##include <string>
#include <iosfwd>
namespace std {
template<size_t N> class bitset;
template<size_t N>
constexpr bitset<N> operator&(const bitset<N>&, const bitset<N>&) noexcept;
template<size_t N>
constexpr bitset<N> operator|(const bitset<N>&, const bitset<N>&) noexcept;
template<size_t N>
constexpr bitset<N> operator^(const bitset<N>&, const bitset<N>&) noexcept;
template<class charT, class traits, size_t N>
basic_istream<charT, traits>&
operator>(basic_istream<charT, traits>& is, bitset<N>& x);
template<class charT, class traits, size_t N>
basic_ostream<charT, traits>&
operator<(basic_ostream<charT, traits>& os, const bitset<N>& x);
}
namespace std {
template<size_t N> class bitset {
public:
class reference {
public:
constexpr reference(const reference& x) noexcept;
constexpr ~reference();
constexpr reference& operator=(bool x) noexcept;
constexpr reference& operator=(const reference& x) noexcept;
constexpr const reference& operator=(bool x) const noexcept;
constexpr operator bool() const noexcept;
constexpr bool operator~() const noexcept;
constexpr reference& flip() noexcept;
friend constexpr void swap(reference x, reference y) noexcept;
friend constexpr void swap(reference x, bool& y) noexcept;
friend constexpr void swap(bool& x, reference y) noexcept;
};
constexpr bitset() noexcept;
constexpr bitset(unsigned long val) noexcept;
template<class charT, class traits, class Allocator>
constexpr explicit bitset(
const basic_string<charT, traits, Allocator>& str,
typename basic_string<charT, traits, Allocator>::size_type pos = 0,
typename basic_string<charT, traits, Allocator>::size_type n
= basic_string<charT, traits, Allocator>::npos,
charT zero = charT('0'),
charT one = charT('1');
template<class charT, class traits>
constexpr explicit bitset(
basic_string_view<charT, traits> str,
typename basic_string_view<charT, traits>::size_type pos = 0,
typename basic_string_view<charT, traits>::size_type n
= basic_string_view<charT, traits>::npos,
charT zero = charT('0'),
charT one = charT('1');
template<class charT>
constexpr explicit bitset(
const charT* str,
typename basic_string_view<charT>::size_type n = basic_string_view<charT>::npos,
charT zero = charT('0'),
charT one = charT('1');
constexpr bitset& operator&=(const bitset& rhs) noexcept;
constexpr bitset& operator|=(const bitset& rhs) noexcept;
constexpr bitset& operator^=(const bitset& rhs) noexcept;
constexpr bitset& operator<=(size_t pos) noexcept;
constexpr bitset& operator>=(size_t pos) noexcept;
constexpr bitset operator<(size_t pos) const noexcept;
constexpr bitset operator>(size_t pos) const noexcept;
constexpr bitset& set() noexcept;
constexpr bitset& set(size_t pos, bool val = true);
constexpr bitset& reset() noexcept;
constexpr bitset& reset(size_t pos);
constexpr bitset operator~() const noexcept;
constexpr bitset& flip() noexcept;
constexpr bitset& flip(size_t pos);
constexpr bool operator[](size_t pos) const;
constexpr reference operator[](size_t pos);
constexpr unsigned long to_ulong() const;
constexpr unsigned long to_ullong() const;
template<class charT = char,
class traits = char_traits<charT>,
class Allocator = allocator<charT>>
constexpr basic_string<charT, traits, Allocator>
to_string(charT zero = charT('0'), charT one = charT('1') const;
constexpr size_t count() const noexcept;
constexpr size_t size() const noexcept;
constexpr bool operator=(const bitset& rhs) const noexcept;
constexpr bool test(size_t pos) const;
constexpr bool all() const noexcept;
constexpr bool any() const noexcept;
constexpr bool none() const noexcept;
};
template<class T> struct hash;
template<size_t N> struct hash<bitset<N>>;
}
The class template
bitset<N>
describes an object that can store a sequence consisting of a fixed number of
bits,
N.Each bit represents either the value zero (reset) or one (set)
.To
toggle
a bit is to change the value zero to one, or the value one to
zero
.Each bit has a non-negative position
pos.When converting
between an object of type
bitset<N>
and a value of some
integral type, bit position
pos corresponds to the
bit value
1 << pos.The integral value corresponding to two
or more bits is the sum of their bit values
.reference
