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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* functions for restoring saved values at the end of a C++ scope */
#ifndef mozilla_AutoRestore_h_
#define mozilla_AutoRestore_h_
#include "mozilla/Attributes.h" // MOZ_STACK_CLASS
namespace mozilla {
/**
* Save the current value of a variable and restore it when the object
* goes out of scope. For example:
* {
* AutoRestore<bool> savePainting(mIsPainting);
* mIsPainting = true;
*
* // ... your code here ...
*
* // mIsPainting is reset to its old value at the end of this block
* }
*/
template <class T>
class MOZ_RAII AutoRestore {
private:
T& mLocation;
T mValue;
public:
explicit AutoRestore(T& aValue) : mLocation(aValue), mValue(aValue) {}
~AutoRestore() { mLocation = mValue; }
T SavedValue() const { return mValue; }
};
} // namespace mozilla
#endif /* !defined(mozilla_AutoRestore_h_) */