cpython/Include/bitset.h

#ifndef Py_BITSET_H
#define Py_BITSET_H
#ifdef __cplusplus
extern "C" {
#endif

/***********************************************************
Copyright (c) 2000, BeOpen.com.
Copyright (c) 1995-2000, Corporation for National Research Initiatives.
Copyright (c) 1990-1995, Stichting Mathematisch Centrum.
All rights reserved.

See the file "Misc/COPYRIGHT" for information on usage and
redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
******************************************************************/

/* Bitset interface */

#define BYTE		char

typedef BYTE *bitset;

bitset newbitset Py_PROTO((int nbits));
void delbitset Py_PROTO((bitset bs));
#define testbit(ss, ibit) (((ss)[BIT2BYTE(ibit)] & BIT2MASK(ibit)) != 0)
int addbit Py_PROTO((bitset bs, int ibit)); /* Returns 0 if already set */
int samebitset Py_PROTO((bitset bs1, bitset bs2, int nbits));
void mergebitset Py_PROTO((bitset bs1, bitset bs2, int nbits));

#define BITSPERBYTE	(8*sizeof(BYTE))
#define NBYTES(nbits)	(((nbits) + BITSPERBYTE - 1) / BITSPERBYTE)

#define BIT2BYTE(ibit)	((ibit) / BITSPERBYTE)
#define BIT2SHIFT(ibit)	((ibit) % BITSPERBYTE)
#define BIT2MASK(ibit)	(1 << BIT2SHIFT(ibit))
#define BYTE2BIT(ibyte)	((ibyte) * BITSPERBYTE)

#ifdef __cplusplus
}
#endif
#endif /* !Py_BITSET_H */