KF 5 & C++14?

[David Faure]

On Sunday, April 26, 2020 5:30:37 PM CEST Friedrich W. H. Kossebau wrote:
> Hi,
> 
> I just saw that at least kimageformats, knewstuff & kquickcharts all set
> this: set(CMAKE_CXX_STANDARD 14)
>     set(CMAKE_CXX_STANDARD_REQUIRED ON)
> 
> Which ignores a bit that so far C++11 has been the minimum standard
> officially supported in/by KDE Frameworks (by mainly following what Qt 5
> supports).
> 
> Compare also the current text of the policy
> "Frameworks compiler requirements and C++11":
> --- 8< ---
> The following minimal compiler versions are supported by KDE Frameworks:
> * GCC 4.8
> * Clang 3.3
> * VS2013 (MSVC12)
> 
> This means all of the C++11 standards can be used.
> --- 8< ---
> * https://community.kde.org/Frameworks/
> Policies#Frameworks_compiler_requirements_and_C.2B.2B11
> 
> What to make of this? Might it be the time to raise the bars a bit, and how
> much? Surely the lower limit is what the oldest Qt version currently
> supported by KDE Frameworks claims to support:
> https://doc.qt.io/qt-5.12/supported-platforms.html
> 
> Should we go above this?
> Or should kimageformats, knewstuff & kquickcharts be fixed to use C++11 only
> again?
> 
> No own opinion, so far only stumbled over what seems a policy breakage.

The goal was to align with the requirements of the Qt version we require.

But it's hard to know if anyone is actually using gcc 4.8 to build the current 
version of KF5. One way to find out is to... do nothing. Leave the above as is 
and see if anyone actually complains that it doesn't match our promise.

This isn't however a green light for doing this everywhere, not until we wait 
multiple months for feedback. Otherwise the porting effort (down to C++11) 
will be huge.

My two cents,

-- 
David Faure, faure at kde.org, http://www.davidfaure.fr
Working on KDE Frameworks 5