basic_istream::sync
Synchronizes the input device associated with the stream with the stream's buffer.
int sync( );
반환 값
If rdbuf is a null pointer, the function returns -1. Otherwise, it calls rdbuf ->pubsync. If that returns -1, the function calls setstate(badbit) and returns -1. Otherwise, the function returns zero.
요구 사항
Header: <istream>
네임스페이스: std