65. Pointer-iii

A developer implements a simple byte copy using pointer arithmetic:

void my_memcpy(void *dst, const void *src, int n) {
   uint8_t *d = (uint8_t *)dst;
   const uint8_t *s = (const uint8_t *)src;
   while (n--) {
       ___;
   }
}

What goes in the blank?