include/GaudiKernel/finally.h

0001 /***********************************************************************************\
0002 * (c) Copyright 1998-2019 CERN for the benefit of the LHCb and ATLAS collaborations *
0003 *                                                                                   *
0004 * This software is distributed under the terms of the Apache version 2 licence,     *
0005 * copied verbatim in the file "LICENSE".                                            *
0006 *                                                                                   *
0007 * In applying this licence, CERN does not waive the privileges and immunities       *
0008 * granted to it by virtue of its status as an Intergovernmental Organization        *
0009 * or submit itself to any jurisdiction.                                             *
0010 \***********************************************************************************/
0011 #include <utility>
0012 //
0013 //  make it possible to execute an action at the exit of a scope
0014 //
0015 //  auto f = finally( [](){ std::cout << "end of scope!" << std::endl; } );
0016 //
0017 //  the above will execute the provided callable when f goes out of scope,
0018 //  i.e. the 'current' scope ends.
0019
0020 template <typename F>
0021 struct final_action {
0022   F act;
0023   final_action( F&& act ) : act{ std::move( act ) } {}
0024   final_action( final_action&& ) = default;
0025   ~final_action() { act(); }
0026 };
0027
0028 template <typename F>
0029 final_action<F> finally( F&& act ) {
0030   return { std::forward<F>( act ) };
0031 }