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++/ext/sgiexts.html#ch23 for a description of extensions.
Definition at line 644 of file bitset.
| std::bitset< _Nb >::bitset | ( | ) | [inline] |
| std::bitset< _Nb >::bitset | ( | unsigned long | __val | ) | [inline] |
Initial bits bitwise-copied from a single word (others set to zero).
Reimplemented in std::__debug::bitset< _Nb >.
| std::bitset< _Nb >::bitset | ( | const std::basic_string< _CharT, _Traits, _Alloc > & | __s, | |
| size_t | __position = 0 | |||
| ) | [inline, explicit] |
Use a subset of a string.
| s | A string of '0' and '1' characters. | |
| position | Index of the first character in s to use; defaults to zero. |
| 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 753 of file bitset.
References __N, std::bitset< _Nb >::_M_copy_from_string(), and std::basic_string< _CharT, _Traits, _Alloc >::size().
| std::bitset< _Nb >::bitset | ( | const std::basic_string< _CharT, _Traits, _Alloc > & | __s, | |
| size_t | __position, | |||
| size_t | __n | |||
| ) | [inline] |
Use a subset of a string.
| 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. |
| 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 774 of file bitset.
References __N, std::bitset< _Nb >::_M_copy_from_string(), and std::basic_string< _CharT, _Traits, _Alloc >::size().
| bool std::bitset< _Nb >::any | ( | ) | const [inline] |
Tests whether any of the bits are on.
Definition at line 1098 of file bitset.
References std::_Base_bitset< _Nw >::_M_is_any().
| size_t std::bitset< _Nb >::count | ( | ) | const [inline] |
Returns the number of bits which are set.
Definition at line 1060 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_count().
| bitset<_Nb>& std::bitset< _Nb >::flip | ( | size_t | __position | ) | [inline] |
Toggles a given bit to its opposite value.
| position | The index of the bit. |
| std::out_of_range | If pos is bigger the size of the set. |
Reimplemented in std::__debug::bitset< _Nb >.
Definition at line 959 of file bitset.
References __N, and std::bitset< _Nb >::_Unchecked_flip().
| bitset<_Nb>& std::bitset< _Nb >::flip | ( | ) | [inline] |
Toggles every bit to its opposite value.
Reimplemented in std::__debug::bitset< _Nb >.
Definition at line 946 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_flip().
Referenced by std::__debug::bitset< _Nb >::flip().
| bool std::bitset< _Nb >::none | ( | ) | const [inline] |
Tests whether any of the bits are on.
Definition at line 1106 of file bitset.
References std::_Base_bitset< _Nw >::_M_is_any().
| bitset<_Nb>& std::bitset< _Nb >::operator &= | ( | const bitset< _Nb > & | __rhs | ) | [inline] |
Operations on bitsets.
| rhs | A same-sized bitset. |
Definition at line 793 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_and().
| bitset<_Nb> std::bitset< _Nb >::operator<< | ( | size_t | __position | ) | const [inline] |
| bitset<_Nb>& std::bitset< _Nb >::operator<<= | ( | size_t | __position | ) | [inline] |
Operations on bitsets.
| position | The number of places to shift. |
Reimplemented in std::__debug::bitset< _Nb >.
Definition at line 822 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_left_shift(), and std::_Base_bitset< _Nw >::_M_do_reset().
| bool std::bitset< _Nb >::operator== | ( | const bitset< _Nb > & | __rhs | ) | const [inline] |
These comparisons for equality/inequality are, well, bitwise.
Definition at line 1071 of file bitset.
References std::_Base_bitset< _Nw >::_M_is_equal().
| bitset<_Nb> std::bitset< _Nb >::operator>> | ( | size_t | __position | ) | const [inline] |
| bitset<_Nb>& std::bitset< _Nb >::operator>>= | ( | size_t | __position | ) | [inline] |
Operations on bitsets.
| position | The number of places to shift. |
Reimplemented in std::__debug::bitset< _Nb >.
Definition at line 835 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_reset(), and std::_Base_bitset< _Nw >::_M_do_right_shift().
| reference std::bitset< _Nb >::operator[] | ( | size_t | __position | ) | [inline] |
Array-indexing support.
| position | Index into the bitset. |
Reimplemented in std::__debug::bitset< _Nb >.
Definition at line 989 of file bitset.
References std::bitset< _Nb >::reference.
| bitset<_Nb>& std::bitset< _Nb >::operator^= | ( | const bitset< _Nb > & | __rhs | ) | [inline] |
Operations on bitsets.
| rhs | A same-sized bitset. |
Definition at line 807 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_xor().
| bitset<_Nb>& std::bitset< _Nb >::operator|= | ( | const bitset< _Nb > & | __rhs | ) | [inline] |
Operations on bitsets.
| rhs | A same-sized bitset. |
Definition at line 800 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_or().
| bitset<_Nb> std::bitset< _Nb >::operator~ | ( | ) | const [inline] |
| bitset<_Nb>& std::bitset< _Nb >::reset | ( | size_t | __position | ) | [inline] |
Sets a given bit to false.
| position | The index of the bit. |
| std::out_of_range | If pos is bigger the size of the set. |
set(pos,false).
Reimplemented in std::__debug::bitset< _Nb >.
Definition at line 935 of file bitset.
References __N, and std::bitset< _Nb >::_Unchecked_reset().
| bitset<_Nb>& std::bitset< _Nb >::reset | ( | ) | [inline] |
Sets every bit to false.
Reimplemented in std::__debug::bitset< _Nb >.
Definition at line 921 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_reset().
Referenced by std::bitset< _Nb >::_M_copy_from_string(), and std::__debug::bitset< _Nb >::reset().
| bitset<_Nb>& std::bitset< _Nb >::set | ( | size_t | __position, | |
| bool | __val = true | |||
| ) | [inline] |
Sets a given bit to a particular value.
| position | The index of the bit. | |
| val | Either true or false, defaults to true. |
| std::out_of_range | If pos is bigger the size of the set. |
Reimplemented in std::__debug::bitset< _Nb >.
Definition at line 910 of file bitset.
References __N, and std::bitset< _Nb >::_Unchecked_set().
| bitset<_Nb>& std::bitset< _Nb >::set | ( | ) | [inline] |
Sets every bit to true.
Reimplemented in std::__debug::bitset< _Nb >.
Definition at line 896 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_set().
Referenced by std::__debug::bitset< _Nb >::set().
| size_t std::bitset< _Nb >::size | ( | ) | const [inline] |
| bool std::bitset< _Nb >::test | ( | size_t | __position | ) | const [inline] |
Tests the value of a bit.
| position | The index of a bit. |
| std::out_of_range | If pos is bigger the size of the set. |
Definition at line 1086 of file bitset.
References __N, and std::bitset< _Nb >::_Unchecked_test().
| std::basic_string<_CharT, _Traits, _Alloc> std::bitset< _Nb >::to_string | ( | ) | const [inline] |
Retuns a character interpretation of the bitset.
Reimplemented in std::__debug::bitset< _Nb >, std::__debug::bitset< _Nb >, std::__debug::bitset< _Nb >, and std::__debug::bitset< _Nb >.
Definition at line 1017 of file bitset.
References std::bitset< _Nb >::_M_copy_to_string().
| unsigned long std::bitset< _Nb >::to_ulong | ( | ) | const [inline] |
Retuns a numerical interpretation of the bitset.
| std::overflow_error | If there are too many bits to be represented in an unsigned long. |
Definition at line 1004 of file bitset.
References std::_Base_bitset< _Nw >::_M_do_to_ulong().
1.5.1