Object Integrity while Allowing Aliasing

摘要

Aliasing is a fundamental programming concept in object oriented software design. Aliasing means that a subordinate object is referenced by several objects. This can be problematic, if the integrity of those objects depends on the state of the shared subordinate object, since the referring objects may not be aware of each other. Changes made to the subordinate object must respect all invariants dealing with it at the time of change.