RWBitVec(3C++) RWBitVec(3C++)
NameRWBitVec - Rogue Wave library class
Synopsis
#include <rw/bitvec.h>
RWBitVec v;
Description
Class RWBitVec is a bitvector whose length can be changed at run time.
Because this requires an extra level of indirection, this makes it
slightly less efficient than classes RWGBitVec(size) or RWTBitVec<size>,
whose lengths are fixed at compile time.
Persistence
Simple
Example
#include <rw/bitvec.h>
#include <rw/rstream.h>
main(){
// Allocate a vector with 20 bits, set to TRUE:
RWBitVec av(20, TRUE);
av(2) = FALSE; // Turn bit 2 off
av.clearBit(7); // Turn bit 7 off
av.setBit(2); // Turn bit 2 back on
for(int i=11; i<=14; i++) av(i) = FALSE;
cout << av << endl; // Print the vector out
}
Program output:
[
1 1 1 1 1 1 1 0 1 1 1 0 0 0 0 1 1 1 1 1
Public Constructors
]
RWBitVec();
Page 1
RWBitVec(3C++) RWBitVec(3C++)
Construct a zero lengthed (null) vector.
RWBitVec(size_t N);
Construct a vector with N bits. The initial value of the bits is
undefined.
RWBitVec(size_t N, RWBoolean initVal);
Construct a vector with N bits, each set to the Boolean value initVal.
RWBitVec(const RWByte* bp, size_t N);
Construct a vector with N bits, initialized to the data in the array of
bytes pointed to by bp. This array must be at least long enough to
contain N bits. The identifier RWByte is a typedef for an unsigned char.
RWBitVec(const RWBitVec& v);
Copy constructor. Uses value semantics -- the constructed vector will be
a copy of v.
~RWBitVec();
The destructor. Releases any allocated memory.
Assignment Operators
RWBitVec&
operator=(const RWBitVec& v);
Assignment operator. Value semantics are used -- self will be a copy of
v.
RWBitVec&
operator=(RWBoolean b);
Assignment operator. Sets every bit in self to the boolean value b.
RWBitVec&
operator&=(const RWBitVec& v);
RWBitVec&
operator^=(const RWBitVec& v);
RWBitVec&
operator|=(const RWBitVec& v);
Page 2
RWBitVec(3C++) RWBitVec(3C++)
Logical assignments. Set each element of self to the logical AND, XOR,
or OR, respectively, of self and the corresponding bit in v. Self and v
must have the same number of elements (i.e., be conformal) or an
exception of type RWInternalErr will occur.
Indexing Operators
RWBitRef
operator[](size_t i);
Returns a reference to bit i of self. A helper class, RWBitRef, is used.
The result can be used as an lvalue. The index i must be between 0 and
the length of the vector less one. Bounds checking is performed. If the
index is out of range, then an exception of type RWBoundsErr will occur.
RWBitRef
operator()(size_t i);
Returns a reference to bit i of self. A helper class, RWBitRef, is used.
The result can be used as an lvalue. The index i must be between 0 and
the length of the vector less one. Bounds checking is performed only if
the preprocessor macro RWBOUNDS_CHECK has been defined before including
the header file <rw/bitvec.h>. If so, and if the index is out of range,
then an exception of type RWBoundsErr will occur.
RWBoolean
operator[](size_t i) const;
Returns the boolean value of bit i. The result cannot be used as an
lvalue. The index i must be between 0 and the length of the vector less
one. Bounds checking is performed. If the index is out of range, then
an exception of type RWBoundsErr will occur.
RWBoolean
operator()(size_t i) const;
Returns the boolean value of bit i. The result cannot be used as an
lvalue. The index i must be between 0 and the length of the vector less
one. Bounds checking is performed only if the preprocessor macro
RWBOUNDS_CHECK has been defined before including the header file
<rw/bitvec.h>. If so, and if the index is out of range, then an
exception of type RWBoundsErr will occur.
Logical Operators
RWBoolean
operator==(const RWBitVec& u) const;
Returns TRUE if self and v have the same length and if each bit of self
Page 3
RWBitVec(3C++) RWBitVec(3C++)
is set to the same value as the corresponding bit in v. Otherwise,
returns FALSE.
