Split cborstream feature in two

Reading of Cbor streams is substantially more complicated than writing
as it requires float16 support. When writing Cbor, we can just choose to
always write 32bit floats, even if we could compress the numbers into
16 bits.

We need Cbor writing in the bootstrap library, but we cannot easily add
float16 support.

Furthermore, Cbor reading is required for plugin support, but not Cbor
writing. It might make sense for some users to build a custom Qt with
Cbor writing disabled.

Therefore, provide two features, cborstreamreader and cborstreamwriter,
split up the code in cborstream.{h|cpp} into several files, and enable
Cbor writing in the bootstrap library.

Change-Id: I15450afb0e328a84a22ebca9379cffc4f900a75a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

11 files changed, 1685 insertions, 1362 deletions

diff --git a/src/corelib/serialization/qcborcommon.cpp b/src/corelib/serialization/qcborcommon.cpp
new file mode 100644
index 0000000000..37fb198744
--- /dev/null
+++ b/src/corelib/serialization/qcborcommon.cpp
@@ -0,0 +1,328 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Intel Corporation.
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** 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
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#define CBOR_NO_ENCODER_API
+#define CBOR_NO_PARSER_API
+#include "qcborcommon_p.h"
+
+#include <QtCore/qdatastream.h>
+
+QT_BEGIN_NAMESPACE
+
+#include <cborerrorstrings.c>
+
+/*!
+   \headerfile <QtCborCommon>
+
+   \brief The <QtCborCommon> header contains definitions common to both the
+   streaming classes (QCborStreamReader and QCborStreamWriter) and to
+   QCborValue.
+ */
+
+/*!
+   \enum QCborSimpleType
+   \relates <QtCborCommon>
+
+   This enum contains the possible "Simple Types" for CBOR. Simple Types range
+   from 0 to 255 and are types that carry no further value.
+
+   The following values are currently known:
+
+   \value False             A "false" boolean.
+   \value True              A "true" boolean.
+   \value Null              Absence of value (null).
+   \value Undefined         Missing or deleted value, usually an error.
+
+   Qt CBOR API supports encoding and decoding any Simple Type, whether one of
+   those above or any other value.
+
+   Applications should only use further values if a corresponding specification
+   has been published, otherwise interpretation and validation by the remote
+   may fail. Values 24 to 31 are reserved and must not be used.
+
+   The current authoritative list is maintained by IANA in the
+   \l{https://www.iana.org/assignments/cbor-simple-values/cbor-simple-values.xml}{Simple
+   Values registry}.
+
+   \sa QCborStreamWriter::append(QCborSimpleType), QCborStreamReader::isSimpleType(),
+       QCborStreamReader::toSimpleType(), QCborValue::isSimpleType(), QCborValue::toSimpleType()
+ */
+
+#if !defined(QT_NO_DATASTREAM)
+QDataStream &operator<<(QDataStream &ds, QCborSimpleType st)
+{
+    return ds << quint8(st);
+}
+
+QDataStream &operator>>(QDataStream &ds, QCborSimpleType &st)
+{
+    quint8 v;
+    ds >> v;
+    st = QCborSimpleType(v);
+    return ds;
+}
+#endif
+
+/*!
+   \enum QCborTag
+   \relates <QtCborCommon>
+
+   This enum contains no enumeration and is used only to provide type-safe
+   access to a CBOR tag.
+
+   CBOR tags are 64-bit numbers that are attached to generic CBOR types to
+   provide further semantic meaning. QCborTag may be constructed from an
+   enumeration found in QCborKnownTags or directly by providing the numeric
+   representation.
+
+   For example, the following creates a QCborValue containing a byte array
+   tagged with a tag 2.
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 0
+
+   \sa QCborKnownTags, QCborStreamWriter::append(QCborTag),
+       QCborStreamReader::isTag(), QCborStreamReader::toTag(),
+       QCborValue::isTag(), QCborValue::tag()
+ */
+
+/*!
+   \enum QCborKnownTags
+   \relates <QtCborCommon>
+
+   This enum contains a list of CBOR tags, known at the time of the Qt
+   implementation. This list is not meant to be complete and contains only
+   tags that are either backed by an RFC or specifically used by the Qt
+   implementation.
+
+   The authoritative list is maintained by IANA in the
+   \l{https://www.iana.org/assignments/cbor-tags/cbor-tags.xhtml}{CBOR tag
+   registry}.
+
+   \value DateTimeString        A date and time string, formatted according to RFC 3339, as refined
+                                by RFC 4287. It is the same format as Qt::ISODate and
+                                Qt::ISODateWithMs.
+   \value UnixTime_t            A numerical representation of seconds elapsed since
+                                1970-01-01T00:00Z.
+   \value PositiveBignum        A positive number of arbitrary length, encoded as a byte array in
+                                network byte order. For example, the number 2\sup{64} is represented by
+                                a byte array containing the byte value 0x01 followed by 8 zero bytes.
+   \value NegativeBignum        A negative number of arbirary length, encoded as the absolute value
+                                of that number, minus one. For example, a byte array containing
+                                byte value 0x02 followed by 8 zero bytes represents the number
+                                -2\sup{65} - 1.
+   \value Decimal               A decimal fraction, encoded as an array of two integers: the first
+                                is the exponent of the power of 10, the second the integral
+                                mantissa. The value 273.15 would be encoded as array \c{[-2, 27315]}.
+   \value Bigfloat              Similar to Decimal, but the exponent is a power of 2 instead.
+   \value COSE_Encrypt0         An \c Encrypt0 map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
+                                (CBOR Object Signing and Encryption).
+   \value COSE_Mac0             A \c Mac0 map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
+                                (CBOR Object Signing and Encryption).
+   \value COSE_Sign1            A \c Sign1 map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
+                                (CBOR Object Signing and Encryption).
+   \value ExpectedBase64url     Indicates that the byte array should be encoded using Base64url
+                                if the stream is converted to JSON.
+   \value ExpectedBase64        Indicates that the byte array should be encoded using Base64
+                                if the stream is converted to JSON.
+   \value ExpectedBase16        Indicates that the byte array should be encoded using Base16 (hex)
+                                if the stream is converted to JSON.
+   \value EncodedCbor           Indicates that the byte array contains a CBOR stream.
+   \value Url                   Indicates that the string contains a URL.
+   \value Base64url             Indicates that the string contains data encoded using Base64url.
+   \value Base64                Indicates that the string contains data encoded using Base64.
+   \value RegularExpression     Indicates that the string contains a Perl-Compatible Regular
+                                Expression pattern.
+   \value MimeMessage           Indicates that the string contains a MIME message (according to
+                                \l{https://tools.ietf.org/html/rfc2045}){RFC 2045}.
+   \value Uuid                  Indicates that the byte array contains a UUID.
+   \value COSE_Encrypt          An \c Encrypt map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
+                                (CBOR Object Signing and Encryption).
+   \value COSE_Mac              A \c Mac map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
+                                (CBOR Object Signing and Encryption).
+   \value COSE_Sign             A \c Sign map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
+                                (CBOR Object Signing and Encryption).
+   \value Signature             No change in interpretation; this tag can be used as the outermost
+                                tag in a CBOR stream as the file header.
+
+   The following tags are interpreted by QCborValue during decoding and will
+   produce objects with extended Qt types, and it will use those tags when
+   encoding the same extended types.
+
+   \value DateTimeString        \l QDateTime
+   \value UnixTime_t            \l QDateTime (only in decoding)
+   \value Url                   \l QUrl
+   \value Uuid                  \l QUuid
+
+   Additionally, if a QCborValue containing a QByteArray is tagged using one of
+   \c ExpectedBase64url, \c ExpectedBase64 or \c ExpectedBase16, QCborValue
+   will use the expected encoding when converting to JSON (see
+   QCborValue::toJsonValue).
+
+   \sa QCborTag, QCborStreamWriter::append(QCborTag),
+       QCborStreamReader::isTag(), QCborStreamReader::toTag(),
+       QCborValue::isTag(), QCborValue::tag()
+ */
+
+/*!
+   \class QCborError
+   \inmodule QtCore
+   \relates <QtCborCommon>
+   \reentrant
+   \since 5.12
+
+   \brief The QCborError class holds the error condition found while parsing or
+   validating a CBOR stream.
+
+   \sa QCborStreamReader, QCborValue, QCborParserError
+ */
+
+/*!
+   \enum QCborError::Code
+
+   This enum contains the possible error condition codes.
+
+   \value NoError           No error was detected.
+   \value UnknownError      An unknown error occurred and no further details are available.
+   \value AdvancePastEnd    QCborStreamReader::next() was called but there are no more elements in
+                            the current context.
+   \value InputOutputError  An I/O error with the QIODevice occurred.
+   \value GarbageAtEnd      Data was found in the input stream after the last element.
+   \value EndOfFile         The end of the input stream was unexpectedly reached while processing an
+                            element.
+   \value UnexpectedBreak   The CBOR stream contains a Break where it is not allowed (data is
+                            corrupt and the error is not recoverable).
+   \value UnknownType       The CBOR stream contains an unknown/unparseable Type (data is corrupt
+                            and the and the error is not recoverable).
+   \value IllegalType       The CBOR stream contains a known type in a position it is not allowed
+                            to exist (data is corrupt and the error is not recoverable).
+   \value IllegalNumber     The CBOR stream appears to be encoding a number larger than 64-bit
+                            (data is corrupt and the error is not recoverable).
+   \value IllegalSimpleType The CBOR stream contains a Simple Type encoded incorrectly (data is
+                            corrupt and the error is not recoverable).
+   \value InvalidUtf8String The CBOR stream contains a text string that does not decode properly
+                            as UTF-8 (data is corrupt and the error is not recoverable).
+   \value DataTooLarge      CBOR string, map or array is too big and cannot be parsed by Qt
+                            (internal limitation, but the error is not recoverable).
+   \value NestingTooDeep    Too many levels of arrays or maps encountered while processing the
+                            input (internal limitation, but the error is not recoverable).
+   \value UnsupportedType   The CBOR stream contains a known type that the implementation does not
+                            support (internal limitation, but the error is not recoverable).
+ */
+
+/*!
+   \variable QCborError::c
+   \internal
+ */
+
+/*!
+   \fn QCborError::operator Code() const
+
+   Returns the error code that this QCborError object stores.
+ */
+
+/*!
+   Returns a text string that matches the error code in this QCborError object.
+
+   Note: the string is not translated. Applications whose interface allow users
+   to parse CBOR streams need to provide their own, translated strings.
+
+   \sa QCborError::Code
+ */
+QString QCborError::toString() const
+{
+    switch (c) {
+    case NoError:
+        Q_STATIC_ASSERT(int(NoError) == int(CborNoError));
+        return QString();
+
+    case UnknownError:
+        Q_STATIC_ASSERT(int(UnknownError) == int(CborUnknownError));
+        return QStringLiteral("Unknown error");
+    case AdvancePastEnd:
+        Q_STATIC_ASSERT(int(AdvancePastEnd) == int(CborErrorAdvancePastEOF));
+        return QStringLiteral("Read past end of buffer (more bytes needed)");
+    case InputOutputError:
+        Q_STATIC_ASSERT(int(InputOutputError) == int(CborErrorIO));
+        return QStringLiteral("Input/Output error");
+    case GarbageAtEnd:
+        Q_STATIC_ASSERT(int(GarbageAtEnd) == int(CborErrorGarbageAtEnd));
+        return QStringLiteral("Data found after the end of the stream");
+    case EndOfFile:
+        Q_STATIC_ASSERT(int(EndOfFile) == int(CborErrorUnexpectedEOF));
+        return QStringLiteral("Unexpected end of input data (more bytes needed)");
+    case UnexpectedBreak:
+        Q_STATIC_ASSERT(int(UnexpectedBreak) == int(CborErrorUnexpectedBreak));
+        return QStringLiteral("Invalid CBOR stream: unexpected 'break' byte");
+    case UnknownType:
+        Q_STATIC_ASSERT(int(UnknownType) == int(CborErrorUnknownType));
+        return QStringLiteral("Invalid CBOR stream: unknown type");
+    case IllegalType:
+        Q_STATIC_ASSERT(int(IllegalType) == int(CborErrorIllegalType));
+        return QStringLiteral("Invalid CBOR stream: illegal type found");
+    case IllegalNumber:
+        Q_STATIC_ASSERT(int(IllegalNumber) == int(CborErrorIllegalNumber));
+        return QStringLiteral("Invalid CBOR stream: illegal number encoding (future extension)");
+    case IllegalSimpleType:
+        Q_STATIC_ASSERT(int(IllegalSimpleType) == int(CborErrorIllegalSimpleType));
+        return QStringLiteral("Invalid CBOR stream: illegal simple type");
+    case InvalidUtf8String:
+        Q_STATIC_ASSERT(int(InvalidUtf8String) == int(CborErrorInvalidUtf8TextString));
+        return QStringLiteral("Invalid CBOR stream: invalid UTF-8 text string");
+    case DataTooLarge:
+        Q_STATIC_ASSERT(int(DataTooLarge) == int(CborErrorDataTooLarge));
+        return QStringLiteral("Internal limitation: data set too large");
+    case NestingTooDeep:
+        Q_STATIC_ASSERT(int(NestingTooDeep) == int(CborErrorNestingTooDeep));
+        return QStringLiteral("Internal limitation: data nesting too deep");
+    case UnsupportedType:
+        Q_STATIC_ASSERT(int(UnsupportedType) == int(CborErrorUnsupportedType));
+        return QStringLiteral("Internal limitation: unsupported type");
+    }
+
+    // get the error string from TinyCBOR
+    CborError err = CborError(int(c));
+    return QString::fromLatin1(cbor_error_string(err));
+}
+
+QT_END_NAMESPACE
+
+#ifndef QT_BOOTSTRAPPED
+#include "moc_qcborcommon.cpp"
+#endif
diff --git a/src/corelib/serialization/qcborcommon.h b/src/corelib/serialization/qcborcommon.h
index 3dfe50cd09..bec46399ce 100644
--- a/src/corelib/serialization/qcborcommon.h
+++ b/src/corelib/serialization/qcborcommon.h
@@ -148,6 +148,8 @@ inline uint qHash(QCborTag tag, uint seed = 0)
     return qHash(quint64(tag), seed);
 }
 
