you could also use `take_from_bytes` to know how many you consumed, and just append them, because semantically tuples are sequential in the byte stream, so you could do something like:

```
// when writing:
to_slice::<(V1, V2, V3>(...);

// when reading from v1/v2/v3:
let (v1, remainder) = take_from_bytes::<V1>(...).unwrap();
let maybe_v2 = None;
let maybe_v3 = None;

if let Ok(v2, remainder) = take_from_bytes::<V2>(remainder) {
    maybe_v2 = Some(v2);
    if let Ok(v3, _) = take_from_bytes::<V3>(remainder) {
        maybe_v3 = Some(v3);
    }
}
```

etc.