is a class that simulates a reference to a single bit in the sequence
. constexpr reference::reference(const reference& x) noexcept;
Effects: Initializes
*this to refer to the same bit as
x. constexpr reference::~reference();
constexpr reference& reference::operator=(bool x) noexcept;
constexpr reference& reference::operator=(const reference& x) noexcept;
constexpr const reference& reference::operator=(bool x) const noexcept;
Effects: Sets the bit referred to by
*this if
bool(x) is
true,
and clears it otherwise
. constexpr void swap(reference x, reference y) noexcept;
constexpr void swap(reference x, bool& y) noexcept;
constexpr void swap(bool& x, reference y) noexcept;
Effects: Exchanges the values denoted by x and y as if by:
bool b = x;
x = y;
y = b;
constexpr reference& reference::flip() noexcept;
The functions described in
[template.bitset] can report three kinds of
errors, each associated with a distinct exception:
constexpr bitset() noexcept;
Effects: Initializes all bits in
*this to zero
. constexpr bitset(unsigned long val) noexcept;
Effects: Initializes the first
M bit positions to the corresponding bit
values in
val. M is the smaller of
N and the number of bits in the value
representation (
[basic.types.general]) of
unsigned long. If
M < N, the remaining bit positions are initialized to zero
.template<class charT, class traits, class Allocator>
constexpr explicit bitset(
const basic_string<charT, traits, Allocator>& str,
typename basic_string<charT, traits, Allocator>::size_type pos = 0,
typename basic_string<charT, traits, Allocator>::size_type n
= basic_string<charT, traits, Allocator>::npos,
charT zero = charT('0'),
charT one = charT('1');
template<class charT, class traits>
constexpr explicit bitset(
basic_string_view<charT, traits> str,
typename basic_string_view<charT, traits>::size_type pos = 0,
typename basic_string_view<charT, traits>::size_type n
= basic_string_view<charT, traits>::npos,
charT zero = charT('0'),
charT one = charT('1');
Effects: Determines the effective length
rlen of the initializing string as the smaller of
n and
str.size() - pos. Initializes the first
M bit
positions to values determined from the corresponding characters in the string
str.M is the smaller of
N and
rlen. An element of the constructed object has value zero if the
corresponding character in
str, beginning at position
pos, is
zero.Otherwise, the element has the value one
.Character position
pos + M - 1 corresponds to bit position zero
.Subsequent decreasing character positions correspond to increasing bit positions
.The function uses
traits::eq
to compare the character values
.Throws:
out_of_range if
pos > str.size() or
invalid_argument if any of
the
rlen characters in
str
beginning at position
pos
is other than
zero or
one. template<class charT>
constexpr explicit bitset(
const charT* str,
typename basic_string_view<charT>::size_type n = basic_string_view<charT>::npos,
charT zero = charT('0'),
charT one = charT('1');
Effects: As if by:
bitset(n == basic_string_view<charT>::npos
? basic_string_view<charT>(str)
: basic_string_view<charT>(str, n),
0, n, zero, one)
constexpr bitset& operator&=(const bitset& rhs) noexcept;
Effects: Clears each bit in
*this
for which the corresponding bit in
rhs is clear, and leaves all other bits unchanged
. constexpr bitset& operator|=(const bitset& rhs) noexcept;
Effects: Sets each bit in
*this
for which the corresponding bit in
rhs is set, and leaves all other bits unchanged
. constexpr bitset& operator^=(const bitset& rhs) noexcept;
Effects: Toggles each bit in
*this
for which the corresponding bit in
rhs is set, and leaves all other bits unchanged
. constexpr bitset& operator<=(size_t pos) noexcept;
Effects: Replaces each bit at position
I in
*this
with a value determined as follows:
- If I < pos, the new value is zero;
- If I >= pos, the new value is the previous
value of the bit at position I - pos.
constexpr bitset& operator>=(size_t pos) noexcept;
Effects: Replaces each bit at position
I in
*this
with a value determined as follows:
- If pos >= N - I, the new value is zero;
- If pos < N - I, the new value is the previous value of the bit at position I + pos.
