The bitset class represents a fixed-size sequence of bits.
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List of all members.
Classes
Public Member Functions
- constexpr bitset ()
- constexpr bitset (unsigned long long __val)
- template<class _CharT , class _Traits , class _Alloc > bitset (const std::basic_string< _CharT, _Traits, _Alloc > &__s, size_t __position, size_t __n)
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template<class _CharT , class _Traits , class _Alloc > bitset (const std::basic_string< _CharT, _Traits, _Alloc > &__s, size_t __position, size_t __n, _CharT __zero, _CharT __one=_CharT('1'))
- template<class _CharT , class _Traits , class _Alloc > bitset (const std::basic_string< _CharT, _Traits, _Alloc > &__s, size_t __position=0)
- template<typename _CharT > bitset (const _CharT *__str, typename std::basic_string< _CharT >::size_type __n=std::basic_string< _CharT >::npos, _CharT __zero=_CharT('0'), _CharT __one=_CharT('1'))
- size_t _Find_first () const
- size_t _Find_next (size_t __prev) const
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template<class _CharT , class _Traits > void _M_copy_from_ptr (const _CharT *, size_t, size_t, size_t, _CharT, _CharT)
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template<class _CharT , class _Traits , class _Alloc > void _M_copy_from_string (const std::basic_string< _CharT, _Traits, _Alloc > &__s, size_t __pos, size_t __n, _CharT __zero, _CharT __one)
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template<class _CharT , class _Traits , class _Alloc > void _M_copy_from_string (const std::basic_string< _CharT, _Traits, _Alloc > &__s, size_t __pos, size_t __n)
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template<class _CharT , class _Traits , class _Alloc > void _M_copy_to_string (std::basic_string< _CharT, _Traits, _Alloc > &, _CharT, _CharT) const
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template<class _CharT , class _Traits , class _Alloc > void _M_copy_to_string (std::basic_string< _CharT, _Traits, _Alloc > &__s) const
- bool all () const
- bool any () const
- size_t count () const
- bitset< _Nb > & flip ()
- bitset< _Nb > & flip (size_t __position)
- bool none () const
- bitset< _Nb > operator~ () const
- bitset< _Nb > & reset ()
- bitset< _Nb > & reset (size_t __position)
- bitset< _Nb > & set ()
- bitset< _Nb > & set (size_t __position, bool __val=true)
- constexpr size_t size () const
- bool test (size_t __position) const
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template<class _CharT , class _Traits > std::basic_string< _CharT,
_Traits, std::allocator
< _CharT > > to_string () const
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template<class _CharT > std::basic_string< _CharT,
std::char_traits< _CharT >
, std::allocator< _CharT > > to_string () const
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template<class _CharT > std::basic_string< _CharT,
std::char_traits< _CharT >
, std::allocator< _CharT > > to_string (_CharT __zero, _CharT __one=_CharT('1')) const
- template<class _CharT , class _Traits , class _Alloc > std::basic_string< _CharT,
_Traits, _Alloc > to_string () const
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template<class _CharT , class _Traits > std::basic_string< _CharT,
_Traits, std::allocator
< _CharT > > to_string (_CharT __zero, _CharT __one=_CharT('1')) const
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template<class _CharT , class _Traits , class _Alloc > std::basic_string< _CharT,
_Traits, _Alloc > to_string (_CharT __zero, _CharT __one=_CharT('1')) const
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std::basic_string< char,
std::char_traits< char >
, std::allocator< char > > to_string (char __zero, char __one= '1') const
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std::basic_string< char,
std::char_traits< char >
, std::allocator< char > > to_string () const
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unsigned long long to_ullong () const
- unsigned long to_ulong () const
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Private Member Functions
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size_t _M_are_all_aux () const
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void _M_do_and (const _Base_bitset< _Nw > &__x)
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size_t _M_do_count () const
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size_t _M_do_find_first (size_t __not_found) const
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size_t _M_do_find_next (size_t __prev, size_t __not_found) const
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void _M_do_flip ()
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void _M_do_left_shift (size_t __shift)
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void _M_do_or (const _Base_bitset< _Nw > &__x)
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void _M_do_reset ()
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void _M_do_right_shift (size_t __shift)
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void _M_do_set ()
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unsigned long long _M_do_to_ullong () const
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unsigned long _M_do_to_ulong () const
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void _M_do_xor (const _Base_bitset< _Nw > &__x)
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const _WordT * _M_getdata () const
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_WordT & _M_getword (size_t __pos)
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_WordT _M_getword (size_t __pos) const
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_WordT & _M_hiword ()
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constexpr _WordT _M_hiword () const
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bool _M_is_any () const
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bool _M_is_equal (const _Base_bitset< _Nw > &__x) const
Static Private Member Functions
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static constexpr _WordT _S_maskbit (size_t __pos)
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static constexpr size_t _S_whichbit (size_t __pos)
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static constexpr size_t _S_whichbyte (size_t __pos)
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static constexpr size_t _S_whichword (size_t __pos)
Private Attributes
Friends
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class hash
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class reference
Detailed Description
template<size_t _Nb>
class std::bitset< _Nb >
The bitset class represents a fixed-size sequence of bits.
