add "missing" (bit) operator for hw_address, ip_address, ipv6_address

[stubbfel]

Hi,
last i play a bit with ipv6 and address caclulation and so i added some operator functions the address classes.

• add or-operator and a simlple unit test for hw_address, ip_address, ipv6_address
• add not-operator and a simlple unit test for hw_address, ip_address, ipv6_address
• add greater-then-operator and a simlple unit test for ipv6_address
• add new constructor and a simlple unit test for network_interface, which use a ipv6_address to find the nic
• add override the function gateway_from_ip for ipv6_address parameter (untested)

[stubbfel]

hmm looks like that some ipv6 adresses more invalid on windows then on linux.

[mfontanini]

Sorry it took me a few days to reply. This looks good! I'll have a deeper look later today or tomorrow and I'll probably merge it.

[mfontanini]

Ugh sorry it took me so long to get back at this. I initially implemented operator< so we could store these addresses inside std::map/set and operator==/operator!= so you could... well, check for equality or inequality which is a thing you often do. In this case if we're adding operator>, I think it makes sense to implement operator<= and operator>= so address types are fully comparable. These should just be implemented in terms of the other operators (e.g. operator<= is implemented in terms of operator>).

Can you add those ones? It should be a one liner for all of them.

[stubbfel]

ok, add these operators fo hw, ip and ip6 address

[mfontanini]

I'm curious why some operators are implemented as friends while the same operator in a different class is just a regular operator?

[stubbfel]

??? sry im not sure what you mean with implemented as friends? if i see correctly all operators, which i added are public and did not use the friend "visiblity". may you can give an example please?

[mfontanini]

Sure, for example IPv6Address::operator~ is a free funcion. It's defined inside IPv6Address but since it's defined with friend visibility it's actually a free function (defined here).

Then the same member but for HWAddress::operator~ that's actually a member function. Is there any reason why they're not both defined in the same way?

[stubbfel]

dam yes, i think i just copied & paste the friend signature from " TINS_API friend std::ostream& operator<<(std::ostream& os, const IPv6Address& addr);" and forget to remove the friend keyword
🤦‍♂️ . ill fix it later

[stubbfel]

was the refactoring of the operator so ok?

[mfontanini]

Yep, looks good! Thanks for the PR!