47 lines
1.3 KiB
C++
47 lines
1.3 KiB
C++
/*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
* Copyright 2018, Danny Robson <danny@nerdcruft.net>
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
|
|
namespace util::scoped {
|
|
///////////////////////////////////////////////////////////////////////////
|
|
/// restores a referenced target variable to its original value at
|
|
/// destruction time. the type must be copyable.
|
|
template <typename ValueT>
|
|
class restore {
|
|
public:
|
|
restore (ValueT &_target):
|
|
m_target (_target),
|
|
m_value (_target)
|
|
{ ; }
|
|
|
|
~restore ()
|
|
{
|
|
m_target = m_value;
|
|
}
|
|
|
|
private:
|
|
ValueT &m_target;
|
|
ValueT const m_value;
|
|
};
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename ValueT>
|
|
restore (ValueT&) -> restore<ValueT>;
|
|
}
|