Handle bitsets in ANSI C

bitset.c

/**
 * cc -pedantic -ansi -pedantic-errors -Wall -Werror bitset.c -o bitset
 */

#include <stdint.h>
#include <stdlib.h>

typedef enum {			/* no use for stdbool.h with ANSI C */
	false = 0,
	true
} bool;

bool
getbit(uint8_t * s, size_t n)
{
	return s += n / 8, (bool) (!(*s & (1 << (n % 8))));
}

bool
setbit(uint8_t * s, size_t n, bool v)
{
	return s += n / 8,
	    (bool) (v ? (*s |= 1 << (n % 8)) : (*s &= ~(1 << (n % 8))));
}

#include <stdio.h>

int
main(void)
{
	uint8_t bitset[28] = { false };	/* 224 bits = (224+7)/8 = 28 */
	char *bit[2] = { "true", "false" };

	/* get last bit */
	printf("%s\n", bit[getbit(bitset, 223) ? 1 : 0]);
	/* set last bit and print it */
	printf("%s\n", bit[setbit(bitset, 223, true) ? 1 : 0]);
	printf("%s\n", bit[getbit(bitset, 223) ? 1 : 0]);
	/* clear last bit and print it */
	printf("%s\n", bit[setbit(bitset, 223, false) ? 1 : 0]);
	printf("%s\n", bit[getbit(bitset, 223) ? 1 : 0]);
	return 0;
}