1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/xpcom/glue/AutoRestore.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,46 @@
1.4 +/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/* functions for restoring saved values at the end of a C++ scope */
1.10 +
1.11 +#ifndef mozilla_AutoRestore_h_
1.12 +#define mozilla_AutoRestore_h_
1.13 +
1.14 +#include "mozilla/Attributes.h" // MOZ_STACK_CLASS
1.15 +#include "mozilla/GuardObjects.h"
1.16 +
1.17 +namespace mozilla {
1.18 +
1.19 + /**
1.20 + * Save the current value of a variable and restore it when the object
1.21 + * goes out of scope. For example:
1.22 + * {
1.23 + * AutoRestore<bool> savePainting(mIsPainting);
1.24 + * mIsPainting = true;
1.25 + *
1.26 + * // ... your code here ...
1.27 + *
1.28 + * // mIsPainting is reset to its old value at the end of this block
1.29 + * }
1.30 + */
1.31 + template <class T>
1.32 + class MOZ_STACK_CLASS AutoRestore
1.33 + {
1.34 + private:
1.35 + T& mLocation;
1.36 + T mValue;
1.37 + MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
1.38 + public:
1.39 + AutoRestore(T& aValue MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
1.40 + : mLocation(aValue), mValue(aValue)
1.41 + {
1.42 + MOZ_GUARD_OBJECT_NOTIFIER_INIT;
1.43 + }
1.44 + ~AutoRestore() { mLocation = mValue; }
1.45 + };
1.46 +
1.47 +} // namespace mozilla
1.48 +
1.49 +#endif /* !defined(mozilla_AutoRestore_h_) */
