On this very specific point, for this specific problem, I think that `Rc<str>` is criminally underused. It's a great type if you need a heap allocated string, b

On this very specific point, for this specific problem, I think that `Rc<str>` is criminally underused. It's a great type if you need a heap allocated string, but want to hold on to copies of it in various places; and it derefs to `&str`, so you can use it transparently with most of `std`.