[Qt-creator] CONFIG variables not as expected

[Bob Babcock]

=?UTF-8?Q?Andr=c3=a9_Hartmann?= <aha_1980 at gmx.de> wrote in news:709647cd-
724b-693d-893a-7bed3bb43750 at gmx.de:

>> but detecting the compiler version is more awkward.
> Why?

I can do
   win32-msvc2015 { Do stuff... }
but not
   win32-msvc2017 { Do stuff... }

The only way I see to tell that it's 2017 is to check if it isn't any other 
MS compiler that I use.  Perhaps it's silly, but I try to maintain 
compatibility with 2013, 2015 and 2017 and Qt back to 5.9x.

I use some 3rd party libraries that are built separately and it seems 
safest to use libraries built with a matching compiler.  Less important, I 
include compiler version in my About screen and use DEFINES to get that 
info into the code.