Change WTF::TemporaryChange to be an alias for AutoReset

third_party/WebKit/Source/wtf/TemporaryChange.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef TemporaryChange_h
 #define TemporaryChange_h
 
-#include "wtf/Noncopyable.h"
+#include "base/auto_reset.h"
 
 namespace WTF {
 
-// TemporaryChange<> is useful for setting a variable to a new value only within a
-// particular scope. An TemporaryChange<> object changes a variable to its original
-// value upon destruction, making it an alternative to writing "var = false;"
-// or "var = oldVal;" at all of a block's exit points.
-//
-// This should be obvious, but note that an TemporaryChange<> instance should have a
-// shorter lifetime than its scopedVariable, to prevent invalid memory writes
-// when the TemporaryChange<> object is destroyed.
+// WTF::TemporaryChange is base::AutoReset. See base/auto_reset.h for documentation.
 
-template<typename T>
-class TemporaryChange {
-    WTF_MAKE_NONCOPYABLE(TemporaryChange);
-public:
-    TemporaryChange(T& scopedVariable, T newValue)
-        : m_scopedVariable(scopedVariable)
-        , m_originalValue(scopedVariable)
-    {
-        m_scopedVariable = newValue;
-    }
-
-    ~TemporaryChange()
-    {
-        m_scopedVariable = m_originalValue;
-    }
-
-
-private:
-    T& m_scopedVariable;
-    T m_originalValue;
-};
+template <typename T>
+using TemporaryChange = typename base::AutoReset<T>;

[Yuta Kitamura, 2016/07/15 03:04:41]

A compiler in my brain tells this "typename" is unnecessary. But it comes
with no guarantee ;)

[jsbell, 2016/07/18 18:42:37]

Copy/pasta. Will remove.

 
 } // namespace WTF
 
 using WTF::TemporaryChange;
 
 #endif