
440 }
442 // find the next "on" bit that follows "prev"
443 size_t
444 _M_do_find_next(size_t __prev, size_t __not_found) const
445 {
446 ++__prev;
447 if (__prev >= ((size_t) _GLIBCXX_BITSET_BITS_PER_WORD))
448 return __not_found;
450 _WordT __x = _M_w >> __prev;
451 if (__x != 0)
452 return __builtin_ctzl(__x) + __prev;
453 else
454 return __not_found;
455 }
456 };
458 /**
459 * Base class, specialization for no storage (zero-length %bitset).
460 *
461 * See documentation for bitset.
462 */
463 template<>
464 struct _Base_bitset<0>
465 {
466 typedef unsigned long _WordT;
468 _Base_bitset()
469 { }
471 _Base_bitset(unsigned long)
472 { }
474 static size_t
475 _S_whichword(size_t __pos )
476 { return __pos / _GLIBCXX_BITSET_BITS_PER_WORD; }
478 static size_t
479 _S_whichbyte(size_t __pos )
480 { return (__pos % _GLIBCXX_BITSET_BITS_PER_WORD) / __CHAR_BIT__; }
482 static size_t
483 _S_whichbit(size_t __pos )
484 { return __pos % _GLIBCXX_BITSET_BITS_PER_WORD; }
486 static _WordT
487 _S_maskbit(size_t __pos )
488 { return (static_cast<_WordT>(1)) << _S_whichbit(__pos); }
490 // This would normally give access to the data. The bounds-checking
491 // in the bitset class will prevent the user from getting this far,
492 // but (1) it must still return an lvalue to compile, and (2) the
493 // user might call _Unchecked_set directly, in which case this /needs/
494 // to fail. Let's not penalize zero-length users unless they actually
495 // make an unchecked call; all the memory ugliness is therefore
496 // localized to this single should-never-get-this-far function.
497 _WordT&
498 _M_getword(size_t) const
499 {
500 __throw_out_of_range(__N("_Base_bitset::_M_getword"));
501 return *new _WordT;
502 }
504 _WordT
505 _M_hiword() const
506 { return 0; }
508 void
509 _M_do_and(const _Base_bitset<0>&)
510 { }
512 void
513 _M_do_or(const _Base_bitset<0>&)
514 { }
516 void
517 _M_do_xor(const _Base_bitset<0>&)
518 { }
520 void
521 _M_do_left_shift(size_t)
522 { }
524 void
525 _M_do_right_shift(size_t)
526 { }
528 void
529 _M_do_flip()
530 { }
532 void
533 _M_do_set()
534 { }
536 void
537 _M_do_reset()
538 { }
540 // Are all empty bitsets equal to each other? Are they equal to
541 // themselves? How to compare a thing which has no state? What is
542 // the sound of one zero-length bitset clapping?
543 bool
544 _M_is_equal(const _Base_bitset<0>&) const
545 { return true; }
547 size_t
548 _M_are_all_aux() const
549 { return 0; }
551 bool
552 _M_is_any() const
553 { return false; }
555 size_t
556 _M_do_count() const
557 { return 0; }
559 unsigned long
560 _M_do_to_ulong() const
561 { return 0; }
563 // Normally "not found" is the size, but that could also be
564 // misinterpreted as an index in this corner case. Oh well.
565 size_t
566 _M_do_find_first(size_t) const
567 { return 0; }
569 size_t
570 _M_do_find_next(size_t, size_t) const
571 { return 0; }
572 };
575 // Helper class to zero out the unused high-order bits in the highest word.
576 template<size_t _Extrabits>
577 struct _Sanitize
578 {
579 static void _S_do_sanitize(unsigned long& __val)
580 { __val &= ~((~static_cast<unsigned long>(0)) << _Extrabits); }
581 };
583 template<>
584 struct _Sanitize<0>
585 { static void _S_do_sanitize(unsigned long) {} };
587 /**
588 * @brief The %bitset class represents a @e fixed-size sequence of bits.
