std::bitset< _Nb > Class Template Reference
[Containers]

The bitset class represents a fixed-size sequence of bits. More...

List of all members.

Public Methods

 bitset ()
 All bits set to zero. More...

 bitset (unsigned long __val)
 Initial bits bitwise-copied from a single word (others set to zero). More...

template<class _CharT, class _Traits, class _Alloc>  bitset (const basic_string< _CharT, _Traits, _Alloc > &__s, size_t __pos=0)
 Use a subset of a string. More...

template<class _CharT, class _Traits, class _Alloc>  bitset (const basic_string< _CharT, _Traits, _Alloc > &__s, size_t __pos, size_t __n)
 Use a subset of a string. More...

bitset< _Nb > & set ()
 Sets every bit to true. More...

bitset< _Nb > & set (size_t __pos, bool __val=true)
 Sets a given bit to a particular value. More...

bitset< _Nb > & reset ()
 Sets every bit to false. More...

bitset< _Nb > & reset (size_t __pos)
 Sets a given bit to false. More...

bitset< _Nb > & flip ()
 Toggles every bit to its opposite value. More...

bitset< _Nb > & flip (size_t __pos)
 Toggles a given bit to its opposite value. More...

bitset< _Nb > operator~ () const
 See the no-argument flip(). More...

unsigned long to_ulong () const
 Retuns a numerical interpretation of the bitset. More...

template<class _CharT, class _Traits, class _Alloc> basic_string< _CharT, _Traits,
_Alloc > 
to_string () const
 Retuns a character interpretation of the bitset. More...

size_t count () const
 Returns the number of bits which are set. More...

size_t size () const
 Returns the total number of bits. More...

bool test (size_t __pos) const
 Tests the value of a bit. More...

bool any () const
 Tests whether any of the bits are on. More...

bool none () const
 Tests whether any of the bits are on. More...

size_t _Find_first () const
 Finds the index of the first "on" bit. More...

size_t _Find_next (size_t __prev) const
 Finds the index of the next "on" bit after prev. More...

bitset< _Nb > & operator &= (const bitset< _Nb > &__rhs)
 Operations on bitsets. More...

bitset< _Nb > & operator|= (const bitset< _Nb > &__rhs)
 Operations on bitsets. More...

bitset< _Nb > & operator^= (const bitset< _Nb > &__rhs)
 Operations on bitsets. More...

bitset< _Nb > & operator<<= (size_t __pos)
 Operations on bitsets. More...

bitset< _Nb > & operator>>= (size_t __pos)
 Operations on bitsets. More...

bitset< _Nb > & _Unchecked_set (size_t __pos)
bitset< _Nb > & _Unchecked_set (size_t __pos, int __val)
bitset< _Nb > & _Unchecked_reset (size_t __pos)
bitset< _Nb > & _Unchecked_flip (size_t __pos)
bool _Unchecked_test (size_t __pos) const
reference operator[] (size_t __pos)
 Array-indexing support. More...

bool operator[] (size_t __pos) const
 Array-indexing support. More...

bool operator== (const bitset< _Nb > &__rhs) const
 These comparisons for equality/inequality are, well, bitwise. More...

bool operator!= (const bitset< _Nb > &__rhs) const
 These comparisons for equality/inequality are, well, bitwise. More...

bitset< _Nb > operator<< (size_t __pos) const
 Self-explanatory. More...

bitset< _Nb > operator>> (size_t __pos) const
 Self-explanatory. More...


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 nonzero number of type size_t.

A bitset of size N has N % (sizeof(unsigned long) * CHAR_BIT) unused bits. (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 N-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++/ext/sgiexts.html#ch23

Definition at line 540 of file bitset.


Constructor & Destructor Documentation

template<size_t _Nb>
std::bitset< _Nb >::bitset   [inline]
 

All bits set to zero.

Definition at line 628 of file bitset.

template<size_t _Nb>
std::bitset< _Nb >::bitset unsigned long    __val [inline]
 

Initial bits bitwise-copied from a single word (others set to zero).

Definition at line 631 of file bitset.

template<size_t _Nb>
template<class _CharT, class _Traits, class _Alloc>
std::bitset< _Nb >::bitset const basic_string< _CharT, _Traits, _Alloc > &    __s,
size_t    __pos = 0
[inline, explicit]
 

Use a subset of a string.

Parameters:
s  A string of '0' and '1' characters.
pos  Index of the first character in s to use; defaults to zero.
Exceptions:
std::out_of_range  If pos is bigger the size of s.
std::invalid_argument  If a character appears in the string which is neither '0' nor '1'.

Definition at line 644 of file bitset.

template<size_t _Nb>
template<class _CharT, class _Traits, class _Alloc>
std::bitset< _Nb >::bitset const basic_string< _CharT, _Traits, _Alloc > &    __s,
size_t    __pos,
size_t    __n
[inline]
 

Use a subset of a string.

Parameters:
s  A string of '0' and '1' characters.
pos  Index of the first character in s to use.
n  The number of characters to copy.
Exceptions:
std::out_of_range  If pos is bigger the size of s.
std::invalid_argument  If a character appears in the string which is neither '0' nor '1'.

Definition at line 664 of file bitset.


Member Function Documentation

template<size_t _Nb>
bool std::bitset< _Nb >::any   const [inline]
 

Tests whether any of the bits are on.

Returns:
True if at least one bit is set.

