bitset(3C++)

Standard C++ Library
Copyright 1998, Rogue Wave Software, Inc.

NAME

bitset

- A template class and related functions for storing and manipulating fixed-size sequences of bits.

SYNOPSIS

#include <bitset>
template <size_t N>
class bitset ;

DESCRIPTION

bitset<size_t_N> is a class that describes objects that can store a sequence consisting of a fixed number of bits, N. Each bit represents either the value zero (reset) or one (set) and has a non-negative position pos.

ERRORS AND EXCEPTIONS

Bitset constructors and member functions may report the following three types of errors - each associated with a distinct exception:

•Invalid-argument error or invalid_argument() exception;

•Out-of-range error or out_of_range() exception;

•Overflow error or over-flow_error() exception;

If exceptions are not supported on your compiler, you get an assertion failure instead of an exception.

INTERFACE

template <size_t N>
class bitset {

public:

// bit reference:

class reference {

friend class bitset;

public:

~reference();

reference& operator= (bool);
reference& operator= (const reference&);
bool operator~() const;
operator bool() const;
reference& flip();
};

// Constructors

bitset ();
bitset (unsigned long);
template<class charT, class traits, class Allocator>
explicit bitset

(const basic_string<charT, traits, Allocator>,
typename basic_string<charT, traits,

Allocator>::size_type=0,

typename basic_string<charT, traits,

Allocator>::size_type=

basic_string<charT, traits, Allocator>::npos);

bitset (const bitset<N>&);
bitset<N>& operator= (const bitset<N>&);

// Bitwise Operators and Bitwise Operator Assignment

bitset<N>& operator&= (const bitset<N>&);
bitset<N>& operator|= (const bitset<N>&);
bitset<N>& operator^= (const bitset<N>&);
bitset<N>& operator<<= (size_t);
bitset<N>& operator>>= (size_t);

// Set, Reset, Flip

bitset<N>& set ();
bitset<N>& set (size_t, int = 1);
bitset<N>& reset ();
bitset<N>& reset (size_t);
bitset<N> operator~() const;
bitset<N>& flip ();
bitset<N>& flip (size_t);

// element access

reference operator[] (size_t);
unsigned long to_ulong() const;
template<class charT, class traits, class Allocator>
basic_string<charT, traits, Allocator> to_string();
size_t count() const;
size_t size() const;
bool operator== (const bitset<N>&) const;
bool operator!= (const bitset<N>&) const;
bool test (size_t) const;
bool any() const;
bool none() const;
bitset<N> operator<< (size_t) const;
bitset<N> operator>> (size_t) const;

};

// Non-member operators
template <size_t N>
bitset<N> operator& (const bitset<N>&, const bitset<N>&);

template <size_t N>
bitset<N> operator| (const bitset<N>&, const bitset<N>&);

template <size_t N>
bitset<N> operator^ (const bitset<N>&, const bitset<N>&);

template <size_t N>
istream& operator>> (istream&, bitset<N>&);

template <size_t N>
ostream& operator<< (ostream&, const bitset<N>&)

CONSTRUCTORS

bitset();

Constructs an object of class bitset<N>, initializing all bit values to zero.

bitset(unsigned long val);

Constructs an object of class bitset<N>, initializing the first M bit values to the corresponding bits in val. M is the smaller of N and the value CHAR_BIT ∗ sizeof(unsigned long). If M < N, remaining bit positions are initialized to zero. Note: CHAR_BIT is defined in <climits>.

template<class charT, class traits, class Allocator>

explicit

bitset (const basic_string<charT, traits, Allocator>,

typename basic_string<charT, traits,

Allocator>::size_type=0,

typename basic_string<charT, traits,

Allocator>::size_type=

basic_string<charT, traits, Allocator>::npos);

Determines the effective length rlen of the initializing string as the smaller of n and str.size() - pos. The function throws an invalid_argument exception if any of the rlen characters in str, beginning at position pos, is other than 0 or 1. Otherwise, the function constructs an object of class bitset<N>, initializing the first M bit positions to values determined from the corresponding characters in the string str. M is the smaller of N and rlen. This constructor expects pos <= str.size(). If that is not true, the constructor throws an out_of_range exception.

bitset(const bitset<N>& rhs);

Creates a copy of rhs.

ASSIGNMENT OPERATORS

bitset<N>&
operator=(const bitset<N>& rhs);

Erases all bits in self, then inserts into self a copy of each bit in rhs. Returns a reference to ∗this.