+enum class QCborNegativeInteger : quint64 {};
+
 QT_END_NAMESPACE
 
 Q_DECLARE_METATYPE(QCborTag)
diff --git a/src/corelib/serialization/qcborcommon_p.h b/src/corelib/serialization/qcborcommon_p.h
new file mode 100644
index 0000000000..9b7f4b7099
--- /dev/null
+++ b/src/corelib/serialization/qcborcommon_p.h
@@ -0,0 +1,84 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Intel Corporation.
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** 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
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QCBORCOMMON_P_H
+#define QCBORCOMMON_P_H
+
+#include "qcborcommon.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.
+//
+
+QT_BEGIN_NAMESPACE
+
+#ifdef QT_NO_DEBUG
+#  define NDEBUG 1
+#endif
+#undef assert
+#define assert Q_ASSERT
+
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_GCC("-Wunused-function")
+QT_WARNING_DISABLE_CLANG("-Wunused-function")
+QT_WARNING_DISABLE_CLANG("-Wundefined-internal")
+
+#define CBOR_NO_VALIDATION_API  1
+#define CBOR_NO_PRETTY_API      1
+#define CBOR_API static inline
+#define CBOR_PRIVATE_API static inline
+#define CBOR_INLINE_API static inline
+
+#include <cbor.h>
+
+QT_WARNING_POP
+
+Q_DECLARE_TYPEINFO(CborValue, Q_PRIMITIVE_TYPE);
+
+QT_END_NAMESPACE
+
+#endif // QCBORCOMMON_P_H
diff --git a/src/corelib/serialization/qcborstream.h b/src/corelib/serialization/qcborstream.h
index 08bf680cca..f2b88820cd 100644
--- a/src/corelib/serialization/qcborstream.h
+++ b/src/corelib/serialization/qcborstream.h
@@ -1,5 +1,6 @@
 /****************************************************************************
 **
+** Copyright (C) 2019 The Qt Company Ltd.
 ** Copyright (C) 2018 Intel Corporation.
 ** Contact: https://www.qt.io/licensing/
 **
@@ -40,230 +41,17 @@
 #ifndef QCBORSTREAM_H
 #define QCBORSTREAM_H
 
-#include <QtCore/qbytearray.h>
-#include <QtCore/qcborcommon.h>
-#include <QtCore/qfloat16.h>
-#include <QtCore/qscopedpointer.h>
-#include <QtCore/qstring.h>
-#include <QtCore/qstringview.h>
+#include <QtCore/qglobal.h>
 
-QT_REQUIRE_CONFIG(cborstream);
-
-// See qcborcommon.h for why we check
-#if defined(QT_X11_DEFINES_FOUND)
-#  undef True
-#  undef False
+#if QT_CONFIG(cborstreamreader)
+#include <QtCore/qcborstreamreader.h>
 #endif
 
-QT_BEGIN_NAMESPACE
-
-class QIODevice;
-
-enum class QCborNegativeInteger : quint64 {};
-
-class QCborStreamWriterPrivate;
-class Q_CORE_EXPORT QCborStreamWriter
-{
-public:
-    explicit QCborStreamWriter(QIODevice *device);
-    explicit QCborStreamWriter(QByteArray *data);
-    ~QCborStreamWriter();
-    Q_DISABLE_COPY(QCborStreamWriter)
-
-    void setDevice(QIODevice *device);
-    QIODevice *device() const;
-
-    void append(quint64 u);
-    void append(qint64 i);
-    void append(QCborNegativeInteger n);
-    void append(const QByteArray &ba)       { appendByteString(ba.constData(), ba.size()); }
-    void append(QLatin1String str);
-    void append(QStringView str);
-    void append(QCborTag tag);
-    void append(QCborKnownTags tag)         { append(QCborTag(tag)); }
-    void append(QCborSimpleType st);
-    void append(std::nullptr_t)             { append(QCborSimpleType::Null); }
-    void append(qfloat16 f);
-    void append(float f);
-    void append(double d);
-
-    void appendByteString(const char *data, qsizetype len);
-    void appendTextString(const char *utf8, qsizetype len);
-
-    // convenience
-    void append(bool b)     { append(b ? QCborSimpleType::True : QCborSimpleType::False); }
-    void appendNull()       { append(QCborSimpleType::Null); }
-    void appendUndefined()  { append(QCborSimpleType::Undefined); }
-
-#ifndef Q_QDOC
-    // overloads to make normal code not complain
-    void append(int i)      { append(qint64(i)); }
-    void append(uint u)     { append(quint64(u)); }
-#endif
-#ifndef QT_NO_CAST_FROM_ASCII
-    void append(const char *str, qsizetype size = -1)
-    { appendTextString(str, (str && size == -1)  ? int(strlen(str)) : size); }
+#if QT_CONFIG(cborstreamwriter)
+#include <QtCore/qcborstreamwriter.h>
 #endif
 
-    void startArray();
-    void startArray(quint64 count);
-    bool endArray();
-    void startMap();
-    void startMap(quint64 count);
-    bool endMap();
-
-    // no API for encoding chunked strings
-
-private:
-    QScopedPointer<QCborStreamWriterPrivate> d;
-};
-
-class QCborStreamReaderPrivate;
-class Q_CORE_EXPORT QCborStreamReader
-{
-    Q_GADGET
-public:
-    enum Type : quint8 {
-        UnsignedInteger     = 0x00,
-        NegativeInteger     = 0x20,
-        ByteString          = 0x40,
-        ByteArray           = ByteString,
-        TextString          = 0x60,
-        String              = TextString,
-        Array               = 0x80,
-        Map                 = 0xa0,
-        Tag                 = 0xc0,
-        SimpleType          = 0xe0,
-        HalfFloat           = 0xf9,
-        Float16             = HalfFloat,
-        Float               = 0xfa,
-        Double              = 0xfb,
-
-        Invalid             = 0xff
-    };
-    Q_ENUM(Type)
-
-    enum StringResultCode {
-        EndOfString = 0,
-        Ok = 1,
-        Error = -1
-    };
-    template <typename Container> struct StringResult {
-        Container data;
-        StringResultCode status = Error;
-    };
-    Q_ENUM(StringResultCode)
-
-    QCborStreamReader();
-    QCborStreamReader(const char *data, qsizetype len);
-    QCborStreamReader(const quint8 *data, qsizetype len);
-    explicit QCborStreamReader(const QByteArray &data);
-    explicit QCborStreamReader(QIODevice *device);
-    ~QCborStreamReader();
-    Q_DISABLE_COPY(QCborStreamReader)
-
-    void setDevice(QIODevice *device);
-    QIODevice *device() const;
-    void addData(const QByteArray &data);
-    void addData(const char *data, qsizetype len);
-    void addData(const quint8 *data, qsizetype len)
-    { addData(reinterpret_cast<const char *>(data), len); }
-    void reparse();
-    void clear();
-    void reset();
-
-    QCborError lastError();
-
-    qint64 currentOffset() const;
-
-    bool isValid() const        { return !isInvalid(); }
-
-    int containerDepth() const;
-    QCborStreamReader::Type parentContainerType() const;
-    bool hasNext() const noexcept Q_DECL_PURE_FUNCTION;
-    bool next(int maxRecursion = 10000);
-
-    Type type() const               { return QCborStreamReader::Type(type_); }
-    bool isUnsignedInteger() const  { return type() == UnsignedInteger; }
-    bool isNegativeInteger() const  { return type() == NegativeInteger; }
-    bool isInteger() const          { return quint8(type()) <= quint8(NegativeInteger); }
-    bool isByteArray() const        { return type() == ByteArray; }
-    bool isString() const           { return type() == String; }
-    bool isArray() const            { return type() == Array; }
-    bool isMap() const              { return type() == Map; }
-    bool isTag() const              { return type() == Tag; }
-    bool isSimpleType() const       { return type() == SimpleType; }
-    bool isFloat16() const          { return type() == Float16; }
-    bool isFloat() const            { return type() == Float; }
-    bool isDouble() const           { return type() == Double; }
-    bool isInvalid() const          { return type() == Invalid; }
-
-    bool isSimpleType(QCborSimpleType st) const { return isSimpleType() && toSimpleType() == st; }
-    bool isFalse() const            { return isSimpleType(QCborSimpleType::False); }
-    bool isTrue() const             { return isSimpleType(QCborSimpleType::True); }
-    bool isBool() const             { return isFalse() || isTrue(); }
-    bool isNull() const             { return isSimpleType(QCborSimpleType::Null); }
-    bool isUndefined() const        { return isSimpleType(QCborSimpleType::Undefined); }
-
-    bool isLengthKnown() const noexcept Q_DECL_PURE_FUNCTION;
-    quint64 length() const;
-
-    bool isContainer() const            { return isMap() || isArray(); }
-    bool enterContainer()               { Q_ASSERT(isContainer()); return _enterContainer_helper(); }
-    bool leaveContainer();
-
-    StringResult<QString> readString()      { Q_ASSERT(isString()); return _readString_helper(); }
-    StringResult<QByteArray> readByteArray(){ Q_ASSERT(isByteArray()); return _readByteArray_helper(); }
-    qsizetype currentStringChunkSize() const{ Q_ASSERT(isString() || isByteArray()); return _currentStringChunkSize(); }
-    StringResult<qsizetype> readStringChunk(char *ptr, qsizetype maxlen);
-
-    bool toBool() const                 { Q_ASSERT(isBool()); return value64 - int(QCborSimpleType::False); }
-    QCborTag toTag() const              { Q_ASSERT(isTag()); return QCborTag(value64); }
-    quint64 toUnsignedInteger() const   { Q_ASSERT(isUnsignedInteger()); return value64; }
-    QCborNegativeInteger toNegativeInteger() const { Q_ASSERT(isNegativeInteger()); return QCborNegativeInteger(value64 + 1); }
-    QCborSimpleType toSimpleType() const{ Q_ASSERT(isSimpleType()); return QCborSimpleType(value64); }
-    qfloat16 toFloat16() const          { Q_ASSERT(isFloat16()); return _toFloatingPoint<qfloat16>(); }
-    float toFloat() const               { Q_ASSERT(isFloat()); return _toFloatingPoint<float>(); }
-    double toDouble() const             { Q_ASSERT(isDouble()); return _toFloatingPoint<double>(); }
-
-    qint64 toInteger() const
-    {
-        Q_ASSERT(isInteger());
-        qint64 v = qint64(value64);
-        if (isNegativeInteger())
-            return -v - 1;
-        return v;
-    }
-
-private:
-    void preparse();
-    bool _enterContainer_helper();
-    StringResult<QString> _readString_helper();
-    StringResult<QByteArray> _readByteArray_helper();
-    qsizetype _currentStringChunkSize() const;
-
-    template <typename FP> FP _toFloatingPoint() const noexcept
-    {
-        using UIntFP = typename QIntegerForSizeof<FP>::Unsigned;
-        UIntFP u = UIntFP(value64);
-        FP f;
-        memcpy(static_cast<void *>(&f), &u, sizeof(f));
-        return f;
-    }
-
-    friend QCborStreamReaderPrivate;
-    friend class QCborContainerPrivate;
-    quint64 value64;
-    QScopedPointer<QCborStreamReaderPrivate> d;
-    quint8 type_;
-    quint8 reserved[3] = {};
-};
-
+QT_BEGIN_NAMESPACE
 QT_END_NAMESPACE
 
-#if defined(QT_X11_DEFINES_FOUND)
-#  define True  1
-#  define False 0
-#endif
-
 #endif // QCBORSTREAM_H
diff --git a/src/corelib/serialization/qcborstream.cpp b/src/corelib/serialization/qcborstreamreader.cpp
index a232f7eef7..112fc6e226 100644
--- a/src/corelib/serialization/qcborstream.cpp
+++ b/src/corelib/serialization/qcborstreamreader.cpp
@@ -37,65 +37,36 @@
 **
 ****************************************************************************/
 
-#include "qcborstream.h"
+#include "qcborstreamreader.h"
+
+#define CBOR_NO_ENCODER_API
+#include <private/qcborcommon_p.h>
 
 #include <private/qnumeric_p.h>
 #include <private/qutfcodec_p.h>
-#include <qbuffer.h>
 #include <qdebug.h>
 #include <qstack.h>
-#include <qdatastream.h>
 
 QT_BEGIN_NAMESPACE
 
-#ifdef QT_NO_DEBUG
-#  define NDEBUG 1
-#endif
-#undef assert
-#define assert Q_ASSERT
-
-QT_WARNING_PUSH
-QT_WARNING_DISABLE_GCC("-Wunused-function")
-QT_WARNING_DISABLE_CLANG("-Wunused-function")
-QT_WARNING_DISABLE_CLANG("-Wundefined-internal")
-QT_WARNING_DISABLE_MSVC(4334) // '<<': result of 32-bit shift implicitly converted to 64 bits (was 64-bit shift intended?)
-
-#define CBOR_ENCODER_NO_CHECK_USER
-
-#define CBOR_NO_VALIDATION_API  1
-#define CBOR_NO_PRETTY_API      1
-#define CBOR_API static inline
-#define CBOR_PRIVATE_API static inline
-#define CBOR_INLINE_API static inline
-
-#include <cbor.h>
-
-static CborError qt_cbor_encoder_write_callback(void *token, const void *data, size_t len, CborEncoderAppendType);
 static bool qt_cbor_decoder_can_read(void *token, size_t len);
 static void qt_cbor_decoder_advance(void *token, size_t len);
 static void *qt_cbor_decoder_read(void *token, void *userptr, size_t offset, size_t len);
 static CborError qt_cbor_decoder_transfer_string(void *token, const void **userptr, size_t offset, size_t len);
 
-#define CBOR_ENCODER_WRITER_CONTROL     1
-#define CBOR_ENCODER_WRITE_FUNCTION     qt_cbor_encoder_write_callback
-
 #define CBOR_PARSER_READER_CONTROL              1
 #define CBOR_PARSER_CAN_READ_BYTES_FUNCTION     qt_cbor_decoder_can_read
 #define CBOR_PARSER_ADVANCE_BYTES_FUNCTION      qt_cbor_decoder_advance
 #define CBOR_PARSER_TRANSFER_STRING_FUNCTION    qt_cbor_decoder_transfer_string
 #define CBOR_PARSER_READ_BYTES_FUNCTION         qt_cbor_decoder_read
 
-#include "../3rdparty/tinycbor/src/cborencoder.c"
-#include "../3rdparty/tinycbor/src/cborerrorstrings.c"
-#include "../3rdparty/tinycbor/src/cborparser.c"
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_MSVC(4334) // '<<': result of 32-bit shift implicitly converted to 64 bits (was 64-bit shift intended?)
+
+#include <cborparser.c>
+
+QT_WARNING_POP
 
-// silence compilers that complain about this being a static function declared
-// but never defined
-static CborError cbor_encoder_close_container_checked(CborEncoder*, const CborEncoder*)
-{
-    Q_UNREACHABLE();
-    return CborErrorInternalError;
-}
 static CborError _cbor_value_dup_string(const CborValue *, void **, size_t *, CborValue *)
 {
     Q_UNREACHABLE();
@@ -106,15 +77,6 @@ static CborError cbor_value_get_half_float_as_float(const CborValue *, float *)
     Q_UNREACHABLE();
     return CborErrorInternalError;
 }
-static CborError cbor_encode_float_as_half_float(CborEncoder *, float)
-{
-    Q_UNREACHABLE();
-    return CborErrorInternalError;
-}
-QT_WARNING_POP
-
-Q_DECLARE_TYPEINFO(CborEncoder, Q_PRIMITIVE_TYPE);
-Q_DECLARE_TYPEINFO(CborValue, Q_PRIMITIVE_TYPE);
 
