You can't easily do that with a C++ process indeed, which is why my example was about IntelliJ, not Chrome or any other C++ app. It's much easier to debug and change code on the fly when it's running on a VM like the JVM. I'm not arguing that something like Genera can be matched by any modern app, just that a few operating-system-like apps with similar properties do exist. We just don't think of them as operating systems because they pose as something else. Sort of like how emacs is a Symbolics Lisp-like environment posing as a text editor.

If you're going to argue that it's not the same unless it goes all the way down to the metal, well, people have built Java/JVM based operating systems before like JNode. It's technologically possible. Just not worth it. Being able to edit a function in the middle of your filesystem driver without reloading it is neat in theory but I wouldn't want to actually develop a filesystem that way.