If you implement the actual game logic in a scripting language like Lua, hot reloading becomes trivial. sol2 is a really awesome Lua binding library for C++: https://github.com/ThePhD/sol2

Thanks for the Lua bindings suggestion!

It's just that I quite dislike using such a scripting language. It's personal preference, for sure, but here's a bit more context https://news.ycombinator.com/item?id=47220602