 // confirm our constants match TinyCBOR's
 Q_STATIC_ASSERT(int(QCborStreamReader::UnsignedInteger) == CborIntegerType);
@@ -130,1083 +92,6 @@ Q_STATIC_ASSERT(int(QCborStreamReader::Double) == CborDoubleType);
 Q_STATIC_ASSERT(int(QCborStreamReader::Invalid) == CborInvalidType);
 
 /*!
-   \headerfile <QtCborCommon>
-
-   \brief The <QtCborCommon> header contains definitions common to both the
-   streaming classes (QCborStreamReader and QCborStreamWriter) and to
-   QCborValue.
- */
-
-/*!
-   \enum QCborSimpleType
-   \relates <QtCborCommon>
-
-   This enum contains the possible "Simple Types" for CBOR. Simple Types range
-   from 0 to 255 and are types that carry no further value.
-
-   The following values are currently known:
-
-   \value False             A "false" boolean.
-   \value True              A "true" boolean.
-   \value Null              Absence of value (null).
-   \value Undefined         Missing or deleted value, usually an error.
-
-   Qt CBOR API supports encoding and decoding any Simple Type, whether one of
-   those above or any other value.
-
-   Applications should only use further values if a corresponding specification
-   has been published, otherwise interpretation and validation by the remote
-   may fail. Values 24 to 31 are reserved and must not be used.
-
-   The current authoritative list is maintained by IANA in the
-   \l{https://www.iana.org/assignments/cbor-simple-values/cbor-simple-values.xml}{Simple
-   Values registry}.
-
-   \sa QCborStreamWriter::append(QCborSimpleType), QCborStreamReader::isSimpleType(),
-       QCborStreamReader::toSimpleType(), QCborValue::isSimpleType(), QCborValue::toSimpleType()
- */
-
-#if !defined(QT_NO_DATASTREAM)
-QDataStream &operator<<(QDataStream &ds, QCborSimpleType st)
-{
-    return ds << quint8(st);
-}
-
-QDataStream &operator>>(QDataStream &ds, QCborSimpleType &st)
-{
-    quint8 v;
-    ds >> v;
-    st = QCborSimpleType(v);
-    return ds;
-}
-#endif
-
-/*!
-   \enum QCborTag
-   \relates <QtCborCommon>
-
-   This enum contains no enumeration and is used only to provide type-safe
-   access to a CBOR tag.
-
-   CBOR tags are 64-bit numbers that are attached to generic CBOR types to
-   provide further semantic meaning. QCborTag may be constructed from an
-   enumeration found in QCborKnownTags or directly by providing the numeric
-   representation.
-
-   For example, the following creates a QCborValue containing a byte array
-   tagged with a tag 2.
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 0
-
-   \sa QCborKnownTags, QCborStreamWriter::append(QCborTag),
-       QCborStreamReader::isTag(), QCborStreamReader::toTag(),
-       QCborValue::isTag(), QCborValue::tag()
- */
-
-/*!
-   \enum QCborKnownTags
-   \relates <QtCborCommon>
-
-   This enum contains a list of CBOR tags, known at the time of the Qt
-   implementation. This list is not meant to be complete and contains only
-   tags that are either backed by an RFC or specifically used by the Qt
-   implementation.
-
-   The authoritative list is maintained by IANA in the
-   \l{https://www.iana.org/assignments/cbor-tags/cbor-tags.xhtml}{CBOR tag
-   registry}.
-
-   \value DateTimeString        A date and time string, formatted according to RFC 3339, as refined
-                                by RFC 4287. It is the same format as Qt::ISODate and
-                                Qt::ISODateWithMs.
-   \value UnixTime_t            A numerical representation of seconds elapsed since
-                                1970-01-01T00:00Z.
-   \value PositiveBignum        A positive number of arbitrary length, encoded as a byte array in
-                                network byte order. For example, the number 2\sup{64} is represented by
-                                a byte array containing the byte value 0x01 followed by 8 zero bytes.
-   \value NegativeBignum        A negative number of arbirary length, encoded as the absolute value
-                                of that number, minus one. For example, a byte array containing
-                                byte value 0x02 followed by 8 zero bytes represents the number
-                                -2\sup{65} - 1.
-   \value Decimal               A decimal fraction, encoded as an array of two integers: the first
-                                is the exponent of the power of 10, the second the integral
-                                mantissa. The value 273.15 would be encoded as array \c{[-2, 27315]}.
-   \value Bigfloat              Similar to Decimal, but the exponent is a power of 2 instead.
-   \value COSE_Encrypt0         An \c Encrypt0 map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
-                                (CBOR Object Signing and Encryption).
-   \value COSE_Mac0             A \c Mac0 map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
-                                (CBOR Object Signing and Encryption).
-   \value COSE_Sign1            A \c Sign1 map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
-                                (CBOR Object Signing and Encryption).
-   \value ExpectedBase64url     Indicates that the byte array should be encoded using Base64url
-                                if the stream is converted to JSON.
-   \value ExpectedBase64        Indicates that the byte array should be encoded using Base64
-                                if the stream is converted to JSON.
-   \value ExpectedBase16        Indicates that the byte array should be encoded using Base16 (hex)
-                                if the stream is converted to JSON.
-   \value EncodedCbor           Indicates that the byte array contains a CBOR stream.
-   \value Url                   Indicates that the string contains a URL.
-   \value Base64url             Indicates that the string contains data encoded using Base64url.
-   \value Base64                Indicates that the string contains data encoded using Base64.
-   \value RegularExpression     Indicates that the string contains a Perl-Compatible Regular
-                                Expression pattern.
-   \value MimeMessage           Indicates that the string contains a MIME message (according to
-                                \l{https://tools.ietf.org/html/rfc2045}){RFC 2045}.
-   \value Uuid                  Indicates that the byte array contains a UUID.
-   \value COSE_Encrypt          An \c Encrypt map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
-                                (CBOR Object Signing and Encryption).
-   \value COSE_Mac              A \c Mac map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
-                                (CBOR Object Signing and Encryption).
-   \value COSE_Sign             A \c Sign map as specified by \l{https://tools.ietf.org/html/rfc8152}{RFC 8152}
-                                (CBOR Object Signing and Encryption).
-   \value Signature             No change in interpretation; this tag can be used as the outermost
-                                tag in a CBOR stream as the file header.
-
-   The following tags are interpreted by QCborValue during decoding and will
-   produce objects with extended Qt types, and it will use those tags when
-   encoding the same extended types.
-
-   \value DateTimeString        \l QDateTime
-   \value UnixTime_t            \l QDateTime (only in decoding)
-   \value Url                   \l QUrl
-   \value Uuid                  \l QUuid
-
-   Additionally, if a QCborValue containing a QByteArray is tagged using one of
-   \c ExpectedBase64url, \c ExpectedBase64 or \c ExpectedBase16, QCborValue
-   will use the expected encoding when converting to JSON (see
-   QCborValue::toJsonValue).
-
-   \sa QCborTag, QCborStreamWriter::append(QCborTag),
-       QCborStreamReader::isTag(), QCborStreamReader::toTag(),
-       QCborValue::isTag(), QCborValue::tag()
- */
-
-/*!
-   \class QCborError
-   \inmodule QtCore
-   \relates <QtCborCommon>
-   \reentrant
-   \since 5.12
-
-   \brief The QCborError class holds the error condition found while parsing or
-   validating a CBOR stream.
-
-   \sa QCborStreamReader, QCborValue, QCborParserError
- */
-
-/*!
-   \enum QCborError::Code
-
-   This enum contains the possible error condition codes.
-
-   \value NoError           No error was detected.
-   \value UnknownError      An unknown error occurred and no further details are available.
-   \value AdvancePastEnd    QCborStreamReader::next() was called but there are no more elements in
-                            the current context.
-   \value InputOutputError  An I/O error with the QIODevice occurred.
-   \value GarbageAtEnd      Data was found in the input stream after the last element.
-   \value EndOfFile         The end of the input stream was unexpectedly reached while processing an
-                            element.
-   \value UnexpectedBreak   The CBOR stream contains a Break where it is not allowed (data is
-                            corrupt and the error is not recoverable).
-   \value UnknownType       The CBOR stream contains an unknown/unparseable Type (data is corrupt
-                            and the and the error is not recoverable).
-   \value IllegalType       The CBOR stream contains a known type in a position it is not allowed
-                            to exist (data is corrupt and the error is not recoverable).
-   \value IllegalNumber     The CBOR stream appears to be encoding a number larger than 64-bit
-                            (data is corrupt and the error is not recoverable).
-   \value IllegalSimpleType The CBOR stream contains a Simple Type encoded incorrectly (data is
-                            corrupt and the error is not recoverable).
-   \value InvalidUtf8String The CBOR stream contains a text string that does not decode properly
-                            as UTF-8 (data is corrupt and the error is not recoverable).
-   \value DataTooLarge      CBOR string, map or array is too big and cannot be parsed by Qt
-                            (internal limitation, but the error is not recoverable).
-   \value NestingTooDeep    Too many levels of arrays or maps encountered while processing the
-                            input (internal limitation, but the error is not recoverable).
-   \value UnsupportedType   The CBOR stream contains a known type that the implementation does not
-                            support (internal limitation, but the error is not recoverable).
- */
-
-// Convert from CborError to QCborError.
-//
-// Centralized in a function in case we need to make more adjustments in the
-// future.
-static QCborError fromCborError(CborError err)
-{
-    return { QCborError::Code(int(err)) };
-}
-
-// Convert to CborError from QCborError.
-//
-// Centralized in a function in case we need to make more adjustments in the
-// future.
-static CborError toCborError(QCborError c)
-{
-    return CborError(int(c.c));
-}
-
-/*!
-   \variable QCborError::c
-   \internal
- */
-
-/*!
-   \fn QCborError::operator Code() const
-
-   Returns the error code that this QCborError object stores.
- */
-
-/*!
-   Returns a text string that matches the error code in this QCborError object.
-
-   Note: the string is not translated. Applications whose interface allow users
-   to parse CBOR streams need to provide their own, translated strings.
-
-   \sa QCborError::Code
- */
-QString QCborError::toString() const
-{
-    switch (c) {
-    case NoError:
-        Q_STATIC_ASSERT(int(NoError) == int(CborNoError));
-        return QString();
-
-    case UnknownError:
-        Q_STATIC_ASSERT(int(UnknownError) == int(CborUnknownError));
-        return QStringLiteral("Unknown error");
-    case AdvancePastEnd:
-        Q_STATIC_ASSERT(int(AdvancePastEnd) == int(CborErrorAdvancePastEOF));
-        return QStringLiteral("Read past end of buffer (more bytes needed)");
-    case InputOutputError:
-        Q_STATIC_ASSERT(int(InputOutputError) == int(CborErrorIO));
-        return QStringLiteral("Input/Output error");
-    case GarbageAtEnd:
-        Q_STATIC_ASSERT(int(GarbageAtEnd) == int(CborErrorGarbageAtEnd));
-        return QStringLiteral("Data found after the end of the stream");
-    case EndOfFile:
-        Q_STATIC_ASSERT(int(EndOfFile) == int(CborErrorUnexpectedEOF));
-        return QStringLiteral("Unexpected end of input data (more bytes needed)");
-    case UnexpectedBreak:
-        Q_STATIC_ASSERT(int(UnexpectedBreak) == int(CborErrorUnexpectedBreak));
-        return QStringLiteral("Invalid CBOR stream: unexpected 'break' byte");
-    case UnknownType:
-        Q_STATIC_ASSERT(int(UnknownType) == int(CborErrorUnknownType));
-        return QStringLiteral("Invalid CBOR stream: unknown type");
-    case IllegalType:
-        Q_STATIC_ASSERT(int(IllegalType) == int(CborErrorIllegalType));
-        return QStringLiteral("Invalid CBOR stream: illegal type found");
-    case IllegalNumber:
-        Q_STATIC_ASSERT(int(IllegalNumber) == int(CborErrorIllegalNumber));
-        return QStringLiteral("Invalid CBOR stream: illegal number encoding (future extension)");
-    case IllegalSimpleType:
-        Q_STATIC_ASSERT(int(IllegalSimpleType) == int(CborErrorIllegalSimpleType));
-        return QStringLiteral("Invalid CBOR stream: illegal simple type");
-    case InvalidUtf8String:
-        Q_STATIC_ASSERT(int(InvalidUtf8String) == int(CborErrorInvalidUtf8TextString));
-        return QStringLiteral("Invalid CBOR stream: invalid UTF-8 text string");
-    case DataTooLarge:
-        Q_STATIC_ASSERT(int(DataTooLarge) == int(CborErrorDataTooLarge));
-        return QStringLiteral("Internal limitation: data set too large");
-    case NestingTooDeep:
-        Q_STATIC_ASSERT(int(NestingTooDeep) == int(CborErrorNestingTooDeep));
-        return QStringLiteral("Internal limitation: data nesting too deep");
-    case UnsupportedType:
-        Q_STATIC_ASSERT(int(UnsupportedType) == int(CborErrorUnsupportedType));
-        return QStringLiteral("Internal limitation: unsupported type");
-    }
-
-    // get the error string from TinyCBOR
-    CborError err = toCborError(*this);
-    return QString::fromLatin1(cbor_error_string(err));
-}
-
-/*!
-   \class QCborStreamWriter
-   \inmodule QtCore
-   \ingroup cbor
-   \reentrant
-   \since 5.12
-
-   \brief The QCborStreamWriter class is a simple CBOR encoder operating on a
-   one-way stream.
-
-   This class can be used to quickly encode a stream of CBOR content directly
-   to either a QByteArray or QIODevice. CBOR is the Concise Binary Object
-   Representation, a very compact form of binary data encoding that is
-   compatible with JSON. It was created by the IETF Constrained RESTful
-   Environments (CoRE) WG, which has used it in many new RFCs. It is meant to
-   be used alongside the \l{https://tools.ietf.org/html/rfc7252}{CoAP
-   protocol}.
-
-   QCborStreamWriter provides a StAX-like API, similar to that of
-   \l{QXmlStreamWriter}. It is rather low-level and requires a bit of knowledge
-   of CBOR encoding. For a simpler API, see \l{QCborValue} and especially the
-   encoding function QCborValue::toCbor().
-
-   The typical use of QCborStreamWriter is to create the object on the target
-   QByteArray or QIODevice, then call one of the append() overloads with the
-   desired type to be encoded. To create arrays and maps, QCborStreamWriter
-   provides startArray() and startMap() overloads, which must be terminated by
-   the corresponding endArray() and endMap() functions.
-
-   The following example encodes the equivalent of this JSON content:
-
-   \div{class="pre"}
-     {
-       "label": "journald",
-       "autoDetect": false,
-       "condition": "libs.journald",
-       "output": [ "privateFeature" ]
-     }
-   \enddiv
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 1
-
-   \section1 CBOR support
-
-   QCborStreamWriter supports all CBOR features required to create canonical
-   and strict streams. It implements almost all of the features specified in
-   \l {https://tools.ietf.org/html/rfc7049}{RFC 7049}.
-
-   The following table lists the CBOR features that QCborStreamWriter supports.
-
-   \table
-     \header \li Feature                        \li Support
-     \row   \li Unsigned numbers                \li Yes (full range)
-     \row   \li Negative numbers                \li Yes (full range)
-     \row   \li Byte strings                    \li Yes
-     \row   \li Text strings                    \li Yes
-     \row   \li Chunked strings                 \li No
-     \row   \li Tags                            \li Yes (arbitrary)
-     \row   \li Booleans                        \li Yes
-     \row   \li Null                            \li Yes
-     \row   \li Undefined                       \li Yes
-     \row   \li Arbitrary simple values         \li Yes
-     \row   \li Half-precision float (16-bit)   \li Yes
-     \row   \li Single-precision float (32-bit) \li Yes
-     \row   \li Double-precision float (64-bit) \li Yes
-     \row   \li Infinities and NaN floating point \li Yes
-     \row   \li Determinate-length arrays and maps \li Yes
-     \row   \li Indeterminate-length arrays and maps \li Yes
-     \row   \li Map key types other than strings and integers \li Yes (arbitrary)
-   \endtable
-
-   \section2 Canonical CBOR encoding
-
-   Canonical CBOR encoding is defined by
-   \l{https://tools.ietf.org/html/rfc7049#section-3.9}{Section 3.9 of RFC
-   7049}. Canonical encoding is not a requirement for Qt's CBOR decoding
-   functionality, but it may be required for some protocols. In particular,
-   protocols that require the ability to reproduce the same stream identically
-   may require this.
-
-   In order to be considered "canonical", a CBOR stream must meet the
-   following requirements:
-
-   \list
-     \li Integers must be as small as possible. QCborStreamWriter always
-         does this (no user action is required and it is not possible
-         to write overlong integers).
-     \li Array, map and string lengths must be as short as possible. As
-         above, QCborStreamWriter automatically does this.
-     \li Arrays, maps and strings must use explicit length. QCborStreamWriter
-         always does this for strings; for arrays and maps, be sure to call
-         startArray() and startMap() overloads with explicit length.
-     \li Keys in every map must be sorted in ascending order. QCborStreamWriter
-         offers no help in this item: the developer must ensure that before
-         calling append() for the map pairs.
-     \li Floating point values should be as small as possible. QCborStreamWriter
-         will not convert floating point values; it is up to the developer
-         to perform this check prior to calling append() (see those functions'
-         examples).
-   \endlist
-
-   \section2 Strict CBOR mode
-
-   Strict mode is defined by
-   \l{https://tools.ietf.org/html/rfc7049#section-3.10}{Section 3.10 of RFC
-   7049}. As for Canonical encoding above, QCborStreamWriter makes it possible
-   to create strict CBOR streams, but does not require them or validate that
-   the output is so.
-
-   \list
-     \li Keys in a map must be unique. QCborStreamWriter performs no validation
-         of map keys.
-     \li Tags may be required to be paired only with the correct types,
-         according to their specification. QCborStreamWriter performs no
-         validation of tag usage.
-     \li Text Strings must be properly-encoded UTF-8. QCborStreamWriter always
-         writes proper UTF-8 for strings added with append(), but performs no
-         validation for strings added with appendTextString().
-   \endlist
-
-   \section2 Invalid CBOR stream
-
-   It is also possible to misuse QCborStreamWriter and produce invalid CBOR
-   streams that will fail to be decoded by a receiver. The following actions
-   will produce invalid streams:
-
-   \list
-     \li Append a tag and not append the corresponding tagged value
-         (QCborStreamWriter produces no diagnostic).
-     \li Append too many or too few items to an array or map with explicit
-         length (endMap() and endArray() will return false and
-         QCborStreamWriter will log with qWarning()).
-   \endlist
-
-   \sa QCborStreamReader, QCborValue, QXmlStreamWriter
- */
-
-class QCborStreamWriterPrivate
-{
-public:
-    static Q_CONSTEXPR quint64 IndefiniteLength = (std::numeric_limits<quint64>::max)();
-
-    QIODevice *device;
-    CborEncoder encoder;
-    QStack<CborEncoder> containerStack;
-    bool deleteDevice = false;
-
-    QCborStreamWriterPrivate(QIODevice *device)
-        : device(device)
-    {
-        cbor_encoder_init_writer(&encoder, qt_cbor_encoder_write_callback, this);
-    }
-
-    ~QCborStreamWriterPrivate()
-    {
-        if (deleteDevice)
-            delete device;
-    }
-
-    template <typename... Args> void executeAppend(CborError (*f)(CborEncoder *, Args...), Args... args)
-    {
-        f(&encoder, std::forward<Args>(args)...);
-    }
-
-    void createContainer(CborError (*f)(CborEncoder *, CborEncoder *, size_t), quint64 len = IndefiniteLength)
-    {
-        Q_STATIC_ASSERT(size_t(IndefiniteLength) == CborIndefiniteLength);
-        if (sizeof(len) != sizeof(size_t) && len != IndefiniteLength) {
-            if (Q_UNLIKELY(len >= CborIndefiniteLength)) {
-                // TinyCBOR can't do this in 32-bit mode
-                qWarning("QCborStreamWriter: container of size %llu is too big for a 32-bit build; "
-                         "will use indeterminate length instead", len);
-                len = CborIndefiniteLength;
