Beginning C++ Programming

Input and output iterators

As the name suggests, an input iterator will only move forward and will have read access, and an output iterator will only move forward but will have write access. These iterators do not have random access and they do not allow backward movement. For example, an output stream may be used with an output iterator: you assign the dereferenced iterator with a data item in order to write that data item to the stream. Similarly, an input stream could have an input iterator and you dereference the iterator to get access to the next item in the stream. This behavior means that for an output iterator the only valid use of the dereference operator (*) is on the left-hand side of an assignment. It makes no sense to check the ...