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Diffstat (limited to 'src/qml/qml/ftw/qqmlnullablevalue_p.h')
-rw-r--r-- | src/qml/qml/ftw/qqmlnullablevalue_p.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/src/qml/qml/ftw/qqmlnullablevalue_p.h b/src/qml/qml/ftw/qqmlnullablevalue_p.h new file mode 100644 index 0000000000..202c2b79d7 --- /dev/null +++ b/src/qml/qml/ftw/qqmlnullablevalue_p.h @@ -0,0 +1,73 @@ +/**************************************************************************** +** +** Copyright (C) 2015 The Qt Company Ltd. +** Contact: http://www.qt.io/licensing/ +** +** This file is part of the QtQml module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL21$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see http://www.qt.io/terms-conditions. For further +** information use the contact form at http://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 or version 3 as published by the Free +** Software Foundation and appearing in the file LICENSE.LGPLv21 and +** LICENSE.LGPLv3 included in the packaging of this file. Please review the +** following information to ensure the GNU Lesser General Public License +** requirements will be met: https://www.gnu.org/licenses/lgpl.html and +** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** As a special exception, The Qt Company gives you certain additional +** rights. These rights are described in The Qt Company LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#ifndef QQMLNULLABLEVALUE_P_H +#define QQMLNULLABLEVALUE_P_H + +// +// W A R N I N G +// ------------- +// +// This file is not part of the Qt API. It exists purely as an +// implementation detail. This header file may change from version to +// version without notice, or even be removed. +// +// We mean it. +// + +QT_BEGIN_NAMESPACE + +template<typename T> +struct QQmlNullableValue +{ + QQmlNullableValue() + : isNull(true), value(T()) {} + QQmlNullableValue(const QQmlNullableValue<T> &o) + : isNull(o.isNull), value(o.value) {} + QQmlNullableValue(const T &t) + : isNull(false), value(t) {} + QQmlNullableValue<T> &operator=(const T &t) + { isNull = false; value = t; return *this; } + QQmlNullableValue<T> &operator=(const QQmlNullableValue<T> &o) + { isNull = o.isNull; value = o.value; return *this; } + operator T() const { return value; } + + void invalidate() { isNull = true; } + bool isValid() const { return !isNull; } + bool isNull; + T value; +}; + +QT_END_NAMESPACE + +#endif // QQMLNULLABLEVALUE_P_H |