# `type.match_wildcard_closed`

Wildcard on a value whose cases can be listed.

Area 3, [Logic](../topics/logic.md); not declinable; the next step is usually the agent's.

An enum, a `Bool` or a nullable value lists every case, so a case added later is caught:


```jadpo
function describe(state: DeliveryState) -> Label {
    return match state {
        DeliveryState.pending -> "Pending"
        _ -> "Other"
    }
}
```

```text
error: `_` can't stand for the rest of a `DeliveryState`
 --> main.jadpo:4:9
  |
4 |         _ -> "Other"
  |         ^ wildcard
  reason: On enums, `Bool` and nullable values every case is listed, so a case added later is caught at every `match` that has to consider it.
  next: Replace `_` with arms for `DeliveryState.sent` and `DeliveryState.failed` (agent)
  rule: type.match_wildcard_closed
  help: https://jadpo.dev/docs/errors/type.match_wildcard_closed

check failed: 1 error, 2 files
```