1. A method in a computer system for generating a data structure for accessing virtual function members of a derived class, the derived class having a base class, the base class having a plurality of virtual function members, the derived class having a virtual function member, the method comprising the computer-implemented steps of: creating a message entry table of message entries for the base class, each message entry identifying a virtual function member of the base class; creating a message map for the base class and storing in the message map for the base class a reference to the message entry table for the base class; creating a virtual function table for the base class and storing in the virtual function table for the base class a reference to a get message map function, the get message map function, when invoked, returns a reference to the message map for the base class; creating a message entry table of a message entries for the derived class, the message entry table for the derived class having a message entry identifying the overriding virtual function member of the derived class; creating a message map for the derived class and storing in the message map for the derived class a reference to the message entry table for the derived class and a reference to the message map for the base class; and creating a virtual function table for the derived class and storing in the virtual function table for the derived class a reference to a get message map function, the get message map function, when invoked, returns a reference to the message map for the derived class; and wherein when a visual function member of the derived class is invoked, the reference to the message entry table of the derived class is retrieved using the get message map function for the derived class and the message map for derived class, the message entry table for the derived class is searched to determine whether it contains a message entry that identifies the virtual function member to be invoked, and the message entry table for the base class is searched to determine whether it contains a message entry that identifies the virtual function member to be invoked.