re.c:1454
static int
rb_reg_get_kcode(re)
    VALUE re;
{
    switch (RBASIC(re)->flags & KCODE_MASK) {
      case KCODE_NONE:
	return 16;
      case KCODE_EUC:
	return 32;
      case KCODE_SJIS:
	return 48;
      case KCODE_UTF8:
	return 64;
      default:
	return 0;
    }
}
