iterator/doc/transform_iterator_abstract.rst

.. Copyright David Abrahams 2006. Distributed under the Boost
.. Software License, Version 1.0. (See accompanying
.. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

The transform iterator adapts an iterator by modifying the
``operator*`` to apply a function object to the result of
dereferencing the iterator and returning the result.