kicad/include/scoped_set_reset.h

69 lines
2.0 KiB
C++

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2016 KiCad Developers, see AUTHORS.txt for contributors.
*
* 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, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#ifndef __SCOPED_SET_RESET_H
#define __SCOPED_SET_RESET_H
/**
* RAII class that sets an value at construction and resets it to the original value
* at destruction.
*
* @note There is no type deduction for template classes until C++17, \
* so you can't do this:
*
* int target = 0;
* SCOPED_SET_RESET( target, 42 );
*
* Instead, you can use a type alias, for example:
*
* using SCOPED_INT_SET_RESET = SCOPED_SET_RESET<int>;
* int target = 0;
* SCOPED_INT_SET_RESET( target , 42 );
*/
template <typename VAL_TYPE>
class SCOPED_SET_RESET
{
public:
SCOPED_SET_RESET( VAL_TYPE& target, VAL_TYPE value ):
m_target( target )
{
m_original = target;
m_target = value;
}
/**
* Destruct the class, and return the target to its original value.
*/
~SCOPED_SET_RESET()
{
m_target = m_original;
}
private:
VAL_TYPE m_original;
VAL_TYPE& m_target;
};
#endif // __SCOPED_SET_RESET_H