The reason for not implementing this is as told in mail, if two arrays of same datatype are declared, then the PDataType being an enum any instance level declared in this would always be static.  So if Array 1 and Array 2 are of type double but with 4 and 5 elements each, Array 2 would also be pointing to 4 elements.  So doing getByteSize() from the type is not the right way atleast for the arrays.