I use this declaration for an array which must contain a bit for every minute in a day:
UCHAR minutesOfDay[(60 * 24 / CHAR_BIT) + (((60 * 24) % CHAR_BIT) ? 1 : 0)];
However, this look pretty awful. Is there a simpler way to state the same? It can be in C or C++.
Alternate: use integer truncation of division. Add 1 less than the divisor, then divide.
// location of CHAR_BIT
#include <limits.h>
#define MINUTES_PER_DAY (24u * 60)
#define UCHAR_PER_DAY ((MINUTES_PER_DAY + CHAR_BIT - 1)/ CHAR_BIT)
UCHAR minutesOfDay[UCHAR_PER_DAY];
This assumes UCHAR is unsigned char. To avoid that assumption:
#define UCHAR_PER_DAY ((MINUTES_PER_DAY + CHAR_BIT*sizeof(UCHAR) - 1) / \
(CHAR_BIT*sizeof(UCHAR)))
UCHAR minutesOfDay[UCHAR_PER_DAY];
Pedantically this is not correct had we needed some other unsigned integer type like unsigned or unsigned long. unsigned char, assuming that what UCHAR is, cannot have padding bits. Esoteric platforms could have padding bits with wider unsigned types.
Yes, wrap it in a macro:
#ifdef CHAR_BIT
#define BIT_PER_MIN_IN_DAY ((60 * 24 / CHAR_BIT) + (((60 * 24) % CHAR_BIT) ? 1 : 0))
#else
#error "Platform not supported"
#endif
UCHAR minutesOfDay[BIT_PER_MIN_IN_DAY];
