[Development] qsizetype and classes working with QStrings or QList

[Matthew Woehlke]

On 25/08/2020 01.24, Philippe wrote:
> But then there would be the need to make QAbstractSlider be able to
> handle 64 bit quantities too.

Well, since you mentioned it:

https://github.com/Kitware/qtextensions/blob/master/widgets/qtDoubleSlider.h

No, that isn't a two-headed slider, it's a slider that works on 
`double`. Doesn't derive from QAbstractSlider because it can't.

These are hardly uncommon; GIMP has tons of examples, for instance, in 
many, many filter options dialogs (although the widget they use isn't 
entirely like QSlider). Yes, you can sort-of emulate them with integers 
under the hood, but doing so adds an annoying level of dissonance to the 
code.

Q[Abstract]Slider being limited to `int` is indeed an irritation. We 
have QDoubleSpinbox, why not QDoubleSlider?

-- 
Matthew