Java sealed classes and exhaustive pattern matching

Automated excerpt

Java 17 introduced sealed classes, which allow you to explicitly list the allowed sub-types of an interface or base class. For example, here’s a toy example using a sealed interface and records (inner classes are implicitly added to the permitted sub-types if an explicit list is not given): OK, not so exciting. For example, adding a new TypeC case to our example will cause the main method to fail to compile due to the missing case.

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