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

succeeds, the function returns the wide-character conversion. Otherwise, it returns WEOF.
fgetwc
wint_t fgetwc(FILE *stream);
The function reads the next wide character c (if present) from the input stream stream, advances the
file-position indicator (if defined), and returns (wint_t)c. If the function sets either the end-of-file
indicator or the error indicator, it returns WEOF.
fgetws
wchar_t *fgetws(wchar_t *s, int n, FILE *stream);
The function reads wide characters from the input stream stream and stores them in successive elements
of the array beginning at s and continuing until it stores n - 1 wide characters, stores an NL wide
character, or sets the end-of-file or error indicators. If fgetws stores any wide characters, it concludes by
storing a null wide character in the next element of the array. It returns s if it stores any wide characters
and it has not set the error indicator for the stream; otherwise, it returns a null pointer. If it sets the error
indicator, the array contents are indeterminate.
fputwc
wint_t fputwc(wchar_t c, FILE *stream);
The function writes the wide character c to the output stream stream, advances the file-position indicator
(if defined), and returns (wint_t)c. If the function sets the error indicator for the stream, it returns
WEOF.
fputws
int fputws(const wchar_t *s, FILE *stream);
The function accesses wide characters from the string s and writes them to the output stream stream. The
function does not write the terminating null wide character. It returns a nonnegative value if it has not set
the error indicator; otherwise, it returns WEOF.
fwide
int fwide(FILE *stream, int mode);
The function determines the orientation of the stream stream. If mode is greater than zero, it first
attempts to make the stream wide oriented. If mode is less than zero, it first attempts to make the stream
byte oriented. In any event, the function returns:
a value greater than zero if the stream is left wide oriented●
zero if the stream is left unbound●