Definition at line 955 of file bitset.

template<size_t _Nb>
size_t std::bitset< _Nb >::count   const [inline]
 

Returns the number of bits which are set.

Definition at line 919 of file bitset.

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::flip size_t    __pos [inline]
 

Toggles a given bit to its opposite value.

Parameters:
pos  The index of the bit.
Exceptions:
std::out_of_range  If pos is bigger the size of the set.

Definition at line 840 of file bitset.

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::flip   [inline]
 

Toggles every bit to its opposite value.

Definition at line 827 of file bitset.

template<size_t _Nb>
bool std::bitset< _Nb >::none   const [inline]
 

Tests whether any of the bits are on.

Returns:
True if none of the bits are set.

Definition at line 962 of file bitset.

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::operator &= const bitset< _Nb > &    __rhs [inline]
 

Operations on bitsets.

Parameters:
rhs  A same-sized bitset.
These should be self-explanatory.

Definition at line 682 of file bitset.

template<size_t _Nb>
bool std::bitset< _Nb >::operator!= const bitset< _Nb > &    __rhs const [inline]
 

These comparisons for equality/inequality are, well, bitwise.

Definition at line 932 of file bitset.

template<size_t _Nb>
bitset<_Nb> std::bitset< _Nb >::operator<< size_t    __pos const [inline]
 

Self-explanatory.

Definition at line 967 of file bitset.

References std::operator<<().

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::operator<<= size_t    __pos [inline]
 

Operations on bitsets.

Parameters:
pos  The number of places to shift.
These should be self-explanatory.

Definition at line 711 of file bitset.

template<size_t _Nb>
bool std::bitset< _Nb >::operator== const bitset< _Nb > &    __rhs const [inline]
 

These comparisons for equality/inequality are, well, bitwise.

Definition at line 928 of file bitset.

template<size_t _Nb>
bitset<_Nb> std::bitset< _Nb >::operator>> size_t    __pos const [inline]
 

Self-explanatory.

Definition at line 971 of file bitset.

References std::operator>>().

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::operator>>= size_t    __pos [inline]
 

Operations on bitsets.

Parameters:
pos  The number of places to shift.
These should be self-explanatory.

Definition at line 719 of file bitset.

template<size_t _Nb>
bool std::bitset< _Nb >::operator[] size_t    __pos const [inline]
 

Array-indexing support.

Parameters:
pos  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.

Definition at line 872 of file bitset.

template<size_t _Nb>
reference std::bitset< _Nb >::operator[] size_t    __pos [inline]
 

Array-indexing support.

Parameters:
pos  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.

Definition at line 869 of file bitset.

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::operator^= const bitset< _Nb > &    __rhs [inline]
 

Operations on bitsets.

Parameters:
rhs  A same-sized bitset.
These should be self-explanatory.

Definition at line 696 of file bitset.

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::operator|= const bitset< _Nb > &    __rhs [inline]
 

Operations on bitsets.

Parameters:
rhs  A same-sized bitset.
These should be self-explanatory.

Definition at line 689 of file bitset.

template<size_t _Nb>
bitset<_Nb> std::bitset< _Nb >::operator~   const [inline]
 

See the no-argument flip().

Definition at line 849 of file bitset.

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::reset size_t    __pos [inline]
 

Sets a given bit to false.

Parameters:
pos  The index of the bit.
Exceptions:
std::out_of_range  If pos is bigger the size of the set.
Same as writing set(pos,false).

Definition at line 816 of file bitset.

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::reset   [inline]
 

Sets every bit to false.

Definition at line 802 of file bitset.

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::set size_t    __pos,
bool    __val = true
[inline]
 

Sets a given bit to a particular value.

Parameters:
pos  The index of the bit.
val  Either true or false, defaults to true.
Exceptions:
std::out_of_range  If pos is bigger the size of the set.

Definition at line 791 of file bitset.

template<size_t _Nb>
bitset<_Nb>& std::bitset< _Nb >::set   [inline]
 

Sets every bit to true.

Definition at line 777 of file bitset.

template<size_t _Nb>
size_t std::bitset< _Nb >::size   const [inline]
 

Returns the total number of bits.

Definition at line 923 of file bitset.

template<size_t _Nb>
bool std::bitset< _Nb >::test size_t    __pos const [inline]
 

Tests the value of a bit.

Parameters:
pos  The index of a bit.
Returns:
The value at pos.
Exceptions:
std::out_of_range  If pos is bigger the size of the set.

Definition at line 943 of file bitset.

template<size_t _Nb>
template<class _CharT, class _Traits, class _Alloc>
basic_string<_CharT, _Traits, _Alloc> std::bitset< _Nb >::to_string   const [inline]
 

Retuns 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).

Also note that you must specify the string's template parameters explicitly. Given a bitset bs and a string @s:

     s = bs.to_string<char,char_traits<char>,allocator<char> >();

Definition at line 900 of file bitset.

template<size_t _Nb>
unsigned long std::bitset< _Nb >::to_ulong   const [inline]
 

Retuns a numerical interpretation of the bitset.

Returns:
The integral equivalent of the bits.
Exceptions:
std::overflow_error  If there are too many bits to be represented in an unsigned long.

Definition at line 882 of file bitset.


The documentation for this class was generated from the following file:
Generated on Wed May 1 19:20:10 2002 for libstdc++-v3 Source by doxygen1.2.15