| blob | 01e3f904e470f8b0178698263ab75dbe5eac8e76 |
1 // <bitset> -*- C++ -*-
3 // Copyright (C) 2001, 2002, 2003, 2004 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.
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.
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.
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.
30 /*
31 * Copyright (c) 1998
32 * Silicon Graphics Computer Systems, Inc.
33 *
34 * Permission to use, copy, modify, distribute and sell this software
35 * and its documentation for any purpose is hereby granted without fee,
36 * provided that the above copyright notice appear in all copies and
37 * that both that copyright notice and this permission notice appear
38 * in supporting documentation. Silicon Graphics makes no
39 * representations about the suitability of this software for any
40 * purpose. It is provided "as is" without express or implied warranty.
41 */
43 /** @file bitset
44 * This is a Standard C++ Library header. You should @c #include this header
45 * in your programs, rather than any of the "st[dl]_*.h" implementation files.
46 */
48 #ifndef _GLIBCXX_BITSET
49 #define _GLIBCXX_BITSET 1
51 #pragma GCC system_header
53 #include <cstddef> // For size_t
54 #include <cstring> // For memset
55 #include <limits> // For numeric_limits
56 #include <string>
57 #include <bits/functexcept.h> // For invalid_argument, out_of_range,
58 // overflow_error
59 #include <ostream> // For ostream (operator<<)
60 #include <istream> // For istream (operator>>)
62 #define _GLIBCXX_BITSET_BITS_PER_WORD numeric_limits<unsigned long>::digits
63 #define _GLIBCXX_BITSET_WORDS(__n) \
64 ((__n) < 1 ? 0 : ((__n) + _GLIBCXX_BITSET_BITS_PER_WORD - 1)/_GLIBCXX_BITSET_BITS_PER_WORD)
66 namespace _GLIBCXX_STD
67 {
68 /**
69 * @if maint
70 * Base class, general case. It is a class inveriant that _Nw will be
71 * nonnegative.
72 *
73 * See documentation for bitset.
74 * @endif
75 */
76 template<size_t _Nw>
77 struct _Base_bitset
78 {
79 typedef unsigned long _WordT;
81 /// 0 is the least significant word.
82 _WordT _M_w[_Nw];
84 _Base_bitset() { _M_do_reset(); }
85 _Base_bitset(unsigned long __val)
86 {
87 _M_do_reset();
88 _M_w[0] = __val;
89 }
91 static size_t
92 _S_whichword(size_t __pos )
93 { return __pos / _GLIBCXX_BITSET_BITS_PER_WORD; }
95 static size_t
96 _S_whichbyte(size_t __pos )
97 { return (__pos % _GLIBCXX_BITSET_BITS_PER_WORD) / __CHAR_BIT__; }
99 static size_t
100 _S_whichbit(size_t __pos )
101 { return __pos % _GLIBCXX_BITSET_BITS_PER_WORD; }
103 static _WordT
104 _S_maskbit(size_t __pos )
105 { return (static_cast<_WordT>(1)) << _S_whichbit(__pos); }
107 _WordT&
108 _M_getword(size_t __pos)
109 { return _M_w[_S_whichword(__pos)]; }
111 _WordT
112 _M_getword(size_t __pos) const
113 { return _M_w[_S_whichword(__pos)]; }
115 _WordT&
116 _M_hiword() { return _M_w[_Nw - 1]; }
118 _WordT
119 _M_hiword() const { return _M_w[_Nw - 1]; }
121 void
122 _M_do_and(const _Base_bitset<_Nw>& __x)
123 {
124 for (size_t __i = 0; __i < _Nw; __i++)
125 _M_w[__i] &= __x._M_w[__i];
126 }
128 void
129 _M_do_or(const _Base_bitset<_Nw>& __x)
130 {
131 for (size_t __i = 0; __i < _Nw; __i++)
132 _M_w[__i] |= __x._M_w[__i];
133 }
135 void
136 _M_do_xor(const _Base_bitset<_Nw>& __x)
137 {
138 for (size_t __i = 0; __i < _Nw; __i++)
139 _M_w[__i] ^= __x._M_w[__i];
140 }
142 void
143 _M_do_left_shift(size_t __shift);
145 void
146 _M_do_right_shift(size_t __shift);
148 void
149 _M_do_flip()
150 {
151 for (size_t __i = 0; __i < _Nw; __i++)
152 _M_w[__i] = ~_M_w[__i];
153 }
155 void
156 _M_do_set()
157 {
158 for (size_t __i = 0; __i < _Nw; __i++)
159 _M_w[__i] = ~static_cast<_WordT>(0);
160 }
162 void
163 _M_do_reset() { memset(_M_w, 0, _Nw * sizeof(_WordT)); }
165 bool
166 _M_is_equal(const _Base_bitset<_Nw>& __x) const
167 {
168 for (size_t __i = 0; __i < _Nw; ++__i)
169 {
170 if (_M_w[__i] != __x._M_w[__i])
171 return false;
172 }
173 return true;
174 }
176 bool
177 _M_is_any() const
178 {
179 for (size_t __i = 0; __i < _Nw; __i++)
180 {
181 if (_M_w[__i] != static_cast<_WordT>(0))
182 return true;
183 }
184 return false;
185 }
187 size_t
188 _M_do_count() const
189 {
190 size_t __result = 0;
191 for (size_t __i = 0; __i < _Nw; __i++)
192 __result += __builtin_popcountl(_M_w[__i]);
193 return __result;
194 }
196 unsigned long
197 _M_do_to_ulong() const;
199 // find first "on" bit
200 size_t
201 _M_do_find_first(size_t __not_found) const;
203 // find the next "on" bit that follows "prev"
204 size_t
205 _M_do_find_next(size_t __prev, size_t __not_found) const;
206 };
208 // Definitions of non-inline functions from _Base_bitset.
