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Struct uuid::Uuid

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

A Universally Unique Identifier (UUID).

Implementations

The ‘nil UUID’.

The nil UUID is 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:

use uuid::Uuid;

let uuid = Uuid::nil();

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

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

Errors

This function will return an error if d4’s length is not 8 bytes.

Examples

Basic usage:

use uuid::Uuid;

let d4 = [12, 3, 9, 56, 54, 43, 8, 9];

let uuid = Uuid::from_fields(42, 12, 5, &d4);
let uuid = uuid.map(|uuid| uuid.to_hyphenated().to_string());

let expected_uuid =
    Ok(String::from("0000002a-000c-0005-0c03-0938362b0809"));

assert_eq!(expected_uuid, uuid);

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

The bytes in the d1, d2 and d3 fields will be converted into big-endian order.

Examples
use uuid::Uuid;

let d1 = 0xAB3F1097u32;
let d2 = 0x501Eu16;
let d3 = 0xB736u16;
let d4 = [12, 3, 9, 56, 54, 43, 8, 9];

let uuid = Uuid::from_fields_le(d1, d2, d3, &d4);
let uuid = uuid.map(|uuid| uuid.to_hyphenated().to_string());

let expected_uuid =
    Ok(String::from("97103fab-1e50-36b7-0c03-0938362b0809"));

assert_eq!(expected_uuid, uuid);

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

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

Creates a UUID using the supplied big-endian bytes.

Errors

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

Examples

Basic usage:

use uuid::Uuid;

let bytes = [4, 54, 67, 12, 43, 2, 98, 76, 32, 50, 87, 5, 1, 33, 43, 87];

let uuid = Uuid::from_slice(&bytes);
let uuid = uuid.map(|uuid| uuid.to_hyphenated().to_string());

let expected_uuid =
    Ok(String::from("0436430c-2b02-624c-2032-570501212b57"));

assert_eq!(expected_uuid, uuid);

An incorrect number of bytes:

use uuid::Uuid;

let bytes = [4, 54, 67, 12, 43, 2, 98, 76];

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

assert!(uuid.is_err());

Creates a UUID using the supplied big-endian bytes.

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

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

Get a Hyphenated formatter.

Get a borrowed HyphenatedRef formatter.

Get a Simple formatter.

Get a borrowed SimpleRef formatter.

Get a Urn formatter.

Get a borrowed UrnRef formatter.

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_bytes function instead.

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

Examples

Basic usage:

use uuid::Uuid;

let uuid = Uuid::new_v4();

UUID namespace for Domain Name System (DNS).

UUID namespace for ISO Object Identifiers (OIDs).

UUID namespace for Uniform Resource Locators (URLs).

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

Returns the variant of the UUID structure.

This determines the interpretation of the structure of the UUID. Currently only the RFC4122 variant is generated by this module.

Returns the version number of the UUID.

This represents the algorithm used to generate the contents.

Currently only the Random (V4) algorithm is supported by this module. There are security and privacy implications for using older versions - see Wikipedia: Universally Unique Identifier for details.

Returns the version of the UUID.

This represents the algorithm used to generate the contents

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

These values can be passed to the 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
use uuid::Uuid;

fn main() -> Result<(), uuid::Error> {
    let uuid = Uuid::nil();
    assert_eq!(uuid.as_fields(), (0, 0, 0, &[0u8; 8]));

    let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8")?;
    assert_eq!(
        uuid.as_fields(),
        (
            0x936DA01F,
            0x9ABD,
            0x4D9D,
            b"\x80\xC7\x02\xAF\x85\xC8\x22\xA8"
        )
    );

    Ok(())
}

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.

Examples
use uuid::Uuid;

fn main() -> Result<(), uuid::Error> {
    let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8")?;
    assert_eq!(
        uuid.to_fields_le(),
        (
            0x1FA06D93,
            0xBD9A,
            0x9D4D,
            b"\x80\xC7\x02\xAF\x85\xC8\x22\xA8"
        )
    );
    Ok(())
}

Returns a 128bit value containing the UUID data.

The bytes in the UUID will be packed into a u128, like the Uuid::as_bytes method.

Examples
use uuid::Uuid;

fn main() -> Result<(), uuid::Error> {
    let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8")?;
    assert_eq!(
        uuid.as_u128(),
        0x936DA01F9ABD4D9D80C702AF85C822A8,
    );
    Ok(())
}

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

The bytes in the UUID will be reversed and packed into a u128. 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
use uuid::Uuid;

fn main() -> Result<(), uuid::Error> {
    let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8")?;

    assert_eq!(
        uuid.to_u128_le(),
        0xA822C885AF02C7809D4DBD9A1FA06D93,
    );
    Ok(())
}

Returns an array of 16 octets containing the UUID data.

Tests if the UUID is nil.

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

Examples
use uuid::Uuid;

let uuid = Uuid::nil();

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

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

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

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

Formats the value using the given formatter. Read more

Performs the conversion.

Performs the conversion.

Performs the conversion.

Performs the conversion.

Performs the conversion.

Performs the conversion.

The associated error which can be returned from parsing.

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

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

Formats the value using the given formatter.

This method returns an Ordering between self and other. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

Restrict a value to a certain interval. Read more

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

This method tests for !=.

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

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

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

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

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

Formats the value using the given formatter.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

Uses borrowed data to replace owned data, usually by cloning. Read more

Converts the given value to a String. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.