qtimezone.cpp

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// Copyright (C) 2022 The Qt Company Ltd.
// Copyright (C) 2013 John Layt <jlayt@kde.org>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qtimezone.h"
#if QT_CONFIG(timezone)
#  include "qtimezoneprivate_p.h"
#endif
 
#include <QtCore/qdatastream.h>
#include <QtCore/qdatetime.h>
 
#include <qdebug.h>
 
#include <algorithm>
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
 
#if QT_CONFIG(timezone)
// Create default time zone using appropriate backend
static QTimeZonePrivate *newBackendTimeZone()
{
#if defined(Q_OS_DARWIN)
    return new QMacTimeZonePrivate();
#elif defined(Q_OS_ANDROID)
    return new QAndroidTimeZonePrivate();
#elif defined(Q_OS_UNIX)
    return new QTzTimeZonePrivate();
#elif QT_CONFIG(icu)
    return new QIcuTimeZonePrivate();
#elif defined(Q_OS_WIN)
    return new QWinTimeZonePrivate();
#else
    return new QUtcTimeZonePrivate();
#endif // Backend selection
}
 
// Create named time zone using appropriate backend
static QTimeZonePrivate *newBackendTimeZone(const QByteArray &ianaId)
{
    Q_ASSERT(!ianaId.isEmpty());
#if defined(Q_OS_DARWIN)
    return new QMacTimeZonePrivate(ianaId);
#elif defined(Q_OS_ANDROID)
    return new QAndroidTimeZonePrivate(ianaId);
#elif defined(Q_OS_UNIX)
    return new QTzTimeZonePrivate(ianaId);
#elif QT_CONFIG(icu)
    return new QIcuTimeZonePrivate(ianaId);
#elif defined(Q_OS_WIN)
    return new QWinTimeZonePrivate(ianaId);
#else
    return new QUtcTimeZonePrivate(ianaId);
#endif // Backend selection
}
 
class QTimeZoneSingleton
{
public:
    QTimeZoneSingleton() : backend(newBackendTimeZone()) {}
 
    // The global_tz is the tz to use in static methods such as
    // availableTimeZoneIds() and isTimeZoneIdAvailable() and to create named
    // IANA time zones. This is usually the host system, but may be different if
    // the host resources are insufficient. A simple UTC backend is used if no
    // alternative is available.
    QExplicitlySharedDataPointer<QTimeZonePrivate> backend;
};
 
Q_GLOBAL_STATIC(QTimeZoneSingleton, global_tz);
#endif // feature timezone
 
#if QT_CONFIG(timezone)
#endif // timezone backends
 
QTimeZone::Data::Data() noexcept : d(nullptr)
{
    // Assumed by the conversion between spec and mode:
    static_assert(int(Qt::TimeZone) == 3);
}
 
QTimeZone::Data::Data(const Data &other) noexcept
{
#if QT_CONFIG(timezone)
    if (!other.isShort() && other.d)
        other.d->ref.ref();
#endif
    d = other.d;
}
 
QTimeZone::Data::Data(QTimeZonePrivate *dptr) noexcept
    : d(dptr)
{
#if QT_CONFIG(timezone)
    if (d)
        d->ref.ref();
#endif
}
 
QTimeZone::Data::~Data()
{
#if QT_CONFIG(timezone)
    if (!isShort() && d && !d->ref.deref())
        delete d;
    d = nullptr;
#endif
}
 
QTimeZone::Data &QTimeZone::Data::operator=(const QTimeZone::Data &other) noexcept
{
#if QT_CONFIG(timezone)
    if (!other.isShort())
        return *this = other.d;
    if (!isShort() && d && !d->ref.deref())
        delete d;
#endif
    d = other.d;
    return *this;
}
 
QTimeZone::QTimeZone() noexcept
{
    // Assumed by (at least) Data::swap() and {copy,move} {assign,construct}:
    static_assert(sizeof(ShortData) <= sizeof(Data::d));
    // Needed for ShortData::offset to represent all valid offsets:
    static_assert(qintptr(1) << (sizeof(void *) * 8 - 2) >= MaxUtcOffsetSecs);
}
 
#if QT_CONFIG(timezone)
QTimeZone::Data &QTimeZone::Data::operator=(QTimeZonePrivate *dptr) noexcept
{
    if (!isShort()) {
        if (d == dptr)
            return *this;
        if (d && !d->ref.deref())
            delete d;
    }
    if (dptr)
        dptr->ref.ref();
    d = dptr;
    Q_ASSERT(!isShort());
    return *this;
}
 
