Add swap and move operator to QHostInfo

Also mark as shared-come-qt6,

[ChangeLog][QtNetwork][QHostInfo] Added swap() and move operator.

Change-Id: I8f422868f0487a37aeba3bc74685dc4912e9b3a4
Coverity-Id: 168204
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

src/network/kernel/qhostinfo.cpp

@@ -278,6 +278,27 @@ int QHostInfo::lookupHost(const QString &name, QObject *receiver,
     return id;
 }
 
+/*!
+    \fn QHostInfo &QHostInfo::operator=(QHostInfo &&other)
+
+    Move-assigns \a other to this QHostInfo instance.
+
+    \note The moved-from object \a other is placed in a
+    partially-formed state, in which the only valid operations are
+    destruction and assignment of a new value.
+
+    \since 5.10
+*/
+
+/*!
+    \fn void QHostInfo::swap(QHostInfo &other)
+
+    Swaps host-info \other with this host-info. This operation is
+    very fast and never fails.
+
+    \since 5.10
+*/
+
 /*!
     \fn int QHostInfo::lookupHost(const QString &name, const QObject *receiver, PointerToMemberFunction function)
 

src/network/kernel/qhostinfo.h

@@ -63,8 +63,11 @@ public:
     explicit QHostInfo(int lookupId = -1);
     QHostInfo(const QHostInfo &d);
     QHostInfo &operator=(const QHostInfo &d);
+    QHostInfo &operator=(QHostInfo &&other) Q_DECL_NOTHROW { swap(other); return *this; }
     ~QHostInfo();
 
+    void swap(QHostInfo &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+
     QString hostName() const;
     void setHostName(const QString &name);
 
@@ -154,6 +157,8 @@ private:
                               QtPrivate::QSlotObjectBase *slotObj);
 };
 
+Q_DECLARE_SHARED_NOT_MOVABLE_UNTIL_QT6(QHostInfo)
+
 QT_END_NAMESPACE
 
 Q_DECLARE_METATYPE(QHostInfo)

tests/auto/network/kernel/qhostinfo/tst_qhostinfo.cpp

@@ -86,6 +86,8 @@ class tst_QHostInfo : public QObject
 private slots:
     void init();
     void initTestCase();
+    void swapFunction();
+    void moveOperator();
     void getSetCheck();
     void staticInformation();
     void lookupIPv4_data();
@@ -129,6 +131,29 @@ private:
 #endif
 };
 
+void tst_QHostInfo::swapFunction()
+{
+    QHostInfo obj1, obj2;
+    obj1.setError(QHostInfo::HostInfoError(0));
+    obj2.setError(QHostInfo::HostInfoError(1));
+    obj1.swap(obj2);
+    QCOMPARE(QHostInfo::HostInfoError(0), obj2.error());
+    QCOMPARE(QHostInfo::HostInfoError(1), obj1.error());
+}
+
+void tst_QHostInfo::moveOperator()
+{
+    QHostInfo obj1, obj2, obj3(1);
+    obj1.setError(QHostInfo::HostInfoError(0));
+    obj2.setError(QHostInfo::HostInfoError(1));
+    obj1 = std::move(obj2);
+    obj2 = obj3;
+    QCOMPARE(QHostInfo::HostInfoError(1), obj1.error());
+    QCOMPARE(obj3.lookupId(), obj2.lookupId());
+}
+
+
+
 // Testing get/set functions
 void tst_QHostInfo::getSetCheck()
 {