Struct uuid::Uuid

#[repr(transparent)]
pub struct Uuid(_);

A Universally Unique Identifier (UUID).

Examples

Parse a UUID given in the simple format and print it as a urn:

let my_uuid = Uuid::parse_str("a1a2a3a4b1b2c1c2d1d2d3d4d5d6d7d8")?;

println!("{}", my_uuid.urn());

Create a new random (V4) UUID and print it out in hexadecimal form:

// Note that this requires the `v4` feature enabled in the uuid crate.
let my_uuid = Uuid::new_v4();

println!("{}", my_uuid);

Formatting

A UUID can be formatted in one of a few ways:

• simple: a1a2a3a4b1b2c1c2d1d2d3d4d5d6d7d8.
• hyphenated: a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8.
• urn: urn:uuid:A1A2A3A4-B1B2-C1C2-D1D2-D3D4D5D6D7D8.
• braced: {a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8}.

The default representation when formatting a UUID with Display is hyphenated:

let my_uuid = Uuid::parse_str("a1a2a3a4b1b2c1c2d1d2d3d4d5d6d7d8")?;

assert_eq!(
    "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
    my_uuid.to_string(),
);

Other formats can be specified using adapter methods on the UUID:

let my_uuid = Uuid::parse_str("a1a2a3a4b1b2c1c2d1d2d3d4d5d6d7d8")?;

assert_eq!(
    "urn:uuid:a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
    my_uuid.urn().to_string(),
);

Endianness

The specification for UUIDs encodes the integer fields that make up the value in big-endian order. This crate assumes integer inputs are already in the correct order by default, regardless of the endianness of the environment. Most methods that accept integers have a _le variant (such as from_fields_le) that assumes any integer values will need to have their bytes flipped, regardless of the endianness of the environment.

Most users won’t need to worry about endianness unless they need to operate on individual fields (such as when converting between Microsoft GUIDs). The important things to remember are:

• The endianness is in terms of the fields of the UUID, not the environment.
• The endianness is assumed to be big-endian when there’s no _le suffix somewhere.
• Byte-flipping in _le methods applies to each integer.
• Endianness roundtrips, so if you create a UUID with from_fields_le you’ll get the same values back out with to_fields_le.

ABI

The Uuid type is always guaranteed to be have the same ABI as Bytes.

Implementations

impl Uuid

pub const fn nil() -> Self

The ‘nil UUID’.

The nil UUID is a special form of UUID that is specified to have all 128 bits set to zero, as defined in IETF RFC 4122 Section 4.1.7.

Examples

Basic usage:

let uuid = Uuid::nil();

assert_eq!(
    "00000000-0000-0000-0000-000000000000",
    uuid.hyphenated().to_string(),
);

pub const fn from_fields(d1: u32, d2: u16, d3: u16, d4: &[u8; 8]) -> Uuid

Creates a UUID from four field values.

Examples

Basic usage:

let d1 = 0xa1a2a3a4;
let d2 = 0xb1b2;
let d3 = 0xc1c2;
let d4 = [0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8];

let uuid = Uuid::from_fields(d1, d2, d3, &d4);

assert_eq!(
    "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
    uuid.hyphenated().to_string(),
);

pub const fn from_fields_le(d1: u32, d2: u16, d3: u16, d4: &[u8; 8]) -> Uuid

Creates a UUID from four field values in little-endian order.

The bytes in the d1, d2 and d3 fields will be flipped to convert into big-endian order. This is based on the endianness of the UUID, rather than the target environment so bytes will be flipped on both big and little endian machines.

Examples

let d1 = 0xa1a2a3a4;
let d2 = 0xb1b2;
let d3 = 0xc1c2;
let d4 = [0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8];

let uuid = Uuid::from_fields_le(d1, d2, d3, &d4);

assert_eq!(
    "a4a3a2a1-b2b1-c2c1-d1d2-d3d4d5d6d7d8",
    uuid.hyphenated().to_string(),
);

pub const fn from_u128(v: u128) -> Self

Creates a UUID from a 128bit value.

