Key exception -- thrown when an error event was reported for a selected key.
See Source File
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.
Key exception -- thrown when an error event was reported for a selected key.