-            }
-        }
-
-        containerStack.push(encoder);
-        f(&containerStack.top(), &encoder, len);
-    }
-
-    bool closeContainer()
-    {
-        if (containerStack.isEmpty()) {
-            qWarning("QCborStreamWriter: closing map or array that wasn't open");
-            return false;
-        }
-
-        CborEncoder container = containerStack.pop();
-        CborError err = cbor_encoder_close_container(&container, &encoder);
-        encoder = container;
-
-        if (Q_UNLIKELY(err)) {
-            if (err == CborErrorTooFewItems)
-                qWarning("QCborStreamWriter: not enough items added to array or map");
-            else if (err == CborErrorTooManyItems)
-                qWarning("QCborStreamWriter: too many items added to array or map");
-            return false;
-        }
-
-        return true;
-    }
-};
-
-static CborError qt_cbor_encoder_write_callback(void *self, const void *data, size_t len, CborEncoderAppendType)
-{
-    auto that = static_cast<QCborStreamWriterPrivate *>(self);
-    if (!that->device)
-        return CborNoError;
-    qint64 written = that->device->write(static_cast<const char *>(data), len);
-    return (written == qsizetype(len) ? CborNoError : CborErrorIO);
-}
-
-/*!
-   Creates a QCborStreamWriter object that will write the stream to \a device.
-   The device must be opened before the first append() call is made. This
-   constructor can be used with any class that derives from QIODevice, such as
-   QFile, QProcess or QTcpSocket.
-
-   QCborStreamWriter has no buffering, so every append() call will result in
-   one or more calls to the device's \l {QIODevice::}{write()} method.
-
-   The following example writes an empty map to a file:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 2
-
-   QCborStreamWriter does not take ownership of \a device.
-
-   \sa device(), setDevice()
- */
-QCborStreamWriter::QCborStreamWriter(QIODevice *device)
-    : d(new QCborStreamWriterPrivate(device))
-{
-}
-
-/*!
-   Creates a QCborStreamWriter object that will append the stream to \a data.
-   All streaming is done immediately to the byte array, without the need for
-   flushing any buffers.
-
-   The following example writes a number to a byte array then returns
-   it.
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 3
-
-   QCborStreamWriter does not take ownership of \a data.
- */
-QCborStreamWriter::QCborStreamWriter(QByteArray *data)
-    : d(new QCborStreamWriterPrivate(new QBuffer(data)))
-{
-    d->deleteDevice = true;
-    d->device->open(QIODevice::WriteOnly | QIODevice::Unbuffered);
-}
-
-/*!
-   Destroys this QCborStreamWriter object and frees any resources associated.
-
-   QCborStreamWriter does not perform error checking to see if all required
-   items were written to the stream prior to the object being destroyed. It is
-   the programmer's responsibility to ensure that it was done.
- */
-QCborStreamWriter::~QCborStreamWriter()
-{
-}
-
-/*!
-   Replaces the device or byte array that this QCborStreamWriter object is
-   writing to with \a device.
-
-   \sa device()
- */
-void QCborStreamWriter::setDevice(QIODevice *device)
-{
-    if (d->deleteDevice)
-        delete d->device;
-    d->device = device;
-    d->deleteDevice = false;
-}
-
-/*!
-   Returns the QIODevice that this QCborStreamWriter object is writing to. The
-   device must have previously been set with either the constructor or with
-   setDevice().
-
-   If this object was created by writing to a QByteArray, this function will
-   return an internal instance of QBuffer, which is owned by QCborStreamWriter.
-
-   \sa setDevice()
- */
-QIODevice *QCborStreamWriter::device() const
-{
-    return d->device;
-}
-
-/*!
-   \overload
-
-   Appends the 64-bit unsigned value \a u to the CBOR stream, creating a CBOR
-   Unsigned Integer value. In the following example, we write the values 0,
-   2\sup{32} and \c UINT64_MAX:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 4
-
-   \sa QCborStreamReader::isUnsignedInteger(), QCborStreamReader::toUnsignedInteger()
- */
-void QCborStreamWriter::append(quint64 u)
-{
-    d->executeAppend(cbor_encode_uint, uint64_t(u));
-}
-
-/*!
-   \overload
-
-   Appends the 64-bit signed value \a i to the CBOR stream. This will create
-   either a CBOR Unsigned Integer or CBOR NegativeInteger value based on the
-   sign of the parameter. In the following example, we write the values 0, -1,
-   2\sup{32} and \c INT64_MAX:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 5
-
-   \sa QCborStreamReader::isInteger(), QCborStreamReader::toInteger()
- */
-void QCborStreamWriter::append(qint64 i)
-{
-    d->executeAppend(cbor_encode_int, int64_t(i));
-}
-
-/*!
-   \overload
-
-   Appends the 64-bit negative value \a n to the CBOR stream.
-   QCborNegativeInteger is a 64-bit enum that holds the absolute value of the
-   negative number we want to write. If n is zero, the value written will be
-   equivalent to 2\sup{64} (that is, -18,446,744,073,709,551,616).
-
-   In the following example, we write the values -1, -2\sup{32} and INT64_MIN:
-   \snippet code/src_corelib_serialization_qcborstream.cpp 6
-
-   Note how this function can be used to encode numbers that cannot fit a
-   standard computer's 64-bit signed integer like \l qint64. That is, if \a n
-   is larger than \c{std::numeric_limits<qint64>::max()} or is 0, this will
-   represent a negative number smaller than
-   \c{std::numeric_limits<qint64>::min()}.
-
-   \sa QCborStreamReader::isNegativeInteger(), QCborStreamReader::toNegativeInteger()
- */
-void QCborStreamWriter::append(QCborNegativeInteger n)
-{
-    d->executeAppend(cbor_encode_negative_int, uint64_t(n));
-}
-
-/*!
-   \fn void QCborStreamWriter::append(const QByteArray &ba)
-   \overload
-
-   Appends the byte array \a ba to the stream, creating a CBOR Byte String
-   value. QCborStreamWriter will attempt to write the entire string in one
-   chunk.
-
-   The following example will load and append the contents of a file to the
-   stream:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 7
-
-   As the example shows, unlike JSON, CBOR requires no escaping for binary
-   content.
-
-   \sa appendByteString(), QCborStreamReader::isByteArray(),
-       QCborStreamReader::readByteArray()
- */
-
-/*!
-   \overload
-
-   Appends the text string \a str to the stream, creating a CBOR Text String
-   value. QCborStreamWriter will attempt to write the entire string in one
-   chunk.
-
-   The following example appends a simple string to the stream:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 8
-
-   \b{Performance note}: CBOR requires that all Text Strings be encoded in
-   UTF-8, so this function will iterate over the characters in the string to
-   determine whether the contents are US-ASCII or not. If the string is found
-   to contain characters outside of US-ASCII, it will allocate memory and
-   convert to UTF-8. If this check is unnecessary, use appendTextString()
-   instead.
-
-   \sa QCborStreamReader::isString(), QCborStreamReader::readString()
- */
-void QCborStreamWriter::append(QLatin1String str)
-{
-    // We've got Latin-1 but CBOR wants UTF-8, so check if the string is the
-    // common subset (US-ASCII).
-    if (QtPrivate::isAscii(str)) {
-        // it is plain US-ASCII
-        appendTextString(str.latin1(), str.size());
-    } else {
-        // non-ASCII, so we need a pass-through UTF-16
-        append(QString(str));
-    }
-}
-
-/*!
-   \overload
-
-   Appends the text string \a str to the stream, creating a CBOR Text String
-   value. QCborStreamWriter will attempt to write the entire string in one
-   chunk.
-
-   The following example writes an arbitrary QString to the stream:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 9
-
-   \sa QCborStreamReader::isString(), QCborStreamReader::readString()
- */
-void QCborStreamWriter::append(QStringView str)
-{
-    QByteArray utf8 = str.toUtf8();
-    appendTextString(utf8.constData(), utf8.size());
-}
-
-/*!
-   \overload
-
-   Appends the CBOR tag \a tag to the stream, creating a CBOR Tag value. All
-   tags must be followed by another type which they provide meaning for.
-
-   In the following example, we append a CBOR Tag 36 (Regular Expression) and a
-   QRegularExpression's pattern to the stream:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 10
-
-   \sa QCborStreamReader::isTag(), QCborStreamReader::toTag()
- */
-void QCborStreamWriter::append(QCborTag tag)
-{
-    d->executeAppend(cbor_encode_tag, CborTag(tag));
-}
-
-/*!
-   \fn void QCborStreamWriter::append(QCborKnownTags tag)
-   \overload
-
-   Appends the CBOR tag \a tag to the stream, creating a CBOR Tag value. All
-   tags must be followed by another type which they provide meaning for.
-
-   In the following example, we append a CBOR Tag 1 (Unix \c time_t) and an
-   integer representing the current time to the stream, obtained using the \c
-   time() function:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 11
-
-   \sa QCborStreamReader::isTag(), QCborStreamReader::toTag()
- */
-
-/*!
-   \overload
-
-   Appends the CBOR simple type \a st to the stream, creating a CBOR Simple
-   Type value. In the following example, we write the simple type for Null as
-   well as for type 32, which Qt has no support for.
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 12
-
-   \note Using Simple Types for which there is no specification can lead to
-   validation errors by the remote receiver. In addition, simple type values 24
-   through 31 (inclusive) are reserved and must not be used.
-
-   \sa QCborStreamReader::isSimpleType(), QCborStreamReader::toSimpleType()
- */
-void QCborStreamWriter::append(QCborSimpleType st)
-{
-    d->executeAppend(cbor_encode_simple_value, uint8_t(st));
-}
-
-/*!
-   \overload
-
-   Appends the floating point number \a f to the stream, creating a CBOR 16-bit
-   Half-Precision Floating Point value. The following code can be used to convert
-   a C++ \tt float to \c qfloat16 if there's no loss of precision and append it, or
-   instead append the \tt float.
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 13
-
-   \sa QCborStreamReader::isFloat16(), QCborStreamReader::toFloat16()
- */
-void QCborStreamWriter::append(qfloat16 f)
-{
-    d->executeAppend(cbor_encode_half_float, static_cast<const void *>(&f));
-}
-
-/*!
-   \overload
-
-   Appends the floating point number \a f to the stream, creating a CBOR 32-bit
-   Single-Precision Floating Point value. The following code can be used to convert
-   a C++ \tt double to \tt float if there's no loss of precision and append it, or
-   instead append the \tt double.
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 14
-
-   \sa QCborStreamReader::isFloat(), QCborStreamReader::toFloat()
- */
-void QCborStreamWriter::append(float f)
-{
-    d->executeAppend(cbor_encode_float, f);
-}
-
-/*!
-   \overload
-
-   Appends the floating point number \a d to the stream, creating a CBOR 64-bit
-   Double-Precision Floating Point value. QCborStreamWriter always appends the
-   number as-is, performing no check for whether the number is the canonical
-   form for NaN, an infinite, whether it is denormal or if it could be written
-   with a shorter format.
-
-   The following code performs all those checks, except for the denormal one,
-   which is expected to be taken into account by the system FPU or floating
-   point emulation directly.
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 15
-
-   Determining if a double can be converted to an integral with no loss of
-   precision is left as an exercise to the reader.
-
-   \sa QCborStreamReader::isDouble(), QCborStreamReader::toDouble()
- */
-void QCborStreamWriter::append(double d)
-{
-    this->d->executeAppend(cbor_encode_double, d);
-}
-
-/*!
-   Appends \a len bytes of data starting from \a data to the stream, creating a
-   CBOR Byte String value. QCborStreamWriter will attempt to write the entire
-   string in one chunk.
-
-   Unlike the QByteArray overload of append(), this function is not limited by
-   QByteArray's size limits. However, note that neither
-   QCborStreamReader::readByteArray() nor QCborValue support reading CBOR
-   streams with byte arrays larger than 2 GB.
-
-   \sa append(), appendTextString(),
-       QCborStreamReader::isByteArray(), QCborStreamReader::readByteArray()
- */
-void QCborStreamWriter::appendByteString(const char *data, qsizetype len)
-{
-    d->executeAppend(cbor_encode_byte_string, reinterpret_cast<const uint8_t *>(data), size_t(len));
-}
-
-/*!
-   Appends \a len bytes of text starting from \a utf8 to the stream, creating a
-   CBOR Text String value. QCborStreamWriter will attempt to write the entire
-   string in one chunk.
-
-   The string pointed to by \a utf8 is expected to be properly encoded UTF-8.
-   QCborStreamWriter performs no validation that this is the case.
-
-   Unlike the QLatin1String overload of append(), this function is not limited
-   to 2 GB. However, note that neither QCborStreamReader::readString() nor
-   QCborValue support reading CBOR streams with text strings larger than 2 GB.
-
-   \sa append(QLatin1String), append(QStringView),
-       QCborStreamReader::isString(), QCborStreamReader::readString()
- */
-void QCborStreamWriter::appendTextString(const char *utf8, qsizetype len)
-{
-    d->executeAppend(cbor_encode_text_string, utf8, size_t(len));
-}
-
-/*!
-   \fn void QCborStreamWriter::append(const char *str, qsizetype size)
-   \overload
-
-   Appends \a size bytes of text starting from \a str to the stream, creating a
-   CBOR Text String value. QCborStreamWriter will attempt to write the entire
-   string in one chunk. If \a size is -1, this function will write \c strlen(\a
-   str) bytes.
-
-   The string pointed to by \a str is expected to be properly encoded UTF-8.
-   QCborStreamWriter performs no validation that this is the case.
-
-   Unlike the QLatin1String overload of append(), this function is not limited
-   to 2 GB. However, note that neither QCborStreamReader nor QCborValue support
-   reading CBOR streams with text strings larger than 2 GB.
-
-   \sa append(QLatin1String), append(QStringView),
-       QCborStreamReader::isString(), QCborStreamReader::readString()
- */
-
-/*!
-   \fn void QCborStreamWriter::append(bool b)
-   \overload
-
-   Appends the boolean value \a b to the stream, creating either a CBOR False
-   value or a CBOR True value. This function is equivalent to (and implemented
-   as):
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 16
-
-   \sa appendNull(), appendUndefined(),
-       QCborStreamReader::isBool(), QCborStreamReader::toBool()
- */
-
-/*!
-   \fn void QCborStreamWriter::append(std::nullptr_t)
-   \overload
-
-   Appends a CBOR Null value to the stream. This function is equivalent to (and
-   implemented as): The parameter is ignored.
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 17
-
-   \sa appendNull(), append(QCborSimpleType), QCborStreamReader::isNull()
- */
-
-/*!
-   \fn void QCborStreamWriter::appendNull()
-
-   Appends a CBOR Null value to the stream. This function is equivalent to (and
-   implemented as):
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 18
-
-   \sa append(std::nullptr_t), append(QCborSimpleType), QCborStreamReader::isNull()
- */
-
-/*!
-   \fn void QCborStreamWriter::appendUndefined()
-
-   Appends a CBOR Undefined value to the stream. This function is equivalent to (and
-   implemented as):
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 19
-
-   \sa append(QCborSimpleType), QCborStreamReader::isUndefined()
- */
-
-/*!
-   Starts a CBOR Array with indeterminate length in the CBOR stream. Each
-   startArray() call must be paired with one endArray() call and the current
-   CBOR element extends until the end of the array.
-
-   The array created by this function has no explicit length. Instead, its
-   length is implied by the elements contained in it. Note, however, that use
-   of indeterminate-length arrays is not compliant with canonical CBOR encoding.
-
-   The following example appends elements from the linked list of strings
-   passed as input:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 20
-
-   \sa startArray(quint64), endArray(), startMap(), QCborStreamReader::isArray(),
-   QCborStreamReader::isLengthKnown()
- */
-void QCborStreamWriter::startArray()
-{
-    d->createContainer(cbor_encoder_create_array);
-}
-
-/*!
-   \overload
-
-   Starts a CBOR Array with explicit length of \a count items in the CBOR
-   stream. Each startArray call must be paired with one endArray() call and the
-   current CBOR element extends until the end of the array.
-
-   The array created by this function has an explicit length and therefore
-   exactly \a count items must be added to the CBOR stream. Adding fewer or
-   more items will result in failure during endArray() and the CBOR stream will
-   be corrupt. However, explicit-length arrays are required by canonical CBOR
-   encoding.
-
-   The following example appends all strings found in the \l QStringList passed as input:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 21
-
-   \b{Size limitations}: The parameter to this function is quint64, which would
-   seem to allow up to 2\sup{64}-1 elements in the array. However, both
-   QCborStreamWriter and QCborStreamReader are currently limited to 2\sup{32}-2
-   items on 32-bit systems and 2\sup{64}-2 items on 64-bit ones. Also note that
-   QCborArray is currently limited to 2\sup{27} elements in any platform.
-
-   \sa startArray(), endArray(), startMap(), QCborStreamReader::isArray(),
-   QCborStreamReader::isLengthKnown()
- */
-void QCborStreamWriter::startArray(quint64 count)
-{
-    d->createContainer(cbor_encoder_create_array, count);
-}
-
-/*!
-   Terminates the array started by either overload of startArray() and returns
-   true if the correct number of elements was added to the array. This function
-   must be called for every startArray() used.
-
-   A return of false indicates error in the application and an unrecoverable
-   error in this stream. QCborStreamWriter also writes a warning using
-   qWarning() if that happens.
-
-   Calling this function when the current container is not an array is also an
-   error, though QCborStreamWriter cannot currently detect this condition.
-
-   \sa startArray(), startArray(quint64), endMap()
- */
-bool QCborStreamWriter::endArray()
-{
-    return d->closeContainer();
-}
-
-/*!
-   Starts a CBOR Map with indeterminate length in the CBOR stream. Each
-   startMap() call must be paired with one endMap() call and the current CBOR
-   element extends until the end of the map.
-
-   The map created by this function has no explicit length. Instead, its length
-   is implied by the elements contained in it. Note, however, that use of
-   indeterminate-length maps is not compliant with canonical CBOR encoding
-   (canonical encoding also requires keys to be unique and in sorted order).
-
-   The following example appends elements from the linked list of int and
-   string pairs passed as input:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 22
-
-   \sa startMap(quint64), endMap(), startArray(), QCborStreamReader::isMap(),
-       QCborStreamReader::isLengthKnown()
- */
-void QCborStreamWriter::startMap()
-{
-    d->createContainer(cbor_encoder_create_map);
-}
-
-/*!
-   \overload
-
-   Starts a CBOR Map with explicit length of \a count items in the CBOR
-   stream. Each startMap call must be paired with one endMap() call and the
-   current CBOR element extends until the end of the map.
-
-   The map created by this function has an explicit length and therefore
-   exactly \a count pairs of items must be added to the CBOR stream. Adding
-   fewer or more items will result in failure during endMap() and the CBOR
-   stream will be corrupt. However, explicit-length map are required by
-   canonical CBOR encoding.
-
-   The following example appends all strings found in the \l QMap passed as input:
-
-   \snippet code/src_corelib_serialization_qcborstream.cpp 23
-
-   \b{Size limitations}: The parameter to this function is quint64, which would
-   seem to allow up to 2\sup{64}-1 pairs in the map. However, both
-   QCborStreamWriter and QCborStreamReader are currently limited to 2\sup{31}-1
-   items on 32-bit systems and 2\sup{63}-1 items on 64-bit ones. Also note that
-   QCborMap is currently limited to 2\sup{26} elements in any platform.
-
-   \sa startMap(), endMap(), startArray(), QCborStreamReader::isMap(),
-       QCborStreamReader::isLengthKnown()
- */
-void QCborStreamWriter::startMap(quint64 count)
-{
-    d->createContainer(cbor_encoder_create_map, count);
-}
-
-/*!
-   Terminates the map started by either overload of startMap() and returns
-   true if the correct number of elements was added to the array. This function
-   must be called for every startMap() used.
-
-   A return of false indicates error in the application and an unrecoverable
-   error in this stream. QCborStreamWriter also writes a warning using
-   qWarning() if that happens.
-
-   Calling this function when the current container is not a map is also an
-   error, though QCborStreamWriter cannot currently detect this condition.
-
-   \sa startMap(), startMap(quint64), endArray()
- */
-bool QCborStreamWriter::endMap()
-{
-    return d->closeContainer();
-}
-
-/*!
    \class QCborStreamReader
    \inmodule QtCore
    \ingroup cbor
@@ -1756,7 +641,7 @@ public:
         if (err != CborErrorUnexpectedEOF)
             corrupt = true;
 