Examples

Basic usage:

let v = 0xa1a2a3a4b1b2c1c2d1d2d3d4d5d6d7d8u128;

let uuid = Uuid::from_u128(v);

assert_eq!(
    "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
    uuid.hyphenated().to_string(),
);

pub const fn from_u128_le(v: u128) -> Self

Creates a UUID from a 128bit value in little-endian order.

The entire value will be flipped to convert into big-endian order. This is based on the endianness of the UUID, rather than the target environment so bytes will be flipped on both big and little endian machines.

Examples

Basic usage:

let v = 0xa1a2a3a4b1b2c1c2d1d2d3d4d5d6d7d8u128;

let uuid = Uuid::from_u128_le(v);

assert_eq!(
    "d8d7d6d5-d4d3-d2d1-c2c1-b2b1a4a3a2a1",
    uuid.hyphenated().to_string(),
);

pub const fn from_u64_pair(high_bits: u64, low_bits: u64) -> Self

Creates a UUID from two 64bit values.

Examples

Basic usage:

let hi = 0xa1a2a3a4b1b2c1c2u64;
let lo = 0xd1d2d3d4d5d6d7d8u64;

let uuid = Uuid::from_u64_pair(hi, lo);

assert_eq!(
    "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
    uuid.hyphenated().to_string(),
);

pub fn from_slice(b: &[u8]) -> Result<Uuid, Error>

Creates a UUID using the supplied bytes.

Errors

This function will return an error if b has any length other than 16.

Examples

Basic usage:

let bytes = [
    0xa1, 0xa2, 0xa3, 0xa4,
    0xb1, 0xb2,
    0xc1, 0xc2,
    0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
];

let uuid = Uuid::from_slice(&bytes)?;

assert_eq!(
    "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8",
    uuid.hyphenated().to_string(),
);

pub fn from_slice_le(b: &[u8]) -> Result<Uuid, Error>

Creates a UUID using the supplied bytes in little endian order.

The individual fields encoded in the buffer will be flipped.

Errors

This function will return an error if b has any length other than 16.

Examples

Basic usage:

let bytes = [
    0xa1, 0xa2, 0xa3, 0xa4,
    0xb1, 0xb2,
    0xc1, 0xc2,
    0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
];

let uuid = Uuid::from_slice_le(&bytes)?;

assert_eq!(
    uuid.hyphenated().to_string(),
    "a4a3a2a1-b2b1-c2c1-d1d2-d3d4d5d6d7d8"
);

pub const fn from_bytes(bytes: Bytes) -> Uuid

Creates a UUID using the supplied bytes.

Examples

Basic usage:

let bytes = [
    0xa1, 0xa2, 0xa3, 0xa4,
    0xb1, 0xb2,
    0xc1, 0xc2,
    0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
];

let uuid = Uuid::from_bytes(bytes);

assert_eq!(
    uuid.hyphenated().to_string(),
    "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8"
);

pub const fn from_bytes_le(b: Bytes) -> Uuid

Creates a UUID using the supplied bytes in little endian order.

The individual fields encoded in the buffer will be flipped.

Examples

Basic usage:

let bytes = [
    0xa1, 0xa2, 0xa3, 0xa4,
    0xb1, 0xb2,
    0xc1, 0xc2,
    0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
];

let uuid = Uuid::from_bytes_le(bytes);

assert_eq!(
    "a4a3a2a1-b2b1-c2c1-d1d2-d3d4d5d6d7d8",
    uuid.hyphenated().to_string(),
);

pub fn from_bytes_ref(bytes: &Bytes) -> &Uuid

Creates a reference to a UUID from a reference to the supplied bytes.

Examples

Basic usage:

let bytes = [
    0xa1, 0xa2, 0xa3, 0xa4,
    0xb1, 0xb2,
    0xc1, 0xc2,
    0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
];

let uuid = Uuid::from_bytes_ref(&bytes);

assert_eq!(
    uuid.hyphenated().to_string(),
    "a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8"
);

assert!(std::ptr::eq(
    uuid as *const Uuid as *const u8,
    &bytes as *const [u8; 16] as *const u8,
));

impl Uuid

pub fn parse_str(input: &str) -> Result<Uuid, Error>

Parses a Uuid from a string of hexadecimal digits with optional hyphens.

Any of the formats generated by this module (simple, hyphenated, urn, Microsoft GUID) are supported by this parsing function.

