In Swift, structures are a lot more like classes than they are in C or Objective-C.
Major differences between Structures and Classes:
– Structures cannot Inherit from other types.
– Classes use type-casting to treat a class as a superclass or subclass,
as well as check protocol adoption. Structs can only use the protocol adoption part.
– Structures do not have deinitializers.
– Structures cannot have multiple references to the same instance.