589 *
590 * @ingroup Containers
591 *
592 * (Note that %bitset does @e not meet the formal requirements of a
593 * <a href="tables.html#65">container</a>. Mainly, it lacks iterators.)
594 *
595 * The template argument, @a Nb, may be any non-negative number,
596 * specifying the number of bits (e.g., "0", "12", "1024*1024").
597 *
598 * In the general unoptimized case, storage is allocated in word-sized
599 * blocks. Let B be the number of bits in a word, then (Nb+(B-1))/B
600 * words will be used for storage. B - Nb%B bits are unused. (They are
601 * the high-order bits in the highest word.) It is a class invariant
602 * that those unused bits are always zero.
603 *
604 * If you think of %bitset as "a simple array of bits," be aware that
605 * your mental picture is reversed: a %bitset behaves the same way as
606 * bits in integers do, with the bit at index 0 in the "least significant
607 * / right-hand" position, and the bit at index Nb-1 in the "most
608 * significant / left-hand" position. Thus, unlike other containers, a
609 * %bitset's index "counts from right to left," to put it very loosely.
610 *
611 * This behavior is preserved when translating to and from strings. For
612 * example, the first line of the following program probably prints
613 * "b('a') is 0001100001" on a modern ASCII system.
614 *
615 * @code
616 * #include <bitset>
617 * #include <iostream>
618 * #include <sstream>
619 *
620 * using namespace std;
621 *
622 * int main()
623 * {
624 * long a = 'a';
625 * bitset<10> b(a);
626 *
627 * cout << "b('a') is " << b << endl;
628 *
629 * ostringstream s;
630 * s << b;
631 * string str = s.str();
632 * cout << "index 3 in the string is " << str[3] << " but\n"
633 * << "index 3 in the bitset is " << b[3] << endl;
634 * }
635 * @endcode
636 *
637 * Also see http://gcc.gnu.org/onlinedocs/libstdc++/ext/sgiexts.html#ch23
638 * for a description of extensions.
639 *
640 * Most of the actual code isn't contained in %bitset<> itself, but in the
641 * base class _Base_bitset. The base class works with whole words, not with
642 * individual bits. This allows us to specialize _Base_bitset for the
643 * important special case where the %bitset is only a single word.
644 *
645 * Extra confusion can result due to the fact that the storage for
646 * _Base_bitset @e is a regular array, and is indexed as such. This is
647 * carefully encapsulated.
648 */
649 template<size_t _Nb>
650 class bitset
651 : private _Base_bitset<_GLIBCXX_BITSET_WORDS(_Nb)>
652 {
653 private:
654 typedef _Base_bitset<_GLIBCXX_BITSET_WORDS(_Nb)> _Base;
655 typedef unsigned long _WordT;
657 void
658 _M_do_sanitize()
659 {
660 _Sanitize<_Nb % _GLIBCXX_BITSET_BITS_PER_WORD>::
661 _S_do_sanitize(this->_M_hiword());
662 }
664 public:
665 /**
666 * This encapsulates the concept of a single bit. An instance of this
667 * class is a proxy for an actual bit; this way the individual bit
668 * operations are done as faster word-size bitwise instructions.
669 *
670 * Most users will never need to use this class directly; conversions
671 * to and from bool are automatic and should be transparent. Overloaded
672 * operators help to preserve the illusion.
673 *
674 * (On a typical system, this "bit %reference" is 64 times the size of
675 * an actual bit. Ha.)
