Struct Id 

pub struct Id<Label, const SIZE: usize = 16> { /* private fields */ }

An identifier with a statically associated label type

Use the Label generic to describe what this Id is for. If you have an existing struct, you can use that:

struct User {
    name: String,
    id: Id<User>,
}

// It might be convenient to define a type alias:
type UserId = Id<User>;

By default, Ids are 16 bytes long. This should provide good collision resistance – i.e. you can assume that 2 randomly generated Ids are distinct for all practical purposes. You can customize the Id size with the SIZE const generic:

type TinyId<Label> = Id<Label, 4>;

let _id: TinyId<User> = [0, 0, 0, 42].into();

Implementations

impl<Label, const SIZE: usize> Id<Label, SIZE>

pub fn new_random() -> Self

Generate a new random Id

struct User;

let a = Id::<User>::new_random();
let b = Id::<User>::new_random();

// For all practical purposes, we can assume that 2 random IDs will be different
// (As long as you use the default ID size or larger)
assert_ne!(a, b);

pub fn as_bytes(&self) -> &[u8; SIZE]

The bytes representing this Id

struct Product;

let id: Id<Product, 4> = [1,2,3,4].into();
assert_eq!(id.as_bytes(), [1,2,3,4].as_slice());

pub fn cast_label<NewLabel>(self) -> Id<NewLabel, SIZE>

Change the label type of this Id

struct User;
struct Player;

let user_id :Id<User>= Id::new_random();
let player_id: Id<Player> = user_id.cast_label();
assert_eq!(user_id.as_bytes(), player_id.as_bytes());

Trait Implementations

impl<Label, const SIZE: usize> Clone for Id<Label, SIZE>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<Label, const SIZE: usize> Debug for Id<Label, SIZE>

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

Formats the Id for debugging purposes

let id: Id<String> = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255].into();
assert_eq!(
    format!("{:?}", id),
    "Id<alloc::string::String>(000000000000000000000000000000ff)"
);

Note: the Debug representation may change in the future

impl<'de, Label, const SIZE: usize> Deserialize<'de> for Id<Label, SIZE>

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<Label, const SIZE: usize> Display for Id<Label, SIZE>

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

Produces the hex representation of the Id

let id: Id<String> = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255].into();
assert_eq!(
    format!("{:}", id),
    "000000000000000000000000000000ff"
);

Note: the Display representation may change in the future

impl<Label, const SIZE: usize> From<[u8; SIZE]> for Id<Label, SIZE>

fn from(data: [u8; SIZE]) -> Self

Converts to this type from the input type.

impl<Label, const SIZE: usize> Hash for Id<Label, SIZE>

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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<Label, const SIZE: usize> Into<[u8; SIZE]> for Id<Label, SIZE>

fn into(self) -> [u8; SIZE]

Converts this type into the (usually inferred) input type.

impl<Label, const SIZE: usize> Ord for Id<Label, SIZE>

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

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

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

where Self: Sized,

Restrict a value to a certain interval.

impl<Label, const SIZE: usize> PartialEq for Id<Label, SIZE>

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<Label, const SIZE: usize> PartialOrd for Id<Label, SIZE>

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl<Label, const SIZE: usize> Serialize for Id<Label, SIZE>

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl<Label, const SIZE: usize> Copy for Id<Label, SIZE>

impl<Label, const SIZE: usize> Eq for Id<Label, SIZE>

impl<Label, const SIZE: usize> Send for Id<Label, SIZE>

impl<Label, const SIZE: usize> Sync for Id<Label, SIZE>