[Development] Qt6 source changes

[Thiago Macieira]

On Wednesday, 31 October 2018 03:19:46 PDT Иван Комиссаров wrote:
> Hello, Thiago wrote in the "buildsystem thread" that Qt 6 will be source
> compatible with Qt5. As long as I fully support source-compatibility with
> both hands, I would like to ask several questions about possible
> source-breaking changes.

Qt6 won't be fully source-compatible. The idea is that we'll break it to fix 
things, but attempt to keep compatible as much as possible to avoid death by a 
thousand paper cuts.

> 2) QVariantList/QList<QImage> and friends. I would like to to see most of
> QList usages in Qt eliminated in favor of QVector. I won't repeat Marc's
> arguments against QList. Instead, I want to ask the other thing - is
> breaking user code that uses "QList<T> list = someQtApiFunc();" is
> forbidden too? If Assumption that QVector is API-compatible with QList
> (which is not true, I suppose, but can be mostly fixed) that should not be
> a big deal to replace the usages of a QList with "auto list =
> someQtApiFunc();". Qt should really evolve and stucking with QList for the
> next 10 years is a bad idea IMO.

We're studying what to do with QList, but the idea is that the name "QList" 
will be completely ok and identical to QVector. The technical mechanism is in 
flux.

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center