From b1d6af35a45860ad9dfbd65979ca1df44abae446 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@kdab.com>
Date: Sun, 9 Mar 2014 11:56:56 +0100
Subject: [PATCH] QWeakPointer: add member-swap

[ChangeLog][QtCore][QWeakPointer] Added member-swap function.

Change-Id: Ide3672dc74a9d8153e5f930290d938e8c23993b5
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/tools/qsharedpointer.cpp          |  8 +++++++
 src/corelib/tools/qsharedpointer.h            |  2 ++
 src/corelib/tools/qsharedpointer_impl.h       |  6 +++++
 .../qsharedpointer/tst_qsharedpointer.cpp     | 24 +++++++++++++++++++
 4 files changed, 40 insertions(+)

diff --git a/src/corelib/tools/qsharedpointer.cpp b/src/corelib/tools/qsharedpointer.cpp
index 19c88fcf1c..2ced3d6a7c 100644
--- a/src/corelib/tools/qsharedpointer.cpp
+++ b/src/corelib/tools/qsharedpointer.cpp
@@ -770,6 +770,14 @@
     you will get a compiler error.
 */
 
+/*!
+    \fn void QWeakPointer::swap(QWeakPointer<T> &other)
+    \since 5.4
+
+    Swaps this weak pointer instance with \a other. This function is
+    very fast and never fails.
+*/
+
 /*!
     \fn bool QWeakPointer::isNull() const
 
diff --git a/src/corelib/tools/qsharedpointer.h b/src/corelib/tools/qsharedpointer.h
index ea9b4fbf27..d9de48b7f4 100644
--- a/src/corelib/tools/qsharedpointer.h
+++ b/src/corelib/tools/qsharedpointer.h
@@ -122,6 +122,8 @@ public:
     QWeakPointer(const QObject *other);
     QWeakPointer<T> operator=(const QObject *other);
 
+    void swap(QWeakPointer<T> &other);
+
     T *data() const;
     void clear();
 
diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h
index e59efce7ae..f70e398cfe 100644
--- a/src/corelib/tools/qsharedpointer_impl.h
+++ b/src/corelib/tools/qsharedpointer_impl.h
@@ -587,6 +587,12 @@ public:
         return *this;
     }
 
+    inline void swap(QWeakPointer &other)
+    {
+        qSwap(this->d, other.d);
+        qSwap(this->value, other.value);
+    }
+
     inline QWeakPointer(const QSharedPointer<T> &o) : d(o.d), value(o.data())
     { if (d) d->weakref.ref();}
     inline QWeakPointer &operator=(const QSharedPointer<T> &o)
diff --git a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
index 1d466a4734..9bcce60e93 100644
--- a/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
+++ b/tests/auto/corelib/tools/qsharedpointer/tst_qsharedpointer.cpp
@@ -392,6 +392,30 @@ void tst_QSharedPointer::swap()
     QVERIFY(p2 != control);
     QVERIFY(p2.isNull());
     QVERIFY(*p1 == 42);
+
+    QWeakPointer<int> w1, w2 = control;
+
+    QVERIFY(w1.isNull());
+    QVERIFY(!w2.isNull());
+    QVERIFY(w2.lock() == control);
+    QVERIFY(!w1.lock());
+
+    w1.swap(w2);
+    QVERIFY(w2.isNull());
+    QVERIFY(!w1.isNull());
+    QVERIFY(w1.lock() == control);
+    QVERIFY(!w2.lock());
+
+    qSwap(w1, w2);
+    QVERIFY(w1.isNull());
+    QVERIFY(w2.lock() == control);
+
+    p1.reset();
+    p2.reset();
+    control.reset();
+
+    QVERIFY(w1.isNull());
+    QVERIFY(w2.isNull());
 }
 
 void tst_QSharedPointer::useOfForwardDeclared()