209 template<size_t _Nw>
210 void
211 _Base_bitset<_Nw>::_M_do_left_shift(size_t __shift)
212 {
213 if (__builtin_expect(__shift != 0, 1))
214 {
215 const size_t __wshift = __shift / _GLIBCXX_BITSET_BITS_PER_WORD;
216 const size_t __offset = __shift % _GLIBCXX_BITSET_BITS_PER_WORD;
218 if (__offset == 0)
219 for (size_t __n = _Nw - 1; __n >= __wshift; --__n)
220 _M_w[__n] = _M_w[__n - __wshift];
221 else
222 {
223 const size_t __sub_offset = _GLIBCXX_BITSET_BITS_PER_WORD - __offset;
224 for (size_t __n = _Nw - 1; __n > __wshift; --__n)
225 _M_w[__n] = (_M_w[__n - __wshift] << __offset) |
226 (_M_w[__n - __wshift - 1] >> __sub_offset);
227 _M_w[__wshift] = _M_w[0] << __offset;
228 }
230 std::fill(_M_w + 0, _M_w + __wshift, static_cast<_WordT>(0));
231 }
232 }
234 template<size_t _Nw>
235 void
236 _Base_bitset<_Nw>::_M_do_right_shift(size_t __shift)
237 {
238 if (__builtin_expect(__shift != 0, 1))
239 {
240 const size_t __wshift = __shift / _GLIBCXX_BITSET_BITS_PER_WORD;
241 const size_t __offset = __shift % _GLIBCXX_BITSET_BITS_PER_WORD;
242 const size_t __limit = _Nw - __wshift - 1;
244 if (__offset == 0)
245 for (size_t __n = 0; __n <= __limit; ++__n)
246 _M_w[__n] = _M_w[__n + __wshift];
247 else
248 {
249 const size_t __sub_offset = _GLIBCXX_BITSET_BITS_PER_WORD - __offset;
250 for (size_t __n = 0; __n < __limit; ++__n)
251 _M_w[__n] = (_M_w[__n + __wshift] >> __offset) |
252 (_M_w[__n + __wshift + 1] << __sub_offset);
253 _M_w[__limit] = _M_w[_Nw-1] >> __offset;
254 }
256 std::fill(_M_w + __limit + 1, _M_w + _Nw, static_cast<_WordT>(0));
257 }
258 }
260 template<size_t _Nw>
261 unsigned long
262 _Base_bitset<_Nw>::_M_do_to_ulong() const
263 {
264 for (size_t __i = 1; __i < _Nw; ++__i)
265 if (_M_w[__i])
266 __throw_overflow_error(__N("_Base_bitset::_M_do_to_ulong"));
267 return _M_w[0];
268 }
270 template<size_t _Nw>
271 size_t
272 _Base_bitset<_Nw>::_M_do_find_first(size_t __not_found) const
273 {
274 for (size_t __i = 0; __i < _Nw; __i++)
275 {
276 _WordT __thisword = _M_w[__i];
277 if (__thisword != static_cast<_WordT>(0))
278 return __i * _GLIBCXX_BITSET_BITS_PER_WORD
279 + __builtin_ctzl(__thisword);
280 }
281 // not found, so return an indication of failure.
282 return __not_found;
283 }
285 template<size_t _Nw>
286 size_t
287 _Base_bitset<_Nw>::_M_do_find_next(size_t __prev, size_t __not_found) const
288 {
289 // make bound inclusive
290 ++__prev;
292 // check out of bounds
293 if (__prev >= _Nw * _GLIBCXX_BITSET_BITS_PER_WORD)
294 return __not_found;
296 // search first word
297 size_t __i = _S_whichword(__prev);
298 _WordT __thisword = _M_w[__i];
300 // mask off bits below bound
301 __thisword &= (~static_cast<_WordT>(0)) << _S_whichbit(__prev);
303 if (__thisword != static_cast<_WordT>(0))
304 return __i * _GLIBCXX_BITSET_BITS_PER_WORD
305 + __builtin_ctzl(__thisword);
307 // check subsequent words
308 __i++;
309 for ( ; __i < _Nw; __i++ )
310 {
311 __thisword = _M_w[__i];
312 if (__thisword != static_cast<_WordT>(0))
313 return __i * _GLIBCXX_BITSET_BITS_PER_WORD
314 + __builtin_ctzl(__thisword);
315 }
316 // not found, so return an indication of failure.
