Hi, I am trying to write my own iterator - class and using for that the boost::iterator_adaptor. I could find on the webpage several examples of how to connect an existing iterator like std::string::iterator or a simple array as "base-class" for my new iterator, but what can I do if I dont have any base-iterator? In the documentation I found the following sentence: "The Iterator Adaptor library allows you transform an arbitrary ``base'' type into a standard-conforming iterator with the behaviors you choose. Doing so is especially easy if the ``base'' type is itself an iterator." In my situation I dont have any base type which is an iterator, so how should I now create such a base-type? Which are the specifications of such a base-type? Where can I get information on how to create a new base-type? I am trying to write an iterator which reads records from a file or a database and always when I do the it++ the next record is read from the file or database. Thanks a lot in advance Julia