71 строка
2.5 KiB
C++
71 строка
2.5 KiB
C++
/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
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/* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is nsAutoRestore.h.
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*
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* The Initial Developer of the Original Code is the Mozilla Foundation.
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* Portions created by the Initial Developer are Copyright (C) 2009
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* the Initial Developer. All Rights Reserved.
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*
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* Contributor(s):
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* L. David Baron <dbaron@dbaron.org>, Mozilla Corporation (original author)
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*
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* Alternatively, the contents of this file may be used under the terms of
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* either the GNU General Public License Version 2 or later (the "GPL"), or
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* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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*
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* ***** END LICENSE BLOCK ***** */
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/* functions for restoring saved values at the end of a C++ scope */
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#ifndef mozilla_AutoRestore_h_
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#define mozilla_AutoRestore_h_
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namespace mozilla {
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/**
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* Save the current value of a variable and restore it when the object
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* goes out of scope. For example:
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* {
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* AutoRestore<PRBool> savePainting(mIsPainting);
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* mIsPainting = PR_TRUE;
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*
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* // ... your code here ...
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*
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* // mIsPainting is reset to its old value at the end of this block
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* }
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*/
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template <class T>
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class AutoRestore
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{
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private:
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T& mLocation;
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T mValue;
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public:
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AutoRestore(T& aValue) : mLocation(aValue), mValue(aValue) {}
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~AutoRestore() { mLocation = mValue; }
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};
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}
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#endif /* !defined(mozilla_AutoRestore_h_) */
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