Prefer try_parse unless you need detailed user-facing diagnostics. This method will be eventually deprecated in favor of try_parse.

Examples

Parse a hyphenated UUID:

let uuid = Uuid::parse_str("550e8400-e29b-41d4-a716-446655440000")?;

assert_eq!(Some(Version::Random), uuid.get_version());
assert_eq!(Variant::RFC4122, uuid.get_variant());

pub const fn try_parse(input: &str) -> Result<Uuid, Error>

Parses a Uuid from a string of hexadecimal digits with optional hyphens.

This function is similar to parse_str, in fact parse_str shares the same underlying parser. The difference is that if try_parse fails, it won’t generate very useful error messages. The parse_str function will eventually be deprecated in favor or try_parse.

To parse a UUID from a byte stream instead of a UTF8 string, see try_parse_ascii.

Examples

Parse a hyphenated UUID:

let uuid = Uuid::try_parse("550e8400-e29b-41d4-a716-446655440000")?;

assert_eq!(Some(Version::Random), uuid.get_version());
assert_eq!(Variant::RFC4122, uuid.get_variant());

pub const fn try_parse_ascii(input: &[u8]) -> Result<Uuid, Error>

Parses a Uuid from a string of hexadecimal digits with optional hyphens.

The input is expected to be a string of ASCII characters. This method can be more convenient than try_parse if the UUID is being parsed from a byte stream instead of from a UTF8 string.

Examples

Parse a hyphenated UUID:

let uuid = Uuid::try_parse_ascii(b"550e8400-e29b-41d4-a716-446655440000")?;

assert_eq!(Some(Version::Random), uuid.get_version());
assert_eq!(Variant::RFC4122, uuid.get_variant());

impl Uuid

pub const fn hyphenated(self) -> Hyphenated

Get a Hyphenated formatter.

pub fn as_hyphenated(&self) -> &Hyphenated

Get a borrowed Hyphenated formatter.

pub const fn simple(self) -> Simple

Get a Simple formatter.

pub fn as_simple(&self) -> &Simple

Get a borrowed Simple formatter.

pub const fn urn(self) -> Urn

Get a Urn formatter.

pub fn as_urn(&self) -> &Urn

Get a borrowed Urn formatter.

pub const fn braced(self) -> Braced

Get a Braced formatter.

pub fn as_braced(&self) -> &Braced

Get a borrowed Braced formatter.

impl Uuid

pub fn new_v4() -> Uuid

Creates a random UUID.

This uses the getrandom crate to utilise the operating system’s RNG as the source of random numbers. If you’d like to use a custom generator, don’t use this method: generate random bytes using your custom generator and pass them to the uuid::Builder::from_random_bytes function instead.

Note that usage of this method requires the v4 feature of this crate to be enabled.

Examples

Basic usage:

let uuid = Uuid::new_v4();

assert_eq!(Some(Version::Random), uuid.get_version());

impl Uuid

pub const NAMESPACE_DNS: Self

UUID namespace for Domain Name System (DNS).

pub const NAMESPACE_OID: Self

UUID namespace for ISO Object Identifiers (OIDs).

pub const NAMESPACE_URL: Self

UUID namespace for Uniform Resource Locators (URLs).

pub const NAMESPACE_X500: Self

UUID namespace for X.500 Distinguished Names (DNs).

pub const fn get_variant(&self) -> Variant

Returns the variant of the UUID structure.

This determines the interpretation of the structure of the UUID. This method simply reads the value of the variant byte. It doesn’t validate the rest of the UUID as conforming to that variant.

Examples

Basic usage:

let my_uuid = Uuid::parse_str("02f09a3f-1624-3b1d-8409-44eff7708208")?;

assert_eq!(Variant::RFC4122, my_uuid.get_variant());

References

• Variant in RFC4122

pub const fn get_version_num(&self) -> usize

Returns the version number of the UUID.

This represents the algorithm used to generate the value. This method is the future-proof alternative to Uuid::get_version.

Examples

Basic usage:

let my_uuid = Uuid::parse_str("02f09a3f-1624-3b1d-8409-44eff7708208")?;

assert_eq!(3, my_uuid.get_version_num());

References

• Version in RFC4122

pub const fn get_version(&self) -> Option<Version>

Returns the version of the UUID.

