- int (*diff)(const uint8_t *a, const uint8_t *b, int s);
- int (*comb)(const uint8_t *a, const uint8_t *b, int s);
- int (*var )(const uint8_t *a, const uint8_t *b, int s);
+ int (*diff)(const uint8_t *a, const uint8_t *b, ptrdiff_t s);
+ int (*comb)(const uint8_t *a, const uint8_t *b, ptrdiff_t s);
+ int (*var )(const uint8_t *a, const uint8_t *b, ptrdiff_t s);