30 Input/output library [input.output]

30.7 Formatting and manipulators [iostream.format]

30.7.5 Output streams [output.streams]

30.7.5.1 Class template basic_­ostream [ostream]

30.7.5.1.2 Class basic_­ostream assign and swap [ostream.assign]

basic_ostream& operator=(basic_ostream&& rhs);
Effects: As if by swap(rhs).
Returns: *this.
void swap(basic_ostream& rhs);
Effects: Calls basic_­ios<charT, traits>​::​swap(rhs).