strspn.c File Reference

#include <stdint.h>
#include <string.h>

Include dependency graph for strspn.c:

Go to the source code of this file.

Macros
#define	BITOP(a, b, op)   ((a)[(size_t)(b) / (8 * sizeof *(a))] op(size_t) 1 << ((size_t)(b) % (8 * sizeof *(a))))

Functions
size_t	strspn (const char *s, const char *c)

Macro Definition Documentation

BITOP

#define BITOP	(		a,
			b,
			op
	)		((a)[(size_t)(b) / (8 * sizeof *(a))] op(size_t) 1 << ((size_t)(b) % (8 * sizeof *(a))))

Definition at line 4 of file strspn.c.

Function Documentation

strspn()

size_t strspn	(	const char *	s,
		const char *	c
	)

Definition at line 7 of file strspn.c.

{
    const char* a = s;
    size_t byteset[32 / sizeof(size_t)] = {0};

    if(!c[0])
    {
        return 0;
    }

    if(!c[1])
    {
        for(; *s == *c; s++)
        {
            {
                ;
            }
        }
        return (uintptr_t)s - (uintptr_t)a;
    }

    for(; *c && BITOP(byteset, *(const unsigned char*)c, |=); c++)
    {
        {
            ;
        }
    }
    for(; *s && BITOP(byteset, *(const unsigned char*)s, &); s++)
    {
        {
            ;
        }
    }

    return (uintptr_t)s - (uintptr_t)a;
}

References BITOP.