Struct Id 

pub struct Id<T> { /* private fields */ }

A stable generational handle into an Arena<T>. 指向 Arena<T> 的稳定代际句柄。

An Id is two packed integers (slot index + generation) and never stores a reference, so it can outlive the arena without dangling. Id 由两个打包的整数（槽位索引 + 代际）组成，且从不存储引用，因此可以比 arena 存活更久而不会悬垂。 Once a slot is removed, its generation advances, invalidating all previously issued Ids. 一旦槽位被移除，其代际就会递增，从而使所有先前发出的 Id 失效。

The T parameter is phantom: it exists only to make IDs of different arenas distinct types at compile time. T 参数是幻影的：它仅用于让不同 arena 的 ID 在编译期成为不同的类型。 Trait impls are written by hand so that Id<T> is always Copy/Eq/Hash regardless of T. 特质实现均为手写，以便无论 T 为何，Id<T> 始终是 Copy/Eq/Hash。

Implementations

impl<T> Id<T>

pub fn index(self) -> u32

pub fn generation(self) -> u32

Trait Implementations

impl<T> Clone for Id<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Copy for Id<T>

impl<T> Debug for Id<T>

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

Formats the value using the given formatter.

impl<T> Eq for Id<T>

impl<T> Hash for Id<T>

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<T> Ord for Id<T>

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<T> PartialEq for Id<T>

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

Equality operator ==.

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

Inequality operator !=.

impl<T> PartialOrd for Id<T>

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.