[Development] The future of smart pointers in Qt API

[André Pönitz]

On Thu, Feb 13, 2020 at 09:42:23AM +0000, Karsten Heimrich wrote:
> -----Original Message-----
> >From: André Pönitz <apoenitz at t-online.de> Sent: Mittwoch, 12. Februar
> >2020 19:38 Uhr To: Vitaly Fanaskov <vitaly.fanaskov at qt.io> Cc:
> >Karsten Heimrich <Karsten.Heimrich at qt.io>; development at qt-project.org
> >Subject: Re: [Development] The future of smart pointers in Qt API
> >
> >On Wed, Feb 12, 2020 at 11:13:17AM +0000, Vitaly Fanaskov wrote:
> >> >> We should also move Qt smart pointers to Qt5Compat module. The
> >> >> destiny of QPointer is not well defined so far.
> >> >
> >> > This was not part of the research and should probably discussed
> >> > separately.
> >>
> >> I agree. But if we decide using standard smart pointers, why should
> >> we keep Qt smart pointers as a part of Qt6?
> >
> >https://www.qt.io/blog/2019/08/07/technical-vision-qt-6
> >
> > "Compatibility with older versions is extremely important and is a
> > major requirement when we develop Qt 6. There are billions of lines
> > of code written using our framework and any incompatible change we
> > do will thus have a cost for our users. Furthermore, the more work
> > the change to Qt 6 requires from our users the slower the adoption
> > will be, which leads to more cost on our side to maintain the last
> > version of Qt 5."
> >
> >Already now the jump from, say, 5.12 to Qt dev is way bigger than the
> >whole Qt 4 -> Qt 5 upgrade was, adding more to that does definitely
> >not help with Qt 6 adoption.
> 
> We probably could move it to Qt5Compat first, so that lifetime ends
> with Qt6.

I wouldn't even object to that.

Except, maybe, that in the age of limited resources spending there might
me more beneficial ways to spend them ;-}

> But as mentioned already, we did not even discuss anything
> there like...

Indeed.

Andre'