1 /*

     2  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)

     3  *           (C) 2000 Antti Koivisto (koivisto@kde.org)

     4  *           (C) 2000 Dirk Mueller (mueller@kde.org)

     5  * Copyright (C) 2003, 2005, 2008 Apple Inc. All rights reserved.

     6  *

     7  * This library is free software; you can redistribute it and/or

     8  * modify it under the terms of the GNU Library General Public

     9  * License as published by the Free Software Foundation; either

    10  * version 2 of the License, or (at your option) any later version.

    11  *

    12  * This library is distributed in the hope that it will be useful,

    13  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    15  * Library General Public License for more details.

    16  *

    17  * You should have received a copy of the GNU Library General Public License

    18  * along with this library; see the file COPYING.LIB.  If not, write to

    19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

    20  * Boston, MA 02110-1301, USA.

    21  *

    22  */

    23 

    24 #ifndef DataRef_h

    25 #define DataRef_h

    26 

    27 #include <wtf/RefPtr.h>

    28 

    29 namespace WebCore {

    30 

    31 template <typename T> class DataRef {

    32 public:

    33     const T* get() const { return m_data.get(); }

    34 

    35     const T& operator*() const { return *get(); }

    36     const T* operator->() const { return get(); }

    37 

    38     T* access()

    39     {

    40         if (!m_data->hasOneRef())

    41             m_data = m_data->copy();

    42         return m_data.get();

    43     }

    44 

    45     void init()

    46     {

    47         ASSERT(!m_data);

    48         m_data = T::create();

    49     }

    50 

    51     bool operator==(const DataRef<T>& o) const

    52     {

    53         ASSERT(m_data);

    54         ASSERT(o.m_data);

    55         return m_data == o.m_data || *m_data == *o.m_data;

    56     }

    57     

    58     bool operator!=(const DataRef<T>& o) const

    59     {

    60         ASSERT(m_data);

    61         ASSERT(o.m_data);

    62         return m_data != o.m_data && *m_data != *o.m_data;

    63     }

    64 

    65 private:

    66     RefPtr<T> m_data;

    67 };

    68 

    69 } // namespace WebCore

    70 

    71 #endif // DataRef_h