Patent US 6,412,019

Methods and apparatus in an object oriented programming environment for invocation of objects with interface inheritance. An object reference using mtables contains two parts, more specifically, a pointer to the data for an object and a pointer to the methods on the object. The methods on the object are represented by a collection of mtables. An mtable for a given interface consists of pointers to mtables for inherited interfaces and pointers to functions implementing the operations declared in the interface. An mtable pointer in an object reference points to an mtable for an apparent interface of the object reference. Mtables for any inherited interfaces are reached by indirection from the mtables for the apparent interface.