What limitation do you encounter with `impl Trait`? They might be removed by `type Alias = impl Trait;` soon. https://rust-lang.github.io/rfcs/2515-type_alias_

What limitation do you encounter with `impl Trait`? They might be removed by `type Alias = impl Trait;` soon. https://rust-lang.github.io/rfcs/2515-type_alias_impl_trait.html https://rust-lang.github.io/rfcs/2515-type_alias_impl_trait....