Apache C++ Standard Library User's Guide

## 43.1 Definition

Stream iterators are used to access an existing input or output stream using iterators. In the C++ standard, the template classes istream_iterator and ostream_iterator are referred to as the stream iterators. istream_iterator reads successive elements from the stream for which it was constructed using the extraction `operator>>()`; ostream_iterator writes values to its respective stream using the insertion `operator<<()`.

The class templates istreambuf_iterator and ostreambuf_iterator are used to extract and insert individual characters from stream buffers.