/****************************************************************************
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** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
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** This file is part of the QtQml module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
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** accordance with the commercial license agreement provided with the
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** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
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** 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
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** packaging of this file.  Please review the following information to
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****************************************************************************/

#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