676 */
677 class reference
678 {
679 friend class bitset;
681 _WordT *_M_wp;
682 size_t _M_bpos;
684 // left undefined
685 reference();
687 public:
688 reference(bitset& __b, size_t __pos)
689 {
690 _M_wp = &__b._M_getword(__pos);
691 _M_bpos = _Base::_S_whichbit(__pos);
692 }
694 ~reference()
695 { }
697 // For b[i] = __x;
698 reference&
699 operator=(bool __x)
700 {
701 if (__x)
702 *_M_wp |= _Base::_S_maskbit(_M_bpos);
703 else
704 *_M_wp &= ~_Base::_S_maskbit(_M_bpos);
705 return *this;
706 }
708 // For b[i] = b[__j];
709 reference&
710 operator=(const reference& __j)
711 {
712 if ((*(__j._M_wp) & _Base::_S_maskbit(__j._M_bpos)))
713 *_M_wp |= _Base::_S_maskbit(_M_bpos);
714 else
715 *_M_wp &= ~_Base::_S_maskbit(_M_bpos);
716 return *this;
717 }
719 // Flips the bit
720 bool
721 operator~() const
722 { return (*(_M_wp) & _Base::_S_maskbit(_M_bpos)) == 0; }
724 // For __x = b[i];
725 operator bool() const
726 { return (*(_M_wp) & _Base::_S_maskbit(_M_bpos)) != 0; }
728 // For b[i].flip();
729 reference&
730 flip()
731 {
732 *_M_wp ^= _Base::_S_maskbit(_M_bpos);
733 return *this;
734 }
735 };
736 friend class reference;
738 // 23.3.5.1 constructors:
739 /// All bits set to zero.
740 bitset()
741 { }
743 /// Initial bits bitwise-copied from a single word (others set to zero).
744 bitset(unsigned long __val)
745 : _Base(__val)
746 { _M_do_sanitize(); }
748 /**
749 * @brief Use a subset of a string.
750 * @param s A string of '0' and '1' characters.
751 * @param position Index of the first character in @a s to use;
752 * defaults to zero.
753 * @throw std::out_of_range If @a pos is bigger the size of @a s.
754 * @throw std::invalid_argument If a character appears in the string
755 * which is neither '0' nor '1'.
756 */
757 template<class _CharT, class _Traits, class _Alloc>
758 explicit
759 bitset(const std::basic_string<_CharT, _Traits, _Alloc>& __s,
760 size_t __position = 0)
761 : _Base()
762 {
763 if (__position > __s.size())
764 __throw_out_of_range(__N("bitset::bitset initial position "
765 "not valid"));
766 _M_copy_from_string(__s, __position,
767 std::basic_string<_CharT, _Traits, _Alloc>::npos);
768 }
770 /**
771 * @brief Use a subset of a string.
772 * @param s A string of '0' and '1' characters.
773 * @param position Index of the first character in @a s to use.
774 * @param n The number of characters to copy.
775 * @throw std::out_of_range If @a pos is bigger the size of @a s.
776 * @throw std::invalid_argument If a character appears in the string
777 * which is neither '0' nor '1'.
778 */
779 template<class _CharT, class _Traits, class _Alloc>
780 bitset(const std::basic_string<_CharT, _Traits, _Alloc>& __s,
781 size_t __position, size_t __n)
782 : _Base()
783 {
784 if (__position > __s.size())
785 __throw_out_of_range(__N("bitset::bitset initial position "
786 "not valid"));
787 _M_copy_from_string(__s, __position, __n);
788 }
790 // 23.3.5.2 bitset operations:
791 //@{
792 /**
793 * @brief Operations on bitsets.
794 * @param rhs A same-sized bitset.
795 *
796 * These should be self-explanatory.
797 */
798 bitset<_Nb>&
799 operator&=(const bitset<_Nb>& __rhs)
800 {
801 this->_M_do_and(__rhs);
802 return *this;
803 }
805 bitset<_Nb>&
806 operator|=(const bitset<_Nb>& __rhs)
807 {
808 this->_M_do_or(__rhs);
809 return *this;
810 }
812 bitset<_Nb>&
813 operator^=(const bitset<_Nb>& __rhs)
814 {
815 this->_M_do_xor(__rhs);
816 return *this;
817 }
818 //@}
820 //@{
821 /**
822 * @brief Operations on bitsets.
823 * @param position The number of places to shift.
824 *
825 * These should be self-explanatory.
