<corecode[m]> "it's about the bytes to rust..." <- You could do something like this and move the key to the type level:

```rust
trait KeyValue {
    const KEY: u16;
}

#[derive(Serialize, Deserialize)]
struct MyValue(DateTime);

impl KeyValue for MyValue {
    const KEY: u16 = 42;
}

fn store_value<V: KeyValue>(value: V) {
    let bytes = value.serialize_with_postcard_or_whatever();
    store_kv(V::KEY, bytes);
}

fn read_value<V: KeyValue>() -> V {
    let bytes = read_kv(V::KEY);
    V::deserialize_somehow(bytes)
}
```