Checking error by calling error functions

In order to check a certain kind of error, the corresponding error object has to be provided and checked by calling CheckError(). Usually, the system throws an exception in order to indicate an error and explicitly checking for errors in not necessary. Sometimes, however, the application might be interested in getting information about application errors thrown somewhere else or may need to set an error. odaba interface classes provide a rather limited error support and hence, C++ programmers may use extended error support provided by the Error class.