826 */
827 bitset<_Nb>&
828 operator<<=(size_t __position)
829 {
830 if (__builtin_expect(__position < _Nb, 1))
831 {
832 this->_M_do_left_shift(__position);
833 this->_M_do_sanitize();
834 }
835 else
836 this->_M_do_reset();
837 return *this;
838 }
840 bitset<_Nb>&
841 operator>>=(size_t __position)
842 {
843 if (__builtin_expect(__position < _Nb, 1))
844 {
845 this->_M_do_right_shift(__position);
846 this->_M_do_sanitize();
847 }
848 else
849 this->_M_do_reset();
850 return *this;
851 }
852 //@}
854 //@{
855 /**
856 * These versions of single-bit set, reset, flip, and test are
857 * extensions from the SGI version. They do no range checking.
858 * @ingroup SGIextensions
859 */
860 bitset<_Nb>&
861 _Unchecked_set(size_t __pos)
862 {
863 this->_M_getword(__pos) |= _Base::_S_maskbit(__pos);
864 return *this;
865 }
867 bitset<_Nb>&
868 _Unchecked_set(size_t __pos, int __val)
869 {
870 if (__val)
871 this->_M_getword(__pos) |= _Base::_S_maskbit(__pos);
872 else
873 this->_M_getword(__pos) &= ~_Base::_S_maskbit(__pos);
874 return *this;
875 }
877 bitset<_Nb>&
878 _Unchecked_reset(size_t __pos)
879 {
880 this->_M_getword(__pos) &= ~_Base::_S_maskbit(__pos);
881 return *this;
882 }
884 bitset<_Nb>&
885 _Unchecked_flip(size_t __pos)
886 {
887 this->_M_getword(__pos) ^= _Base::_S_maskbit(__pos);
888 return *this;
889 }
891 bool
892 _Unchecked_test(size_t __pos) const
893 { return ((this->_M_getword(__pos) & _Base::_S_maskbit(__pos))
894 != static_cast<_WordT>(0)); }
895 //@}
897 // Set, reset, and flip.
898 /**
899 * @brief Sets every bit to true.
900 */
901 bitset<_Nb>&
902 set()
903 {
904 this->_M_do_set();
905 this->_M_do_sanitize();
906 return *this;
907 }
909 /**
910 * @brief Sets a given bit to a particular value.
911 * @param position The index of the bit.
912 * @param val Either true or false, defaults to true.
913 * @throw std::out_of_range If @a pos is bigger the size of the %set.
914 */
915 bitset<_Nb>&
916 set(size_t __position, bool __val = true)
917 {
918 if (__position >= _Nb)
919 __throw_out_of_range(__N("bitset::set"));
920 return _Unchecked_set(__position, __val);
921 }
923 /**
924 * @brief Sets every bit to false.
925 */
926 bitset<_Nb>&
927 reset()
928 {
929 this->_M_do_reset();
930 return *this;
931 }
933 /**
934 * @brief Sets a given bit to false.
935 * @param position The index of the bit.
936 * @throw std::out_of_range If @a pos is bigger the size of the %set.
937 *
938 * Same as writing @c set(pos,false).
939 */
940 bitset<_Nb>&
941 reset(size_t __position)
942 {
943 if (__position >= _Nb)
944 __throw_out_of_range(__N("bitset::reset"));
945 return _Unchecked_reset(__position);
946 }
948 /**
949 * @brief Toggles every bit to its opposite value.
950 */
951 bitset<_Nb>&
952 flip()
953 {
954 this->_M_do_flip();
955 this->_M_do_sanitize();
956 return *this;
957 }
959 /**
960 * @brief Toggles a given bit to its opposite value.
961 * @param position The index of the bit.
962 * @throw std::out_of_range If @a pos is bigger the size of the %set.
963 */
964 bitset<_Nb>&
965 flip(size_t __position)
966 {
967 if (__position >= _Nb)
968 __throw_out_of_range(__N("bitset::flip"));
969 return _Unchecked_flip(__position);
970 }
972 /// See the no-argument flip().
