Abstract entity codec template class. Provides
Boost Software License Version 1.0. See LICENSE_BOOST.txt for details. Alternatively, this file may be distributed under the terms of the Tango 3-Clause BSD License (see LICENSE_BSD.txt for details).
Copyright (c) 2009-2016 dunnhumby Germany GmbH. All rights reserved.
An abstract class template representing an entity de/coder, over a specific set of entities.
The class has various abstract methods, which must be implemented, to decode and encode strings.