31 Input/output library [input.output]

31.7 Formatting and manipulators [iostream.format]

31.7.4 Input streams [input.streams]

31.7.4.2 Class template basic_­istream [istream]

31.7.4.2.3 Assignment and swap [istream.assign]

basic_istream& operator=(basic_istream&& rhs);
Effects: Equivalent to: swap(rhs).
Returns: *this.
void swap(basic_istream& rhs);
Effects: Calls basic_­ios<charT, traits>​::​swap(rhs).
Exchanges the values returned by gcount() and rhs.gcount().