QUuid Class | Qt Core (original) (raw)

This class is strongly comparable.

This class is strongly comparable with GUID.

Note: Comparison with GUID is Windows-only.

Member Function Documentation

[constexpr noexcept] QUuid::QUuid()

Creates the null UUID. toString() will output the null UUID as "{00000000-0000-0000-0000-000000000000}".

[explicit noexcept] QUuid::QUuid(QAnyStringView text)

Creates a QUuid object from the string text, which must be formatted as five hex fields separated by '-', e.g., "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" where each 'x' is a hex digit. The curly braces shown here are optional, but it is normal to include them. If the conversion fails, a null UUID is created. See toString() for an explanation of how the five hex fields map to the public data members in QUuid.

Note: In Qt versions prior to 6.3, this constructor was an overload set consisting of QString, QByteArray and const char* instead of one constructor taking QAnyStringView.

See also toString() and QUuid().

[constexpr noexcept] QUuid::QUuid(const GUID &guid)

Casts a Windows guid to a Qt QUuid.

Warning: This function is only for Windows platforms.

[explicit noexcept, since 6.6] QUuid::QUuid(QUuid::Id128Bytes id128, QSysInfo::Endian order = QSysInfo::BigEndian)

Creates a QUuid based on the integral id128 parameter. The input id128 parameter is considered to have byte order order.

This function was introduced in Qt 6.6.

See also fromBytes(), toBytes(), toRfc4122(), and toUInt128().

[constexpr noexcept] QUuid::QUuid(uint l, ushort w1, ushort w2, uchar b1, uchar b2, uchar b3, uchar b4, uchar b5, uchar b6, uchar b7, uchar b8)

Creates a UUID with the value specified by the parameters, l, w1, w2, b1, b2, b3, b4, b5, b6, b7, b8.

Example:

// {67C8770B-44F1-410A-AB9A-F9B5446F13EE} QUuid IID_MyInterface(0x67c8770b, 0x44f1, 0x410a, 0xab, 0x9a, 0xf9, 0xb5, 0x44, 0x6f, 0x13, 0xee);

[static] QUuid QUuid::createUuid()

On any platform other than Windows, this function returns a new UUID with variant QUuid::DCE and version QUuid::Random. On Windows, a GUID is generated using the Windows API and will be of the type that the API decides to create.

See also variant() and version().

[static noexcept] QUuid QUuid::createUuidV3(QUuid ns, QByteArrayView baseData)

This function returns a new UUID with variant QUuid::DCE and version QUuid::Md5. ns is the namespace and baseData is the basic data as described by RFC 4122.

See also variant(), version(), createUuidV5(), and createUuidV7().

[static] QUuid QUuid::createUuidV3(const QUuid &ns, const QString &baseData)

This function returns a new UUID with variant QUuid::DCE and version QUuid::Md5. ns is the namespace and baseData is the basic data as described by RFC 4122.

See also variant(), version(), createUuidV5(), and createUuidV7().

[static noexcept] QUuid QUuid::createUuidV5(QUuid ns, QByteArrayView baseData)

This function returns a new UUID with variant QUuid::DCE and version QUuid::Sha1. ns is the namespace and baseData is the basic data as described by RFC 4122.

See also variant(), version(), and createUuidV3().

[static] QUuid QUuid::createUuidV5(const QUuid &ns, const QString &baseData)

This function returns a new UUID with variant QUuid::DCE and version QUuid::Sha1. ns is the namespace and baseData is the basic data as described by RFC 4122.

See also variant(), version(), and createUuidV3().

[static, since 6.9] QUuid QUuid::createUuidV7()

This function returns a new UUID with variant QUuid::DCE and version QUuid::UnixEpoch.

It uses a time-ordered value field derived from the number of milliseconds since the UNIX Epoch as described by RFC9562.

This function was introduced in Qt 6.9.

See also variant(), version(), createUuidV3(), and createUuidV5().

[static, since 6.6] QUuid QUuid::fromBytes(const void *bytes, QSysInfo::Endian order = QSysInfo::BigEndian)

Reads 128 bits (16 bytes) from bytes using byte order order and returns the QUuid corresponding to those bytes. This function does the same as fromRfc4122() if the byte order order is QSysInfo::BigEndian.

This function was introduced in Qt 6.6.

See also fromRfc4122().

[static] QUuid QUuid::fromCFUUID(CFUUIDRef uuid)

Constructs a new QUuid containing a copy of the uuid CFUUID.

Note: this function is only available on Apple platforms.

[static] QUuid QUuid::fromNSUUID(const NSUUID *uuid)

Constructs a new QUuid containing a copy of the uuid NSUUID.

Note: this function is only available on Apple platforms.

[static noexcept] QUuid QUuid::fromRfc4122(QByteArrayView bytes)

Creates a QUuid object from the binary representation of the UUID, as specified by RFC 4122 section 4.1.2. See toRfc4122() for a further explanation of the order of bytes required.

The byte array accepted is NOT a human readable format.

If the conversion fails, a null UUID is created.

See also toRfc4122(), QUuid(), and fromBytes().

[static noexcept] QUuid QUuid::fromString(QAnyStringView string)

Creates a QUuid object from the string string, which must be formatted as five hex fields separated by '-', e.g., "{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}" where each 'x' is a hex digit. The curly braces shown here are optional, but it is normal to include them. If the conversion fails, a null UUID is returned. See toString() for an explanation of how the five hex fields map to the public data members in QUuid.

