{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"///"}]}
    /// - `a` and `b` will have a different FieldIdx, but otherwise `b`'s may be lower
    /// - `b` is not at offset 0, because `V` is not a 1ZST type.
    ///   or they may not be adjacent, due to arbitrary numbers of 1ZST fields that