317 return __not_found;
318 } // end _M_do_find_next
321 /**
322 * @if maint
323 * Base class, specialization for a single word.
324 *
325 * See documentation for bitset.
326 * @endif
327 */
328 template<>
329 struct _Base_bitset<1>
330 {
331 typedef unsigned long _WordT;
332 _WordT _M_w;
334 _Base_bitset( void ) : _M_w(0) {}
335 _Base_bitset(unsigned long __val) : _M_w(__val) {}
337 static size_t
338 _S_whichword(size_t __pos )
339 { return __pos / _GLIBCXX_BITSET_BITS_PER_WORD; }
341 static size_t
342 _S_whichbyte(size_t __pos )
343 { return (__pos % _GLIBCXX_BITSET_BITS_PER_WORD) / __CHAR_BIT__; }
345 static size_t
346 _S_whichbit(size_t __pos )
347 { return __pos % _GLIBCXX_BITSET_BITS_PER_WORD; }
349 static _WordT
350 _S_maskbit(size_t __pos )
351 { return (static_cast<_WordT>(1)) << _S_whichbit(__pos); }
353 _WordT&
354 _M_getword(size_t) { return _M_w; }
356 _WordT
357 _M_getword(size_t) const { return _M_w; }
359 _WordT&
360 _M_hiword() { return _M_w; }
362 _WordT
363 _M_hiword() const { return _M_w; }
365 void
366 _M_do_and(const _Base_bitset<1>& __x) { _M_w &= __x._M_w; }
368 void
369 _M_do_or(const _Base_bitset<1>& __x) { _M_w |= __x._M_w; }
371 void
372 _M_do_xor(const _Base_bitset<1>& __x) { _M_w ^= __x._M_w; }
374 void
375 _M_do_left_shift(size_t __shift) { _M_w <<= __shift; }
377 void
378 _M_do_right_shift(size_t __shift) { _M_w >>= __shift; }
380 void
381 _M_do_flip() { _M_w = ~_M_w; }
383 void
384 _M_do_set() { _M_w = ~static_cast<_WordT>(0); }
386 void
387 _M_do_reset() { _M_w = 0; }
389 bool
390 _M_is_equal(const _Base_bitset<1>& __x) const
391 { return _M_w == __x._M_w; }
393 bool
394 _M_is_any() const { return _M_w != 0; }
396 size_t
397 _M_do_count() const { return __builtin_popcountl(_M_w); }
399 unsigned long
400 _M_do_to_ulong() const { return _M_w; }
402 size_t
403 _M_do_find_first(size_t __not_found) const
404 {
405 if (_M_w != 0)
406 return __builtin_ctzl(_M_w);
407 else
408 return __not_found;
409 }
411 // find the next "on" bit that follows "prev"
412 size_t
413 _M_do_find_next(size_t __prev, size_t __not_found) const
414 {
415 ++__prev;
416 if (__prev >= ((size_t) _GLIBCXX_BITSET_BITS_PER_WORD))
417 return __not_found;
419 _WordT __x = _M_w >> __prev;
420 if (__x != 0)
421 return __builtin_ctzl(__x) + __prev;
422 else
423 return __not_found;
424 }
425 };
428 /**
429 * @if maint
430 * Base class, specialization for no storage (zero-length %bitset).
431 *
432 * See documentation for bitset.
433 * @endif
434 */
435 template<>
436 struct _Base_bitset<0>
437 {
438 typedef unsigned long _WordT;
440 _Base_bitset() {}
441 _Base_bitset(unsigned long) {}
443 static size_t
444 _S_whichword(size_t __pos )
445 { return __pos / _GLIBCXX_BITSET_BITS_PER_WORD; }
447 static size_t
448 _S_whichbyte(size_t __pos )
449 { return (__pos % _GLIBCXX_BITSET_BITS_PER_WORD) / __CHAR_BIT__; }
451 static size_t
452 _S_whichbit(size_t __pos )
453 { return __pos % _GLIBCXX_BITSET_BITS_PER_WORD; }
455 static _WordT
456 _S_maskbit(size_t __pos )
457 { return (static_cast<_WordT>(1)) << _S_whichbit(__pos); }
459 // This would normally give access to the data. The bounds-checking
460 // in the bitset class will prevent the user from getting this far,
461 // but (1) it must still return an lvalue to compile, and (2) the
462 // user might call _Unchecked_set directly, in which case this /needs/
463 // to fail. Let's not penalize zero-length users unless they actually
464 // make an unchecked call; all the memory ugliness is therefore
465 // localized to this single should-never-get-this-far function.
