/usr/share/puppet/modules.available/puppetlabs-stdlib/types/compat/ipv4.pp is in puppet-module-puppetlabs-stdlib 4.14.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | # Emulate the validate_ipv4_address and is_ipv4_address functions
type Stdlib::Compat::Ipv4 = Pattern[/^((([0-9](?!\d)|[1-9][0-9](?!\d)|1[0-9]{2}(?!\d)|2[0-4][0-9](?!\d)|25[0-5](?!\d))[.]){3}([0-9](?!\d)|[1-9][0-9](?!\d)|1[0-9]{2}(?!\d)|2[0-4][0-9](?!\d)|25[0-5](?!\d)))(\/((([0-9](?!\d)|[1-9][0-9](?!\d)|1[0-9]{2}(?!\d)|2[0-4][0-9](?!\d)|25[0-5](?!\d))[.]){3}([0-9](?!\d)|[1-9][0-9](?!\d)|1[0-9]{2}(?!\d)|2[0-4][0-9](?!\d)|25[0-5](?!\d))|[0-9]+))?$/]
|