And of course the trick is to avoid the nasty surprises and do do it in such a way that is still is easy to program. If you can only do it by adding additional

And of course the trick is to avoid the nasty surprises and do do it in such a way that is still is easy to program. If you can only do it by adding additional hoops for a programmer to jump through (like having to annotate all your function parameters with lifetimes), it's not ideal. Val's subscripts are a nice idea; they make writing a function that returns a reference quite easy. On the other hand, it doesn't look as flexible as a regular function, so maybe it has the same amount of hoops, just different ones.