[Development] QList for Qt 6 (was: Re: Build system for Qt 6)

[Philippe]

I did some benchmarking (as we were worried about the different performance characteristics of QList and QVector) and with the exception of prepending in a loop pretty much all other operations gets faster with this change.

Another exception is certainly the sorting of large objects that are not implicit-shared classes.

Ok anyway. But keeping the old QList under a new name, cannot harm.

Much of Qt was built with QList, so QList can't be that bad ;)


Philippe

On Fri, 2 Nov 2018 07:51:22 +0000
Lars Knoll <lars.knoll at qt.io> wrote:

Renaming the subthread (it’s got nothing to do with build systems
) 
> 
> 
> I believe I have a solution to get rid of QList without breaking SC in any major way. See https://codereview.qt-project.org/#/c/242199/ and the following changes.
> 
> 
> I did some benchmarking (as we were worried about the different performance characteristics of QList and QVector) and with the exception of prepending in a loop pretty much all other operations gets faster with this change.
> 
> 
> So to re-iterate: We will not break SC in major ways. The goal is to make porting from Qt 5.x to 6 as easy as possible.
> 
> 
> Cheers,
> Lars
> 
>> On 30 Oct 2018, at 20:21, NIkolai Marchenko <enmarantispam at gmail.com> wrote:
>> 
>> >  No, we will break source compatibility in a minor way. 
>> 
>> 
>> I am not aware of what was the end result of QList discussion, but didn't you want to deprecate/majorly change that at some point?
>> That alone would be rather huge.
>> 
>> 
>> On Tue, Oct 30, 2018 at 10:19 PM Thiago Macieira <thiago.macieira at intel.com> wrote:
>> 
>> On Tuesday, 30 October 2018 12:11:38 PDT NIkolai Marchenko wrote:
>>> >  >  That's not going to happen any more than our breaking source
>>> > 
>>> > compatibility in
>>> > a major way.
>>> > 
>>> > You are breaking source compatibility in a major way with Qt6 ... ;)
>>> 
>>> No, we will break source compatibility in a minor way.
>>> 
>>> -- 
>>> Thiago Macieira - thiago.macieira (AT) <http://intel.com/>intel.com
>>>   Software Architect - Intel Open Source Technology Center
>>> 
>>> 
>>> 
>>> _______________________________________________
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