QTimeZone::QTimeZone(const QByteArray &ianaId)
{
    // Try and see if it's a recognized UTC offset ID - just as quick by
    // creating as by looking up.
    d = new QUtcTimeZonePrivate(ianaId);
    // If not recognized, try creating it with the system backend.
    if (!d->isValid()) {
        if (ianaId.isEmpty())
            d = newBackendTimeZone();
        else // Constructor MUST produce invalid for unsupported ID.
            d = newBackendTimeZone(ianaId);
    }
    // Can also handle UTC with arbitrary (valid) offset, but only do so as
    // fall-back, since either of the above may handle it more informatively.
    if (!d->isValid()) {
        qint64 offset = QUtcTimeZonePrivate::offsetFromUtcString(ianaId);
        if (offset != QTimeZonePrivate::invalidSeconds()) {
            // Should have abs(offset) < 24 * 60 * 60 = 86400.
            qint32 seconds = qint32(offset);
            Q_ASSERT(qint64(seconds) == offset);
            // NB: this canonicalises the name, so it might not match ianaId
            d = new QUtcTimeZonePrivate(seconds);
        }
    }
}
 
QTimeZone::QTimeZone(int offsetSeconds)
    : d((offsetSeconds >= MinUtcOffsetSecs && offsetSeconds <= MaxUtcOffsetSecs)
        ? new QUtcTimeZonePrivate(offsetSeconds) : nullptr)
{
}
 
QTimeZone::QTimeZone(const QByteArray &zoneId, int offsetSeconds, const QString &name,
                     const QString &abbreviation, QLocale::Territory territory, const QString &comment)
    : d(QUtcTimeZonePrivate().isTimeZoneIdAvailable(zoneId)
        || global_tz->backend->isTimeZoneIdAvailable(zoneId)
        ? nullptr // Don't let client code hijack a real zone name.
        : new QUtcTimeZonePrivate(zoneId, offsetSeconds, name, abbreviation, territory, comment))
{
}
 
QTimeZone::QTimeZone(QTimeZonePrivate &dd)
    : d(&dd)
{
}
 
QTimeZone QTimeZone::asBackendZone() const
{
    switch (timeSpec()) {
    case Qt::TimeZone:
        return *this;
    case Qt::LocalTime:
        return systemTimeZone();
    case Qt::UTC:
        return utc();
    case Qt::OffsetFromUTC:
        return QTimeZone(*new QUtcTimeZonePrivate(int(d.s.offset)));
    }
    return QTimeZone();
}
#endif // timezone backends
 
QTimeZone::QTimeZone(const QTimeZone &other) noexcept
    : d(other.d)
{
}
 
QTimeZone::~QTimeZone()
{
}
 
QTimeZone &QTimeZone::operator=(const QTimeZone &other)
{
    d = other.d;
    return *this;
}
 
bool comparesEqual(const QTimeZone &lhs, const QTimeZone &rhs) noexcept
{
    if (lhs.d.isShort())
        return rhs.d.isShort() && lhs.d.s == rhs.d.s;
 
    if (!rhs.d.isShort()) {
        if (lhs.d.d == rhs.d.d)
            return true;
#if QT_CONFIG(timezone)
        return lhs.d.d && rhs.d.d && *lhs.d.d == *rhs.d.d;
#endif
    }
 
    return false;
}
 
bool QTimeZone::isValid() const
{
#if QT_CONFIG(timezone)
    if (!d.isShort())
        return d.d && d->isValid();
#endif
    return d.isShort();
}
 
#if QT_CONFIG(timezone)
QByteArray QTimeZone::id() const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::UTC:
            return QTimeZonePrivate::utcQByteArray();
        case Qt::LocalTime:
            return systemTimeZoneId();
        case Qt::OffsetFromUTC:
            return QUtcTimeZonePrivate(d.s.offset).id();
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (d.d) {
        return d->id();
    }
    return QByteArray();
}
 
QLocale::Territory QTimeZone::territory() const
{
    if (d.isShort()) {
        if (d.s.spec() == Qt::LocalTime)
            return systemTimeZone().territory();
    } else if (isValid()) {
        return d->territory();
    }
    return QLocale::AnyTerritory;
}
 
#if QT_DEPRECATED_SINCE(6, 6)
QLocale::Country QTimeZone::country() const
{
    return territory();
}
#endif
 
