_ISDIGIT
ctn->ctype |= _ISDIGIT;
if (ctn->ctype & _ISDIGIT)
if (ctn->ctype & (_ISALPHA|_ISDIGIT|_ISXDIGIT))
(ctn->ctype & (_ISPUNCT|_ISDIGIT)))
(ctn->ctype & (_ISDIGIT|_ISALPHA|_ISXDIGIT)))
ctn->ctype |= (_ISDIGIT | _ISGRAPH | _ISPRINT | _ISXDIGIT);
# define isdigit(__a) (_IS(__a,_ISDIGIT))
#define _ISALNUM (_ISALPHA | _ISDIGIT)
#define _CTYPE_D _ISDIGIT /* Digit */
DEFN_ISTYPE(digit, _ISDIGIT)