Bulk I/O is a strenuous operation in terms of performance and resource allocation. For example, say you need to debug a container and wish to dump its content to cout as well as to a file. You'll need to hardcode every such operation, writing ad-hoc code that serves for very pinpointed uses, none of which can be modified easily. This process would be tedious, time-consuming, and potentially complicated.
Thankfully, the <iterator> library allows you to ignore the underlying type of data sources and targetsfiles, containers, the standard input, the standard output etc., thus freeing you from having to deal with the peculiarities of each type of data source or target.
When using stream iterators, the system can optimize your code as it conceptually performs an I/O operation in one shot. More importantly, the use of stream iterators provides more flexibility because it allows you to switch from one data source or target to another almost seamlessly.
In this solution, learn how to use the <interator> library to enhance your apps' design and performance while reducing manual labor.
How to transfer data between containers, files, and streams efficiently and uniformly?
Use istream_iterator and ostream_iterator for sequential input and output.