Someone, maybe Tolnay?, recently posted a short Go snippet that segfaults because the virtual function table pointer and data pointer aren't copied atomically or mutexed. The same thing works in swift, because neither is thread safe. Swift is also slower than go unless you pass unchecked making it even less safe than go. C#/f# are safer from that particular problem and more performant than either go or swift, but have suffered from the same deserialization attacks that java does. Right now if you want true memory and thread safety, you need to limit a GC language to zero concurrency, use a borrow checker, i.e. rust, or be purely functional which in production would mean haskell. None of those are effortless, and which is easiest depends on you and your problem. Rust is easiest for me, but I keep thinking if I justvwrite enough haskell it will all click. I'm worried if my brain starts working that way about the impacts on things other than writing Haskell.