_CTYPE_B
#define isblank(c) __sbistype((c), _CTYPE_B)
XLOCALE_ISCTYPE(blank, _CTYPE_B)
DEFN_ISWTYPE(blank, _CTYPE_B)
_CTYPE_C|_CTYPE_S|_CTYPE_B, \
_CTYPE_S|_CTYPE_B|_CTYPE_R, \
{ "blank", _CTYPE_B },