smart cast
Also written: smart casts
Kotlin treating a value as a narrower type after a check. After `if (email != null)`, `email` is a plain String, and after `is Card`, `payment` is a Card.
Also written: smart casts
Kotlin treating a value as a narrower type after a check. After `if (email != null)`, `email` is a plain String, and after `is Card`, `payment` is a Card.