-        lastError = fromCborError(err);
+        lastError = QCborError { QCborError::Code(int(err)) };
     }
 
     void updateBufferAfterString(qsizetype offset, qsizetype size)
@@ -2645,5 +1530,4 @@ QCborStreamReader::readStringChunk(char *ptr, qsizetype maxlen)
 
 QT_END_NAMESPACE
 
-#include "moc_qcborcommon.cpp"
-#include "moc_qcborstream.cpp"
+#include "moc_qcborstreamreader.cpp"
diff --git a/src/corelib/serialization/qcborstreamreader.h b/src/corelib/serialization/qcborstreamreader.h
new file mode 100644
index 0000000000..6d5feccfcf
--- /dev/null
+++ b/src/corelib/serialization/qcborstreamreader.h
@@ -0,0 +1,210 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Intel Corporation.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** 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
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QCBORSTREAMREADER_H
+#define QCBORSTREAMREADER_H
+
+#include <QtCore/qbytearray.h>
+#include <QtCore/qcborcommon.h>
+#include <QtCore/qfloat16.h>
+#include <QtCore/qscopedpointer.h>
+#include <QtCore/qstring.h>
+#include <QtCore/qstringview.h>
+
+QT_REQUIRE_CONFIG(cborstreamreader);
+
+// See qcborcommon.h for why we check
+#if defined(QT_X11_DEFINES_FOUND)
+#  undef True
+#  undef False
+#endif
+
+QT_BEGIN_NAMESPACE
+
+class QIODevice;
+
+class QCborStreamReaderPrivate;
+class Q_CORE_EXPORT QCborStreamReader
+{
+    Q_GADGET
+public:
+    enum Type : quint8 {
+        UnsignedInteger     = 0x00,
+        NegativeInteger     = 0x20,
+        ByteString          = 0x40,
+        ByteArray           = ByteString,
+        TextString          = 0x60,
+        String              = TextString,
+        Array               = 0x80,
+        Map                 = 0xa0,
+        Tag                 = 0xc0,
+        SimpleType          = 0xe0,
+        HalfFloat           = 0xf9,
+        Float16             = HalfFloat,
+        Float               = 0xfa,
+        Double              = 0xfb,
+
+        Invalid             = 0xff
+    };
+    Q_ENUM(Type)
+
+    enum StringResultCode {
+        EndOfString = 0,
+        Ok = 1,
+        Error = -1
+    };
+    template <typename Container> struct StringResult {
+        Container data;
+        StringResultCode status = Error;
+    };
+    Q_ENUM(StringResultCode)
+
+    QCborStreamReader();
+    QCborStreamReader(const char *data, qsizetype len);
+    QCborStreamReader(const quint8 *data, qsizetype len);
+    explicit QCborStreamReader(const QByteArray &data);
+    explicit QCborStreamReader(QIODevice *device);
+    ~QCborStreamReader();
+    Q_DISABLE_COPY(QCborStreamReader)
+
+    void setDevice(QIODevice *device);
+    QIODevice *device() const;
+    void addData(const QByteArray &data);
+    void addData(const char *data, qsizetype len);
+    void addData(const quint8 *data, qsizetype len)
+    { addData(reinterpret_cast<const char *>(data), len); }
+    void reparse();
+    void clear();
+    void reset();
+
+    QCborError lastError();
+
+    qint64 currentOffset() const;
+
+    bool isValid() const        { return !isInvalid(); }
+
+    int containerDepth() const;
+    QCborStreamReader::Type parentContainerType() const;
+    bool hasNext() const noexcept Q_DECL_PURE_FUNCTION;
+    bool next(int maxRecursion = 10000);
+
+    Type type() const               { return QCborStreamReader::Type(type_); }
+    bool isUnsignedInteger() const  { return type() == UnsignedInteger; }
+    bool isNegativeInteger() const  { return type() == NegativeInteger; }
+    bool isInteger() const          { return quint8(type()) <= quint8(NegativeInteger); }
+    bool isByteArray() const        { return type() == ByteArray; }
+    bool isString() const           { return type() == String; }
+    bool isArray() const            { return type() == Array; }
+    bool isMap() const              { return type() == Map; }
+    bool isTag() const              { return type() == Tag; }
+    bool isSimpleType() const       { return type() == SimpleType; }
+    bool isFloat16() const          { return type() == Float16; }
+    bool isFloat() const            { return type() == Float; }
+    bool isDouble() const           { return type() == Double; }
+    bool isInvalid() const          { return type() == Invalid; }
+
+    bool isSimpleType(QCborSimpleType st) const { return isSimpleType() && toSimpleType() == st; }
+    bool isFalse() const            { return isSimpleType(QCborSimpleType::False); }
+    bool isTrue() const             { return isSimpleType(QCborSimpleType::True); }
+    bool isBool() const             { return isFalse() || isTrue(); }
+    bool isNull() const             { return isSimpleType(QCborSimpleType::Null); }
+    bool isUndefined() const        { return isSimpleType(QCborSimpleType::Undefined); }
+
+    bool isLengthKnown() const noexcept Q_DECL_PURE_FUNCTION;
+    quint64 length() const;
+
+    bool isContainer() const            { return isMap() || isArray(); }
+    bool enterContainer()               { Q_ASSERT(isContainer()); return _enterContainer_helper(); }
+    bool leaveContainer();
+
+    StringResult<QString> readString()      { Q_ASSERT(isString()); return _readString_helper(); }
+    StringResult<QByteArray> readByteArray(){ Q_ASSERT(isByteArray()); return _readByteArray_helper(); }
+    qsizetype currentStringChunkSize() const{ Q_ASSERT(isString() || isByteArray()); return _currentStringChunkSize(); }
+    StringResult<qsizetype> readStringChunk(char *ptr, qsizetype maxlen);
+
+    bool toBool() const                 { Q_ASSERT(isBool()); return value64 - int(QCborSimpleType::False); }
+    QCborTag toTag() const              { Q_ASSERT(isTag()); return QCborTag(value64); }
+    quint64 toUnsignedInteger() const   { Q_ASSERT(isUnsignedInteger()); return value64; }
+    QCborNegativeInteger toNegativeInteger() const { Q_ASSERT(isNegativeInteger()); return QCborNegativeInteger(value64 + 1); }
+    QCborSimpleType toSimpleType() const{ Q_ASSERT(isSimpleType()); return QCborSimpleType(value64); }
+    qfloat16 toFloat16() const          { Q_ASSERT(isFloat16()); return _toFloatingPoint<qfloat16>(); }
+    float toFloat() const               { Q_ASSERT(isFloat()); return _toFloatingPoint<float>(); }
+    double toDouble() const             { Q_ASSERT(isDouble()); return _toFloatingPoint<double>(); }
+
+    qint64 toInteger() const
+    {
+        Q_ASSERT(isInteger());
+        qint64 v = qint64(value64);
+        if (isNegativeInteger())
+            return -v - 1;
+        return v;
+    }
+
+private:
+    void preparse();
+    bool _enterContainer_helper();
+    StringResult<QString> _readString_helper();
+    StringResult<QByteArray> _readByteArray_helper();
+    qsizetype _currentStringChunkSize() const;
+
+    template <typename FP> FP _toFloatingPoint() const noexcept
+    {
+        using UIntFP = typename QIntegerForSizeof<FP>::Unsigned;
+        UIntFP u = UIntFP(value64);
+        FP f;
+        memcpy(static_cast<void *>(&f), &u, sizeof(f));
+        return f;
+    }
+
+    friend QCborStreamReaderPrivate;
+    friend class QCborContainerPrivate;
+    quint64 value64;
+    QScopedPointer<QCborStreamReaderPrivate> d;
+    quint8 type_;
+    quint8 reserved[3] = {};
+};
+
+QT_END_NAMESPACE
+
+#if defined(QT_X11_DEFINES_FOUND)
+#  define True  1
+#  define False 0
+#endif
+
+#endif // QCBORSTREAMREADER_H
diff --git a/src/corelib/serialization/qcborstreamwriter.cpp b/src/corelib/serialization/qcborstreamwriter.cpp
new file mode 100644
index 0000000000..d7f750b05e
--- /dev/null
+++ b/src/corelib/serialization/qcborstreamwriter.cpp
@@ -0,0 +1,868 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Intel Corporation.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** 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
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qcborstreamwriter.h"
+
+#define CBOR_NO_PARSER_API
+#include <private/qcborcommon_p.h>
+
+#include <private/qnumeric_p.h>
+#include <qbuffer.h>
+#include <qdebug.h>
+#include <qstack.h>
+
+QT_BEGIN_NAMESPACE
+
+static CborError qt_cbor_encoder_write_callback(void *token, const void *data, size_t len, CborEncoderAppendType);
+#define CBOR_ENCODER_WRITER_CONTROL     1
+#define CBOR_ENCODER_WRITE_FUNCTION     qt_cbor_encoder_write_callback
+#define CBOR_ENCODER_NO_CHECK_USER
+
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_MSVC(4334) // '<<': result of 32-bit shift implicitly converted to 64 bits (was 64-bit shift intended?)
+
+#include <cborencoder.c>
+
+QT_WARNING_POP
+
+// silence compilers that complain about this being a static function declared
+// but never defined
+static CborError cbor_encoder_close_container_checked(CborEncoder*, const CborEncoder*)
+{
+    Q_UNREACHABLE();
+    return CborErrorInternalError;
+}
+
+static CborError cbor_encode_float_as_half_float(CborEncoder *, float)
+{
+    Q_UNREACHABLE();
+    return CborErrorInternalError;
+}
+
+Q_DECLARE_TYPEINFO(CborEncoder, Q_PRIMITIVE_TYPE);
+
+/*!
+   \class QCborStreamWriter
+   \inmodule QtCore
+   \ingroup cbor
+   \reentrant
+   \since 5.12
+
+   \brief The QCborStreamWriter class is a simple CBOR encoder operating on a
+   one-way stream.
+
+   This class can be used to quickly encode a stream of CBOR content directly
+   to either a QByteArray or QIODevice. CBOR is the Concise Binary Object
+   Representation, a very compact form of binary data encoding that is
+   compatible with JSON. It was created by the IETF Constrained RESTful
+   Environments (CoRE) WG, which has used it in many new RFCs. It is meant to
+   be used alongside the \l{https://tools.ietf.org/html/rfc7252}{CoAP
+   protocol}.
+
+   QCborStreamWriter provides a StAX-like API, similar to that of
+   \l{QXmlStreamWriter}. It is rather low-level and requires a bit of knowledge
+   of CBOR encoding. For a simpler API, see \l{QCborValue} and especially the
+   encoding function QCborValue::toCbor().
+
+   The typical use of QCborStreamWriter is to create the object on the target
+   QByteArray or QIODevice, then call one of the append() overloads with the
+   desired type to be encoded. To create arrays and maps, QCborStreamWriter
+   provides startArray() and startMap() overloads, which must be terminated by
+   the corresponding endArray() and endMap() functions.
+
+   The following example encodes the equivalent of this JSON content:
+
+   \div{class="pre"}
+     {
+       "label": "journald",
+       "autoDetect": false,
+       "condition": "libs.journald",
+       "output": [ "privateFeature" ]
+     }
+   \enddiv
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 1
+
+   \section1 CBOR support
+
+   QCborStreamWriter supports all CBOR features required to create canonical
+   and strict streams. It implements almost all of the features specified in
+   \l {https://tools.ietf.org/html/rfc7049}{RFC 7049}.
+
+   The following table lists the CBOR features that QCborStreamWriter supports.
+
+   \table
+     \header \li Feature                        \li Support
+     \row   \li Unsigned numbers                \li Yes (full range)
+     \row   \li Negative numbers                \li Yes (full range)
+     \row   \li Byte strings                    \li Yes
+     \row   \li Text strings                    \li Yes
+     \row   \li Chunked strings                 \li No
+     \row   \li Tags                            \li Yes (arbitrary)
+     \row   \li Booleans                        \li Yes
+     \row   \li Null                            \li Yes
+     \row   \li Undefined                       \li Yes
+     \row   \li Arbitrary simple values         \li Yes
+     \row   \li Half-precision float (16-bit)   \li Yes
+     \row   \li Single-precision float (32-bit) \li Yes
+     \row   \li Double-precision float (64-bit) \li Yes
+     \row   \li Infinities and NaN floating point \li Yes
+     \row   \li Determinate-length arrays and maps \li Yes
+     \row   \li Indeterminate-length arrays and maps \li Yes
+     \row   \li Map key types other than strings and integers \li Yes (arbitrary)
+   \endtable
+
+   \section2 Canonical CBOR encoding
+
+   Canonical CBOR encoding is defined by
+   \l{https://tools.ietf.org/html/rfc7049#section-3.9}{Section 3.9 of RFC
+   7049}. Canonical encoding is not a requirement for Qt's CBOR decoding
+   functionality, but it may be required for some protocols. In particular,
+   protocols that require the ability to reproduce the same stream identically
+   may require this.
+
+   In order to be considered "canonical", a CBOR stream must meet the
+   following requirements:
+
+   \list
+     \li Integers must be as small as possible. QCborStreamWriter always
+         does this (no user action is required and it is not possible
+         to write overlong integers).
+     \li Array, map and string lengths must be as short as possible. As
+         above, QCborStreamWriter automatically does this.
+     \li Arrays, maps and strings must use explicit length. QCborStreamWriter
+         always does this for strings; for arrays and maps, be sure to call
+         startArray() and startMap() overloads with explicit length.
+     \li Keys in every map must be sorted in ascending order. QCborStreamWriter
+         offers no help in this item: the developer must ensure that before
+         calling append() for the map pairs.
+     \li Floating point values should be as small as possible. QCborStreamWriter
+         will not convert floating point values; it is up to the developer
+         to perform this check prior to calling append() (see those functions'
+         examples).
+   \endlist
+
+   \section2 Strict CBOR mode
+
+   Strict mode is defined by
+   \l{https://tools.ietf.org/html/rfc7049#section-3.10}{Section 3.10 of RFC
