StringLiterals.h

// SPDX-FileCopyrightText: 2021 Linus Jahn <lnj@kaidan.im>
//
// SPDX-License-Identifier: LGPL-2.1-or-later
 
#ifndef STRINGLITERALS_H
#define STRINGLITERALS_H
 
#include <QString>
 
#if QT_VERSION >= QT_VERSION_CHECK(6, 4, 0)
using namespace Qt::Literals::StringLiterals;
#elif QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
inline QString operator"" _s(const char16_t *str, size_t size) noexcept
{
    return QString(QStringPrivate(nullptr, const_cast<char16_t *>(str), qsizetype(size)));
}
 
constexpr inline QLatin1String operator"" _L1(const char *str, size_t size) noexcept
{
    return QLatin1String { str, int(size) };
}
#else
namespace QXmpp::Private {
 
template<std::size_t N>
struct StringLiteralData {
    char16_t data[N];
    std::size_t size = N;
 
    constexpr StringLiteralData(const char16_t (&str)[N])
    {
        std::ranges::copy(str, data);
    }
};
 
template<std::size_t N>
struct StaticStringData {
    QArrayData str = Q_STATIC_STRING_DATA_HEADER_INITIALIZER(N - 1);
    char16_t data[N];
 
    StaticStringData(const char16_t (&str)[N])
    {
        std::ranges::copy(str, data);
    }
 
    QStringData *data_ptr() const
    {
        return const_cast<QStringData *>(static_cast<const QStringData *>(&str));
    }
};
 
}  // namespace QXmpp::Private
 
template<QXmpp::Private::StringLiteralData str>
QString operator""_s()
{
    static const auto staticData = QXmpp::Private::StaticStringData<str.size>(str.data);
    return QString(QStringDataPtr { staticData.data_ptr() });
}
 
constexpr inline QLatin1String operator"" _L1(const char *str, size_t size) noexcept
{
    return QLatin1String { str, int(size) };
}
#endif
 
#endif  // STRINGLITERALS_H