[Qt-creator] CONFIG variables not as expected

[Bob Babcock]

=?UTF-8?Q?Andr=c3=a9_Hartmann?= <andre.hartmann at iseg-hv.de> wrote in
news:c499ad3a-900e-da5a-aec4-19768014aca6 at iseg-hv.de: 

> In your first mail you talked about MinGW, now MSVC, so I still don't 
> get the full picture of your problem. You will need to provide some
> more information.

I build with both, but don't mix them.  The MinGW part of my questions was 
answered by your previous post.  I'm mostly a windows guy, but I have 
written code that works in both Windows and Linux.

> For C++ libraries, that's correct, you cannot mix MinGW and MSVC. For 
> libraries with pure C interface, it does not matter.
> Note that MSVC2015 and 2017 are binary compatible, so you can exchange
> libs. 

I guess I knew that, but somehow it just feels wrong.  From a quick search, 
looks like 2019, which I haven't touched yet, is also binary compatible.  
Are they also compatible when you consider compilation flags, new C++ 
feature support, and bugs to work around? Those are some reasons why you 
might want to detect which MSVC compiler is being used.

Anyway, my remaining question is whether there is a straightforward way to 
detect in the .pro file which Microsoft compiler is being used?  It used to 
be easy.

Thanks.