For which data categories is it appropriate to use the automatic memory management mechanism ARC?

The Automatic Reference Counting (ARC) memory management mechanism in iOS is used for managing the memory of class objects (reference types). ARC automatically tracks the reference count of an object and releases memory when there are no more references.

ARC does not apply to value types, such as structures (struct) and enumerations (enum), as they are managed on the stack and copied upon assignment.

Therefore, ARC is appropriate for class objects that are created on the heap and require lifecycle control.