Properly implement qobject_cast for const pointers.

Instead of using ugly const_cast in public headers and Q_UNUSED
(which expands to nothing in release builds), use a properly-const
method.

Reviewed-By: Bradley T. Hughes

1 files changed, 1 insertions, 5 deletions

diff --git a/src/corelib/kernel/qobject.h b/src/corelib/kernel/qobject.h
index 1b613a6..c533fa1 100644
--- a/src/corelib/kernel/qobject.h
+++ b/src/corelib/kernel/qobject.h
@@ -458,14 +458,10 @@ inline T qobject_cast(QObject *object)
 template <class T>
 inline T qobject_cast(const QObject *object)
 {
-    // this will cause a compilation error if T is not const
-    register T ptr = static_cast<T>(object);
-    Q_UNUSED(ptr);
-
 #if !defined(QT_NO_MEMBER_TEMPLATES) && !defined(QT_NO_QOBJECT_CHECK)
     reinterpret_cast<T>(0)->qt_check_for_QOBJECT_macro(*reinterpret_cast<T>(const_cast<QObject *>(object)));
 #endif
-    return static_cast<T>(const_cast<QObject *>(reinterpret_cast<T>(0)->staticMetaObject.cast(const_cast<QObject *>(object))));
+    return static_cast<T>(reinterpret_cast<T>(0)->staticMetaObject.cast(object));
 }