basic_istringstream& operator=(basic_istringstream&& rhs);
void swap(basic_istringstream& rhs);
Effects: Меняет состояние *this и rhs по вызову basic_istream<charT, traits>::swap(rhs) и sb.swap(rhs.sb).
template <class charT, class traits, class Allocator>
void swap(basic_istringstream<charT, traits, Allocator>& x,
basic_istringstream<charT, traits, Allocator>& y);