(Note that bitset does not meet the formal requirements of a container. Mainly, it lacks iterators.)
The template argument, Nb, may be any non-negative number, specifying the number of bits (e.g., "0", "12", "1024*1024").
In the general unoptimized case, storage is allocated in word-sized blocks. Let B be the number of bits in a word, then (Nb+(B-1))/B words will be used for storage. B - NbB bits are unused. (They are the high-order bits in the highest word.) It is a class invariant that those unused bits are always zero.
If you think of bitset as a simple array of bits, be aware that your mental picture is reversed: a bitset behaves the same way as bits in integers do, with the bit at index 0 in the least significant / right-hand position, and the bit at index Nb-1 in the most significant / left-hand position. Thus, unlike other containers, a bitset's index counts from right to left, to put it very loosely.
This behavior is preserved when translating to and from strings. For example, the first line of the following program probably prints b('a') is 0001100001 on a modern ASCII system.
#include <bitset>
#include <iostream>
#include <sstream>
using namespace std;
int main()
{
long a = 'a';
bitset<10> b(a);
cout << "b('a') is " << b << endl;
ostringstream s;
s << b;
string str = s.str();
cout << "index 3 in the string is " << str[3] << " but\n"
<< "index 3 in the bitset is " << b[3] << endl;
}
Also see: http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt12ch33s02.html for a description of extensions.
Most of the actual code isn't contained in bitset<> itself, but in the base class _Base_bitset. The base class works with whole words, not with individual bits. This allows us to specialize _Base_bitset for the important special case where the bitset is only a single word.
Extra confusion can result due to the fact that the storage for _Base_bitset is a regular array, and is indexed as such. This is carefully encapsulated.
Definition at line 722 of file bitset.
Constructor & Destructor Documentation
All bits set to zero.
Definition at line 816 of file bitset.
Initial bits bitwise-copied from a single word (others set to zero).
Definition at line 821 of file bitset.
template<size_t _Nb>
template<class _CharT , class _Traits , class _Alloc >
Use a subset of a string.
- Parameters:
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| s | A string of 0 and 1 characters. |
| position | Index of the first character in s to use; defaults to zero. |
- Exceptions:
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Definition at line 840 of file bitset.
template<size_t _Nb>
template<class _CharT , class _Traits , class _Alloc >
Use a subset of a string.
- Parameters:
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| s | A string of 0 and 1 characters. |
| position | Index of the first character in s to use. |
| n | The number of characters to copy. |
- Exceptions:
-
Definition at line 862 of file bitset.
template<size_t _Nb>
template<typename _CharT >
Construct from a character array.
- Parameters:
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| str | An array of characters zero and one. |
| n | The number of characters to use. |
| zero | The character corresponding to the value 0. |
| one | The character corresponding to the value 1. |
- Exceptions:
-
Definition at line 898 of file bitset.
Member Function Documentation
Tests whether all the bits are on.
- Returns:
- True if all the bits are set.
Definition at line 1290 of file bitset.
Tests whether any of the bits are on.
- Returns:
- True if at least one bit is set.
Definition at line 1298 of file bitset.
Returns the number of bits which are set.
Definition at line 1250 of file bitset.
