3 #define BITOP(a,b,op) \
4 ((a)[(size_t)(b)/(8*sizeof *(a))] op (size_t)1<<((size_t)(b)%(8*sizeof *(a))))
6 size_t strcspn(const char *s, const char *c)
9 size_t byteset[32/sizeof(size_t)];
11 if (!c[0]) return strlen(s);
12 if (!c[1]) return (s=strchr(s, *c)) ? s-a : strlen(a);
14 memset(byteset, 0, sizeof byteset);
15 for (; *c && BITOP(byteset, *(unsigned char *)c, |=); c++);
16 for (; *s && !BITOP(byteset, *(unsigned char *)s, &); s++);