Add Q_IS_ENUM(), and provide as flag in QMetaType::typeFlags()

Add Q_IS_ENUM() macro to determine if a given type is an
enumeration. Use information from that in QMetaType::registerType()
to store whether custom registered metatypes are enums or not.
This information can then be accessed by calling
QMetaType::typeFlags(int type). This is used by the declarative
code to determine whether a custom type in a variant can be safely
cast to an integer, which is required to allow passing non-local
enums as signal/slot params.

Change-Id: I9733837f56af201fa3017b4a22b761437a3c0de4
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/src/corelib/global/qisenum.h b/src/corelib/global/qisenum.h
new file mode 100644
index 0000000000..c9b6ec6695
--- /dev/null
+++ b/src/corelib/global/qisenum.h
@@ -0,0 +1,64 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/qglobal.h>
+
+#ifndef QISENUM_H
+#define QISENUM_H
+
+QT_BEGIN_HEADER
+QT_BEGIN_NAMESPACE
+
+#ifndef Q_IS_ENUM
+#  if defined(Q_CC_GNU) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))
+#    define Q_IS_ENUM(x) __is_enum(x)
+#  elif defined(Q_CC_MSVC) && defined(_MSC_FULL_VER) && (_MSC_FULL_VER >=140050215)
+#    define Q_IS_ENUM(x) __is_enum(x)
+#  else
+#    include <QtCore/qtypetraits.h>
+#    define Q_IS_ENUM(x) QtPrivate::is_enum<x>::value
+#  endif
+#endif
+
+QT_END_HEADER
+QT_END_NAMESPACE
+
+#endif // QISENUM_H