function int isalnum (int)
function int isalpha (int)
function int iscntrl (int)
function int isdigit (int)
function int isgraph (int)
function int islower (int)
function int isprint (int)
function int ispunct (int)
function int isspace (int)
function int isupper (int)
function int isxdigit (int)
function int tolower (int)
function int toupper (int)

#if !defined ISO && !defined POSIX && !defined XPG4 && !defined XPG42 && !defined UNIX98
function int isblank (int)
#endif

#if !defined ISO && !defined ISO99 && !defined ISO11 && !defined POSIX && !defined POSIX2008
function int isascii (int)
function int toascii (int)

// XPG says the following two are macros.  But we test a bit more strictly.
function int _toupper (int)
function int _tolower (int)
#endif

# if defined XOPEN2K8 || defined POSIX2008
type locale_t

function int isalnum_l (int, locale_t)
function int isalpha_l (int, locale_t)
function int iscntrl_l (int, locale_t)
function int isdigit_l (int, locale_t)
function int isgraph_l (int, locale_t)
function int islower_l (int, locale_t)
function int isprint_l (int, locale_t)
function int ispunct_l (int, locale_t)
function int isspace_l (int, locale_t)
function int isupper_l (int, locale_t)
function int isxdigit_l (int, locale_t)
function int tolower_l (int, locale_t)
function int toupper_l (int, locale_t)
# endif

allow is[abcdefghijklmnopqrstuvwxyz]*
allow to[abcdefghijklmnopqrstuvwxyz]*

#if !defined ISO && !defined ISO99 && !defined ISO11
allow *_t
#endif