Optional

    pub const Optional = packed struct(u32) {
        index: u29,
        kind: Metadata.Kind,
        is_none: bool,

        pub const none: Metadata.Optional = .{ .index = 0, .kind = .string, .is_none = true };
        pub const empty_tuple: Metadata.Optional = Metadata.empty_tuple.toOptional();

        pub fn wrap(metadata: ?Metadata) Metadata.Optional {
            return (metadata orelse return .none).toOptional();
        }
        pub fn unwrap(metadata: Metadata.Optional) ?Metadata {
            return if (metadata.is_none) null else .{ .index = metadata.index, .kind = metadata.kind };
        }
        pub fn toValue(metadata: Metadata.Optional) Value {
            return if (metadata.unwrap()) |m| m.toValue() else .none;
        }
        pub fn toString(metadata: Metadata.Optional) Metadata.String.Optional {
            return if (metadata.unwrap()) |m| m.toString().toOptional() else .none;
        }
    }