The QUuid class defines a Universally Unique Identifier (UUID).
.PP
For objects or declarations that must be uniquely identified, UUIDs (also known as GUIDs) are widely used in order to assign a fixed and easy to compare value to the object or declaration. The 128-bit value of a UUID is generated by an algorithm that guarantees that the value is unique.
.PP
In Qt, UUIDs are wrapped by the QUuid struct which provides convenience functions for handling UUIDs. Most platforms provide a tool to generate new UUIDs, for example, uuidgen and guidgen.
.PP
UUIDs generated by QUuid, are based on the Random version of the DCE (Distributed Computing Environment) standard.
.PP
UUIDs can be constructed from numeric values or from strings, or using the static createUuid() function. They can be converted to a string with toString(). UUIDs have a variant() and a version(), and null UUIDs return TRUE from isNull().
.SS "Member Type Documentation"
.SH "QUuid::Variant"
This enum defines the variant of the UUID, which is the scheme which defines the layout of the 128-bits value.
.TP
\fCQUuid::VarUnknown\fR - Variant is unknown
.TP
\fCQUuid::NCS\fR - Reserved for NCS (Network Computing System) backward compatibility
.TP
\fCQUuid::DCE\fR - Distributed Computing Environment, the scheme used by QUuid
.TP
\fCQUuid::Microsoft\fR - Reserved for Microsoft backward compatibility (GUID)
.TP
\fCQUuid::Reserved\fR - Reserved for future definition
.SH "QUuid::Version"
This enum defines the version of the UUID.
.TP
\fCQUuid::VerUnknown\fR - Version is unknown
.TP
\fCQUuid::Time\fR - Time-based, by using timestamp, clock sequence, and MAC network card address (if available) for the node sections
.TP
\fCQUuid::EmbeddedPOSIX\fR - DCE Security version, with embedded POSIX UUIDs
.TP
\fCQUuid::Name\fR - Name-based, by using values from a name for all sections
.TP
\fCQUuid::Random\fR - Random-based, by using random numbers for all sections
.SH MEMBER FUNCTION DOCUMENTATION
.SH "QUuid::QUuid ()"
Creates the null UUID {00000000-0000-0000-0000-000000000000}.
Creates a UUID with the value specified by the parameters, \fIl\fR, \fIw1\fR, \fIw2\fR, \fIb1\fR, \fIb2\fR, \fIb3\fR, \fIb4\fR, \fIb5\fR, \fIb6\fR, \fIb7\fR, \fIb8\fR.
Creates a QUuid object from the string \fItext\fR. The function can only convert a string in the format {HHHHHHHH-HHHH-HHHH-HHHH-HHHHHHHHHHHH} (where 'H' stands for a hex digit). If the conversion fails a null UUID is created.
.SH "QUuid QUuid::createUuid ()\fC [static]\fR"
Returns a new UUID of DCE variant, and Random type. The UUIDs generated are based on the platform specific pseudo-random generator, which is usually not a cryptographic-quality random number generator. Therefore, a UUID is not guaranteed to be unique cross application instances.
.PP
On Windows, the new UUID is extremely likely to be unique on the same or any other system, networked or not.
.PP
See also variant() and version().
.SH "bool QUuid::isNull () const"
Returns TRUE if this is the null UUID {00000000-0000-0000-0000-000000000000}; otherwise returns FALSE.
