Probably not a good answer - but a GitHub search for c++ embedded returns a list of repos. Maybe worth browsing at the very least.
https://github.com/search?l=C%2B%2B&q=c%2B%2B+embedded&type=...
https://github.com/search?l=C%2B%2B&q=c%2B%2B+embedded&type=...
I really want to find something that has good attributes so that I minimize the learning of bad habits.