What is abstract?
abstract is a storage-class specifier, like static or extern. When attached to a top-level type declaration, it means that other files can use the type but cannot look at the internals of the type (e.g., other files cannot access the fields of an abstract struct). Otherwise, abstract has the same meaning as the auto (default) storage class. Hence abstract is a way to state within a Cyclone file that a type’s representation cannot be exported.
