Synchronizing the stream buffer.
Declared in <bslstl_istringstream.h>
int
sync();If rdbuf() is a null pointer, returns -1.
Otherwise, calls rdbuf()->pubsync(), and if that returns -1, sets badbit and returns -1.
Otherwise, returns 0.
This function does not count the number of characters extracted, if any, and therefore does not affect the next call to gcount().
0 on success, -1 on failure