Should the PVP be changed with regards to instances?

Ivan Lazar Miljenovic ivan.miljenovic at
Wed Dec 21 01:37:43 CET 2011

On 21 December 2011 03:55, Ganesh Sittampalam <ganesh at> wrote:
> On 20/12/2011 16:12, Johan Tibell wrote:
>> 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!
>> Thoughts?
> I'd argue against this: users who write orphan instances typically have
> no choice, even if they know it's problematic. Contrast this to the fact
> that we do allow new exports, because a cautious user of the package can
> avoid problems by explicitly listing what they import.
> Major version bumps are indeed expensive, but IMO we should address the
> problem at source by to making them cheaper - e.g. with automated
> testing/reporting.

Agreed. (i.e. -1 to the proposal)

Ivan Lazar Miljenovic
Ivan.Miljenovic at

More information about the Libraries mailing list