973 bitset<_Nb>
974 operator~() const
975 { return bitset<_Nb>(*this).flip(); }
977 //@{
978 /**
979 * @brief Array-indexing support.
980 * @param position Index into the %bitset.
981 * @return A bool for a 'const %bitset'. For non-const bitsets, an
982 * instance of the reference proxy class.
983 * @note These operators do no range checking and throw no exceptions,
984 * as required by DR 11 to the standard.
985 *
986 * _GLIBCXX_RESOLVE_LIB_DEFECTS Note that this implementation already
987 * resolves DR 11 (items 1 and 2), but does not do the range-checking
988 * required by that DR's resolution. -pme
989 * The DR has since been changed: range-checking is a precondition
990 * (users' responsibility), and these functions must not throw. -pme
991 */
992 reference
993 operator[](size_t __position)
994 { return reference(*this,__position); }
996 bool
997 operator[](size_t __position) const
998 { return _Unchecked_test(__position); }
999 //@}
1001 /**
1002 * @brief Returns a numerical interpretation of the %bitset.
1003 * @return The integral equivalent of the bits.
1004 * @throw std::overflow_error If there are too many bits to be
1005 * represented in an @c unsigned @c long.
1006 */
1007 unsigned long
1008 to_ulong() const
1009 { return this->_M_do_to_ulong(); }
1011 /**
1012 * @brief Returns a character interpretation of the %bitset.
1013 * @return The string equivalent of the bits.
1014 *
1015 * Note the ordering of the bits: decreasing character positions
1016 * correspond to increasing bit positions (see the main class notes for
1017 * an example).
1018 */
1019 template<class _CharT, class _Traits, class _Alloc>
1020 std::basic_string<_CharT, _Traits, _Alloc>
1021 to_string() const
1022 {
1023 std::basic_string<_CharT, _Traits, _Alloc> __result;
1024 _M_copy_to_string(__result);
1025 return __result;
1026 }
1028 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1029 // 434. bitset::to_string() hard to use.
1030 template<class _CharT, class _Traits>
1031 std::basic_string<_CharT, _Traits, std::allocator<_CharT> >
1032 to_string() const
1033 { return to_string<_CharT, _Traits, std::allocator<_CharT> >(); }
1035 template<class _CharT>
1036 std::basic_string<_CharT, std::char_traits<_CharT>,
1037 std::allocator<_CharT> >
1038 to_string() const
1039 {
1040 return to_string<_CharT, std::char_traits<_CharT>,
1041 std::allocator<_CharT> >();
1042 }
1044 std::basic_string<char, std::char_traits<char>, std::allocator<char> >
1045 to_string() const
1046 {
1047 return to_string<char, std::char_traits<char>,
1048 std::allocator<char> >();
1049 }
1051 // Helper functions for string operations.
1052 template<class _CharT, class _Traits, class _Alloc>
1053 void
1054 _M_copy_from_string(const std::basic_string<_CharT,
1055 _Traits, _Alloc>& __s,
1056 size_t, size_t);
1058 template<class _CharT, class _Traits, class _Alloc>
1059 void
1060 _M_copy_to_string(std::basic_string<_CharT, _Traits, _Alloc>&) const;
1062 /// Returns the number of bits which are set.
1063 size_t
1064 count() const
1065 { return this->_M_do_count(); }
1067 /// Returns the total number of bits.
1068 size_t
1069 size() const
1070 { return _Nb; }
1072 //@{
1073 /// These comparisons for equality/inequality are, well, @e bitwise.
1074 bool
1075 operator==(const bitset<_Nb>& __rhs) const
1076 { return this->_M_is_equal(__rhs); }
1078 bool
1079 operator!=(const bitset<_Nb>& __rhs) const
1080 { return !this->_M_is_equal(__rhs); }
1081 //@}
1083 /**
1084 * @brief Tests the value of a bit.
1085 * @param position The index of a bit.
1086 * @return The value at @a pos.
1087 * @throw std::out_of_range If @a pos is bigger the size of the %set.