See also toString() and QUuid().

[static constexpr noexcept, since 6.6] QUuid QUuid::fromUInt128(quint128 uuid, QSysInfo::Endian order = QSysInfo::BigEndian)

Creates a QUuid based on the integral uuid parameter. The input uuid parameter is considered to have byte order order.

Note: This function is only present on platforms that offer a 128-bit integer type.

This function was introduced in Qt 6.6.

See also toUInt128(), fromBytes(), toBytes(), and toRfc4122().

[constexpr noexcept] bool QUuid::isNull() const

Returns true if this is the null UUID {00000000-0000-0000-0000-000000000000}; otherwise returns false.

QByteArray QUuid::toByteArray(QUuid::StringFormat mode = WithBraces) const

Returns the string representation of this QUuid, with the formattiong controlled by the mode parameter. From left to right, the five hex fields are obtained from the four public data members in QUuid as follows:

[noexcept, since 6.6] QUuid::Id128Bytes QUuid::toBytes(QSysInfo::Endian order = QSysInfo::BigEndian) const

Returns a 128-bit ID created from this QUuid on the byte order specified by order. The binary content of this function is the same as toRfc4122() if the order is QSysInfo::BigEndian. See that function for more details.

This function was introduced in Qt 6.6.

See also toRfc4122(), fromBytes(), and QUuid().

CFUUIDRef QUuid::toCFUUID() const

Creates a CFUUID from a QUuid.

The caller owns the CFUUID and is responsible for releasing it.

Note: this function is only available on Apple platforms.

NSUUID *QUuid::toNSUUID() const

Creates a NSUUID from a QUuid.

The NSUUID is autoreleased.

Note: this function is only available on Apple platforms.

QByteArray QUuid::toRfc4122() const

Returns the binary representation of this QUuid. The byte array is in big endian format, and formatted according to RFC 4122, section 4.1.2 - "Layout and byte order".

The order is as follows:

The bytes in the byte array returned by this function contains the same binary content as toBytes().

See also toBytes().

QString QUuid::toString(QUuid::StringFormat mode = WithBraces) const

Returns the string representation of this QUuid, with the formattiong controlled by the mode parameter. From left to right, the five hex fields are obtained from the four public data members in QUuid as follows:

[constexpr noexcept, since 6.6] quint128 QUuid::toUInt128(QSysInfo::Endian order = QSysInfo::BigEndian) const

Returns a 128-bit integer created from this QUuid on the byte order specified by order. The binary content of this function is the same as toRfc4122() if the order is QSysInfo::BigEndian. See that function for more details.

Note: This function is only present on platforms that offer a 128-bit integer type.

This function was introduced in Qt 6.6.

See also toRfc4122(), fromUInt128(), toBytes(), fromBytes(), and QUuid().

[constexpr noexcept] QUuid::Variant QUuid::variant() const

Returns the value in the variant field of the UUID. If the return value is QUuid::DCE, call version() to see which layout it uses. The null UUID is considered to be of an unknown variant.

See also version().

[constexpr noexcept] QUuid::Version QUuid::version() const

Returns the version field of the UUID, if the UUID's variant field is QUuid::DCE. Otherwise it returns QUuid::VerUnknown.

See also variant().

[constexpr noexcept] GUID QUuid::operator GUID() const

Returns a Windows GUID from a QUuid.

Warning: This function is only for Windows platforms.

[constexpr noexcept] QUuid &QUuid::operator=(const GUID &guid)

Assigns a Windows guid to a Qt QUuid.

Warning: This function is only for Windows platforms.

Related Non-Members

[constexpr noexcept] bool operator<(const QUuid &lhs, const QUuid &rhs)

[constexpr noexcept] bool operator<=(const QUuid &lhs, const QUuid &rhs)

[constexpr noexcept] bool operator>(const QUuid &lhs, const QUuid &rhs)

[constexpr noexcept] bool operator>=(const QUuid &lhs, const QUuid &rhs)

Performs a comparison of lhs against rhs and returns true if the relative sorting of lhs and rhs is correct for the operation in question, false otherwise. Note that the sorting performed by this functions may not be equal to the sorting of the strings created by toString(), nor the integers toId128(), or the byte array returned by toBytes() and toRfc4122().

See also variant().

[noexcept] size_t qHash(const QUuid &key, size_t seed = 0)

Returns the hash value for key, using seed to seed the calculation.

[constexpr noexcept] bool operator!=(const QUuid &lhs, const GUID &rhs)

Returns true if lhs UUID is not equal to the Windows GUID rhs; otherwise returns false.

[constexpr noexcept] bool operator!=(const QUuid &lhs, const QUuid &rhs)

Returns true if lhs QUuid and the rhs QUuid are different; otherwise returns false.

QDataStream &operator<<(QDataStream &s, const QUuid &id)

Writes the UUID id to the data stream s.

QDebug operator<<(QDebug dbg, const QUuid &id)

Writes the UUID id to the output stream for debugging information dbg.

[constexpr noexcept] bool operator==(const QUuid &lhs, const GUID &rhs)

Returns true if lhs UUID is equal to the Windows GUID rhs; otherwise returns false.

[constexpr noexcept] bool operator==(const QUuid &lhs, const QUuid &rhs)

Returns true if lhs QUuid and the rhs QUuid are identical; otherwise returns false.

QDataStream &operator>>(QDataStream &s, QUuid &id)

Reads a UUID from the stream s into id.