[Interest] Advantage of Qt5 over Qt4 for C++/Widgets

[John Layt]

On 13 September 2013 16:44, Syam Krishnan <syamcr at gmail.com> wrote:
> Hi
>
>    We've been use Qt4 to create desktop applications on Linux written in
> C++.
>
> My requirements:
> 1. Need best possible performance from Qt - we always use C++ for coding
> 2. Not interested in coding application logic in Javascript
> 3. Have not tried QML for GUI, probably do not prefer to use Javascript
> to program user interactions
> 4. Would like to have our C++ applications support scripting by using
> Javascript (and be good at it - V8?)
>
> My question is: does Qt5 provide any advantages for such a use-case? Are
> we better off sticking with Qt 4.8?
>
> I'm asking because on one hand I hear that 'Widgets', as you call in Qt5
> is 'done' and so we can't expect any further improvements on that. On
> the other hand, I hear there are performance improvements in the
> underlying components like QStrings.
>
> So, can somebody please throw some light on this..
>
> Thanks,

Consider this:
1) Qt 4.8 is in bug-fix mode only, so no new features or performance
improvements, so QtWidgets 4 is also effectively "Done"
2) Policy is all bug fixes go to Qt5 first, then Qt 4.8, so you do get
the same Widget bug-fixes in Qt5
3) Porting to Qt5 is generally fairly easy
4) Qt5 is getting new features, even QtWidgets is open for small
improvements if someone is maintaining it
5) Since the buy-out Digia has stated their focus is back on the desktop
6) Qt5 has lots of other new fast shiny stuff, like faster QString
7) If you want to play with QML for GUI's, then QML2 is faster and better
8) Scripting, I don't know about.

Seems fairly obvious to me that Qt 5 should be on your migration plan :-)

John.