Anyone interested in "package versioning"?

[Anton Vodonosov]

22.05.2016, 17:36, "Anton Vodonosov" <avodonosov at yandex.ru>:
> 22.05.2016, 17:18, "Stelian Ionescu" <sionescu at cddr.org>:
>
>>  It's easy to come up with such a case, where a library:
>>  *) switches from CL epoch timestamps(1900-based) to Unix epoch(1970)
>>  *) switches from Unix namestrings to URIs
>>  *) switches from relative CL pathnames with implicit base to absolute
>>  pathnames
>
> Please clarify, switches how? Where?

Because I was asking for examples of what Hans describes:
how object created by one version of a library gets passed
to another version of the library somewhere on higher level
of the software.

My point is that I don't see how that can happen, if the
the different versions of the library are different APIs.