From: Johan Tibell
Hi,
I find myself reluctant to add new instances to the unordered-containers package, because doing so would require a major version bump according to the PVP. Major version bumps are annoying for several reasons:
* Libraries that depend on unordered-containers need to be updated and make new releases. * We get rapid successions of major releases without many actual changes (i.e. none as far as most users are concerned).
Introducing new instances is unlikely to break users, as they will only get into trouble if they use orphan instances, which is already asking for trouble!
I'm in the same situation, however I'm quite hesitant to add new instances in a minor version. Adding new dependencies can cause breakage even without orphan instances, if downstream packages import a different version of that dependency already. Practically this may be an acceptable short-term solution, but I agree with Ganesh that major version bumps should be made less painful. I've never really liked the PVP anyway as it relies upon a (rather shaky, it now appears) convention. I'd much prefer an automated solution that uses exported/declared interfaces (autoconf is right in principle). I would contribute towards a system like that to replace the PVP and version number-based dependencies as a long-term goal. John L.