31 Input/output library [input.output]

31.7 Formatting and manipulators [iostream.format]

31.7.5 Input streams [input.streams]

31.7.5.7 Class template basic_iostream [iostreamclass]

31.7.5.7.4 Assignment and swap [iostream.assign]

basic_iostream& operator=(basic_iostream&& rhs);
Effects: Equivalent to: swap(rhs).
void swap(basic_iostream& rhs);
Effects: Calls basic_istream<charT, traits>​::​swap(rhs).