Microsoft Technology Licensing, LLC

D T Jones

Jan Stephen Gray

Martin O'Riordan

A method and system in an object-oriented environment for determining the offset of a data member of a derived class when the derived class has a virtually inherited base class and the data member is defined in the base class. In a preferred embodiment, the base class has a data structure and a class address. The base class data structure has the data member located at a data member offset from the base class address. The derived class has a data structure and a class address. The derived class data structure includes an occurrence of the base class data structure. The occurrence of the base class data structure is located at a base class offset from the derived class address. In a preferred embodiment, the base class offset is stored at a memory location, a first field and a second field for a pointer to the data member are allocated, the data member offset is stored in the first field, an indicator of the stored base class offset is stored in the second field, the pointer is dereferenced by retrieving the base class offset using the indicator stored in the second field, retrieving the data member offset from the first field, and adding the retrieved base class offset to the retrieved data member offset to give the offset of the data member within the derived data structure.

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Preston, WA, United States of America

D T Jones