Requirements
A FormattedOutputFunction is a stream output function that performs the following:
Constructs an object of type basic_ostream::sentry with automatic storage duration, which performs the following if eofbit or badbit are set on the output stream, sets the failbit as well, and if exceptions on failbit are enabled in this output stream's exception mask, throws ios_base::failure. flushes the tie()'d output stream, if applicable.
Checks the status of the sentry by calling sent