/****************************************************************************
**
** Copyright (C) 2021 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtQml module of the Qt Toolkit.
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** $QT_BEGIN_LICENSE:LGPL$
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** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
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**/
#ifndef QQMLDOMFUNCTIONREF_P_H
#define QQMLDOMFUNCTIONREF_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 <functional>
// function_ref has been proposed for the C++20 standard, see
//    http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0792r2.html
// uses it if available, replace it with a const ref to std::function otherwise

#ifndef __cpp_lib_function_ref

QT_BEGIN_NAMESPACE
namespace QQmlJS {
namespace Dom {
template <typename T>
using function_ref = const std::function<T> &;
} // namespace Dom
} // namespace QQmlJS
QT_END_NAMESPACE

#else

QT_BEGIN_NAMESPACE
namespace QQmlJS {
namespace Dom {
using std::function_ref;
} // namespace Dom
} // namespace QQmlJS
QT_END_NAMESPACE

#endif // __cpp_lib_function_ref

#endif // QQMLDOMFUNCTIONREF_P_H