Reset the get pointer of the streambuf held by this object to refer to the byte following the last processed byte, if the held streambuf supports seeking, and return an error otherwise leaving this object unchanged. Return 0 on success, and a non‐zero value otherwise. The behavior is undefined unless reset has been called. Note that after a successful function return users can read data from the streambuf that was specified during reset from where this object stopped. Also note that this call implies the end of processing for this object and any subsequent methods invoked on this object should only be done after calling reset and specifying a new streambuf.