QString QTimeZone::comment() const
{
    if (d.isShort()) {
        // TODO: anything ?  Or just stick with empty string ?
    } else if (isValid()) {
        return d->comment();
    }
    return QString();
}
 
QString QTimeZone::displayName(const QDateTime &atDateTime, NameType nameType,
                               const QLocale &locale) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().displayName(atDateTime, nameType, locale);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return QUtcTimeZonePrivate(d.s.offset).displayName(
                atDateTime.toMSecsSinceEpoch(), nameType, locale);
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (isValid()) {
        return d->displayName(atDateTime.toMSecsSinceEpoch(), nameType, locale);
    }
 
    return QString();
}
 
QString QTimeZone::displayName(TimeType timeType, NameType nameType,
                               const QLocale &locale) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().displayName(timeType, nameType, locale);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return QUtcTimeZonePrivate(d.s.offset).displayName(timeType, nameType, locale);
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (isValid()) {
        return d->displayName(timeType, nameType, locale);
    }
 
    return QString();
}
 
QString QTimeZone::abbreviation(const QDateTime &atDateTime) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().abbreviation(atDateTime);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return QUtcTimeZonePrivate(d.s.offset).abbreviation(atDateTime.toMSecsSinceEpoch());
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (isValid()) {
        return d->abbreviation(atDateTime.toMSecsSinceEpoch());
    }
 
    return QString();
}
 
int QTimeZone::offsetFromUtc(const QDateTime &atDateTime) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().offsetFromUtc(atDateTime);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return d.s.offset;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (isValid()) {
        const int offset = d->offsetFromUtc(atDateTime.toMSecsSinceEpoch());
        if (offset !=  QTimeZonePrivate::invalidSeconds())
            return offset;
    }
    return 0;
}
 
int QTimeZone::standardTimeOffset(const QDateTime &atDateTime) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().standardTimeOffset(atDateTime);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return d.s.offset;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (isValid()) {
        const int offset = d->standardTimeOffset(atDateTime.toMSecsSinceEpoch());
        if (offset !=  QTimeZonePrivate::invalidSeconds())
            return offset;
    }
    return 0;
}
 
int QTimeZone::daylightTimeOffset(const QDateTime &atDateTime) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().daylightTimeOffset(atDateTime);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return 0;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (hasDaylightTime()) {
        const int offset = d->daylightTimeOffset(atDateTime.toMSecsSinceEpoch());
        if (offset !=  QTimeZonePrivate::invalidSeconds())
            return offset;
    }
    return 0;
}
 
bool QTimeZone::hasDaylightTime() const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().hasDaylightTime();
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return false;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (isValid()) {
        return d->hasDaylightTime();
    }
    return false;
}
 
bool QTimeZone::isDaylightTime(const QDateTime &atDateTime) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().isDaylightTime(atDateTime);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return false;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (hasDaylightTime()) {
        return d->isDaylightTime(atDateTime.toMSecsSinceEpoch());
    }
    return false;
}
 
QTimeZone::OffsetData QTimeZone::offsetData(const QDateTime &forDateTime) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().offsetData(forDateTime);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return { abbreviation(forDateTime), forDateTime, int(d.s.offset), int(d.s.offset), 0 };
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    }
    if (isValid())
        return QTimeZonePrivate::toOffsetData(d->data(forDateTime.toMSecsSinceEpoch()));
 
    return QTimeZonePrivate::invalidOffsetData();
}
 
bool QTimeZone::hasTransitions() const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().hasTransitions();
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            return false;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (isValid()) {
        return d->hasTransitions();
    }
    return false;
}
 
QTimeZone::OffsetData QTimeZone::nextTransition(const QDateTime &afterDateTime) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().nextTransition(afterDateTime);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            break;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (hasTransitions()) {
        return QTimeZonePrivate::toOffsetData(d->nextTransition(afterDateTime.toMSecsSinceEpoch()));
    }
 
    return QTimeZonePrivate::invalidOffsetData();
}
 
QTimeZone::OffsetData QTimeZone::previousTransition(const QDateTime &beforeDateTime) const
{
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().previousTransition(beforeDateTime);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            break;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (hasTransitions()) {
        return QTimeZonePrivate::toOffsetData(
            d->previousTransition(beforeDateTime.toMSecsSinceEpoch()));
    }
 
