Yes, and the "Memory Safety" arguments apply to the other resources too. For example Rust eventually grew I/O safety, so your File Handles (in Unix, OwnedFd) or

Yes, and the "Memory Safety" arguments apply to the other resources too. For example Rust eventually grew I/O safety, so your File Handles (in Unix, OwnedFd) or just straight up Handles (in Windows, OwnedHandle) are owned objects, not just integers like the number 4 At the surface this looks like it's just about avoiding dumb mistakes like using arithmetic on handles or mistakenly using reserved values as sentinels -- but the ownership model also means anything tricky we're doing with handles has explicit ownership, transparent to future maintainers.