_CTYPE_N
#define isnumber(c) __sbistype((c), _CTYPE_D|_CTYPE_N)
#define isalnum(c) __sbistype((c), _CTYPE_A|_CTYPE_D|_CTYPE_N)
XLOCALE_ISCTYPE(alnum, _CTYPE_A|_CTYPE_D|_CTYPE_N)
XLOCALE_ISCTYPE(number, _CTYPE_D|_CTYPE_N)
DEFN_ISWTYPE(number, _CTYPE_N)