Class::accessor::class provides a simple way to create accessor and mutator methods for class variables, just as class::accessor provides for objects. it can use either an enclosed lexical variable, or a package variable.

this module was once implemented in terms of class::accessor, but changes to that module broke this relationship. class::accessor::class is still a subclass of class::accessor, strictly for historical reasons. as a side benefit, a class that isa class::accessor::class is also a class::accessor and can use its methods.