+   7049}. As for Canonical encoding above, QCborStreamWriter makes it possible
+   to create strict CBOR streams, but does not require them or validate that
+   the output is so.
+
+   \list
+     \li Keys in a map must be unique. QCborStreamWriter performs no validation
+         of map keys.
+     \li Tags may be required to be paired only with the correct types,
+         according to their specification. QCborStreamWriter performs no
+         validation of tag usage.
+     \li Text Strings must be properly-encoded UTF-8. QCborStreamWriter always
+         writes proper UTF-8 for strings added with append(), but performs no
+         validation for strings added with appendTextString().
+   \endlist
+
+   \section2 Invalid CBOR stream
+
+   It is also possible to misuse QCborStreamWriter and produce invalid CBOR
+   streams that will fail to be decoded by a receiver. The following actions
+   will produce invalid streams:
+
+   \list
+     \li Append a tag and not append the corresponding tagged value
+         (QCborStreamWriter produces no diagnostic).
+     \li Append too many or too few items to an array or map with explicit
+         length (endMap() and endArray() will return false and
+         QCborStreamWriter will log with qWarning()).
+   \endlist
+
+   \sa QCborStreamReader, QCborValue, QXmlStreamWriter
+ */
+
+class QCborStreamWriterPrivate
+{
+public:
+    static Q_CONSTEXPR quint64 IndefiniteLength = (std::numeric_limits<quint64>::max)();
+
+    QIODevice *device;
+    CborEncoder encoder;
+    QStack<CborEncoder> containerStack;
+    bool deleteDevice = false;
+
+    QCborStreamWriterPrivate(QIODevice *device)
+        : device(device)
+    {
+        cbor_encoder_init_writer(&encoder, qt_cbor_encoder_write_callback, this);
+    }
+
+    ~QCborStreamWriterPrivate()
+    {
+        if (deleteDevice)
+            delete device;
+    }
+
+    template <typename... Args> void executeAppend(CborError (*f)(CborEncoder *, Args...), Args... args)
+    {
+        f(&encoder, std::forward<Args>(args)...);
+    }
+
+    void createContainer(CborError (*f)(CborEncoder *, CborEncoder *, size_t), quint64 len = IndefiniteLength)
+    {
+        Q_STATIC_ASSERT(size_t(IndefiniteLength) == CborIndefiniteLength);
+        if (sizeof(len) != sizeof(size_t) && len != IndefiniteLength) {
+            if (Q_UNLIKELY(len >= CborIndefiniteLength)) {
+                // TinyCBOR can't do this in 32-bit mode
+                qWarning("QCborStreamWriter: container of size %llu is too big for a 32-bit build; "
+                         "will use indeterminate length instead", len);
+                len = CborIndefiniteLength;
+            }
+        }
+
+        containerStack.push(encoder);
+        f(&containerStack.top(), &encoder, len);
+    }
+
+    bool closeContainer()
+    {
+        if (containerStack.isEmpty()) {
+            qWarning("QCborStreamWriter: closing map or array that wasn't open");
+            return false;
+        }
+
+        CborEncoder container = containerStack.pop();
+        CborError err = cbor_encoder_close_container(&container, &encoder);
+        encoder = container;
+
+        if (Q_UNLIKELY(err)) {
+            if (err == CborErrorTooFewItems)
+                qWarning("QCborStreamWriter: not enough items added to array or map");
+            else if (err == CborErrorTooManyItems)
+                qWarning("QCborStreamWriter: too many items added to array or map");
+            return false;
+        }
+
+        return true;
+    }
+};
+
+static CborError qt_cbor_encoder_write_callback(void *self, const void *data, size_t len, CborEncoderAppendType)
+{
+    auto that = static_cast<QCborStreamWriterPrivate *>(self);
+    if (!that->device)
+        return CborNoError;
+    qint64 written = that->device->write(static_cast<const char *>(data), len);
+    return (written == qsizetype(len) ? CborNoError : CborErrorIO);
+}
+
+/*!
+   Creates a QCborStreamWriter object that will write the stream to \a device.
+   The device must be opened before the first append() call is made. This
+   constructor can be used with any class that derives from QIODevice, such as
+   QFile, QProcess or QTcpSocket.
+
+   QCborStreamWriter has no buffering, so every append() call will result in
+   one or more calls to the device's \l {QIODevice::}{write()} method.
+
+   The following example writes an empty map to a file:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 2
+
+   QCborStreamWriter does not take ownership of \a device.
+
+   \sa device(), setDevice()
+ */
+QCborStreamWriter::QCborStreamWriter(QIODevice *device)
+    : d(new QCborStreamWriterPrivate(device))
+{
+}
+
+/*!
+   Creates a QCborStreamWriter object that will append the stream to \a data.
+   All streaming is done immediately to the byte array, without the need for
+   flushing any buffers.
+
+   The following example writes a number to a byte array then returns
+   it.
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 3
+
+   QCborStreamWriter does not take ownership of \a data.
+ */
+QCborStreamWriter::QCborStreamWriter(QByteArray *data)
+    : d(new QCborStreamWriterPrivate(new QBuffer(data)))
+{
+    d->deleteDevice = true;
+    d->device->open(QIODevice::WriteOnly | QIODevice::Unbuffered);
+}
+
+/*!
+   Destroys this QCborStreamWriter object and frees any resources associated.
+
+   QCborStreamWriter does not perform error checking to see if all required
+   items were written to the stream prior to the object being destroyed. It is
+   the programmer's responsibility to ensure that it was done.
+ */
+QCborStreamWriter::~QCborStreamWriter()
+{
+}
+
+/*!
+   Replaces the device or byte array that this QCborStreamWriter object is
+   writing to with \a device.
+
+   \sa device()
+ */
+void QCborStreamWriter::setDevice(QIODevice *device)
+{
+    if (d->deleteDevice)
+        delete d->device;
+    d->device = device;
+    d->deleteDevice = false;
+}
+
+/*!
+   Returns the QIODevice that this QCborStreamWriter object is writing to. The
+   device must have previously been set with either the constructor or with
+   setDevice().
+
+   If this object was created by writing to a QByteArray, this function will
+   return an internal instance of QBuffer, which is owned by QCborStreamWriter.
+
+   \sa setDevice()
+ */
+QIODevice *QCborStreamWriter::device() const
+{
+    return d->device;
+}
+
+/*!
+   \overload
+
+   Appends the 64-bit unsigned value \a u to the CBOR stream, creating a CBOR
+   Unsigned Integer value. In the following example, we write the values 0,
+   2\sup{32} and \c UINT64_MAX:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 4
+
+   \sa QCborStreamReader::isUnsignedInteger(), QCborStreamReader::toUnsignedInteger()
+ */
+void QCborStreamWriter::append(quint64 u)
+{
+    d->executeAppend(cbor_encode_uint, uint64_t(u));
+}
+
+/*!
+   \overload
+
+   Appends the 64-bit signed value \a i to the CBOR stream. This will create
+   either a CBOR Unsigned Integer or CBOR NegativeInteger value based on the
+   sign of the parameter. In the following example, we write the values 0, -1,
+   2\sup{32} and \c INT64_MAX:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 5
+
+   \sa QCborStreamReader::isInteger(), QCborStreamReader::toInteger()
+ */
+void QCborStreamWriter::append(qint64 i)
+{
+    d->executeAppend(cbor_encode_int, int64_t(i));
+}
+
+/*!
+   \overload
+
+   Appends the 64-bit negative value \a n to the CBOR stream.
+   QCborNegativeInteger is a 64-bit enum that holds the absolute value of the
+   negative number we want to write. If n is zero, the value written will be
+   equivalent to 2\sup{64} (that is, -18,446,744,073,709,551,616).
+
+   In the following example, we write the values -1, -2\sup{32} and INT64_MIN:
+   \snippet code/src_corelib_serialization_qcborstream.cpp 6
+
+   Note how this function can be used to encode numbers that cannot fit a
+   standard computer's 64-bit signed integer like \l qint64. That is, if \a n
+   is larger than \c{std::numeric_limits<qint64>::max()} or is 0, this will
+   represent a negative number smaller than
+   \c{std::numeric_limits<qint64>::min()}.
+
+   \sa QCborStreamReader::isNegativeInteger(), QCborStreamReader::toNegativeInteger()
+ */
+void QCborStreamWriter::append(QCborNegativeInteger n)
+{
+    d->executeAppend(cbor_encode_negative_int, uint64_t(n));
+}
+
+/*!
+   \fn void QCborStreamWriter::append(const QByteArray &ba)
+   \overload
+
+   Appends the byte array \a ba to the stream, creating a CBOR Byte String
+   value. QCborStreamWriter will attempt to write the entire string in one
+   chunk.
+
+   The following example will load and append the contents of a file to the
+   stream:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 7
+
+   As the example shows, unlike JSON, CBOR requires no escaping for binary
+   content.
+
+   \sa appendByteString(), QCborStreamReader::isByteArray(),
+       QCborStreamReader::readByteArray()
+ */
+
+/*!
+   \overload
+
+   Appends the text string \a str to the stream, creating a CBOR Text String
+   value. QCborStreamWriter will attempt to write the entire string in one
+   chunk.
+
+   The following example appends a simple string to the stream:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 8
+
+   \b{Performance note}: CBOR requires that all Text Strings be encoded in
+   UTF-8, so this function will iterate over the characters in the string to
+   determine whether the contents are US-ASCII or not. If the string is found
+   to contain characters outside of US-ASCII, it will allocate memory and
+   convert to UTF-8. If this check is unnecessary, use appendTextString()
+   instead.
+
+   \sa QCborStreamReader::isString(), QCborStreamReader::readString()
+ */
+void QCborStreamWriter::append(QLatin1String str)
+{
+    // We've got Latin-1 but CBOR wants UTF-8, so check if the string is the
+    // common subset (US-ASCII).
+    if (QtPrivate::isAscii(str)) {
+        // it is plain US-ASCII
+        appendTextString(str.latin1(), str.size());
+    } else {
+        // non-ASCII, so we need a pass-through UTF-16
+        append(QString(str));
+    }
+}
+
+/*!
+   \overload
+
+   Appends the text string \a str to the stream, creating a CBOR Text String
+   value. QCborStreamWriter will attempt to write the entire string in one
+   chunk.
+
+   The following example writes an arbitrary QString to the stream:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 9
+
+   \sa QCborStreamReader::isString(), QCborStreamReader::readString()
+ */
+void QCborStreamWriter::append(QStringView str)
+{
+    QByteArray utf8 = str.toUtf8();
+    appendTextString(utf8.constData(), utf8.size());
+}
+
+/*!
+   \overload
+
+   Appends the CBOR tag \a tag to the stream, creating a CBOR Tag value. All
+   tags must be followed by another type which they provide meaning for.
+
+   In the following example, we append a CBOR Tag 36 (Regular Expression) and a
+   QRegularExpression's pattern to the stream:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 10
+
+   \sa QCborStreamReader::isTag(), QCborStreamReader::toTag()
+ */
+void QCborStreamWriter::append(QCborTag tag)
+{
+    d->executeAppend(cbor_encode_tag, CborTag(tag));
+}
+
+/*!
+   \fn void QCborStreamWriter::append(QCborKnownTags tag)
+   \overload
+
+   Appends the CBOR tag \a tag to the stream, creating a CBOR Tag value. All
+   tags must be followed by another type which they provide meaning for.
+
+   In the following example, we append a CBOR Tag 1 (Unix \c time_t) and an
+   integer representing the current time to the stream, obtained using the \c
+   time() function:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 11
+
+   \sa QCborStreamReader::isTag(), QCborStreamReader::toTag()
+ */
+
+/*!
+   \overload
+
+   Appends the CBOR simple type \a st to the stream, creating a CBOR Simple
+   Type value. In the following example, we write the simple type for Null as
+   well as for type 32, which Qt has no support for.
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 12
+
+   \note Using Simple Types for which there is no specification can lead to
+   validation errors by the remote receiver. In addition, simple type values 24
+   through 31 (inclusive) are reserved and must not be used.
+
+   \sa QCborStreamReader::isSimpleType(), QCborStreamReader::toSimpleType()
+ */
+void QCborStreamWriter::append(QCborSimpleType st)
+{
+    d->executeAppend(cbor_encode_simple_value, uint8_t(st));
+}
+
+#ifndef QT_BOOTSTRAPPED
+/*!
+   \overload
+
+   Appends the floating point number \a f to the stream, creating a CBOR 16-bit
+   Half-Precision Floating Point value. The following code can be used to convert
+   a C++ \tt float to \c qfloat16 if there's no loss of precision and append it, or
+   instead append the \tt float.
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 13
+
+   \sa QCborStreamReader::isFloat16(), QCborStreamReader::toFloat16()
+ */
+void QCborStreamWriter::append(qfloat16 f)
+{
+    d->executeAppend(cbor_encode_half_float, static_cast<const void *>(&f));
+}
+#endif // QT_BOOTSTRAPPED
+
+/*!
+   \overload
+
+   Appends the floating point number \a f to the stream, creating a CBOR 32-bit
+   Single-Precision Floating Point value. The following code can be used to convert
+   a C++ \tt double to \tt float if there's no loss of precision and append it, or
+   instead append the \tt double.
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 14
+
+   \sa QCborStreamReader::isFloat(), QCborStreamReader::toFloat()
+ */
+void QCborStreamWriter::append(float f)
+{
+    d->executeAppend(cbor_encode_float, f);
+}
+
+/*!
+   \overload
+
+   Appends the floating point number \a d to the stream, creating a CBOR 64-bit
