QSharedPointer: add reset() member functions

These have been added for std::shared_ptr compatibility,
but in particular to allow tst_qnetworkreply && friends
to drop the implicit conversions added to QSP by
inheritance, so QSP can become final.

Change-Id: I0f0401b02125d65622e52393b40a3b10bd9a850c
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qsharedpointer.cpp

@@ -697,6 +697,35 @@
     the pointer itself will be deleted.
 */
 
+/*!
+    \fn void QSharedPointer::reset()
+    \since 5.0
+
+    Same as clear(). For std::shared_ptr compatibility.
+*/
+
+/*!
+    \fn void QSharedPointer::reset(T *t)
+    \since 5.0
+
+    Resets this QSharedPointer object to point to \a t
+    instead. Equivalent to:
+    \code
+    QSharedPointer<T> other(t); this->swap(other);
+    \endcode
+*/
+
+/*!
+    \fn void QSharedPointer::reset(T *t, Deleter deleter)
+    \since 5.0
+
+    Resets this QSharedPointer object to point to \a t
+    instead, with deleter \a deleter. Equivalent to:
+    \code
+    QSharedPointer<T> other(t, deleter); this->swap(other);
+    \endcode
+*/
+
 /*!
     \fn QWeakPointer::QWeakPointer()
 

src/corelib/tools/qsharedpointer.h

@@ -85,6 +85,11 @@ public:
 
     void clear();
 
+    void reset();
+    void reset(T *t);
+    template <typename Deleter>
+    void reset(T *t, Deleter deleter);
+
     // casts:
     template <class X> QSharedPointer<X> staticCast() const;
     template <class X> QSharedPointer<X> dynamicCast() const;

src/corelib/tools/qsharedpointer_impl.h

@@ -510,6 +510,13 @@ public:
     inline void swap(QSharedPointer &other)
     { QSharedPointer<T>::internalSwap(other); }
 
+    inline void reset() { clear(); }
+    inline void reset(T *t)
+    { QSharedPointer copy(t); swap(copy); }
+    template <typename Deleter>
+    inline void reset(T *t, Deleter deleter)
+    { QSharedPointer copy(t, deleter); swap(copy); }
+
     template <class X>
     QSharedPointer<X> staticCast() const
     {