This represents the algorithm used to generate the value. If the version field doesn’t contain a recognized version then None is returned. If you’re trying to read the version for a future extension you can also use Uuid::get_version_num to unconditionally return a number. Future extensions may start to return Some once they’re standardized and supported.

Examples

Basic usage:

let my_uuid = Uuid::parse_str("02f09a3f-1624-3b1d-8409-44eff7708208")?;

assert_eq!(Some(Version::Md5), my_uuid.get_version());

References

• Version in RFC4122

pub fn as_fields(&self) -> (u32, u16, u16, &[u8; 8])

Returns the four field values of the UUID.

These values can be passed to the Uuid::from_fields method to get the original Uuid back.

• The first field value represents the first group of (eight) hex digits, taken as a big-endian u32 value. For V1 UUIDs, this field represents the low 32 bits of the timestamp.
• The second field value represents the second group of (four) hex digits, taken as a big-endian u16 value. For V1 UUIDs, this field represents the middle 16 bits of the timestamp.
• The third field value represents the third group of (four) hex digits, taken as a big-endian u16 value. The 4 most significant bits give the UUID version, and for V1 UUIDs, the last 12 bits represent the high 12 bits of the timestamp.
• The last field value represents the last two groups of four and twelve hex digits, taken in order. The first 1-3 bits of this indicate the UUID variant, and for V1 UUIDs, the next 13-15 bits indicate the clock sequence and the last 48 bits indicate the node ID.

Examples

let uuid = Uuid::nil();

assert_eq!(uuid.as_fields(), (0, 0, 0, &[0u8; 8]));

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;

assert_eq!(
    uuid.as_fields(),
    (
        0xa1a2a3a4,
        0xb1b2,
        0xc1c2,
        &[0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8],
    )
);

pub fn to_fields_le(&self) -> (u32, u16, u16, &[u8; 8])

Returns the four field values of the UUID in little-endian order.

The bytes in the returned integer fields will be converted from big-endian order. This is based on the endianness of the UUID, rather than the target environment so bytes will be flipped on both big and little endian machines.

Examples

use uuid::Uuid;

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;

assert_eq!(
    uuid.to_fields_le(),
    (
        0xa4a3a2a1,
        0xb2b1,
        0xc2c1,
        &[0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8],
    )
);

pub const fn as_u128(&self) -> u128

Returns a 128bit value containing the value.

The bytes in the UUID will be packed directly into a u128.

Examples

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;

assert_eq!(
    uuid.as_u128(),
    0xa1a2a3a4b1b2c1c2d1d2d3d4d5d6d7d8,
);

pub const fn to_u128_le(&self) -> u128

Returns a 128bit little-endian value containing the value.

The bytes in the u128 will be flipped to convert into big-endian order. This is based on the endianness of the UUID, rather than the target environment so bytes will be flipped on both big and little endian machines.

Note that this will produce a different result than Uuid::to_fields_le, because the entire UUID is reversed, rather than reversing the individual fields in-place.

Examples

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;

assert_eq!(
    uuid.to_u128_le(),
    0xd8d7d6d5d4d3d2d1c2c1b2b1a4a3a2a1,
);

pub const fn as_u64_pair(&self) -> (u64, u64)

Returns two 64bit values containing the value.

The bytes in the UUID will be split into two u64. The first u64 represents the 64 most significant bits, the second one represents the 64 least significant.

Examples

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;
assert_eq!(
    uuid.as_u64_pair(),
    (0xa1a2a3a4b1b2c1c2, 0xd1d2d3d4d5d6d7d8),
);

pub const fn as_bytes(&self) -> &Bytes

Returns a slice of 16 octets containing the value.

This method borrows the underlying byte value of the UUID.

Examples

let bytes1 = [
    0xa1, 0xa2, 0xa3, 0xa4,
    0xb1, 0xb2,
    0xc1, 0xc2,
    0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
];
let uuid1 = Uuid::from_bytes_ref(&bytes1);

let bytes2 = uuid1.as_bytes();
let uuid2 = Uuid::from_bytes_ref(bytes2);

assert_eq!(uuid1, uuid2);

assert!(std::ptr::eq(
    uuid2 as *const Uuid as *const u8,
    &bytes1 as *const [u8; 16] as *const u8,
));

pub const fn into_bytes(self) -> Bytes

Consumes self and returns the underlying byte value of the UUID.

