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// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#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.
//
#include <QtCore/private/qglobal_p.h>
QT_BEGIN_NAMESPACE
template<typename T>
struct QQmlNullableValue
{
QQmlNullableValue() = default;
QQmlNullableValue(const QQmlNullableValue<T> &o)
: m_value(o.m_value)
, m_isNull(o.m_isNull)
{}
QQmlNullableValue(QQmlNullableValue<T> &&o) noexcept
: m_value(std::move(o.value))
, m_isNull(std::exchange(o.m_isNull, true))
{}
QQmlNullableValue(const T &t)
: m_value(t)
, m_isNull(false)
{}
QQmlNullableValue(T &&t) noexcept
: m_value(std::move(t))
, m_isNull(false)
{}
QQmlNullableValue<T> &operator=(const QQmlNullableValue<T> &o)
{
if (&o != this) {
m_value = o.m_value;
m_isNull = o.m_isNull;
}
return *this;
}
QQmlNullableValue<T> &operator=(QQmlNullableValue<T> &&o) noexcept
{
if (&o != this) {
m_value = std::move(o.m_value);
m_isNull = std::exchange(o.m_isNull, true);
}
return *this;
}
QQmlNullableValue<T> &operator=(const T &t)
{
m_value = t;
m_isNull = false;
return *this;
}
QQmlNullableValue<T> &operator=(T &&t) noexcept
{
m_value = std::move(t);
m_isNull = false;
return *this;
}
const T &value() const { return m_value; }
operator T() const { return m_value; }
void invalidate() { m_isNull = true; }
bool isValid() const { return !m_isNull; }
private:
T m_value = T();
bool m_isNull = true;
};
QT_END_NAMESPACE
#endif // QQMLNULLABLEVALUE_P_H
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