Introducing QArrayDataPointer

This class provides RAII functionality for handling QArrayData pointers.

Together with QArrayDataHeader and QArrayDataOps, this offers common
boilerplate code for implementing a container which, itself, defines its
own interface.

Change-Id: If38eba22fbe8f69038a06fff4acb50af434d229e
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>

src/corelib/tools/qarraydatapointer.h

@@ -0,0 +1,161 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QARRAYDATAPOINTER_H
+#define QARRAYDATAPOINTER_H
+
+#include <QtCore/qarraydataops.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Core)
+
+template <class T>
+struct QArrayDataPointer
+{
+private:
+    typedef QTypedArrayData<T> Data;
+    typedef QArrayDataOps<T> DataOps;
+
+public:
+    QArrayDataPointer()
+        : d(Data::sharedNull())
+    {
+    }
+
+    QArrayDataPointer(const QArrayDataPointer &other)
+        : d((other.d->ref.ref(), other.d))
+    {
+    }
+
+    explicit QArrayDataPointer(QTypedArrayData<T> *ptr)
+        : d(ptr)
+    {
+    }
+
+    QArrayDataPointer &operator=(const QArrayDataPointer &other)
+    {
+        QArrayDataPointer tmp(other);
+        this->swap(tmp);
+        return *this;
+    }
+
+    DataOps &operator*() const
+    {
+        Q_ASSERT(d);
+        return *static_cast<DataOps *>(d);
+    }
+
+    DataOps *operator->() const
+    {
+        Q_ASSERT(d);
+        return static_cast<DataOps *>(d);
+    }
+
+    ~QArrayDataPointer()
+    {
+        if (!d->ref.deref()) {
+            (*this)->destroyAll();
+            Data::deallocate(d);
+        }
+    }
+
+    bool isNull() const
+    {
+        return d == Data::sharedNull();
+    }
+
+    Data *data() const
+    {
+        return d;
+    }
+
+    void swap(QArrayDataPointer &other)
+    {
+        qSwap(d, other.d);
+    }
+
+    void clear()
+    {
+        QArrayDataPointer tmp(d);
+        d = Data::sharedEmpty();
+    }
+
+private:
+    Data *d;
+};
+
+template <class T>
+inline bool operator==(const QArrayDataPointer<T> &lhs, const QArrayDataPointer<T> &rhs)
+{
+    return lhs.data() == rhs.data();
+}
+
+template <class T>
+inline bool operator!=(const QArrayDataPointer<T> &lhs, const QArrayDataPointer<T> &rhs)
+{
+    return lhs.data() != rhs.data();
+}
+
+template <class T>
+inline void qSwap(QArrayDataPointer<T> &p1, QArrayDataPointer<T> &p2)
+{
+    p1.swap(p2);
+}
+
+QT_END_NAMESPACE
+
+namespace std
+{
+    template <class T>
+    inline void swap(
+            QT_PREPEND_NAMESPACE(QArrayDataPointer)<T> &p1,
+            QT_PREPEND_NAMESPACE(QArrayDataPointer)<T> &p2)
+    {
+        p1.swap(p2);
+    }
+}
+
+QT_END_HEADER
+
+#endif // include guard

tests/auto/corelib/tools/qarraydata/simplevector.h

@@ -44,7 +44,7 @@
 #define QARRAY_TEST_SIMPLE_VECTOR_H
 
 #include <QtCore/qarraydata.h>
-#include <QtCore/qarraydataops.h>
+#include <QtCore/qarraydatapointer.h>
 
 #include <algorithm>
 
@@ -53,7 +53,6 @@ struct SimpleVector
 {
 private:
     typedef QTypedArrayData<T> Data;
-    typedef QArrayDataOps<T> DataOps;
 
 public:
     typedef T value_type;
@@ -61,28 +60,21 @@ public:
     typedef typename Data::const_iterator const_iterator;
 
     SimpleVector()
-        : d(Data::sharedNull())
     {
     }
 
-    SimpleVector(const SimpleVector &vec)
-        : d(vec.d)
-    {
-        d->ref.ref();
-    }
-
     SimpleVector(size_t n, const T &t)
         : d(Data::allocate(n))
     {
         if (n)
-            static_cast<DataOps *>(d)->copyAppend(n, t);
+            d->copyAppend(n, t);
     }
 
