Reimplement qSwap and Q_DECLARE_SHARED differently.

This enables the use of Q_DECLARE_SHARED with d-pointers that are
QExplicitlySharedDataPointer<PrivateClass>.

Also, this enables swapping atomically QSharedPointers.

Reviewed-by: Harald Fernengel

3 files changed, 31 insertions, 19 deletions

diff --git a/src/corelib/tools/qalgorithms.h b/src/corelib/tools/qalgorithms.h
index 6f623d9..3e5c3cc 100644
--- a/src/corelib/tools/qalgorithms.h
+++ b/src/corelib/tools/qalgorithms.h
@@ -141,23 +141,6 @@ inline void qCount(const Container &container, const T &value, Size &n)
     qCount(container.constBegin(), container.constEnd(), value, n);
 }
 
-
-#if defined Q_CC_MSVC && _MSC_VER < 1300
-template <typename T>
-inline void qSwap(T &value1, T &value2)
-{
-    qSwap_helper<T>(value1, value2, (T *)0);
-}
-#else
-template <typename T>
-inline void qSwap(T &value1, T &value2)
-{
-    T t = value1;
-    value1 = value2;
-    value2 = t;
-}
-#endif
-
 #ifdef qdoc
 template <typename T>
 LessThan qLess()
diff --git a/src/corelib/tools/qshareddata.h b/src/corelib/tools/qshareddata.h
index e13e37c..dde6e88 100644
--- a/src/corelib/tools/qshareddata.h
+++ b/src/corelib/tools/qshareddata.h
@@ -111,6 +111,9 @@ public:
 
     inline bool operator!() const { return !d; }
 
+    inline void swap(QSharedDataPointer &other)
+    { qSwap(d, other.d); }
+
 protected:
     T *clone();
 
@@ -186,6 +189,9 @@ public:
 
     inline bool operator!() const { return !d; }
 
+    inline void swap(QExplicitlySharedDataPointer &other)
+    { qSwap(d, other.d); }
+
 protected:
     T *clone();
 
@@ -235,6 +241,14 @@ template <class T>
 Q_INLINE_TEMPLATE QExplicitlySharedDataPointer<T>::QExplicitlySharedDataPointer(T *adata) : d(adata)
 { if (d) d->ref.ref(); }
 
+template <class T>
+Q_INLINE_TEMPLATE void qSwap(QSharedDataPointer<T> &p1, QSharedDataPointer<T> &p2)
+{ p1.swap(p2); }
+
+template <class T>
+Q_INLINE_TEMPLATE void qSwap(QExplicitlySharedDataPointer<T> &p1, QExplicitlySharedDataPointer<T> &p2)
+{ p1.swap(p2); }
+
 QT_END_NAMESPACE
 
 QT_END_HEADER
diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h
index cbeb79f..1136aa9 100644
--- a/src/corelib/tools/qsharedpointer_impl.h
+++ b/src/corelib/tools/qsharedpointer_impl.h
@@ -171,8 +171,8 @@ namespace QtSharedPointer {
 
         inline ExternalRefCountData()
         {
-            QBasicAtomicInt proto = Q_BASIC_ATOMIC_INITIALIZER(1);
-            weakref = strongref = proto;
+            strongref = 1;
+            weakref = 1;
         }
         inline ExternalRefCountData(Qt::Initialization) { }
         virtual inline ~ExternalRefCountData() { Q_ASSERT(!weakref); Q_ASSERT(strongref <= 0); }
@@ -385,6 +385,12 @@ namespace QtSharedPointer {
                 delete this->value;
         }
 
+        inline void internalSwap(ExternalRefCount &other)
+        {
+            qSwap(d, other.d);
+            qSwap(this->value, other.value);
+        }
+
 #if defined(Q_NO_TEMPLATE_FRIENDS)
     public:
 #else
@@ -465,6 +471,9 @@ public:
     inline QSharedPointer<T> &operator=(const QWeakPointer<X> &other)
     { internalSet(other.d, other.value); return *this; }
 
+    inline void swap(QSharedPointer &other)
+    { internalSwap(other); }
+
     template <class X>
     QSharedPointer<X> staticCast() const
     {
@@ -682,6 +691,12 @@ Q_INLINE_TEMPLATE QWeakPointer<T> QSharedPointer<T>::toWeakRef() const
     return QWeakPointer<T>(*this);
 }
 
+template <class T>
+inline void qSwap(QSharedPointer<T> &p1, QSharedPointer<T> &p2)
+{
+    p1.swap(p2);
+}
+
 namespace QtSharedPointer {
 // helper functions:
     template <class X, class T>