+   Double-Precision Floating Point value. QCborStreamWriter always appends the
+   number as-is, performing no check for whether the number is the canonical
+   form for NaN, an infinite, whether it is denormal or if it could be written
+   with a shorter format.
+
+   The following code performs all those checks, except for the denormal one,
+   which is expected to be taken into account by the system FPU or floating
+   point emulation directly.
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 15
+
+   Determining if a double can be converted to an integral with no loss of
+   precision is left as an exercise to the reader.
+
+   \sa QCborStreamReader::isDouble(), QCborStreamReader::toDouble()
+ */
+void QCborStreamWriter::append(double d)
+{
+    this->d->executeAppend(cbor_encode_double, d);
+}
+
+/*!
+   Appends \a len bytes of data starting from \a data to the stream, creating a
+   CBOR Byte String value. QCborStreamWriter will attempt to write the entire
+   string in one chunk.
+
+   Unlike the QByteArray overload of append(), this function is not limited by
+   QByteArray's size limits. However, note that neither
+   QCborStreamReader::readByteArray() nor QCborValue support reading CBOR
+   streams with byte arrays larger than 2 GB.
+
+   \sa append(), appendTextString(),
+       QCborStreamReader::isByteArray(), QCborStreamReader::readByteArray()
+ */
+void QCborStreamWriter::appendByteString(const char *data, qsizetype len)
+{
+    d->executeAppend(cbor_encode_byte_string, reinterpret_cast<const uint8_t *>(data), size_t(len));
+}
+
+/*!
+   Appends \a len bytes of text starting from \a utf8 to the stream, creating a
+   CBOR Text String value. QCborStreamWriter will attempt to write the entire
+   string in one chunk.
+
+   The string pointed to by \a utf8 is expected to be properly encoded UTF-8.
+   QCborStreamWriter performs no validation that this is the case.
+
+   Unlike the QLatin1String overload of append(), this function is not limited
+   to 2 GB. However, note that neither QCborStreamReader::readString() nor
+   QCborValue support reading CBOR streams with text strings larger than 2 GB.
+
+   \sa append(QLatin1String), append(QStringView),
+       QCborStreamReader::isString(), QCborStreamReader::readString()
+ */
+void QCborStreamWriter::appendTextString(const char *utf8, qsizetype len)
+{
+    d->executeAppend(cbor_encode_text_string, utf8, size_t(len));
+}
+
+/*!
+   \fn void QCborStreamWriter::append(const char *str, qsizetype size)
+   \overload
+
+   Appends \a size bytes of text starting from \a str to the stream, creating a
+   CBOR Text String value. QCborStreamWriter will attempt to write the entire
+   string in one chunk. If \a size is -1, this function will write \c strlen(\a
+   str) bytes.
+
+   The string pointed to by \a str is expected to be properly encoded UTF-8.
+   QCborStreamWriter performs no validation that this is the case.
+
+   Unlike the QLatin1String overload of append(), this function is not limited
+   to 2 GB. However, note that neither QCborStreamReader nor QCborValue support
+   reading CBOR streams with text strings larger than 2 GB.
+
+   \sa append(QLatin1String), append(QStringView),
+       QCborStreamReader::isString(), QCborStreamReader::readString()
+ */
+
+/*!
+   \fn void QCborStreamWriter::append(bool b)
+   \overload
+
+   Appends the boolean value \a b to the stream, creating either a CBOR False
+   value or a CBOR True value. This function is equivalent to (and implemented
+   as):
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 16
+
+   \sa appendNull(), appendUndefined(),
+       QCborStreamReader::isBool(), QCborStreamReader::toBool()
+ */
+
+/*!
+   \fn void QCborStreamWriter::append(std::nullptr_t)
+   \overload
+
+   Appends a CBOR Null value to the stream. This function is equivalent to (and
+   implemented as): The parameter is ignored.
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 17
+
+   \sa appendNull(), append(QCborSimpleType), QCborStreamReader::isNull()
+ */
+
+/*!
+   \fn void QCborStreamWriter::appendNull()
+
+   Appends a CBOR Null value to the stream. This function is equivalent to (and
+   implemented as):
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 18
+
+   \sa append(std::nullptr_t), append(QCborSimpleType), QCborStreamReader::isNull()
+ */
+
+/*!
+   \fn void QCborStreamWriter::appendUndefined()
+
+   Appends a CBOR Undefined value to the stream. This function is equivalent to (and
+   implemented as):
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 19
+
+   \sa append(QCborSimpleType), QCborStreamReader::isUndefined()
+ */
+
+/*!
+   Starts a CBOR Array with indeterminate length in the CBOR stream. Each
+   startArray() call must be paired with one endArray() call and the current
+   CBOR element extends until the end of the array.
+
+   The array created by this function has no explicit length. Instead, its
+   length is implied by the elements contained in it. Note, however, that use
+   of indeterminate-length arrays is not compliant with canonical CBOR encoding.
+
+   The following example appends elements from the linked list of strings
+   passed as input:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 20
+
+   \sa startArray(quint64), endArray(), startMap(), QCborStreamReader::isArray(),
+   QCborStreamReader::isLengthKnown()
+ */
+void QCborStreamWriter::startArray()
+{
+    d->createContainer(cbor_encoder_create_array);
+}
+
+/*!
+   \overload
+
+   Starts a CBOR Array with explicit length of \a count items in the CBOR
+   stream. Each startArray call must be paired with one endArray() call and the
+   current CBOR element extends until the end of the array.
+
+   The array created by this function has an explicit length and therefore
+   exactly \a count items must be added to the CBOR stream. Adding fewer or
+   more items will result in failure during endArray() and the CBOR stream will
+   be corrupt. However, explicit-length arrays are required by canonical CBOR
+   encoding.
+
+   The following example appends all strings found in the \l QStringList passed as input:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 21
+
+   \b{Size limitations}: The parameter to this function is quint64, which would
+   seem to allow up to 2\sup{64}-1 elements in the array. However, both
+   QCborStreamWriter and QCborStreamReader are currently limited to 2\sup{32}-2
+   items on 32-bit systems and 2\sup{64}-2 items on 64-bit ones. Also note that
+   QCborArray is currently limited to 2\sup{27} elements in any platform.
+
+   \sa startArray(), endArray(), startMap(), QCborStreamReader::isArray(),
+   QCborStreamReader::isLengthKnown()
+ */
+void QCborStreamWriter::startArray(quint64 count)
+{
+    d->createContainer(cbor_encoder_create_array, count);
+}
+
+/*!
+   Terminates the array started by either overload of startArray() and returns
+   true if the correct number of elements was added to the array. This function
+   must be called for every startArray() used.
+
+   A return of false indicates error in the application and an unrecoverable
+   error in this stream. QCborStreamWriter also writes a warning using
+   qWarning() if that happens.
+
+   Calling this function when the current container is not an array is also an
+   error, though QCborStreamWriter cannot currently detect this condition.
+
+   \sa startArray(), startArray(quint64), endMap()
+ */
+bool QCborStreamWriter::endArray()
+{
+    return d->closeContainer();
+}
+
+/*!
+   Starts a CBOR Map with indeterminate length in the CBOR stream. Each
+   startMap() call must be paired with one endMap() call and the current CBOR
+   element extends until the end of the map.
+
+   The map created by this function has no explicit length. Instead, its length
+   is implied by the elements contained in it. Note, however, that use of
+   indeterminate-length maps is not compliant with canonical CBOR encoding
+   (canonical encoding also requires keys to be unique and in sorted order).
+
+   The following example appends elements from the linked list of int and
+   string pairs passed as input:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 22
+
+   \sa startMap(quint64), endMap(), startArray(), QCborStreamReader::isMap(),
+       QCborStreamReader::isLengthKnown()
+ */
+void QCborStreamWriter::startMap()
+{
+    d->createContainer(cbor_encoder_create_map);
+}
+
+/*!
+   \overload
+
+   Starts a CBOR Map with explicit length of \a count items in the CBOR
+   stream. Each startMap call must be paired with one endMap() call and the
+   current CBOR element extends until the end of the map.
+
+   The map created by this function has an explicit length and therefore
+   exactly \a count pairs of items must be added to the CBOR stream. Adding
+   fewer or more items will result in failure during endMap() and the CBOR
+   stream will be corrupt. However, explicit-length map are required by
+   canonical CBOR encoding.
+
+   The following example appends all strings found in the \l QMap passed as input:
+
+   \snippet code/src_corelib_serialization_qcborstream.cpp 23
+
+   \b{Size limitations}: The parameter to this function is quint64, which would
+   seem to allow up to 2\sup{64}-1 pairs in the map. However, both
+   QCborStreamWriter and QCborStreamReader are currently limited to 2\sup{31}-1
+   items on 32-bit systems and 2\sup{63}-1 items on 64-bit ones. Also note that
+   QCborMap is currently limited to 2\sup{26} elements in any platform.
+
+   \sa startMap(), endMap(), startArray(), QCborStreamReader::isMap(),
+       QCborStreamReader::isLengthKnown()
+ */
+void QCborStreamWriter::startMap(quint64 count)
+{
+    d->createContainer(cbor_encoder_create_map, count);
+}
+
+/*!
+   Terminates the map started by either overload of startMap() and returns
+   true if the correct number of elements was added to the array. This function
+   must be called for every startMap() used.
+
+   A return of false indicates error in the application and an unrecoverable
+   error in this stream. QCborStreamWriter also writes a warning using
+   qWarning() if that happens.
+
+   Calling this function when the current container is not a map is also an
+   error, though QCborStreamWriter cannot currently detect this condition.
+
+   \sa startMap(), startMap(quint64), endArray()
+ */
+bool QCborStreamWriter::endMap()
+{
+    return d->closeContainer();
+}
+
+QT_END_NAMESPACE
diff --git a/src/corelib/serialization/qcborstreamwriter.h b/src/corelib/serialization/qcborstreamwriter.h
new file mode 100644
index 0000000000..f8c94ceb93
--- /dev/null
+++ b/src/corelib/serialization/qcborstreamwriter.h
@@ -0,0 +1,130 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 Intel Corporation.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** 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
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QCBORSTREAMWRITER_H
+#define QCBORSTREAMWRITER_H
+
+#include <QtCore/qbytearray.h>
+#include <QtCore/qcborcommon.h>
+#include <QtCore/qscopedpointer.h>
+#include <QtCore/qstring.h>
+#include <QtCore/qstringview.h>
+#ifndef QT_BOOTSTRAPPED
+#include <QtCore/qfloat16.h>
+#endif
+
+QT_REQUIRE_CONFIG(cborstreamwriter);
+
+// See qcborcommon.h for why we check
+#if defined(QT_X11_DEFINES_FOUND)
+#  undef True
+#  undef False
+#endif
+
+QT_BEGIN_NAMESPACE
+
+class QIODevice;
+
+class QCborStreamWriterPrivate;
+class Q_CORE_EXPORT QCborStreamWriter
+{
+public:
+    explicit QCborStreamWriter(QIODevice *device);
+    explicit QCborStreamWriter(QByteArray *data);
+    ~QCborStreamWriter();
+    Q_DISABLE_COPY(QCborStreamWriter)
+
+    void setDevice(QIODevice *device);
+    QIODevice *device() const;
+
+    void append(quint64 u);
+    void append(qint64 i);
+    void append(QCborNegativeInteger n);
+    void append(const QByteArray &ba)       { appendByteString(ba.constData(), ba.size()); }
+    void append(QLatin1String str);
+    void append(QStringView str);
+    void append(QCborTag tag);
+    void append(QCborKnownTags tag)         { append(QCborTag(tag)); }
+    void append(QCborSimpleType st);
+    void append(std::nullptr_t)             { append(QCborSimpleType::Null); }
+#ifndef QT_BOOTSTRAPPED
+    void append(qfloat16 f);
+#endif
+    void append(float f);
+    void append(double d);
+
+    void appendByteString(const char *data, qsizetype len);
+    void appendTextString(const char *utf8, qsizetype len);
+
+    // convenience
+    void append(bool b)     { append(b ? QCborSimpleType::True : QCborSimpleType::False); }
+    void appendNull()       { append(QCborSimpleType::Null); }
+    void appendUndefined()  { append(QCborSimpleType::Undefined); }
+
+#ifndef Q_QDOC
+    // overloads to make normal code not complain
+    void append(int i)      { append(qint64(i)); }
+    void append(uint u)     { append(quint64(u)); }
+#endif
+#ifndef QT_NO_CAST_FROM_ASCII
+    void append(const char *str, qsizetype size = -1)
+    { appendTextString(str, (str && size == -1)  ? int(strlen(str)) : size); }
+#endif
+
+    void startArray();
+    void startArray(quint64 count);
+    bool endArray();
+    void startMap();
+    void startMap(quint64 count);
+    bool endMap();
+
+    // no API for encoding chunked strings
+
+private:
+    QScopedPointer<QCborStreamWriterPrivate> d;
+};
+
+QT_END_NAMESPACE
+
+#if defined(QT_X11_DEFINES_FOUND)
+#  define True  1
+#  define False 0
+#endif
+
+#endif // QCBORSTREAMWRITER_H
diff --git a/src/corelib/serialization/qcborvalue.cpp b/src/corelib/serialization/qcborvalue.cpp
index 61d61dd9ae..db2840704c 100644
--- a/src/corelib/serialization/qcborvalue.cpp
+++ b/src/corelib/serialization/qcborvalue.cpp
@@ -43,8 +43,12 @@
 #include "qcborarray.h"
 #include "qcbormap.h"
 
