caf::uuid Class Reference

A universally unique identifier according to RFC 4122. More...

#include <uuid.hpp>

Inheritance diagram for caf::uuid:

Public Types
enum	variant_field {   reserved ,   rfc4122 ,   microsoft }
	Denotes the variant (type) that determines the layout of the UUID. More...
enum	version_field {   time_based = 1 ,   dce_compatible = 2 ,   md5_based = 3 ,   randomized = 4 ,   sha1_based = 5 }
	Denotes the version, i.e., which algorithm was used to create this UUID. More...
using	array_type = std::array< std::byte, 16 >

Public Member Functions
	uuid () noexcept
	Creates the nil UUID with all 128 bits set to zero.
	uuid (const uuid &) noexcept=default
uuid &	operator= (const uuid &) noexcept=default
	uuid (const array_type &bytes) noexcept
const array_type &	bytes () const noexcept
array_type &	bytes () noexcept
	operator bool () const noexcept
	Returns true if this UUID is not nil, false otherwise.
bool	operator! () const noexcept
	Returns true if this UUID is nil, false otherwise.
variant_field	variant () const noexcept
	Returns the variant (type) that determines the layout of the UUID.
version_field	version () const noexcept
	Returns the version (sub type) that identifies the algorithm used to generate this UUID.
uint64_t	timestamp () const noexcept
	The 60-bit timestamp of a time-based UUID.
uint16_t	clock_sequence () const noexcept
	The 14-bit unsigned integer helps to avoid duplicates that could arise when the clock is set backwards in time or if the node ID changes.
uint64_t	node () const noexcept
	48-bit value, representing a network address (time_based UUIDs), a hash (md5_based and sha1_based UUIDs), or a random bit sequence (randomized UUIDs).
size_t	hash () const noexcept
	Returns a platform-specific hash value for this UUID.
int	compare (const uuid &other) const noexcept
	Lexicographically compares this and other.

Static Public Member Functions
static uuid	random () noexcept
	Creates a random UUID.
static uuid	random (unsigned seed) noexcept
	Creates a random UUID with a predefined seed.
static uuid	nil () noexcept
	Convenience function for creating an UUID with all 128 bits set to zero.
static bool	can_parse (std::string_view str) noexcept
	Returns whether parse would produce a valid UUID.

Related Symbols
(Note that these are not member symbols.)
CAF_CORE_EXPORT error	parse (std::string_view str, uuid &dest)
CAF_CORE_EXPORT std::string	to_string (const uuid &x)
CAF_CORE_EXPORT expected< uuid >	make_uuid (std::string_view str)
template<class Inspector >
bool	inspect (Inspector &f, uuid &x)

Detailed Description

A universally unique identifier according to RFC 4122.

While this implementation can read all UUID versions, it can only create random-generated ones.

Member Enumeration Documentation

variant_field

enum caf::uuid::variant_field

Denotes the variant (type) that determines the layout of the UUID.

The interpretation of all other bits in a UUID depend on this field.

version_field

enum caf::uuid::version_field

Denotes the version, i.e., which algorithm was used to create this UUID.

Enumerator
time_based	Time-based algorithm.
dce_compatible	DCE security version with embedded POSIX UIDs.
md5_based	Name-based algorithm using MD5 hashing.
randomized	Random or pseudo-random algorithm.
sha1_based	Name-based algorithm using SHA-1 hashing.

Member Function Documentation

clock_sequence()

uint16_t caf::uuid::clock_sequence ( ) const

noexcept

The 14-bit unsigned integer helps to avoid duplicates that could arise when the clock is set backwards in time or if the node ID changes.

Precondition

version() == time_based

compare()

int caf::uuid::compare ( const uuid &  other ) const

noexcept

Lexicographically compares this and other.

Returns

a negative value if *this < other, zero if *this == other and a positive number if *this > other.

operator bool()

caf::uuid::operator bool ( ) const

noexcept

Returns true if this UUID is not nil, false otherwise.

A UUID is nil if all bits are 0.

timestamp()

uint64_t caf::uuid::timestamp ( ) const

noexcept

The 60-bit timestamp of a time-based UUID.

Usually represents a count of 100- nanosecond intervals since 00:00:00.00, 15 October 1582 in UTC.

Precondition

version() == time_based

variant()

uuid::variant_field caf::uuid::variant ( ) const

noexcept

Returns the variant (type) that determines the layout of the UUID.

Precondition

not nil()

version()

uuid::version_field caf::uuid::version ( ) const

noexcept

Returns the version (sub type) that identifies the algorithm used to generate this UUID.

The algorithms defined in RFC 4122 are:

1. Time-based
2. DCE security with embedded POSIX UIDs
3. Name-based, using MD5 hashing
4. Random or pseudo-random
5. Name-based, using SHA-1 hashing

   Precondition

   not nil()

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The documentation for this class was generated from the following files:

• libcaf_core/caf/uuid.hpp
• libcaf_core/caf/uuid.cpp