21 Internet protocol [internet]

21.4 Class ip::address [internet.address]

21.4.6 ip::address I/O [internet.address.io]

template<class CharT, class Traits> basic_ostream<CharT, Traits>& operator<<( basic_ostream<CharT, Traits>& os, const address& addr);

Returns: os << addr.to_string().c_str().