std::basic_istringstream::swap (3) - Linux Man Pages
void swap( basic_istringstream& other ); (since C++11)
Exchanges the state of the stream with those of other.
This is done by callingbasic_istream<CharT, Traits>::swap(other) and rdbuf()->swap(*other.rdbuf()).
other - stream to exchange the state with
This section is incomplete
Reason: no example
operator= moves the string stream
swap swaps two basic_stringbuf objects