Toggles a given bit to its opposite value.
- Parameters:
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| position | The index of the bit. |
- Exceptions:
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Definition at line 1090 of file bitset.
Toggles every bit to its opposite value.
Definition at line 1077 of file bitset.
Tests whether any of the bits are on.
- Returns:
- True if none of the bits are set.
Definition at line 1306 of file bitset.
These comparisons for equality/inequality are, well, bitwise.
Definition at line 1265 of file bitset.
Operations on bitsets.
- Parameters:
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These should be self-explanatory.
Definition at line 924 of file bitset.
Self-explanatory.
Definition at line 1312 of file bitset.
Operations on bitsets.
- Parameters:
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| position | The number of places to shift. |
These should be self-explanatory.
Definition at line 953 of file bitset.
These comparisons for equality/inequality are, well, bitwise.
Definition at line 1261 of file bitset.
Self-explanatory.
Definition at line 1316 of file bitset.
Operations on bitsets.
- Parameters:
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| position | The number of places to shift. |
These should be self-explanatory.
Definition at line 966 of file bitset.
template<size_t _Nb>
bool std::bitset< _Nb >::operator[] |
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size_t |
__position |
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const [inline] |
Array-indexing support.
- Parameters:
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| position | Index into the bitset. |
- Returns:
- A bool for a const bitset. For non-const bitsets, an instance of the reference proxy class.
- Note:
- These operators do no range checking and throw no exceptions, as required by DR 11 to the standard.
_GLIBCXX_RESOLVE_LIB_DEFECTS Note that this implementation already resolves DR 11 (items 1 and 2), but does not do the range-checking required by that DR's resolution. -pme The DR has since been changed: range-checking is a precondition (users' responsibility), and these functions must not throw. -pme
Definition at line 1122 of file bitset.
Array-indexing support.
- Parameters:
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| position | Index into the bitset. |
- Returns:
- A bool for a const bitset. For non-const bitsets, an instance of the reference proxy class.
- Note:
- These operators do no range checking and throw no exceptions, as required by DR 11 to the standard.
_GLIBCXX_RESOLVE_LIB_DEFECTS Note that this implementation already resolves DR 11 (items 1 and 2), but does not do the range-checking required by that DR's resolution. -pme The DR has since been changed: range-checking is a precondition (users' responsibility), and these functions must not throw. -pme
Definition at line 1118 of file bitset.
Operations on bitsets.
- Parameters:
-
These should be self-explanatory.
Definition at line 938 of file bitset.
Operations on bitsets.
- Parameters:
-
These should be self-explanatory.
Definition at line 931 of file bitset.
Sets every bit to false.
Definition at line 1052 of file bitset.
Sets a given bit to false.
- Parameters:
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| position | The index of the bit. |
- Exceptions:
-
Same as writing set(pos,false)
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Definition at line 1066 of file bitset.
Sets every bit to true.
Definition at line 1027 of file bitset.
Sets a given bit to a particular value.
- Parameters:
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| position | The index of the bit. |
| val | Either true or false, defaults to true. |
- Exceptions:
-
Definition at line 1041 of file bitset.
template<size_t _Nb>
constexpr size_t std::bitset< _Nb >::size |
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const [inline] |
Returns the total number of bits.
Definition at line 1255 of file bitset.
template<size_t _Nb>
bool std::bitset< _Nb >::test |
( |
size_t |
__position |
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const [inline] |
Tests the value of a bit.
- Parameters:
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| position | The index of a bit. |
- Returns:
- The value at pos.
- Exceptions:
-
Definition at line 1276 of file bitset.
template<size_t _Nb>
template<class _CharT , class _Traits , class _Alloc >
Returns a character interpretation of the bitset.
- Returns:
- The string equivalent of the bits.
Note the ordering of the bits: decreasing character positions correspond to increasing bit positions (see the main class notes for an example).
Definition at line 1152 of file bitset.
template<size_t _Nb>
unsigned long std::bitset< _Nb >::to_ulong |
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const [inline] |
Returns a numerical interpretation of the bitset.
- Returns:
- The integral equivalent of the bits.
- Exceptions:
-
Definition at line 1133 of file bitset.
The documentation for this class was generated from the following file: