If GC & runtime is on the table, then there are many nicer languages you can use (Go, D, Swift, Kotlin). I assume that the C and C++ users who haven't switched yet are largely the "GC-hating" crowd that can't.

COM and other refcounted ones get a pass. But I'm surprised that Unreal gets away with a mark-and-sweep GC. Perhaps because it's only required for UObjects, and the rest of the codebase can still easily avoid using the GC? You can even cause use-after-free bugs on UObjects, if you want to.

Isn't Swift also refcounted?

Reference counting is a GC algorithm, as per CS curriculum.

Try to broaden your horizons.. I work in telecoms only one step away from a FPGA, a 1ms pause would be a critical bug report..

My horizons are already broaden.

https://atlas.cern/discover/detector/trigger-daq

You can also try to broaden yours.

https://www.ptc.com/en/products/developer-tools/perc

Will this work for you? I guess most likely not, and you really cannot afford any kind of delay, where even a C++ virtual call would be considered a bug, given the 1ms delay.

The point being that only a very tiny population has such requirements, just like barely anyone writes applications 100% fully in Assembly.

I'll look at your links but to answer to your question: yes virtual functions are not accepted in the code.