[Development] Platform / compiler support

[Olivier Goffart]

On Monday 07 November 2011 19:52:37 Thiago Macieira wrote:
> On Monday, 7 de November de 2011 17:42:22 jan-arve.saether at nokia.com wrote:
> > Don't we need to agree on what criteria a platform needs to fulfill in
> > order to be supported? The supported platforms will change as times go
> > by, so the list will need to be updated by some criteria (it might
> > cause discussion when some platforms are removed from the list, or if
> > some are favored above others)
> > 
> >  * Is the criteria the number of installed platform SDKs?
> >  * Is the criteria availability of platform SDK for people in the
> >  community?> 
> > (e.g. MinGW has wider availability than MSVC) * Is the criteria that it
> > should be used for automatic compile tests?
> > 
> > For instance, I'm not sure if Qt will have significant increased
> > adoption
> > because ICC is a supported platform, (it would be nice with some
> > numbers,
> > maybe a poll would suffice?
> 
> For this purpose, since we're talking about what kind of compiler and
> language features will be allowed in the source code, we have to be very
> broad.

I disagree. it is the set of supported compiler/platform that define the set 
of feature we can or cannot use without #ifdef


> For example, suppose we want to allow template-template parameters
> in the code without restrictions. That means TTPs may enter into our API.
>
> Now imagine someone wants to port Qt to a platform with a compiler that
> doesn't support TTPs. That will be impossible because TTPs are mandatory and
> cannot be worked around. So this port is dead before it even starts
> happening.
> 
> This is why I'm recommending being very conservative. Once we allow a
> feature unrestrictedly and it enters the API, there's no going back.

In that case, #ifdef are going to be added around that kind of API that cannot 
be used with that compiler.
This is one reason rvct did not have QtConcurrent.