1088 */
1089 bool
1090 test(size_t __position) const
1091 {
1092 if (__position >= _Nb)
1093 __throw_out_of_range(__N("bitset::test"));
1094 return _Unchecked_test(__position);
1095 }
1097 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1098 // DR 693. std::bitset::all() missing.
1099 /**
1100 * @brief Tests whether all the bits are on.
1101 * @return True if all the bits are set.
1102 */
1103 bool
1104 all() const
1105 { return this->_M_are_all_aux() == _Nb; }
1107 /**
1108 * @brief Tests whether any of the bits are on.
1109 * @return True if at least one bit is set.
1110 */
1111 bool
1112 any() const
1113 { return this->_M_is_any(); }
1115 /**
1116 * @brief Tests whether any of the bits are on.
1117 * @return True if none of the bits are set.
1118 */
1119 bool
1120 none() const
1121 { return !this->_M_is_any(); }
1123 //@{
1124 /// Self-explanatory.
1125 bitset<_Nb>
1126 operator<<(size_t __position) const
1127 { return bitset<_Nb>(*this) <<= __position; }
1129 bitset<_Nb>
1130 operator>>(size_t __position) const
1131 { return bitset<_Nb>(*this) >>= __position; }
1132 //@}
1134 /**
1135 * @brief Finds the index of the first "on" bit.
1136 * @return The index of the first bit set, or size() if not found.
1137 * @ingroup SGIextensions
1138 * @sa _Find_next
1139 */
1140 size_t
1141 _Find_first() const
1142 { return this->_M_do_find_first(_Nb); }
1144 /**
1145 * @brief Finds the index of the next "on" bit after prev.
1146 * @return The index of the next bit set, or size() if not found.
1147 * @param prev Where to start searching.
1148 * @ingroup SGIextensions
1149 * @sa _Find_first
1150 */
1151 size_t
1152 _Find_next(size_t __prev ) const
1153 { return this->_M_do_find_next(__prev, _Nb); }
1154 };
1156 // Definitions of non-inline member functions.
1157 template<size_t _Nb>
1158 template<class _CharT, class _Traits, class _Alloc>
1159 void
1160 bitset<_Nb>::
1161 _M_copy_from_string(const std::basic_string<_CharT, _Traits,
1162 _Alloc>& __s, size_t __pos, size_t __n)
1163 {
1164 reset();
1165 const size_t __nbits = std::min(_Nb, std::min(__n, __s.size() - __pos));
1166 for (size_t __i = __nbits; __i > 0; --__i)
1167 {
1168 switch(__s[__pos + __nbits - __i])
1169 {
1170 case '0':
1171 break;
1172 case '1':
1173 _Unchecked_set(__i - 1);
1174 break;
1175 default:
1176 __throw_invalid_argument(__N("bitset::_M_copy_from_string"));
1177 }
1178 }
1179 }
1181 template<size_t _Nb>
1182 template<class _CharT, class _Traits, class _Alloc>
1183 void
1184 bitset<_Nb>::
1185 _M_copy_to_string(std::basic_string<_CharT, _Traits, _Alloc>& __s) const
1186 {
1187 __s.assign(_Nb, '0');
1188 for (size_t __i = _Nb; __i > 0; --__i)
1189 if (_Unchecked_test(__i - 1))
1190 __s[_Nb - __i] = '1';
1191 }
1193 // 23.3.5.3 bitset operations:
1194 //@{
1195 /**
1196 * @brief Global bitwise operations on bitsets.
1197 * @param x A bitset.
1198 * @param y A bitset of the same size as @a x.
1199 * @return A new bitset.
1200 *
1201 * These should be self-explanatory.
