These methods are proposed: `IpAddr::is_ipv4()` `SockAddr::is_ipv4()` These return `true` if the underlying IP address is an IPv4 address. `IpAddr::is_ipv6()` `SockAddr::is_ipv6()` These return `true` if the underlying IP address is an IPv6 address. https://github.com/rust-lang/rust/pull/36707 https://github.com/rust-lang/rust/pull/36762