Inherited from file_base.
Basis for seeking
in a file.
Seek to an absolute position.
Seek to an offset relative to the current file position.
Seek to an offset relative to the end of the file.
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)