1202 */
1203 template<size_t _Nb>
1204 inline bitset<_Nb>
1205 operator&(const bitset<_Nb>& __x, const bitset<_Nb>& __y)
1206 {
1207 bitset<_Nb> __result(__x);
1208 __result &= __y;
1209 return __result;
1210 }
1212 template<size_t _Nb>
1213 inline bitset<_Nb>
1214 operator|(const bitset<_Nb>& __x, const bitset<_Nb>& __y)
1215 {
1216 bitset<_Nb> __result(__x);
1217 __result |= __y;
1218 return __result;
1219 }
1221 template <size_t _Nb>
1222 inline bitset<_Nb>
1223 operator^(const bitset<_Nb>& __x, const bitset<_Nb>& __y)
1224 {
1225 bitset<_Nb> __result(__x);
1226 __result ^= __y;
1227 return __result;
1228 }
1229 //@}
1231 //@{
1232 /**
1233 * @brief Global I/O operators for bitsets.
1234 *
1235 * Direct I/O between streams and bitsets is supported. Output is
1236 * straightforward. Input will skip whitespace, only accept '0' and '1'
1237 * characters, and will only extract as many digits as the %bitset will
1238 * hold.
1239 */
1240 template<class _CharT, class _Traits, size_t _Nb>
1241 std::basic_istream<_CharT, _Traits>&
1242 operator>>(std::basic_istream<_CharT, _Traits>& __is, bitset<_Nb>& __x)
1243 {
1244 typedef typename _Traits::char_type char_type;
1245 typedef std::basic_istream<_CharT, _Traits> __istream_type;
1246 typedef typename __istream_type::ios_base __ios_base;
1248 std::basic_string<_CharT, _Traits> __tmp;
1249 __tmp.reserve(_Nb);
1251 typename __ios_base::iostate __state = __ios_base::goodbit;
1252 typename __istream_type::sentry __sentry(__is);
1253 if (__sentry)
1254 {
1255 try
1256 {
1257 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1258 // 303. Bitset input operator underspecified
1259 const char_type __zero = __is.widen('0');
1260 const char_type __one = __is.widen('1');
1261 for (size_t __i = _Nb; __i > 0; --__i)
1262 {
1263 static typename _Traits::int_type __eof = _Traits::eof();
1265 typename _Traits::int_type __c1 = __is.rdbuf()->sbumpc();
1266 if (_Traits::eq_int_type(__c1, __eof))
1267 {
1268 __state |= __ios_base::eofbit;
1269 break;
1270 }
1271 else
1272 {
1273 const char_type __c2 = _Traits::to_char_type(__c1);
1274 if (__c2 == __zero)
1275 __tmp.push_back('0');
1276 else if (__c2 == __one)
1277 __tmp.push_back('1');
1278 else if (_Traits::
1279 eq_int_type(__is.rdbuf()->sputbackc(__c2),
1280 __eof))
1281 {
1282 __state |= __ios_base::failbit;
1283 break;
1284 }
1285 }
1286 }
1287 }
1288 catch(__cxxabiv1::__forced_unwind&)
1289 {
1290 __is._M_setstate(__ios_base::badbit);
1291 __throw_exception_again;
1292 }
1293 catch(...)
1294 { __is._M_setstate(__ios_base::badbit); }
1295 }
1297 if (__tmp.empty() && _Nb)
1298 __state |= __ios_base::failbit;
1299 else
1300 __x._M_copy_from_string(__tmp, static_cast<size_t>(0), _Nb);
1301 if (__state)
1302 __is.setstate(__state);
1303 return __is;
1304 }
1306 template <class _CharT, class _Traits, size_t _Nb>
1307 std::basic_ostream<_CharT, _Traits>&
1308 operator<<(std::basic_ostream<_CharT, _Traits>& __os,
1309 const bitset<_Nb>& __x)
1310 {
1311 std::basic_string<_CharT, _Traits> __tmp;
1312 __x._M_copy_to_string(__tmp);
1313 return __os << __tmp;
1314 }
1315 //@}
1317 _GLIBCXX_END_NESTED_NAMESPACE
1319 #undef _GLIBCXX_BITSET_WORDS
1320 #undef _GLIBCXX_BITSET_BITS_PER_WORD
1322 #ifdef _GLIBCXX_DEBUG
1323 # include <debug/bitset>
1324 #endif
1326 #endif /* _GLIBCXX_BITSET */