livetrax/libs/pbd/pbd/unwind.h

/*
 * Copyright (C) 2012-2015 Paul Davis <paul@linuxaudiosystems.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef __libpbd_unwinder_h__
#define __libpbd_unwinder_h__

#include "pbd/libpbd_visibility.h"

namespace PBD {

template <typename T>
class /*LIBPBD_API*/ Unwinder {
  public:
    Unwinder (T& var, T new_val) : _var (var), _old_val (var) { var = new_val; }
    ~Unwinder () { _var = _old_val; }

  private:
    T& _var;
    T  _old_val;
};

template <typename T>
class /*LIBPBD_API*/ ExceptionSafeIncDec {
  public:
	ExceptionSafeIncDec (T& var) : _var (var) { _var++; }
	~ExceptionSafeIncDec () { _var--; }

  private:
    T& _var;
};

}

#endif /* __libpbd_unwinder_h__ */