     SimpleVector(const T *begin, const T *end)
         : d(Data::allocate(end - begin))
     {
         if (end - begin)
-            static_cast<DataOps *>(d)->copyAppend(begin, end);
+            d->copyAppend(begin, end);
     }
 
     explicit SimpleVector(Data *ptr)
@@ -90,23 +82,8 @@ public:
     {
     }
 
-    ~SimpleVector()
-    {
-        if (!d->ref.deref()) {
-            static_cast<DataOps *>(d)->destroyAll();
-            Data::deallocate(d);
-        }
-    }
-
-    SimpleVector &operator=(const SimpleVector &vec)
-    {
-        SimpleVector temp(vec);
-        this->swap(temp);
-        return *this;
-    }
-
     bool empty() const { return d->size == 0; }
-    bool isNull() const { return d == Data::sharedNull(); }
+    bool isNull() const { return d.isNull(); }
     bool isEmpty() const { return this->empty(); }
 
     bool isSharedWith(const SimpleVector &other) const { return d == other.d; }
@@ -142,7 +119,7 @@ public:
                 && !d->capacityReserved
                 && (d->ref != 1 || (d->capacityReserved = 1, false)))) {
             SimpleVector detached(Data::allocate(n, true));
-            static_cast<DataOps *>(detached.d)->copyAppend(constBegin(), constEnd());
+            detached.d->copyAppend(constBegin(), constEnd());
             detached.swap(*this);
         }
     }
@@ -163,14 +140,14 @@ public:
             SimpleVector detached(Data::allocate(
                         qMax(capacity(), size() + (last - first)), d->capacityReserved));
 
-            static_cast<DataOps *>(detached.d)->copyAppend(first, last);
+            detached.d->copyAppend(first, last);
-            static_cast<DataOps *>(detached.d)->copyAppend(begin, begin + d->size);
+            detached.d->copyAppend(begin, begin + d->size);
             detached.swap(*this);
 
             return;
         }
 
-        static_cast<DataOps *>(d)->insert(begin, first, last);
+        d->insert(begin, first, last);
     }
 
     void append(const_iterator first, const_iterator last)
@@ -185,15 +162,15 @@ public:
 
             if (d->size) {
                 const T *const begin = constBegin();
-                static_cast<DataOps *>(detached.d)->copyAppend(begin, begin + d->size);
+                detached.d->copyAppend(begin, begin + d->size);
             }
-            static_cast<DataOps *>(detached.d)->copyAppend(first, last);
+            detached.d->copyAppend(first, last);
             detached.swap(*this);
 
             return;
         }
 
-        static_cast<DataOps *>(d)->copyAppend(first, last);
+        d->copyAppend(first, last);
     }
 
     void insert(int position, const_iterator first, const_iterator last)
@@ -223,9 +200,9 @@ public:
                         qMax(capacity(), size() + (last - first)), d->capacityReserved));
 
             if (position)
-                static_cast<DataOps *>(detached.d)->copyAppend(begin, where);
+                detached.d->copyAppend(begin, where);
-            static_cast<DataOps *>(detached.d)->copyAppend(first, last);
+            detached.d->copyAppend(first, last);
-            static_cast<DataOps *>(detached.d)->copyAppend(where, end);
+            detached.d->copyAppend(where, end);
             detached.swap(*this);
 
             return;
@@ -235,11 +212,11 @@ public:
         if ((first >= where && first < end)
                 || (last > where && last <= end)) {
             SimpleVector tmp(first, last);
-            static_cast<DataOps *>(d)->insert(where, tmp.constBegin(), tmp.constEnd());
+            d->insert(where, tmp.constBegin(), tmp.constEnd());
             return;
         }
 
-        static_cast<DataOps *>(d)->insert(where, first, last);
+        d->insert(where, first, last);
     }
 
     void swap(SimpleVector &other)
@@ -249,12 +226,11 @@ public:
 
     void clear()
     {
-        SimpleVector tmp(d);
+        d.clear();
-        d = Data::sharedEmpty();
     }
 
 private:
-    Data *d;
+    QArrayDataPointer<T> d;
 };
 
 template <class T>