If a put area exists (e.g. the file was opened for writing), calls overflow() to write all pending output to the file, then flushes the file as if by calling std::fflush.

If a get area exists (e.g. the file was opened for reading), the effect is implementation-defined. Typical implementation may empty out the get area and move the current file position back by the corresponding number of bytes.

Parameters

(none)

Return value

0 in case of success, -1 in case of failure.

Notes

sync() or its equivalent is implicitly called for output streams by close(), seekoff(), and seekpos() and explicitly called by std::basic_streambuf::pubsync()

Example

See also