MetaType: Add assignment operator to the container iterators.

Change-Id: Ib4f2197a0ab6bd41c91de667cd3087fb40e44097
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

src/corelib/kernel/qvariant.cpp

@@ -3508,6 +3508,10 @@ QDebug operator<<(QDebug dbg, const QVariant::Type p)
     Creates a copy of \a other.
 */
 
+/*! \fn QSequentialIterable::const_iterator::const_iterator& QSequentialIterable::const_iterator::operator=(const const_iterator &other)
+    Assigns \a other to this.
+*/
+
 /*! \fn QVariant QSequentialIterable::const_iterator::operator*() const
 
     Returns the current item, converted to a QVariant.
@@ -3684,6 +3688,10 @@ QDebug operator<<(QDebug dbg, const QVariant::Type p)
     Creates a copy of \a other.
 */
 
+/*! \fn QAssociativeIterable::const_iterator::const_iterator& QAssociativeIterable::const_iterator::operator=(const const_iterator &other)
+    Assigns \a other to this.
+*/
+
 /*! \fn QVariant QAssociativeIterable::const_iterator::operator*() const
 
     Returns the current value, converted to a QVariant.

src/corelib/kernel/qvariant.h

@@ -602,6 +602,16 @@ public:
             ref->ref();
         }
 
+        inline const_iterator& operator=(const const_iterator &other)
+        {
+            if (!m_impl.equal(other.m_impl)) {
+                m_impl = other.m_impl;
+                ref = other.ref;
+            }
+            ref->ref();
+            return *this;
+        }
+
         inline const QVariant operator*() const {
             const QtMetaTypePrivate::VariantData d = m_impl.getCurrent();
             if (d.metaTypeId == qMetaTypeId<QVariant>())
@@ -671,6 +681,16 @@ public:
             ref->ref();
         }
 
+        inline const_iterator& operator=(const const_iterator &other)
+        {
+            if (!m_impl.equal(other.m_impl)) {
+                m_impl = other.m_impl;
+                ref = other.ref;
+            }
+            ref->ref();
+            return *this;
+        }
+
         inline const QVariant key() const {
             const QtMetaTypePrivate::VariantData d = m_impl.getCurrentKey();
             QVariant v(d.metaTypeId, d.data, d.flags);

tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp

@@ -3830,13 +3830,8 @@ void tst_QVariant::iterateContainerElements()
         for ( ; it != end; ++it, ++i) {
             QCOMPARE(ints.at(i), *it);
         }
-    }
-    {
-        QVariantList ints;
-        ints << 1 << 2 << 3;
-        QVariant var = QVariant::fromValue(ints);
-        QSequentialIterable iter = var.value<QSequentialIterable>();
-        QSequentialIterable::const_iterator it = iter.begin();
+
+        it = iter.begin();
 
         QVariantList intsCopy;
         intsCopy << *(it++);
@@ -3894,17 +3889,11 @@ void tst_QVariant::iterateContainerElements()
         for ( ; it != end; ++it, ++i) {
             QCOMPARE(*(mapping.begin() + i), (*it).toString());
         }
-    }
-    {
+
         QVariantList nums;
         nums << "one" << "two" << "three";
-        QMap<int, QString> mapping;
-        mapping.insert(1, "one");
-        mapping.insert(2, "two");
-        mapping.insert(3, "three");
-        QVariant var = QVariant::fromValue(mapping);
-        QAssociativeIterable iter = var.value<QAssociativeIterable>();
-        QAssociativeIterable::const_iterator it = iter.begin();
+
+        it = iter.begin();
 
         QVariantList numsCopy;
         numsCopy << *(it++);