Wow, that's an abusive ordering function. Presumably this is a thing people might write in... Javascript? And I'm guessing Javascript has to put up with them do

Wow, that's an abusive ordering function. Presumably this is a thing people might write in... Javascript? And I'm guessing Javascript has to put up with them doing this and they get a coherent result, maybe it's even shuffled, because eh, it worked in one browser so we're stuck with it. In Rust this abuse would either "work" or panic telling you that er, that's not a coherent ordering so you need to stop doing that. Not certain whether the panic can only arise in debug builds (or whether it would detect this particular abuse, it's not specified whether you will panic only that you might if you don't provide a coherent ordering). In C++ this is Undefined Behaviour and there's a fair chance you just introduced an RCE vulnerability into your codebase.