466 _WordT&
467 _M_getword(size_t) const
468 {
469 __throw_out_of_range(__N("_Base_bitset::_M_getword"));
470 return *new _WordT;
471 }
473 _WordT
474 _M_hiword() const { return 0; }
476 void
477 _M_do_and(const _Base_bitset<0>&) { }
479 void
480 _M_do_or(const _Base_bitset<0>&) { }
482 void
483 _M_do_xor(const _Base_bitset<0>&) { }
485 void
486 _M_do_left_shift(size_t) { }
488 void
489 _M_do_right_shift(size_t) { }
491 void
492 _M_do_flip() { }
494 void
495 _M_do_set() { }
497 void
498 _M_do_reset() { }
500 // Are all empty bitsets equal to each other? Are they equal to
501 // themselves? How to compare a thing which has no state? What is
502 // the sound of one zero-length bitset clapping?
503 bool
504 _M_is_equal(const _Base_bitset<0>&) const { return true; }
506 bool
507 _M_is_any() const { return false; }
509 size_t
510 _M_do_count() const { return 0; }
512 unsigned long
513 _M_do_to_ulong() const { return 0; }
515 // Normally "not found" is the size, but that could also be
516 // misinterpreted as an index in this corner case. Oh well.
517 size_t
518 _M_do_find_first(size_t) const { return 0; }
520 size_t
521 _M_do_find_next(size_t, size_t) const { return 0; }
522 };
525 // Helper class to zero out the unused high-order bits in the highest word.
526 template<size_t _Extrabits>
527 struct _Sanitize
528 {
529 static void _S_do_sanitize(unsigned long& __val)
530 { __val &= ~((~static_cast<unsigned long>(0)) << _Extrabits); }
531 };
533 template<>
534 struct _Sanitize<0>
535 { static void _S_do_sanitize(unsigned long) { } };
538 /**
539 * @brief The %bitset class represents a @e fixed-size sequence of bits.
540 *
541 * @ingroup Containers
542 *
543 * (Note that %bitset does @e not meet the formal requirements of a
544 * <a href="tables.html#65">container</a>. Mainly, it lacks iterators.)
545 *
546 * The template argument, @a Nb, may be any non-negative number,
547 * specifying the number of bits (e.g., "0", "12", "1024*1024").
548 *
549 * In the general unoptimized case, storage is allocated in word-sized
550 * blocks. Let B be the number of bits in a word, then (Nb+(B-1))/B
551 * words will be used for storage. B - Nb%B bits are unused. (They are
552 * the high-order bits in the highest word.) It is a class invariant
553 * that those unused bits are always zero.
554 *
555 * If you think of %bitset as "a simple array of bits," be aware that
556 * your mental picture is reversed: a %bitset behaves the same way as
557 * bits in integers do, with the bit at index 0 in the "least significant
558 * / right-hand" position, and the bit at index Nb-1 in the "most
559 * significant / left-hand" position. Thus, unlike other containers, a
560 * %bitset's index "counts from right to left," to put it very loosely.
561 *
562 * This behavior is preserved when translating to and from strings. For
563 * example, the first line of the following program probably prints
564 * "b('a') is 0001100001" on a modern ASCII system.
565 *
566 * @code
567 * #include <bitset>
568 * #include <iostream>
569 * #include <sstream>
570 *
571 * using namespace std;
572 *
573 * int main()
574 * {
575 * long a = 'a';
576 * bitset<10> b(a);
577 *
578 * cout << "b('a') is " << b << endl;
579 *
580 * ostringstream s;
581 * s << b;
582 * string str = s.str();
583 * cout << "index 3 in the string is " << str[3] << " but\n"
584 * << "index 3 in the bitset is " << b[3] << endl;
585 * }
586 * @endcode
587 *
588 * Also see http://gcc.gnu.org/onlinedocs/libstdc++/ext/sgiexts.html#ch23
589 * for a description of extensions.
590 *
591 * @if maint
592 * Most of the actual code isn't contained in %bitset<> itself, but in the
593 * base class _Base_bitset. The base class works with whole words, not with
594 * individual bits. This allows us to specialize _Base_bitset for the
595 * important special case where the %bitset is only a single word.
596 *
597 * Extra confusion can result due to the fact that the storage for
598 * _Base_bitset @e is a regular array, and is indexed as such. This is
599 * carefully encapsulated.
600 * @endif
601 */
602 template<size_t _Nb>
603 class bitset : private _Base_bitset<_GLIBCXX_BITSET_WORDS(_Nb)>
604 {
605 private:
606 typedef _Base_bitset<_GLIBCXX_BITSET_WORDS(_Nb)> _Base;
607 typedef unsigned long _WordT;
609 void
610 _M_do_sanitize()
611 {
612 _Sanitize<_Nb%_GLIBCXX_BITSET_BITS_PER_WORD>::
613 _S_do_sanitize(this->_M_hiword());
614 }
616 public:
617 /**
618 * This encapsulates the concept of a single bit. An instance of this
619 * class is a proxy for an actual bit; this way the individual bit
620 * operations are done as faster word-size bitwise instructions.
