Container
A template class and related functions for storing and manipulating fixed-size sequences of bits.
#include <bitset> template <size_t N> class bitset ;
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.
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 will get an assertion failure instead of an exception.
template <size_t N>
class bitset {
public:
// bit reference:
class reference {
friend class bitset<N>;
public:
~reference();
reference& operator= (bool);
reference& operator= (const reference&);
bool operator~() const;
operator bool() const;
reference& flip();
};
// Constructors
bitset ();
bitset (unsigned long);
explicit bitset (const string&, size_t = 0,
size_t = (size_t)-1);
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;
string to_string() const;
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>&);
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>.
explicit
bitset(const string& str, size_t pos = 0,
size_t n = (size_t)-1);
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 requires that pos <= str.size(), otherwise it throws an out_of_range exception.
bitset(const bitset<N>& rhs);
Copy constructor. Creates a copy of rhs.
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.
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 occurs 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()
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.
string to_string() const;
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.
©Copyright 1996, Rogue Wave Software, Inc.