Standard C++ Library Reference ISO/IEC (VERSION3)

Note that the last rule differs slightly from the corresponding rule for the function isspace, as
indicated above. Note also that an implementation can define a locale other than the "C" locale
in which a character can cause iswalpha (and hence iswalnum) to return nonzero, yet still
cause iswupper and iswlower to return zero.
WEOF
#define WEOF <wint_t constant expression>
The macro yields the return value, of type wint_t, used to signal the end of a wide stream or
to report an error condition.
/* TYPES */
typedef s_type wctrans_t;
typedef s_type wctype_t;
typedef i_type wint_t;
/* FUNCTIONS */
int iswalnum(wint_t c);
int iswalpha(wint_t c);
int iswcntrl(wint_t c);
int iswctype(wint_t c, wctype_t category);
int iswdigit(wint_t c);
int iswgraph(wint_t c);
int iswlower(wint_t c);
int iswprint(wint_t c);
int iswpunct(wint_t c);
int iswspace(wint_t c);
int iswupper(wint_t c);
int iswxdigit(wint_t c);
wint_t towctrans(wint_t c, wctrans_t category);
wint_t towlower(wint_t c);
wint_t towupper(wint_t c);
wctrans_t wctrans(const char *property);
wctype_t wctype(const char *property);