[Development] Proposing CMake as build tool for Qt 6

[Kevin Kofler]

Konstantin Tokarev wrote:
> Autotools provide human-readable options of standardized format
> 
> --with-thing
> --without-thing
> --enable-thing
> --disable-thing

That's already 2 different standards for essentially the same thing (a 
boolean option), and most non-GNU projects (and even some GNU ones) use them 
pretty arbitrarily and inconsistently. (There is supposed to be a semantic 
difference, but it is often arguable, because often a dependency and a 
feature go together. And several upstreams just use the 2 variants 
interchangeably altogether.)

In CMake, there's just:
-DTHING:BOOL=ON
-DTHING:BOOL=OFF
(and it also happily accepts a bunch of other notations for ON/OFF, without 
the CMakeLists.txt having to do anything).

        Kevin Kofler