    return QTimeZonePrivate::invalidOffsetData();
}
 
QTimeZone::OffsetDataList QTimeZone::transitions(const QDateTime &fromDateTime,
                                                 const QDateTime &toDateTime) const
{
    OffsetDataList list;
    if (d.isShort()) {
        switch (d.s.spec()) {
        case Qt::LocalTime:
            return systemTimeZone().transitions(fromDateTime, toDateTime);
        case Qt::UTC:
        case Qt::OffsetFromUTC:
            break;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
    } else if (hasTransitions()) {
        const QTimeZonePrivate::DataList plist = d->transitions(fromDateTime.toMSecsSinceEpoch(),
                                                                toDateTime.toMSecsSinceEpoch());
        list.reserve(plist.size());
        for (const QTimeZonePrivate::Data &pdata : plist)
            list.append(QTimeZonePrivate::toOffsetData(pdata));
    }
    return list;
}
 
// Static methods
 
QByteArray QTimeZone::systemTimeZoneId()
{
    QByteArray sys = global_tz->backend->systemTimeZoneId();
    if (!sys.isEmpty())
        return sys;
    // The system zone, despite the empty ID, may know its real ID anyway:
    return systemTimeZone().id();
}
 
QTimeZone QTimeZone::systemTimeZone()
{
    // Use ID even if empty, as default constructor is invalid but empty-ID
    // constructor goes to backend's default constructor, which may succeed.
    const auto sys = QTimeZone(global_tz->backend->systemTimeZoneId());
    if (!sys.isValid()) {
        static bool neverWarned = true;
        if (neverWarned) {
            // Racey but, at worst, merely repeats the warning.
            neverWarned = false;
            qWarning("Unable to determine system time zone: "
                     "please check your system configuration.");
        }
    }
    return sys;
}
 
QTimeZone QTimeZone::utc()
{
    return QTimeZone(QTimeZonePrivate::utcQByteArray());
}
 
bool QTimeZone::isTimeZoneIdAvailable(const QByteArray &ianaId)
{
#if defined(Q_OS_UNIX) && !(defined(Q_OS_ANDROID) || defined(Q_OS_DARWIN))
    // Keep #if-ery consistent with selection of QTzTimeZonePrivate in
    // newBackendTimeZone(). Skip the pre-check, as the TZ backend accepts POSIX
    // zone IDs, which need not be valid IANA IDs. See also QTBUG-112006.
#else
    // isValidId is not strictly required, but faster to weed out invalid
    // IDs as availableTimeZoneIds() may be slow
    if (!QTimeZonePrivate::isValidId(ianaId))
        return false;
#endif
    return QUtcTimeZonePrivate().isTimeZoneIdAvailable(ianaId)
        || QUtcTimeZonePrivate::offsetFromUtcString(ianaId) != QTimeZonePrivate::invalidSeconds()
        || global_tz->backend->isTimeZoneIdAvailable(ianaId);
}
 
static QList<QByteArray> set_union(const QList<QByteArray> &l1, const QList<QByteArray> &l2)
{
    QList<QByteArray> result;
    result.reserve(l1.size() + l2.size());
    std::set_union(l1.begin(), l1.end(),
                   l2.begin(), l2.end(),
                   std::back_inserter(result));
    return result;
}
 
QList<QByteArray> QTimeZone::availableTimeZoneIds()
{
    return set_union(QUtcTimeZonePrivate().availableTimeZoneIds(),
                     global_tz->backend->availableTimeZoneIds());
}
 
QList<QByteArray> QTimeZone::availableTimeZoneIds(QLocale::Territory territory)
{
    return set_union(QUtcTimeZonePrivate().availableTimeZoneIds(territory),
                     global_tz->backend->availableTimeZoneIds(territory));
}
 
QList<QByteArray> QTimeZone::availableTimeZoneIds(int offsetSeconds)
{
    return set_union(QUtcTimeZonePrivate().availableTimeZoneIds(offsetSeconds),
                     global_tz->backend->availableTimeZoneIds(offsetSeconds));
}
 
QByteArray QTimeZone::ianaIdToWindowsId(const QByteArray &ianaId)
{
    return QTimeZonePrivate::ianaIdToWindowsId(ianaId);
}
 
QByteArray QTimeZone::windowsIdToDefaultIanaId(const QByteArray &windowsId)
{
    return QTimeZonePrivate::windowsIdToDefaultIanaId(windowsId);
}
 
QByteArray QTimeZone::windowsIdToDefaultIanaId(const QByteArray &windowsId,
                                               QLocale::Territory territory)
{
    return QTimeZonePrivate::windowsIdToDefaultIanaId(windowsId, territory);
}
 
