Unreal and UWP/COM developers are perfectly fine with writing C++ code with a GC around.
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.
You can also try to broaden yours.
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.
> Its (thread-local) memory heap is GC'd by default.
What happens to objects that are allocated in one thread, and then have their reference passed to another thread?
It depends on whether shared-memory is a design requirement or an implementation artifact (Erlang does just fine with a largely shared-nothing model).
It also depends on whether a program runs for a short time, or for a long time. If you are running for a short time, why not just avoid the GC entirely; "manage" memory manually by malloc-ing and never free-ing (free-ing too takes time, and doesn't make memory available to other processes anyway).