Bits can be manipulated by the setBit() and clearBit() functions, but it is also possible to use the indexing [] operator to test and set individual bits. The [] operator is a little slower than setBit() and clearBit() because some tricks are required to implement single-bit assignments.
When a QBitArray is constructed the bits are uninitialized. Use fill() to set all the bits to 0 or 1. The array can be resized with resize() and copied with copy(). Bits can be set with setBit() and cleared with clearBit(). Bits can be toggled with toggleBit(). A bit's value can be obtained with testBit() and with at().
.PP
QBitArray supports the & (AND), | (OR), ^ (XOR) and ~ (NOT) operators.
.PP
See also Collection Classes, Implicitly and Explicitly Shared Classes, and Non-GUI Classes.
.SH MEMBER FUNCTION DOCUMENTATION
.SH "QBitArray::QBitArray ()"
Constructs an empty bit array.
.SH "QBitArray::QBitArray ( uint size )"
Constructs a bit array of \fIsize\fR bits. The bits are uninitialized.
.PP
See also fill().
.SH "QBitArray::QBitArray ( const QBitArray & a )"
Constructs a shallow copy of \fIa\fR.
.SH "bool QBitArray::at ( uint index ) const"
Returns the value (0 or 1) of the bit at position \fIindex\fR.
.PP
See also operator[]().
.SH "void QBitArray::clearBit ( uint index )"
Clears the bit at position \fIindex\fR, i.e. sets it to 0.
.PP
See also setBit() and toggleBit().
.SH "QBitArray QBitArray::copy () const"
Returns a deep copy of the bit array.
.PP
See also detach().
.SH "void QBitArray::detach ()\fC [virtual]\fR"
Detaches from shared bit array data and makes sure that this bit array is the only one referring to the data.
.PP
If multiple bit arrays share common data, this bit array dereferences the data and gets a copy of the data. Nothing happens if there is only a single reference.
Fills the bit array with \fIv\fR (1's if \fIv\fR is TRUE, or 0's if \fIv\fR is FALSE).
.PP
fill() resizes the bit array to \fIsize\fR bits if \fIsize\fR is nonnegative.
.PP
Returns FALSE if a nonnegative \fIsize\fR was specified and the bit array could not be resized; otherwise returns TRUE.
.PP
See also resize().
.SH "QBitArray & QBitArray::operator&= ( const QBitArray & a )"
Performs the AND operation between all bits in this bit array and \fIa\fR. Returns a reference to this bit array.
.PP
The result has the length of the longest of the two bit arrays, with any missing bits (i.e. if one array is shorter than the other), taken to be 0.
.PP
.nf
.br
QBitArray a( 3 ), b( 2 );
.br
a[0] = 1; a[1] = 0; a[2] = 1; // a = [1 0 1]
.br
b[0] = 1; b[1] = 0; // b = [1 0]
.br
a &= b; // a = [1 0 0]
.br
.fi
.PP
See also operator|=(), operator^=(), and operator~().
.SH "QBitArray & QBitArray::operator= ( const QBitArray & a )"
Assigns a shallow copy of \fIa\fR to this bit array and returns a reference to this array.
.SH "QBitVal QBitArray::operator[] ( int index )"
Implements the [] operator for bit arrays.
.PP
The returned QBitVal is a context object. It makes it possible to get and set a single bit value by its \fIindex\fR position.
.PP
Example:
.PP
.nf
.br
QBitArray a( 3 );
.br
a[0] = 0;
.br
a[1] = 1;
.br
a[2] = a[0] ^ a[1];
.br
.fi
.PP
The functions testBit(), setBit() and clearBit() are faster.
.PP
See also at().
.SH "bool QBitArray::operator[] ( int index ) const"
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Implements the [] operator for constant bit arrays.
.SH "QBitArray & QBitArray::operator^= ( const QBitArray & a )"
Performs the XOR operation between all bits in this bit array and \fIa\fR. Returns a reference to this bit array.
.PP
The result has the length of the longest of the two bit arrays, with any missing bits (i.e. if one array is shorter than the other), taken to be 0.
.PP
.nf
.br
QBitArray a( 3 ), b( 2 );
.br
a[0] = 1; a[1] = 0; a[2] = 1; // a = [1 0 1]
.br
b[0] = 1; b[1] = 0; // b = [1 0]
.br
a ^= b; // a = [0 0 1]
.br
.fi
.PP
See also operator&=(), operator|=(), and operator~().
.SH "QBitArray & QBitArray::operator|= ( const QBitArray & a )"
Performs the OR operation between all bits in this bit array and \fIa\fR. Returns a reference to this bit array.
.PP
The result has the length of the longest of the two bit arrays, with any missing bits (i.e. if one array is shorter than the other), taken to be 0.
.PP
.nf
.br
QBitArray a( 3 ), b( 2 );
.br
a[0] = 1; a[1] = 0; a[2] = 1; // a = [1 0 1]
.br
b[0] = 1; b[1] = 0; // b = [1 0]
.br
a |= b; // a = [1 0 1]
.br
.fi
.PP
See also operator&=(), operator^=(), and operator~().
.SH "QBitArray QBitArray::operator~ () const"
Returns a bit array that contains the inverted bits of this bit array.
.PP
Example:
.PP
.nf
.br
QBitArray a( 3 ), b;
.br
a[0] = 1; a[1] = 0; a[2] = 1; // a = [1 0 1]
.br
b = ~a; // b = [0 1 0]
.br
.fi
.SH "bool QBitArray::resize ( uint size )"
Resizes the bit array to \fIsize\fR bits and returns TRUE if the bit array could be resized; otherwise returns FALSE. The array becomes a null array if \fIsize\fR == 0.
.PP
If the array is expanded, the new bits are set to 0.
.PP
See also size().
.SH "void QBitArray::setBit ( uint index, bool value )"
Sets the bit at position \fIindex\fR to \fIvalue\fR.
.PP
Equivalent to:
.PP
.nf
.br
if ( value )
.br
setBit( index );
.br
else
.br
clearBit( index );
.br
.fi
.PP
See also clearBit() and toggleBit().
.SH "void QBitArray::setBit ( uint index )"
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
.PP
Sets the bit at position \fIindex\fR to 1.
.PP
See also clearBit() and toggleBit().
.SH "uint QBitArray::size () const"
Returns the bit array's size (number of bits).
.PP
See also resize().
.SH "bool QBitArray::testBit ( uint index ) const"
Returns TRUE if the bit at position \fIindex\fR is set, i.e. is 1; otherwise returns FALSE.
.PP
See also setBit() and clearBit().
.SH "bool QBitArray::toggleBit ( uint index )"
Toggles the bit at position \fIindex\fR.
.PP
If the previous value was 0, the new value will be 1. If the previous value was 1, the new value will be 0.
