Access is provided in an object-oriented computing environment by an instance
of a first class to a selected protected resource of an instance of a second class.
This involves defining a third class that includes a protected virtual method for
accessing the selected protected resource. The first class is defined as a subclass
of the third class such that the first class inherits from the third class an access-resource
method for the protected resource and a pointer to an instance of the second class
as an implementation of the third class. The second class is defined as a subclass
of the third class such that the second class inherits from the third class and
implements the protected virtual method for accessing the selected protected resource
by overloading that method. With this structure in place, an instance of the first
class calls the access-resource method inherited from the third class, which access-resource
method uses the pointer to the instance of the second class and the overloaded
method to access the resource.