un-get wide character from input stream
() function pushes the wide
(converted to an wchar_t) back
onto the input stream pointed to by stream
The pushed-backed wide characters will be returned by subsequent reads on the
stream (in reverse order). A successful intervening call, using the same
stream, to one of the file positioning functions
will discard the
pushed back wide characters.
One wide character of push-back is guaranteed, but as long as there is
sufficient memory, an effectively infinite amount of pushback is allowed.
If a character is successfully pushed back, the end-of-file indicator for the
stream is cleared.
() function returns the wide
character pushed back after the conversion, or
if the operation fails. If the value
of the argument c
, the operation will fail and the
stream will remain unchanged.
() function conforms to
The current implementation uses a fixed sized ungetwc-buffer.