The utility function ExtractDataRef is sometimes called with the expectation that it will return the base of a substring reference and sometimes called with the expectation that it will return nullopt when the argument is not just a DataRef. Add an argument to make the distinction explicit.
The utility function
ExtractDataRefis sometimes called with the expectation that it will return the base of a substring reference and sometimes called with the expectation that it will returnnulloptwhen the argument is not just aDataRef. Add an argument to make the distinction explicit.