[Development] QNX and Dinkumware support for constexpr and nullptr

[Thiago Macieira]

On Wednesday 28 October 2015 11:25:19 Knoll Lars wrote:
> Removing QNX support is not an option; we agreed at the contributor summit
> that QNX 6.6 is part of the baseline, just as much as VS 2012 is. So if
> that toolchain has some issues, we’ll need to work around them just as for
> some other platforms.

Right, but it was implied that its compiler supports at least as much as VS 
2012. That's probably the case, but since I cannot verify, I added it to the 
decision tree. If the GCC backend is older than GCC 4.6, we'd have to revisit 
which C++11 functionality we'd allow in Qt 5.7 and I don't want to do that. 

It's been four months since the discussion ended and that's plenty of time to 
raise concerns if your platform cannot meet the agreed upon baseline. I 
personally tested four compilers on four different operating systems, with a 
total of 12 compiler version+OS combinations. If I alone did that much, why 
couldn't other people do it, especially if they have a vested commercial 
interest?

I did not test:

 * QNX
 * Android
 * iOS
 * MinGW 64-bit

It's extremely unlikely iOS or MinGW 64-bit will have problems, since they use 
good C++ Standard Libraries. I don't know what Android uses.

PS: I didn't test MinGW 64-bit only because I didn't have enough disk space on 
my Windows machine to keep that build. With VS 2010 gone, I should be able to 
build it now.

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