[kazinator]

You don't need the Ex thing with socket addresses because they have a run-time type field: sa_family.

A function that takes a sockaddr * can dereference it to get at that field, and then know exactly which address type it's dealing with.

[dblohm7]

Respectfully, I think you're missing the point. Windows uses idioms like that too (though usually via filling an initial field with the size of the structure in byte), but GP's point of an Ex-style API would be to completely eliminate kludges such as runtime type fields at the beginning of structs and move to something safer.

[kazinator]

I don't see what. Type fields in structs is more or less the pinnacle of what it means to make things safer in C. :) :)

The same bind() API has to work for any kind of socket: AF_UNIX, AF_INET, AF_INET6, AF_X25 or what have you. That any kind of socket pairs with the matching address type, whose type is erased at the API level down to struct sockaddr *. But from the socket type, it is inferred what type it must be and the appropriate network stack that is called can check the type of the address matches.

I don't see how you'd get rid of this with a new bind_ex function, or why you would want to.

Of course we could have a dedicated API for every address family: bind_inet, bind_inet6, bind_unix, ... which is bletcherous.

Strictly speaking, I think we could drop the address family field from addresses, and then just assume they are the right type. The system API's all have a socket argument from which the type can be assumed. Having the type field in the address structure lets there be generic functions that just work with addresses. E.g. an address to text function that works with any sockaddr.