net: Addr does not discriminate between different address families

[larsks]

Calling interface.Addrs() to get the list of addresses assigned to a network interface returns all of the available addresses with no information about the associated address family. This method call should either (a) permit the caller to restrict the returned information to a specific address family (e.g., interface.Addrs(AF_INET) or (b) should return information with each address indicating the associated address family.

Given an interface with addresses from multiple families (e.g., AF_INET, AF_INET6), the only way for a caller to identify addresses of a certain type is to "guess" by matching them against regular expressions, which would be prone to failure in the presence of incompatible address families that happened to use the same format for addresses.

[mikioh]

the only way for a caller to identify addresses of a certain type is to "guess" by matching them against regular expressions

Not true, you can use To4 and To16 methods of net.IP.