[Development] Dropping older compilers for Qt 5.10 (was: Qt 5.10 pre-built bunaries)

[Thiago Macieira]

On quinta-feira, 8 de junho de 2017 10:02:16 PDT Ville Voutilainen wrote:
> On 8 June 2017 at 19:09, Konstantin Tokarev <annulen at yandex.ru> wrote:
> >> So I'm guessing we should require GCC 4.8.5 (all the latest fixes). This
> >> will give us full C++11 support in GCC.
> > 
> > I'd like to insist that GCC 4.8 does not provide full C++11 support (see
> > my previous mail), i.e. targeting GCC 4.8 implementation of C++11 is
> > still substantially different than targeting C++11 standard.
> 
> GCC 5 is the first version of GCC that has full C++11 support, since
> the previous ones don't have
> full library support.

Both arguments are understood, but 4.8.1 (ref qualifiers) + bugfixes in later 
patch releases may be sufficient for Qt's needs. We hardly use the Standard 
Library, so what we need is the core language support.

We just want to get rid of some #ifdefs and macros. For that, we need MSVC 
2015 and GCC 4.8 for:
 * ref qualifiers
 * thread_local

Dropping MSVC 2013 will get us some clean up, but we need to drop GCC 4.7 for 
the above two too.

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