RWBoolean
operator!=(const RWBitVec& u) const;
Returns FALSE if self and v have the same length and if each bit of self
is set to the same value as the corresponding bit in v. Otherwise,
returns TRUE.
RWBoolean
operator==(RWBoolean b) const;
Returns TRUE if every bit of self is set to the boolean value b.
Otherwise FALSE.
RWBoolean
operator!=(RWBoolean b) const;
Returns FALSE if every bit of self is set to the boolean value b.
Otherwise TRUE.
Public Member Functions
void
clearBit(size_t i);
Clears (i.e., sets to FALSE) the bit with index i. The index i must be
between 0 and the length of the vector less one. No bounds checking is
performed. The following are equivalent, although clearBit(size_t) is
slightly smaller and faster than using operator()(size_t):
a(i) = FALSE;
a.clearBit(i);
const RWByte*
data() const;
Returns a const pointer to the raw data of self. Should be used with
care.
Page 4
RWBitVec(3C++) RWBitVec(3C++)
size_t
firstFalse() const;
Returns the index of the first FALSE bit in self. Returns RW_NPOS if
there is no FALSE bit.
size_t
firstTrue() const;
Returns the index of the first TRUE bit in self. Returns RW_NPOS if
there is no TRUE bit.
unsigned
hash() const;
Returns a value suitable for hashing.
RWBoolean
isEqual(const RWBitVec& v) const;
Returns TRUE if self and v have the same length and if each bit of self
is set to the same value as the corresponding bit in v. Otherwise,
returns FALSE.
size_t
length() const;
Returns the number of bits in the vector.
ostream&
printOn(ostream& s) const;
Print the vector v on the output stream s. See the example above for a
sample of the format.
void
resize(size_t N);
Resizes the vector to have length N. If this results in a lengthening of
the vector, the additional bits will be set to FALSE.
istream&
scanFrom(istream&);
Page 5
RWBitVec(3C++) RWBitVec(3C++)
Read the bit vector from the input stream s. The vector will dynamically
be resized as necessary. The vector should be in the same format printed
by member function printOn(ostream&).
void
setBit(size_t i);
Sets (i.e., sets to TRUE) the bit with index i. The index i must be
between 0 and size-1. No bounds checking is performed. The following
are equivalent, although setBit(size_t) is slightly smaller and faster
than using operator()(size_t):
a(i) = TRUE;
a.setBit(i);
RWBoolean
testBit(size_t i) const;
Tests the bit with index i. The index i must be between 0 and size-1.
No bounds checking is performed. The following are equivalent, although
testBit(size_t) is slightly smaller and faster than using
operator()(size_t):
if( a(i) ) doSomething();
if( a.testBit(i) ) doSomething();
Related Global FunctionsRWBitVec
operator!(const RWBitVec& v);
Unary operator that returns the logical negation of vector v.
RWBitVec
operator&(const RWBitVec&,const RWBitVec&);
RWBitVec
operator^(const RWBitVec&,const RWBitVec&);
RWBitVec
operator|(const RWBitVec&,const RWBitVec&);
Page 6
RWBitVec(3C++) RWBitVec(3C++)
Returns a vector that is the logical AND, XOR, or OR of the vectors v1
and v2. The two vectors must have the same length or an exception of
type RWInternalErr will occur.
ostream&
operator<<(ostream& s, const RWBitVec& v);
Calls v.printOn(s).
istream&
operator>>(istream& s, RWBitVec& v);
Calls v.scanFrom(s).
RWvostream&
operator<<(RWvostream&, const RWBitVec& vec);
RWFile&
operator<<(RWFile&, const RWBitVec& vec);
Saves the RWBitVec vec to a virtual stream or RWFile, respectively.
RWvistream&
operator>>(RWvistream&, RWBitVec& vec);
RWFile&
operator>>(RWFile&, RWBitVec& vec);
Restores an RWBitVec into vec from a virtual stream or RWFile,
respectively, replacing the previous contents of vec.
size_t
sum(const RWBitVec& v);
Returns the total number of bits set in the vector v.
Page 7