621 *
622 * Most users will never need to use this class directly; conversions
623 * to and from bool are automatic and should be transparent. Overloaded
624 * operators help to preserve the illusion.
625 *
626 * (On a typical system, this "bit %reference" is 64 times the size of
627 * an actual bit. Ha.)
628 */
629 class reference
630 {
631 friend class bitset;
633 _WordT *_M_wp;
634 size_t _M_bpos;
636 // left undefined
637 reference();
639 public:
640 reference(bitset& __b, size_t __pos)
641 {
642 _M_wp = &__b._M_getword(__pos);
643 _M_bpos = _Base::_S_whichbit(__pos);
644 }
646 ~reference() { }
648 // For b[i] = __x;
649 reference&
650 operator=(bool __x)
651 {
652 if ( __x )
653 *_M_wp |= _Base::_S_maskbit(_M_bpos);
654 else
655 *_M_wp &= ~_Base::_S_maskbit(_M_bpos);
656 return *this;
657 }
659 // For b[i] = b[__j];
660 reference&
661 operator=(const reference& __j)
662 {
663 if ( (*(__j._M_wp) & _Base::_S_maskbit(__j._M_bpos)) )
664 *_M_wp |= _Base::_S_maskbit(_M_bpos);
665 else
666 *_M_wp &= ~_Base::_S_maskbit(_M_bpos);
667 return *this;
668 }
670 // Flips the bit
671 bool
672 operator~() const
673 { return (*(_M_wp) & _Base::_S_maskbit(_M_bpos)) == 0; }
675 // For __x = b[i];
676 operator bool() const
677 { return (*(_M_wp) & _Base::_S_maskbit(_M_bpos)) != 0; }
679 // For b[i].flip();
680 reference&
681 flip()
682 {
683 *_M_wp ^= _Base::_S_maskbit(_M_bpos);
684 return *this;
685 }
686 };
687 friend class reference;
689 // 23.3.5.1 constructors:
690 /// All bits set to zero.
691 bitset() { }
693 /// Initial bits bitwise-copied from a single word (others set to zero).
694 bitset(unsigned long __val) : _Base(__val)
695 { _M_do_sanitize(); }
697 /**
698 * @brief Use a subset of a string.
699 * @param s A string of '0' and '1' characters.
700 * @param position Index of the first character in @a s to use; defaults
701 * to zero.
702 * @throw std::out_of_range If @a pos is bigger the size of @a s.
703 * @throw std::invalid_argument If a character appears in the string
704 * which is neither '0' nor '1'.
705 */
706 template<class _CharT, class _Traits, class _Alloc>
707 explicit bitset(const basic_string<_CharT, _Traits, _Alloc>& __s,
708 size_t __position = 0) : _Base()
709 {
710 if (__position > __s.size())
711 __throw_out_of_range(__N("bitset::bitset initial position "
712 "not valid"));
713 _M_copy_from_string(__s, __position,
714 basic_string<_CharT, _Traits, _Alloc>::npos);
715 }
717 /**
718 * @brief Use a subset of a string.
719 * @param s A string of '0' and '1' characters.
720 * @param position Index of the first character in @a s to use.
721 * @param n The number of characters to copy.
722 * @throw std::out_of_range If @a pos is bigger the size of @a s.
723 * @throw std::invalid_argument If a character appears in the string
724 * which is neither '0' nor '1'.
725 */
726 template<class _CharT, class _Traits, class _Alloc>
727 bitset(const basic_string<_CharT, _Traits, _Alloc>& __s,
728 size_t __position, size_t __n) : _Base()
729 {
730 if (__position > __s.size())
731 __throw_out_of_range(__N("bitset::bitset initial position "
732 "not valid"));
733 _M_copy_from_string(__s, __position, __n);
734 }
736 // 23.3.5.2 bitset operations:
737 //@{
738 /**
739 * @brief Operations on bitsets.
740 * @param rhs A same-sized bitset.
741 *
742 * These should be self-explanatory.
743 */
744 bitset<_Nb>&
745 operator&=(const bitset<_Nb>& __rhs)
746 {
747 this->_M_do_and(__rhs);
748 return *this;
749 }
751 bitset<_Nb>&
752 operator|=(const bitset<_Nb>& __rhs)
753 {
754 this->_M_do_or(__rhs);
755 return *this;
756 }
758 bitset<_Nb>&
759 operator^=(const bitset<_Nb>& __rhs)
760 {
761 this->_M_do_xor(__rhs);
762 return *this;
763 }
764 //@}
766 //@{
767 /**
768 * @brief Operations on bitsets.
769 * @param position The number of places to shift.
