IPAddr doesn't provide helpful methods to get the subnet or IP address
I've implemented it myself using some "wild" code around the .inspect or default return from an IPAddr object from ipadr.rb
It would be nice to, once having loaded an IP range, to then be able to get its subnet, its IP and its CIDR.
I've created a PR: https://github.com/ruby/ruby/pull/1636 (although it's failing, not entirely sure why as Travis works fine on localhost!).