[Development] Deprecation/removal model going into Qt 6

[Kevin Kofler]

Kevin Kofler wrote:
> But we do have the expectation that the CPU will still run our 10-year-old
> code without having to recompile it. Modern CPUs are backwards-compatible
> with restrictions (e.g., you cannot use 16-bit code from a 64-bit OS, at
> least not without dangerous hacks) all the way to the 8080 from 1974, and
> fully backwards-compatible all the way to the 80386 from 1985! Qt does not
> even come close to that level of backwards compatibility.

PS: Imagine the outcry and havoc if Intel decided to tell you, e.g.: "Sorry,
    x87 floating-point is obsolete and hard for us to maintain, we will drop
    it from our next generation of CPUs and force everybody to port their
    software to SSE2 or AVX512 for all floating-point operations." (I hope
    I'm not giving them ideas…) Yet, for some reason I cannot fathom, this
    exact behavior is considered acceptable from software library vendors
    (and compiler vendors too, g++ is a bad offender there, but that is
    off-topic here :-) ).

        Kevin Kofler