std::ipv4_network validation error not correctly reported

[DariushMoh]

I encountered an error while trying to set an ipv4 network on an entity:

Invalid value '172.25.103.22/24', does not match constraint `std::validate_type('ipaddress.IPv4Network',self)

But after some more investigation, it seems I forgot to use the network address. This was not correctly reported by the compiler. When I test the actual python type I get this:

>>> ipaddress.IPv4Network("172.25.103.22/24")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib64/python3.12/ipaddress.py", line 1544, in __init__
    raise ValueError('%s has host bits set' % self)
ValueError: 172.25.103.22/24 has host bits set

This would be good to report this in the compiler output error. Here is the minimal example I used to reproduce the error:

entity A:
    std::ipv4_network net
end
implement A using std::none

A(net="172.25.103.22/24")

[sanderr]

If I understand correctly: the provided address is a valid IP address, but not a valid network addres, because .22 is not the first address in any /24 range, that would be .0. The IPv4Network constructor (and likely pydantic) reports this as "... has host bits set". However, std::validate_type does not report any details as to why it's not a valid type.

[DariushMoh]

Yes this is correct.