Abstract: Alternatives for laying out objects and/or virtual function tables (VFTs), sharing a virtual function table pointer with a direct, virtual base, eliminating the need for an early cast by increasing the number of virtual function table entries, and providing a smart virtual dispatch that eliminates late casts where possible. An object model can be constructed by choosing one option from each of several alternatives. Interaction of alternatives include (1) sharing VFT pointers with a direct, virtual base requires that virtual base pointers are not stored in objects and (2) sharing VFT pointers affects the sharing of virtual base pointers with base classes and placement of late cast adjustment arguments and determining virtual function table entries.