Why can I use the dyn Trait as the field type declaration inside the struct? I usually use &dyn trait, today I forgot put the & at the beginning of type when defining a struct. But rust doesn't complain it.
struct Test {
folder: dyn Iterator<Item = String>,
}
there's a desire to support unsized locals to some extent in the future
there's a desire to better support custom DSTs (dynamically sized types) in the future
So there are places where unsized types don't necessarily make sense today, but they don't throw errors until you try to use them because they don't want to requireSized in those places.