QList<QByteArray> QTimeZone::windowsIdToIanaIds(const QByteArray &windowsId)
{
    return QTimeZonePrivate::windowsIdToIanaIds(windowsId);
}
 
QList<QByteArray> QTimeZone::windowsIdToIanaIds(const QByteArray &windowsId,
                                                QLocale::Territory territory)
{
    return QTimeZonePrivate::windowsIdToIanaIds(windowsId, territory);
}
 
#endif // feature timezone
 
template <typename Stream, typename Wrap>
void QTimeZone::Data::serialize(Stream &out, const Wrap &wrap) const
{
    if (isShort()) {
        switch (s.spec()) {
        case Qt::UTC:
            out << wrap("QTimeZone::UTC");
            break;
        case Qt::LocalTime:
            out << wrap("QTimeZone::LocalTime");
            break;
        case Qt::OffsetFromUTC:
            out << wrap("AheadOfUtcBy") << int(s.offset);
            break;
        case Qt::TimeZone:
            Q_UNREACHABLE();
            break;
        }
        return;
    }
#if QT_CONFIG(timezone)
    if constexpr (std::is_same<Stream, QDataStream>::value) {
        if (d)
            d->serialize(out);
    } else {
        // QDebug, traditionally gets a QString, hence quotes round the (possibly empty) ID:
        out << QString::fromUtf8(d ? QByteArrayView(d->id()) : QByteArrayView());
    }
#endif
}
 
#ifndef QT_NO_DATASTREAM
// Invalid, as an IANA ID: too long, starts with - and has other invalid characters in it
static inline QString invalidId() { return QStringLiteral("-No Time Zone Specified!"); }
 
QDataStream &operator<<(QDataStream &ds, const QTimeZone &tz)
{
    const auto toQString = [](const char *text) {
        return QString(QLatin1StringView(text));
    };
    if (tz.isValid())
        tz.d.serialize(ds, toQString);
    else
        ds << invalidId();
    return ds;
}
 
QDataStream &operator>>(QDataStream &ds, QTimeZone &tz)
{
    QString ianaId;
    ds >> ianaId;
    // That may be various things other than actual IANA IDs:
    if (ianaId == invalidId()) {
        tz = QTimeZone();
    } else if (ianaId == "OffsetFromUtc"_L1) {
        int utcOffset;
        QString name;
        QString abbreviation;
        int territory;
        QString comment;
        ds >> ianaId >> utcOffset >> name >> abbreviation >> territory >> comment;
#if QT_CONFIG(timezone)
        // Try creating as a system timezone, which succeeds (producing a valid
        // zone) iff ianaId is valid; use this if it is a plain offset from UTC
        // zone, with the right offset, ignoring the other data:
        tz = QTimeZone(ianaId.toUtf8());
        if (!tz.isValid() || tz.hasDaylightTime()
            || tz.offsetFromUtc(QDateTime::fromMSecsSinceEpoch(0, QTimeZone::UTC)) != utcOffset) {
            // Construct a custom timezone using the saved values:
            tz = QTimeZone(ianaId.toUtf8(), utcOffset, name, abbreviation,
                           QLocale::Territory(territory), comment);
        }
#else
        tz = QTimeZone::fromSecondsAheadOfUtc(utcOffset);
#endif
    } else if (ianaId == "AheadOfUtcBy"_L1) {
        int utcOffset;
        ds >> utcOffset;
        tz = QTimeZone::fromSecondsAheadOfUtc(utcOffset);
    } else if (ianaId == "QTimeZone::UTC"_L1) {
        tz = QTimeZone(QTimeZone::UTC);
    } else if (ianaId == "QTimeZone::LocalTime"_L1) {
        tz = QTimeZone(QTimeZone::LocalTime);
#if QT_CONFIG(timezone)
    } else {
        tz = QTimeZone(ianaId.toUtf8());
#endif
    }
    return ds;
}
#endif // QT_NO_DATASTREAM
 
#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug dbg, const QTimeZone &tz)
{
    QDebugStateSaver saver(dbg);
    const auto asIs = [](const char *text) { return text; };
    // TODO Include backend and data version details?
    dbg.nospace() << "QTimeZone(";
    tz.d.serialize(dbg, asIs);
    dbg.nospace() << ')';
    return dbg;
}
#endif
 
QT_END_NAMESPACE