770 *
771 * These should be self-explanatory.
772 */
773 bitset<_Nb>&
774 operator<<=(size_t __position)
775 {
776 if (__builtin_expect(__position < _Nb, 1))
777 {
778 this->_M_do_left_shift(__position);
779 this->_M_do_sanitize();
780 }
781 else
782 this->_M_do_reset();
783 return *this;
784 }
786 bitset<_Nb>&
787 operator>>=(size_t __position)
788 {
789 if (__builtin_expect(__position < _Nb, 1))
790 {
791 this->_M_do_right_shift(__position);
792 this->_M_do_sanitize();
793 }
794 else
795 this->_M_do_reset();
796 return *this;
797 }
798 //@}
800 //@{
801 /**
802 * These versions of single-bit set, reset, flip, and test are
803 * extensions from the SGI version. They do no range checking.
804 * @ingroup SGIextensions
805 */
806 bitset<_Nb>&
807 _Unchecked_set(size_t __pos)
808 {
809 this->_M_getword(__pos) |= _Base::_S_maskbit(__pos);
810 return *this;
811 }
813 bitset<_Nb>&
814 _Unchecked_set(size_t __pos, int __val)
815 {
816 if (__val)
817 this->_M_getword(__pos) |= _Base::_S_maskbit(__pos);
818 else
819 this->_M_getword(__pos) &= ~_Base::_S_maskbit(__pos);
820 return *this;
821 }
823 bitset<_Nb>&
824 _Unchecked_reset(size_t __pos)
825 {
826 this->_M_getword(__pos) &= ~_Base::_S_maskbit(__pos);
827 return *this;
828 }
830 bitset<_Nb>&
831 _Unchecked_flip(size_t __pos)
832 {
833 this->_M_getword(__pos) ^= _Base::_S_maskbit(__pos);
834 return *this;
835 }
837 bool
838 _Unchecked_test(size_t __pos) const
839 {
840 return (this->_M_getword(__pos) & _Base::_S_maskbit(__pos))
841 != static_cast<_WordT>(0);
842 }
843 //@}
845 // Set, reset, and flip.
846 /**
847 * @brief Sets every bit to true.
848 */
849 bitset<_Nb>&
850 set()
851 {
852 this->_M_do_set();
853 this->_M_do_sanitize();
854 return *this;
855 }
857 /**
858 * @brief Sets a given bit to a particular value.
859 * @param position The index of the bit.
860 * @param val Either true or false, defaults to true.
861 * @throw std::out_of_range If @a pos is bigger the size of the %set.
862 */
863 bitset<_Nb>&
864 set(size_t __position, bool __val = true)
865 {
866 if (__position >= _Nb)
867 __throw_out_of_range(__N("bitset::set"));
868 return _Unchecked_set(__position, __val);
869 }
871 /**
872 * @brief Sets every bit to false.
873 */
874 bitset<_Nb>&
875 reset()
876 {
877 this->_M_do_reset();
878 return *this;
879 }
881 /**
882 * @brief Sets a given bit to false.
883 * @param position The index of the bit.
884 * @throw std::out_of_range If @a pos is bigger the size of the %set.
885 *
886 * Same as writing @c set(pos,false).
887 */
888 bitset<_Nb>&
889 reset(size_t __position)
890 {
891 if (__position >= _Nb)
892 __throw_out_of_range(__N("bitset::reset"));
893 return _Unchecked_reset(__position);
894 }
896 /**
897 * @brief Toggles every bit to its opposite value.
898 */
899 bitset<_Nb>&
900 flip()
901 {
902 this->_M_do_flip();
903 this->_M_do_sanitize();
904 return *this;
905 }
907 /**
908 * @brief Toggles a given bit to its opposite value.
909 * @param position The index of the bit.
910 * @throw std::out_of_range If @a pos is bigger the size of the %set.
911 */
912 bitset<_Nb>&
913 flip(size_t __position)
914 {
915 if (__position >= _Nb)
916 __throw_out_of_range(__N("bitset::flip"));
917 return _Unchecked_flip(__position);
918 }
920 /// See the no-argument flip().
921 bitset<_Nb>
922 operator~() const { return bitset<_Nb>(*this).flip(); }
924 //@{
925 /**
926 * @brief Array-indexing support.
927 * @param position Index into the %bitset.
928 * @return A bool for a 'const %bitset'. For non-const bitsets, an
929 * instance of the reference proxy class.
930 * @note These operators do no range checking and throw no exceptions,
931 * as required by DR 11 to the standard.
932 *
933 * @if maint
934 * _GLIBCXX_RESOLVE_LIB_DEFECTS Note that this implementation already
935 * resolves DR 11 (items 1 and 2), but does not do the range-checking
936 * required by that DR's resolution. -pme
937 * The DR has since been changed: range-checking is a precondition
938 * (users' responsibility), and these functions must not throw. -pme
939 * @endif
940 */
941 reference
942 operator[](size_t __position) { return reference(*this,__position); }
944 bool
945 operator[](size_t __position) const { return _Unchecked_test(__position); }
946 //@}
948 /**
949 * @brief Retuns a numerical interpretation of the %bitset.
