You would need to add the rule that you can't move from a variable in only one branch of an if statement or from any sort of loop. Like a really primitive compi

You would need to add the rule that you can't move from a variable in only one branch of an if statement or from any sort of loop. Like a really primitive compile time borrow checker. It seems to me that would be enough, but maybe I haven't thought it through properly, or maybe you'd end up having to copy a lot more often than you want to (or use optional half the time, which might defeat the point a bit).