qmultimedia_enum_to_string_converter_p.h

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// Copyright (C) 2025 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 QMULTIMEDIA_ENUM_TO_STRING_CONVERTER_P_H
#define QMULTIMEDIA_ENUM_TO_STRING_CONVERTER_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>
#include <QtCore/qstring.h>
 
#include <optional>
 
QT_BEGIN_NAMESPACE
 
#define QT_MM_CAT(x, y) QT_MM_IMPL_CAT(x, y)
#define QT_MM_IMPL_CAT(x, y) x##y
 
// clang-format off
 
#define QT_MM_IMPL_GEN_CASE_MAP_ENUM_TO_STRING(SYMBOL, STRING)
    case SYMBOL:
        return QStringLiteral(STRING);
 
// clang-format on
 
#define QT_MM_IMPL_GEN_CASES_ENUM_TO_STRING(seq)
    QT_MM_CAT(QT_MM_IMPL_GEN_CASES_ENUM_TO_STRING_1 seq, _END)
    static_assert(true, "force semicolon")
#define QT_MM_IMPL_GEN_CASES_ENUM_TO_STRING_1(x, y)
    QT_MM_IMPL_GEN_CASE_MAP_ENUM_TO_STRING(x, y) QT_MM_IMPL_GEN_CASES_ENUM_TO_STRING_2
#define QT_MM_IMPL_GEN_CASES_ENUM_TO_STRING_2(x, y)
    QT_MM_IMPL_GEN_CASE_MAP_ENUM_TO_STRING(x, y) QT_MM_IMPL_GEN_CASES_ENUM_TO_STRING_1
#define QT_MM_IMPL_GEN_CASES_ENUM_TO_STRING_1_END
#define QT_MM_IMPL_GEN_CASES_ENUM_TO_STRING_2_END
 
namespace QtMultimediaPrivate {
 
struct EnumName
{
};
 
template <typename Enum, typename Role = EnumName>
struct StringResolver
{
    static std::optional<QString> toQString(Enum);
};
 
} // namespace QtMultimediaPrivate
 
// clang-format off
 
#define QT_MM_MAKE_STRING_RESOLVER(Enum, EnumName, ...)
    template <>
    struct QtMultimediaPrivate::StringResolver<Enum, EnumName>
    {
        static std::optional<QString> toQString(Enum arg)
        {
            switch (arg) {
            QT_MM_IMPL_GEN_CASES_ENUM_TO_STRING(__VA_ARGS__);
            default:
                return std::nullopt;
            }
        }
    };
    static_assert(true, "force semicolon")
 
// clang-format on
 
#define QT_MM_DEFINE_QDEBUG_ENUM(EnumType)
    QDebug operator<<(QDebug dbg, EnumType arg)
    {
        std::optional<QString> resolved =
                QtMultimediaPrivate::StringResolver<EnumType>::toQString(arg);
        if (resolved)
            dbg << *resolved;
        else
            dbg << "Unknown Enum value";
        return dbg;
    }
 
QT_END_NAMESPACE
 
#endif // QMULTIMEDIA_ENUM_TO_STRING_CONVERTER_P_H