uuid.h File Reference

Value-typed RFC 4122 UUID and project random-bytes primitive. More...

#include <algorithm>
#include <array>
#include <cstddef>
#include <cstdint>
#include <functional>
#include <iterator>
#include <optional>
#include <ostream>
#include <random>
#include <string>
#include <string_view>
#include <type_traits>
#include <vector>
#include "./macros.h"

Include dependency graph for uuid.h:

Go to the source code of this file.

Classes
class	vlink::Uuid
	Value-typed RFC 4122 UUID. More...
struct	std::hash< vlink::Uuid >
	std::hash specialisation so vlink::Uuid can be used inside unordered containers. More...

Namespaces
	vlink

Functions
bool	vlink::operator== (const Uuid &lhs, const Uuid &rhs) noexcept
bool	vlink::operator!= (const Uuid &lhs, const Uuid &rhs) noexcept
bool	vlink::operator< (const Uuid &lhs, const Uuid &rhs) noexcept

Detailed Description

Value-typed RFC 4122 UUID and project random-bytes primitive.

vlink::Uuid stores 16 bytes in big-endian (network) order matching RFC 4122 section 4.1. The class is trivially comparable, parses and emits both the canonical 36-character hyphenated form and the 32-character compact form, and ships with a thread-local v4 generator backed by std::mt19937.

UUID variant and version reference:

Field	Enumerator	RFC 4122 meaning
Variant	kNcs	NCS backward compatibility (0xxx)
Variant	kRfc	RFC 4122 / DCE 1.1 (10xx)
Variant	kMicrosoft	Microsoft GUID (110x)
Variant	kReserved	Reserved (111x)
Version	kNone	Nil UUID or invalid version nibble
Version	kTimeBased	v1 — gregorian time + node
Version	kDceSecurity	v2 — DCE Security
Version	kNameBasedMd5	v3 — Name + MD5
Version	kRandomBased	v4 — Random / pseudo-random (this generator)
Version	kNameBasedSha1	v5 — Name + SHA-1

Random v4 generation pipeline:

*   std::random_device x8 ---> std::seed_seq ---> std::mt19937 ---> uniform_int(uint32_t)
*                                                       |
*                                                       v
*                                            byte extraction via shifts
*                                                       |
*                                                       v
*                            set variant (octet 8 = 10xxxxxx) + version (octet 6 = 0100xxxx)
* 

Note

Bodies live in uuid.cc; only constexpr operations remain inline so Uuid stays a literal type for compile-time use.