In C++ primer I found this code:
if (cin.fail())
{ // bad input
cerr<< "bad data, try again"; // warn the user
cin.clear(istream::failbit); // reset the stream
continue; // get next input
}
I am confused that why the istream::failbit is used to set the error state flag, I mean that since the error has occurred (hence the flow is right now in if block then the failbit must be set, they why use it to set the error flag with that again. Where am I wrong in understanding this?
EDIT: The book says "We print a warning and clear the failbit state", but IMO clear(istream::failbit) is setting the current state of stream with the value contained in failbit. So why the book is setting the stream's state with that of failbit as it will stop cin from functioning as it will be in error state. ++++ By state of a stream, what bit actually is being talked about, is it eofbit, badbit, goodbit, failbit or a combination of them? How can I know the value of these individual bit as well?