950 * @return The integral equivalent of the bits.
951 * @throw std::overflow_error If there are too many bits to be
952 * represented in an @c unsigned @c long.
953 */
954 unsigned long
955 to_ulong() const { return this->_M_do_to_ulong(); }
957 /**
958 * @brief Retuns a character interpretation of the %bitset.
959 * @return The string equivalent of the bits.
960 *
961 * Note the ordering of the bits: decreasing character positions
962 * correspond to increasing bit positions (see the main class notes for
963 * an example).
964 *
965 * Also note that you must specify the string's template parameters
966 * explicitly. Given a bitset @c bs and a string @s:
967 * @code
968 * s = bs.to_string<char,char_traits<char>,allocator<char> >();
969 * @endcode
970 */
971 template<class _CharT, class _Traits, class _Alloc>
972 basic_string<_CharT, _Traits, _Alloc>
973 to_string() const
974 {
975 basic_string<_CharT, _Traits, _Alloc> __result;
976 _M_copy_to_string(__result);
977 return __result;
978 }
980 // Helper functions for string operations.
981 template<class _CharT, class _Traits, class _Alloc>
982 void
983 _M_copy_from_string(const basic_string<_CharT,_Traits,_Alloc>& __s,
984 size_t, size_t);
986 template<class _CharT, class _Traits, class _Alloc>
987 void
988 _M_copy_to_string(basic_string<_CharT,_Traits,_Alloc>&) const;
990 /// Returns the number of bits which are set.
991 size_t
992 count() const { return this->_M_do_count(); }
994 /// Returns the total number of bits.
995 size_t
996 size() const { return _Nb; }
998 //@{
999 /// These comparisons for equality/inequality are, well, @e bitwise.
1000 bool
1001 operator==(const bitset<_Nb>& __rhs) const
1002 { return this->_M_is_equal(__rhs); }
1004 bool
1005 operator!=(const bitset<_Nb>& __rhs) const
1006 { return !this->_M_is_equal(__rhs); }
1007 //@}
1009 /**
1010 * @brief Tests the value of a bit.
1011 * @param position The index of a bit.
1012 * @return The value at @a pos.
1013 * @throw std::out_of_range If @a pos is bigger the size of the %set.
1014 */
1015 bool
1016 test(size_t __position) const
1017 {
1018 if (__position >= _Nb)
1019 __throw_out_of_range(__N("bitset::test"));
1020 return _Unchecked_test(__position);
1021 }
1023 /**
1024 * @brief Tests whether any of the bits are on.
1025 * @return True if at least one bit is set.
1026 */
1027 bool
1028 any() const { return this->_M_is_any(); }
1030 /**
1031 * @brief Tests whether any of the bits are on.
1032 * @return True if none of the bits are set.
1033 */
1034 bool
1035 none() const { return !this->_M_is_any(); }
1037 //@{
1038 /// Self-explanatory.
1039 bitset<_Nb>
1040 operator<<(size_t __position) const
1041 { return bitset<_Nb>(*this) <<= __position; }
1043 bitset<_Nb>
1044 operator>>(size_t __position) const
1045 { return bitset<_Nb>(*this) >>= __position; }
1046 //@}
1048 /**
1049 * @brief Finds the index of the first "on" bit.
1050 * @return The index of the first bit set, or size() if not found.
1051 * @ingroup SGIextensions
1052 * @sa _Find_next
1053 */
1054 size_t
1055 _Find_first() const
1056 { return this->_M_do_find_first(_Nb); }
1058 /**
1059 * @brief Finds the index of the next "on" bit after prev.
1060 * @return The index of the next bit set, or size() if not found.
1061 * @param prev Where to start searching.
1062 * @ingroup SGIextensions
1063 * @sa _Find_first
1064 */
1065 size_t
1066 _Find_next(size_t __prev ) const
1067 { return this->_M_do_find_next(__prev, _Nb); }
1068 };
1070 // Definitions of non-inline member functions.
1071 template<size_t _Nb>
1072 template<class _CharT, class _Traits, class _Alloc>
1073 void
1074 bitset<_Nb>::_M_copy_from_string(const basic_string<_CharT, _Traits,
1075 _Alloc>& __s, size_t __pos, size_t __n)
1076 {
1077 reset();
1078 const size_t __nbits = std::min(_Nb, std::min(__n, __s.size() - __pos));
1079 for (size_t __i = 0; __i < __nbits; ++__i)
1080 {
1081 switch(__s[__pos + __nbits - __i - 1])
1082 {
1083 case '0':
1084 break;
1085 case '1':
1086 set(__i);
1087 break;
1088 default:
1089 __throw_invalid_argument(__N("bitset::_M_copy_from_string"));
1090 }
1091 }
1092 }
1094 template<size_t _Nb>
1095 template<class _CharT, class _Traits, class _Alloc>
1096 void
1097 bitset<_Nb>::_M_copy_to_string(basic_string<_CharT, _Traits,
1098 _Alloc>& __s) const
1099 {
1100 __s.assign(_Nb, '0');
1101 for (size_t __i = 0; __i < _Nb; ++__i)
1102 if (_Unchecked_test(__i))
1103 __s[_Nb - 1 - __i] = '1';
1104 }
1106 // 23.3.5.3 bitset operations:
1107 //@{
1108 /**
1109 * @brief Global bitwise operations on bitsets.