OPERATORS

bool
operator==(const bitset<N>& rhs) const;

Returns true if the value of each bit in ∗this equals the value of each corresponding bit in rhs. Otherwise returns false.

bool
operator!=(const bitset<N>& rhs) const;

Returns true if the value of any bit in ∗this is not equal to the value of the corresponding bit in rhs. Otherwise returns false.

bitset<N>&
operator&=(const bitset<N>& rhs);

Clears each bit in ∗this for which the corresponding bit in rhs is clear and leaves all other bits unchanged. Returns ∗this.

bitset<N>&
operator|=(const bitset<N>& rhs);

Sets each bit in ∗this for which the corresponding bit in rhs is set, and leaves all other bits unchanged. Returns ∗this.

bitset<N>&
operator^=(const bitset<N>& rhs);

Toggles each bit in ∗this for which the corresponding bit in rhs is set, and leaves all other bits unchanged. Returns ∗this.

bitset<N>&
operator<<=(size_t pos);

Replaces each bit at position I with 0 if I < pos or with the value of the bit at I - pos if I >= pos. Returns ∗this.

bitset<N>&
operator>>=(size_t pos);

Replaces each bit at position I with 0 if pos >= N-I or with the value of the bit at position I + pos if pos < N-I. Returns ∗this.

bitset<N>&
operator>>(size_t pos) const;

Returns bitset<N>(∗this) >>= pos.

bitset<N>&
operator<<(size_t pos) const;

Returns bitset<N>(∗this) <<= pos.

bitset<N>
operator~() const;

Returns the bitset that is the logical complement of each bit in ∗this.

bitset<N>
operator&(const bitset<N>& lhs,

const bitset<N>& rhs);

lhs gets logical AND of lhs with rhs.

bitset<N>
operator|(const bitset<N>& lhs,

const bitset<N>& rhs);

lhs gets logical OR of lhs with rhs.

bitset<N>
operator^(const bitset<N>& lhs,

const bitset<N>& rhs);

lhs gets logical XOR of lhs with rhs.

template <size_t N>
istream&
operator>>(istream& is, bitset<N>& x);

Extracts up to N characters (single-byte) from is. Stores these characters in a temporary object str of type string, 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

-An end-of-file is reached on the input sequence

-The next character is neither ’0’ nor ’1’. In this case, the character is not extracted

Returns is.

template <size_t N>
ostream&
operator<<(ostream& os, const bitset<N>& x);

Returns os << x.to_string()

MEMBER FUNCTIONS

bool
any() const;

Returns true if any bit in ∗this is set. Otherwise returns false.

size_t
count() const;

Returns a count of the number of bits set in ∗this.

bitset<N>&
flip();

Flips all bits in ∗this, and returns ∗this.

bitset<N>&
flip(size_t pos);

Flips the bit at position pos in ∗this and returns ∗this. Throws an out_of_range exception if pos does not correspond to a valid bit position.

bool
none() const;

Returns true if no bit in ∗this is set. Otherwise returns false.

bitset<N>&
reset();

Resets all bits in ∗this, and returns ∗this.

bitset<N>&
reset(size_t pos);

Resets the bit at position pos in ∗this. Throws an out_of_range exception if pos does not correspond to a valid bit position.

bitset<N>&
set();

Sets all bits in ∗this, and returns ∗this.

bitset<N>&
set(size_t pos, int val = 1);

Stores a new value in the bits at position pos in ∗this. If val is nonzero, the stored value is one, otherwise it is zero. Throws an out_of_range exception if pos does not correspond to a valid bit position.

size_t
size() const;

Returns the template parameter N.

bool
test(size_t pos) const;

Returns true if the bit at position pos is set. Throws an out_of_range exception if pos does not correspond to a valid bit position.

template<class charT, class traits, class Allocator>
basic_string<charT, traits, Allocator>
to_string();

Returns an object of type string, N characters long.

Each position in the new string is initialized with a character (’0’ for zero and ’1’ for one) representing the value stored in the corresponding bit position of ∗this. Character position N - 1 corresponds to bit position 0. Subsequent decreasing character positions correspond to increasing bit positions.

unsigned long
to_ulong() const;

Returns the integral value corresponding to the bits in ∗this. Throws an overflow_error if these bits cannot be represented as type unsigned long.

Museum

bitset(3C++)

NAME

SYNOPSIS

DESCRIPTION

ERRORS AND EXCEPTIONS

INTERFACE

CONSTRUCTORS

ASSIGNMENT OPERATORS

OPERATORS

MEMBER FUNCTIONS

SEE ALSO