I am familiar with switch case statements, but not so with switch statement. Is it a new feature added to dart? What does it really do? Here is the code snippet.

 Map.fromEntries(
        inputMap.entries.map(
          (e) {
           
            return MapEntry(
                e.key,
                switch (e.value) {
                  DateTime t => toJsonDateTime(t),
                  Duration d => toJsonDuration(d),
                  Enum t => t.name,
                  _ => e.value,
                });
          },
        ),
      ),