1110 * @param x A bitset.
1111 * @param y A bitset of the same size as @a x.
1112 * @return A new bitset.
1113 *
1114 * These should be self-explanatory.
1115 */
1116 template<size_t _Nb>
1117 inline bitset<_Nb>
1118 operator&(const bitset<_Nb>& __x, const bitset<_Nb>& __y)
1119 {
1120 bitset<_Nb> __result(__x);
1121 __result &= __y;
1122 return __result;
1123 }
1125 template<size_t _Nb>
1126 inline bitset<_Nb>
1127 operator|(const bitset<_Nb>& __x, const bitset<_Nb>& __y)
1128 {
1129 bitset<_Nb> __result(__x);
1130 __result |= __y;
1131 return __result;
1132 }
1134 template <size_t _Nb>
1135 inline bitset<_Nb>
1136 operator^(const bitset<_Nb>& __x, const bitset<_Nb>& __y)
1137 {
1138 bitset<_Nb> __result(__x);
1139 __result ^= __y;
1140 return __result;
1141 }
1142 //@}
1144 //@{
1145 /**
1146 * @brief Global I/O operators for bitsets.
1147 *
1148 * Direct I/O between streams and bitsets is supported. Output is
1149 * straightforward. Input will skip whitespace, only accept '0' and '1'
1150 * characters, and will only extract as many digits as the %bitset will
1151 * hold.
1152 */
1153 template<class _CharT, class _Traits, size_t _Nb>
1154 basic_istream<_CharT, _Traits>&
1155 operator>>(basic_istream<_CharT, _Traits>& __is, bitset<_Nb>& __x)
1156 {
1157 typedef typename _Traits::char_type char_type;
1158 basic_string<_CharT, _Traits> __tmp;
1159 __tmp.reserve(_Nb);
1161 ios_base::iostate __state = ios_base::goodbit;
1162 typename basic_istream<_CharT, _Traits>::sentry __sentry(__is);
1163 if (__sentry)
1164 {
1165 try
1166 {
1167 basic_streambuf<_CharT, _Traits>* __buf = __is.rdbuf();
1168 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1169 // 303. Bitset input operator underspecified
1170 const char_type __zero = __is.widen('0');
1171 const char_type __one = __is.widen('1');
1172 for (size_t __i = 0; __i < _Nb; ++__i)
1173 {
1174 static typename _Traits::int_type __eof = _Traits::eof();
1176 typename _Traits::int_type __c1 = __buf->sbumpc();
1177 if (_Traits::eq_int_type(__c1, __eof))
1178 {
1179 __state |= ios_base::eofbit;
1180 break;
1181 }
1182 else
1183 {
1184 char_type __c2 = _Traits::to_char_type(__c1);
1185 if (__c2 == __zero)
1186 __tmp.push_back('0');
1187 else if (__c2 == __one)
1188 __tmp.push_back('1');
1189 else if (_Traits::eq_int_type(__buf->sputbackc(__c2),
1190 __eof))
1191 {
1192 __state |= ios_base::failbit;
1193 break;
1194 }
1195 }
1196 }
1197 }
1198 catch(...)
1199 { __is._M_setstate(ios_base::badbit); }
1200 }
1202 if (__tmp.empty() && _Nb)
1203 __state |= ios_base::failbit;
1204 else
1205 __x._M_copy_from_string(__tmp, static_cast<size_t>(0), _Nb);
1206 if (__state)
1207 __is.setstate(__state);
1208 return __is;
1209 }
1211 template <class _CharT, class _Traits, size_t _Nb>
1212 basic_ostream<_CharT, _Traits>&
1213 operator<<(basic_ostream<_CharT, _Traits>& __os, const bitset<_Nb>& __x)
1214 {
1215 basic_string<_CharT, _Traits> __tmp;
1216 __x._M_copy_to_string(__tmp);
1217 return __os << __tmp;
1218 }
1219 //@}
1220 } // namespace std
1222 #undef _GLIBCXX_BITSET_WORDS
1223 #undef _GLIBCXX_BITSET_BITS_PER_WORD
1225 #ifdef _GLIBCXX_DEBUG
1226 # include <debug/bitset>
1227 #endif
1229 #endif /* _GLIBCXX_BITSET */