-#if QT_CONFIG(cborstream)
-#include "qcborstream.h"
+#if QT_CONFIG(cborstreamreader)
+#include "qcborstreamreader.h"
+#endif
+
+#if QT_CONFIG(cborstreamwriter)
+#include "qcborstreamwriter.h"
 #endif
 
 #include <qendian.h>
@@ -840,16 +844,20 @@ static QCborValue::Type convertToExtendedType(QCborContainerPrivate *d)
     return QCborValue::Tag;
 }
 
-#if QT_CONFIG(cborstream)
+#if QT_CONFIG(cborstreamreader)
 // in qcborstream.cpp
 extern void qt_cbor_stream_set_error(QCborStreamReaderPrivate *d, QCborError error);
+#endif
 
+#if QT_CONFIG(cborstreamwriter)
 static void writeDoubleToCbor(QCborStreamWriter &writer, double d, QCborValue::EncodingOptions opt)
 {
     if (qt_is_nan(d)) {
-        if (opt & QCborValue::UseFloat16) {
+        if (opt & QCborValue::UseFloat) {
+#ifndef QT_BOOTSTRAPPED
             if ((opt & QCborValue::UseFloat16) == QCborValue::UseFloat16)
                 return writer.append(std::numeric_limits<qfloat16>::quiet_NaN());
+#endif
             return writer.append(std::numeric_limits<float>::quiet_NaN());
         }
         return writer.append(qt_qnan());
@@ -866,15 +874,17 @@ static void writeDoubleToCbor(QCborStreamWriter &writer, double d, QCborValue::E
         }
     }
 
-    if (opt & QCborValue::UseFloat16) {
+    if (opt & QCborValue::UseFloat) {
         float f = float(d);
         if (f == d) {
             // no data loss, we could use float
+#ifndef QT_BOOTSTRAPPED
             if ((opt & QCborValue::UseFloat16) == QCborValue::UseFloat16) {
                 qfloat16 f16 = f;
                 if (f16 == f)
                     return writer.append(f16);
             }
+#endif
 
             return writer.append(f);
         }
@@ -882,7 +892,7 @@ static void writeDoubleToCbor(QCborStreamWriter &writer, double d, QCborValue::E
 
     writer.append(d);
 }
-#endif // QT_CONFIG(cborstream)
+#endif // QT_CONFIG(cborstreamwriter)
 
 static inline int typeOrder(Element e1, Element e2)
 {
@@ -1305,7 +1315,7 @@ int QCborMap::compare(const QCborMap &other) const noexcept
     return compareContainer(d.data(), other.d.data());
 }
 
-#if QT_CONFIG(cborstream)
+#if QT_CONFIG(cborstreamwriter)
 static void encodeToCbor(QCborStreamWriter &writer, const QCborContainerPrivate *d, qsizetype idx,
                          QCborValue::EncodingOptions opt)
 {
@@ -1393,7 +1403,9 @@ static void encodeToCbor(QCborStreamWriter &writer, const QCborContainerPrivate
         qWarning("QCborValue: found unknown type 0x%x", e.type);
     }
 }
+#endif // QT_CONFIG(cborstreamwriter)
 
+#if QT_CONFIG(cborstreamreader)
 static inline double integerOutOfRange(const QCborStreamReader &reader)
 {
     Q_ASSERT(reader.isInteger());
@@ -1650,7 +1662,7 @@ void QCborContainerPrivate::decodeFromCbor(QCborStreamReader &reader)
     if (reader.lastError() == QCborError::NoError)
         reader.leaveContainer();
 }
-#endif // QT_CONFIG(cborstream)
+#endif // QT_CONFIG(cborstreamreader)
 
 /*!
     Creates a QCborValue with byte array value \a ba. The value can later be
@@ -2350,7 +2362,7 @@ QCborValueRef QCborValue::operator[](qint64 key)
     return { container, index };
 }
 
-#if QT_CONFIG(cborstream)
+#if QT_CONFIG(cborstreamreader)
 /*!
     Decodes one item from the CBOR stream found in \a reader and returns the
     equivalent representation. This function is recursive: if the item is a map
@@ -2465,7 +2477,9 @@ QCborValue QCborValue::fromCbor(const QByteArray &ba, QCborParserError *error)
     overload of this function that accepts a QByteArray, also passing \a error,
     if provided.
 */
+#endif // QT_CONFIG(cborstreamreader)
 
+#if QT_CONFIG(cborstreamwriter)
 /*!
     Encodes this QCborValue object to its CBOR representation, using the
     options specified in \a opt, and return the byte array containing that
@@ -2588,7 +2602,7 @@ void QCborValueRef::toCbor(QCborStreamWriter &writer, QCborValue::EncodingOption
 {
     concrete().toCbor(writer, opt);
 }
-#endif // QT_CONFIG(cborstream)
+#endif // QT_CONFIG(cborstreamwriter)
 
 void QCborValueRef::assign(QCborValueRef that, const QCborValue &other)
 {
diff --git a/src/corelib/serialization/qcborvalue.h b/src/corelib/serialization/qcborvalue.h
index 071213e83a..1df8425d45 100644
--- a/src/corelib/serialization/qcborvalue.h
+++ b/src/corelib/serialization/qcborvalue.h
@@ -90,7 +90,9 @@ public:
     enum EncodingOption {
         SortKeysInMaps = 0x01,
         UseFloat = 0x02,
+#ifndef QT_BOOTSTRAPPED
         UseFloat16 = UseFloat | 0x04,
+#endif
         UseIntegers = 0x08,
 
         NoTransformation = 0
@@ -287,13 +289,15 @@ public:
     static QCborValue fromJsonValue(const QJsonValue &v);
     QJsonValue toJsonValue() const;
 
-#if QT_CONFIG(cborstream)
+#if QT_CONFIG(cborstreamreader)
     static QCborValue fromCbor(QCborStreamReader &reader);
     static QCborValue fromCbor(const QByteArray &ba, QCborParserError *error = nullptr);
     static QCborValue fromCbor(const char *data, qsizetype len, QCborParserError *error = nullptr)
     { return fromCbor(QByteArray(data, int(len)), error); }
     static QCborValue fromCbor(const quint8 *data, qsizetype len, QCborParserError *error = nullptr)
     { return fromCbor(QByteArray(reinterpret_cast<const char *>(data), int(len)), error); }
+#endif // QT_CONFIG(cborstreamreader)
+#if QT_CONFIG(cborstreamwriter)
     QByteArray toCbor(EncodingOptions opt = NoTransformation);
     void toCbor(QCborStreamWriter &writer, EncodingOptions opt = NoTransformation);
 #endif
@@ -441,7 +445,7 @@ public:
     QVariant toVariant() const                  { return concrete().toVariant(); }
     QJsonValue toJsonValue() const;
 
-#if QT_CONFIG(cborstream)
+#if QT_CONFIG(cborstreamwriter)
     QByteArray toCbor(QCborValue::EncodingOptions opt = QCborValue::NoTransformation)
     { return concrete().toCbor(opt); }
     void toCbor(QCborStreamWriter &writer, QCborValue::EncodingOptions opt = QCborValue::NoTransformation);
diff --git a/src/corelib/serialization/serialization.pri b/src/corelib/serialization/serialization.pri
index 7407e20d9e..ff653ca8f3 100644
--- a/src/corelib/serialization/serialization.pri
+++ b/src/corelib/serialization/serialization.pri
@@ -3,7 +3,9 @@
 HEADERS += \
     serialization/qcborarray.h \
     serialization/qcborcommon.h \
+    serialization/qcborcommon_p.h \
     serialization/qcbormap.h \
+    serialization/qcborstream.h \
     serialization/qcborvalue.h \
     serialization/qcborvalue_p.h \
     serialization/qdatastream.h \
@@ -22,6 +24,7 @@ HEADERS += \
     serialization/qxmlutils_p.h
 
 SOURCES += \
+    serialization/qcborcommon.cpp \
     serialization/qcbordiagnostic.cpp \
     serialization/qcborvalue.cpp \
     serialization/qdatastream.cpp \
@@ -36,12 +39,20 @@ SOURCES += \
     serialization/qxmlstream.cpp \
     serialization/qxmlutils.cpp
 
-qtConfig(cborstream): {
+qtConfig(cborstreamreader): {
     SOURCES += \
-        serialization/qcborstream.cpp
+        serialization/qcborstreamreader.cpp
 
     HEADERS += \
-        serialization/qcborstream.h
+        serialization/qcborstreamreader.h
+}
+
+qtConfig(cborstreamwriter): {
+    SOURCES += \
+        serialization/qcborstreamwriter.cpp
+
+    HEADERS += \
+        serialization/qcborstreamwriter.h
 }
 
 qtConfig(binaryjson): {