29.9.5 Class template basic_fstream [fstream]
void swap(basic_fstream& rhs);
Effects: Exchanges the state of
*this
and
rhs by calling
basic_iostream<charT,traits>::swap(rhs) and
sb.swap(rhs.sb). template<class charT, class traits>
void swap(basic_fstream<charT, traits>& x,
basic_fstream<charT, traits>& y);
Effects: Equivalent to:
x.swap(y).