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# QUuid Class Reference

The QUuid class defines a Universally Unique Identifier (UUID). More...

All the functions in this class are reentrant when Qt is built with thread support.

`#include <quuid.h>`

List of all member functions.

## Public Members

- QUuid ()
- QUuid ( uint l, ushort w1, ushort w2, uchar b1, uchar b2, uchar b3, uchar b4, uchar b5, uchar b6, uchar b7, uchar b8 )
- QUuid ( const QUuid & orig )
- QUuid ( const QString & text )
- QString toString () const
- operator QString () const
- bool isNull () const
- QUuid & operator= ( const QUuid & uuid )
- bool operator== ( const QUuid & other ) const
- bool operator!= ( const QUuid & other ) const

## Related Functions

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

## Detailed Description

The QUuid class defines a Universally Unique Identifier (UUID).

For objects or declarations that need to be identified uniquely, UUIDs (also known as GUIDs) are widely used in order to assign a fixed and easy to compare value to this object or declaration. The 128bit value of an UUID is generated by an algorithm that guarantees a value that is unique in time and space.

In Qt, UUIDs are wrapped by the QUuid struct which provides convenience functions for comparing and coping this value. Most platforms provide a tool to generate new UUIDs (uuidgen, guidgen).

## Member Function Documentation

### QUuid::QUuid ()

Creates the null UUID {00000000-0000-0000-0000-000000000000}.

### 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 an 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 )

### QUuid::QUuid ( const QUuid & orig )

Creates a copy of the QUuid orig.

### QUuid::QUuid ( const QString & text )

Creates a QUuid object from the string text. Right now, the function can only convert the format {12345678-1234-1234-1234-123456789ABC} and will create the null UUID when the conversion fails.

### bool QUuid::isNull () const

Returns TRUE if this is the null UUID {00000000-0000-0000-0000-000000000000}, otherwise returns FALSE.

### QUuid::operator QString () const

Returns the string representation of the uuid.

See also toString().

### bool QUuid::operator!= ( const QUuid & other ) const

Returns TRUE if this QUuid and the other QUuid are different, otherwise returns FALSE.

### QUuid & QUuid::operator= ( const QUuid & uuid )

Assigns the value of uuid to this QUuid object.

### bool QUuid::operator== ( const QUuid & other ) const

Returns TRUE if this QUuid and the other QUuid are identical, otherwise returns FALSE.

### QString QUuid::toString () const

QString QUuid::toString() const

Returns the string representation of the uuid.

## Related Functions

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

Writes the id to the datastream s.

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

Reads a universally unique id from from the stream s into id.

This file is part of the Qt toolkit. Copyright © 1995-2003 Trolltech. All Rights Reserved.