constexpr bitset operator<(size_t pos) const noexcept;
Returns:
bitset(*this) <<= pos. constexpr bitset operator>(size_t pos) const noexcept;
Returns:
bitset(*this) >>= pos. constexpr bitset& set() noexcept;
Effects: Sets all bits in
*this. constexpr bitset& set(size_t pos, bool val = true);
Effects: Stores a new value in the bit at position
pos in
*this. If
val is
true, the stored value is one, otherwise it is zero
.Throws:
out_of_range if
pos does not correspond to a valid bit position
. constexpr bitset& reset() noexcept;
Effects: Resets all bits in
*this. constexpr bitset& reset(size_t pos);
Effects: Resets the bit at position
pos in
*this. Throws:
out_of_range if
pos does not correspond to a valid bit position
. constexpr bitset operator~() const noexcept;
Effects: Constructs an object
x of class
bitset
and initializes it with
*this. constexpr bitset& flip() noexcept;
Effects: Toggles all bits in
*this. constexpr bitset& flip(size_t pos);
Effects: Toggles the bit at position
pos in
*this. Throws:
out_of_range if
pos does not correspond to a valid bit position
. constexpr bool operator[](size_t pos) const;
Returns:
true if the bit at position
pos in
*this has the value
one, otherwise
false. constexpr bitset::reference operator[](size_t pos);
Returns: An object of type
bitset::reference
such that
(*this)[pos] == this->test(pos),
and such that
(*this)[pos] = val
is equivalent to
this->set(pos, val). Remarks: For the purpose of determining the presence of a data
race (
[intro.multithread]), any access or update through the resulting
reference potentially accesses or modifies, respectively, the entire
underlying bitset
. constexpr unsigned long to_ulong() const;
Throws:
overflow_error if the integral value
x
corresponding to the bits in
*this
cannot be represented as type
unsigned long. constexpr unsigned long to_ullong() const;
Throws:
overflow_error if the integral value
x
corresponding to the bits in
*this
cannot be represented as type
unsigned long. template<class charT = char,
class traits = char_traits<charT>,
class Allocator = allocator<charT>>
constexpr basic_string<charT, traits, Allocator>
to_string(charT zero = charT('0'), charT one = charT('1') const;
Effects: Constructs a string object of the appropriate type
and initializes it to a string of length
N characters
. Each character is determined by the value of its corresponding bit position in
*this.Character position
N - 1 corresponds to bit position zero
.Subsequent decreasing character positions correspond to increasing bit
positions
.Bit value zero becomes the character
zero,
bit value one becomes the character
one.Returns: The created object
. constexpr size_t count() const noexcept;
Returns: A count of the number of bits set in
*this. constexpr size_t size() const noexcept;
constexpr bool operator=(const bitset& rhs) const noexcept;
Returns:
true if the value of each bit in
*this
equals the value of the corresponding bit in
rhs. constexpr bool test(size_t pos) const;
Returns:
true
if the bit at position
pos
in
*this
has the value one
. Throws:
out_of_range if
pos does not correspond to a valid bit position
. constexpr bool all() const noexcept;
Returns:
count() == size(). constexpr bool any() const noexcept;
constexpr bool none() const noexcept;
template<size_t N> struct hash<bitset<N>>;
template<size_t N>
constexpr bitset<N> operator&(const bitset<N>& lhs, const bitset<N>& rhs) noexcept;
Returns:
bitset<N>(lhs) &= rhs. template<size_t N>
constexpr bitset<N> operator|(const bitset<N>& lhs, const bitset<N>& rhs) noexcept;
Returns:
bitset<N>(lhs) |= rhs. template<size_t N>
constexpr bitset<N> operator^(const bitset<N>& lhs, const bitset<N>& rhs) noexcept;
Returns:
bitset<N>(lhs) ^= rhs. template<class charT, class traits, size_t N>
basic_istream<charT, traits>&
operator>(basic_istream<charT, traits>& is, bitset<N>& x);
Effects: Extracts up to
N characters from
is. Stores these characters in a temporary object
str of type
basic_string<charT, traits>,
then evaluates the expression
x = bitset<N>(str).Characters are extracted and stored until any of the following occurs:
- N characters have been extracted and stored;
- end-of-file occurs on the input sequence;
- the next input character is neither
is.widen('0')
nor
is.widen('1')
(in which case the input character is not extracted).
If
N > 0 and no characters are stored in
str,
ios_base::failbit is set in the input function's local error state
before
setstate is called
.template<class charT, class traits, size_t N>
basic_ostream<charT, traits>&
operator<(basic_ostream<charT, traits>& os, const bitset<N>& x);
Returns:
os << x.template to_string<charT, traits, allocator<charT>>(
use_facet<ctype<charT>>(os.getloc().widen('0'),
use_facet<ctype<charT>>(os.getloc().widen('1')
(see
[ostream.formatted])
.