AN ALGEBRAIC SEMANTICS OF SUBOBJECTS

Existing formalisms of inheritance are not sufficient to model the com plexities of the kind of multiple inheritance exemplified in C++. Any satisfactory formalism must model the complicating effects of virtual and non-virtual base classes as well as virtual and non-virtual method s. By abstracting the implementational notion of a subobject and forma lizing subobject selection, we develop a formalism to model this combi nation of features. Not intended as a formal semantics of C++, the res ulting model should nevertheless provide an essential level of underst anding for language theorists and implementers in their dealings with C++ and related languages.