Examples

let bytes = [
    0xa1, 0xa2, 0xa3, 0xa4,
    0xb1, 0xb2,
    0xc1, 0xc2,
    0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
];
let uuid = Uuid::from_bytes(bytes);
assert_eq!(bytes, uuid.into_bytes());

pub const fn is_nil(&self) -> bool

Tests if the UUID is nil.

pub const fn encode_buffer() -> [u8; 45]

A buffer that can be used for encode_... calls, that is guaranteed to be long enough for any of the format adapters.

Examples

let uuid = Uuid::nil();

assert_eq!(
    uuid.simple().encode_lower(&mut Uuid::encode_buffer()),
    "00000000000000000000000000000000"
);

assert_eq!(
    uuid.hyphenated()
        .encode_lower(&mut Uuid::encode_buffer()),
    "00000000-0000-0000-0000-000000000000"
);

assert_eq!(
    uuid.urn().encode_lower(&mut Uuid::encode_buffer()),
    "urn:uuid:00000000-0000-0000-0000-000000000000"
);

Trait Implementations

impl AsRef<[u8]> for Uuid

fn as_ref(&self) -> &[u8]

Performs the conversion.

impl AsRef<Uuid> for Hyphenated

fn as_ref(&self) -> &Uuid

Performs the conversion.

impl AsRef<Uuid> for Simple

fn as_ref(&self) -> &Uuid

Performs the conversion.

impl AsRef<Uuid> for Urn

fn as_ref(&self) -> &Uuid

Performs the conversion.

impl AsRef<Uuid> for Braced

fn as_ref(&self) -> &Uuid

Performs the conversion.

impl Borrow<Uuid> for Hyphenated

fn borrow(&self) -> &Uuid

Immutably borrows from an owned value.

impl Borrow<Uuid> for Simple

fn borrow(&self) -> &Uuid

Immutably borrows from an owned value.

impl Borrow<Uuid> for Urn

fn borrow(&self) -> &Uuid

Immutably borrows from an owned value.

impl Borrow<Uuid> for Braced

fn borrow(&self) -> &Uuid

Immutably borrows from an owned value.

impl Clone for Uuid

fn clone(&self) -> Uuid

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Uuid

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Uuid

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Uuid

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl Display for Uuid

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<Braced> for Uuid

fn from(f: Braced) -> Self

Performs the conversion.

impl From<Hyphenated> for Uuid

fn from(f: Hyphenated) -> Self

Performs the conversion.

impl From<Simple> for Uuid

fn from(f: Simple) -> Self

Performs the conversion.

impl From<Urn> for Uuid

fn from(f: Urn) -> Self

Performs the conversion.

impl From<Uuid> for Hyphenated

fn from(f: Uuid) -> Self

Performs the conversion.

impl From<Uuid> for Simple

fn from(f: Uuid) -> Self

Performs the conversion.

impl From<Uuid> for Urn

fn from(f: Uuid) -> Self

Performs the conversion.

impl From<Uuid> for Braced

fn from(f: Uuid) -> Self

Performs the conversion.

impl FromStr for Uuid

type Err = Error

The associated error which can be returned from parsing.

fn from_str(uuid_str: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for Uuid

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl LowerHex for Uuid

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Ord for Uuid

fn cmp(&self, other: &Uuid) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Uuid> for Uuid

fn eq(&self, other: &Uuid) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Uuid) -> bool

This method tests for !=.

impl PartialOrd<Uuid> for Uuid

fn partial_cmp(&self, other: &Uuid) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for Uuid

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl TryFrom<&'_ str> for Uuid

type Error = Error

The type returned in the event of a conversion error.

fn try_from(uuid_str: &str) -> Result<Self, Self::Error>

Performs the conversion.

impl UpperHex for Uuid

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for Uuid

impl Eq for Uuid

impl StructuralEq for Uuid

impl StructuralPartialEq for Uuid