boost::urls::ipv6_address::is_v4_mapped Return true if the address is a mapped IPv4 address Synopsis Declared in header <boost/url/ipv6_address.hpp> bool is_v4_mapped() const noexcept; Description This address type is used to represent the addresses of IPv4 nodes as IPv6 addresses. 2.5.5.2. IPv4-Mapped IPv6 Address (rfc4291)