[#BloombergLP-bdlb-Guid]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdlb.adoc[bdlb]::Guid
:relfileprefix: ../../
:mrdocs:

This class implements a value‐semantic `Guid` type.

== Synopsis

Declared in `<bdlb_guid.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
class Guid;
----

== Description

Each object represents an unconstrained `Guid` object, but its uniqueness is _not_ guaranteed, and this component provides no ability to generate a GUID.

This class provides a constructor and several accessors with names and parameters phrased using RFC 4122 field names. These names are used (by RFC 4122 and this component) as designators for parts of the GUID even when those names do not accurately describe the parts (for example, `time low` names bytes 0‐3 of the GUID regardless of whether the values of those bytes come from a clock or are generated randomly).

== Enums

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bdlb/Guid/_04enum.adoc[`Unnamed enum`] 
| GUID layout constants.
|===


== Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bdlb/Guid/2constructor-0a.adoc[`Guid`]         [.small]#[constructor]#
| Constructors
| xref:BloombergLP/bdlb/Guid/operator_assign-025.adoc[`operator=`] 
| Assignment operators
| xref:BloombergLP/bdlb/Guid/begin.adoc[`begin`] 
| Return a pointer to the first byte of this GUID.
| xref:BloombergLP/bdlb/Guid/clockSeqHi.adoc[`clockSeqHi`] 
| Return the 5‐bit value of the `clk_seq_hi_res` field of this guid as specified in RFC 4122, excluding the variant bits.
| xref:BloombergLP/bdlb/Guid/clockSeqHiRes.adoc[`clockSeqHiRes`] 
| Return the 8‐bit `clk_seq_hi_res` field of this guid as specified in RFC 4122.
| xref:BloombergLP/bdlb/Guid/clockSeqLow.adoc[`clockSeqLow`] 
| Return the 8‐bit `clk_seq_low` field of this guid as specified in RFC 4122.
| xref:BloombergLP/bdlb/Guid/data.adoc[`data`] 
| Return a pointer offering unmodifiable access to the most significant byte of this guid object.
| xref:BloombergLP/bdlb/Guid/end.adoc[`end`] 
| Return a pointer one past the end of the least significant byte of this guid object.
| xref:BloombergLP/bdlb/Guid/format.adoc[`format`] 
| Write the value of this object to the specified output `buffer`.
| xref:BloombergLP/bdlb/Guid/node.adoc[`node`] 
| Return the 48‐bit `node` field of this guid as specified in RFC 4122.
| xref:BloombergLP/bdlb/Guid/operator_subs.adoc[`operator[]`] 
| Return the byte at the specified `offset` in this guid.
| xref:BloombergLP/bdlb/Guid/print.adoc[`print`] 
| Write the value of this object to the specified output `stream`.
| xref:BloombergLP/bdlb/Guid/timeHi.adoc[`timeHi`] 
| Return the 12‐bit value of the `time_hi_and_version` field of this guid as specified in RFC 4122, excluding the `version` bits.
| xref:BloombergLP/bdlb/Guid/timeHiAndVersion.adoc[`timeHiAndVersion`] 
| Return the 16‐bit `time_hi_and_version` field of this guid as specified in RFC 4122.
| xref:BloombergLP/bdlb/Guid/timeLow.adoc[`timeLow`] 
| Return the 32‐bit `time_low` field of this guid as specified in RFC 4122.
| xref:BloombergLP/bdlb/Guid/timeMid.adoc[`timeMid`] 
| Return the 16‐bit `time_mid` field of this guid as specified in RFC 4122.
| xref:BloombergLP/bdlb/Guid/variant.adoc[`variant`] 
| Return the 3‐bit `variant` portion of the `clk_seq_hi_res` field of this guid as specified in RFC 4122.
| xref:BloombergLP/bdlb/Guid/version.adoc[`version`] 
| Return the four‐bit `version` portion of the `time_hi_and_version` field of this guid as specified in RFC 4122.
| xref:BloombergLP/bdlb/Guid/2conversion.adoc[`operator BloombergLP::bslmf::NestedTraitDeclaration<Guid, is_trivially_copyable>`] 
| Declare that this type is bitwise equality comparable.
|===


== Friends

[cols="1,4"]
|===
| Name| Description
| `xref:BloombergLP/bdlb/operator_not_eq-0ef.adoc[BloombergLP::bdlb::operator!=]`
| Return `true` if the specified `lhs` and `rhs` have different values.
| `xref:BloombergLP/bdlb/operator_eq-03b.adoc[BloombergLP::bdlb::operator==]`
| Return `true` if the specified `lhs` and `rhs` have the same value.
|===

== Non-Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:BloombergLP/bdlb/operator_lt-01e.adoc[`operator<`]
| Return `true` if the specified `lhs` is less than the specified `rhs`.
| xref:BloombergLP/bdlb/operator_le-0f5.adoc[`operator<=`]
| Return `true` if the specified `lhs` is less than or equal to `rhs`.
| xref:BloombergLP/bdlb/operator_gt-0f6.adoc[`operator>`]
| Return `true` if the specified `lhs` is greater than the specified `rhs`.
| xref:BloombergLP/bdlb/operator_ge-05f.adoc[`operator>=`]
| Return `true` if the specified `lhs` is greater than or equal to `rhs`.
|===


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