[Development] Private Qt helper libraries?

[Sorvig Morten]

On 03 Jul 2014, at 17:13, Sune Vuorela <nospam at vuorela.dk> wrote:

> On 2014-07-03, Milian Wolff <milian.wolff at kdab.com> wrote:
>> I imagine, it could work by create just a normal library but not install and 
>> public headers, only private ones. That should be OK then, or what do you 
>> think?
> 
> We have too many private headers already. We should work on getting rid
> of them, not to create new ways to increase our collective headaches.
> 
> So, a proper documented and stable api and abi would be much preferred.

Let me offer a (small) challenge to that statement:

Creating documented and stable API from private API can be hard:
- it’s x times more work (2x? 5x?)
- the API is now frozen, restricting further development
- the work often has to be done by someone else than the person who would like to use it right now

I think it’s reasonable for a project the size of Qt to have private API.

Instead we could go in slightly different direction and formalize what private API we have by creating internal documentation for it. This can include QPA and platform private API (which is currently hidden away in plugins, inaccessible to the rest of Qt).

Well-documented, stable private API can then be promoted to public API when it’s ready.

Morten