- https://doc.rust-lang.org/nightly/std/ops/enum.RangeInclusive.html ``` rust pub enum RangeInclusive<Idx> { pub Empty { pub at: Idx, }, pub NonEmpty { pub start: Idx, pub end: Idx, }, } ``` This is no longer valid Rust: https://doc.rust-lang.org/error-index.html#E0449 Incidentally, tuple-like enum variants seems to be free from this issue: - https://doc.rust-lang.org/nightly/std/path/enum.Component.html ``` pub enum Component<'a> { Prefix(PrefixComponent<'a>), RootDir, CurDir, ParentDir, Normal(&'a OsStr), } ```