Struct Version 

pub struct Version(/* private fields */);

Represents the version of a slot, combining generation and state.

The lowest 2 bits represent the state:

• 0b00: Vacant
• 0b01: Reserved
• 0b11: Occupied

The upper 30 bits represent the generation.

表示 slot 的版本，结合了代数（generation）和状态。

最低 2 位表示状态：

• 0b00: 空闲 (Vacant)
• 0b01: 预留 (Reserved)
• 0b11: 占用 (Occupied)

高 30 位表示代数。

Implementations

impl Version

pub fn new(generation: Generation, state: u32) -> Self

Create a new Version with specified generation and state

使用指定的代数和状态创建一个新 Version

pub fn sentinel() -> Self

Create a sentinel version

创建哨兵版本

pub fn generation(&self) -> Generation

Get the generation part

获取代数部分

pub fn state(&self) -> u32

Get the state part (lowest 2 bits)

获取状态部分（最低 2 位）

pub fn is_vacant(&self) -> bool

Check if logic state is Vacant (0b00)

检查逻辑状态是否为空闲 (0b00)

pub fn is_reserved(&self) -> bool

Check if logic state is Reserved (0b01)

检查逻辑状态是否为预留 (0b01)

pub fn is_occupied(&self) -> bool

Check if logic state is Occupied (0b11)

检查逻辑状态是否被占用 (0b11)

pub fn vacant_to_reserved(&mut self)

Transition: Vacant -> Reserved

Increases value by 1 (0bXX00 -> 0bXX01)

状态转换：空闲 -> 预留

值增加 1 (0bXX00 -> 0bXX01)

pub fn reserved_to_occupied(&mut self)

Transition: Reserved -> Occupied

Increases value by 2 (0bXX01 -> 0bXX11)

状态转换：预留 -> 占用

值增加 2 (0bXX01 -> 0bXX11)

pub fn occupied_to_vacant(&mut self)

Transition: Occupied -> Vacant (Next Generation)

Increases value by 1 (0bXX11 -> 0bYY00), handles generation wrap

状态转换：占用 -> 空闲（下一代）

值增加 1 (0bXX11 -> 0bYY00)，处理代数回绕

pub fn reserved_to_vacant(&mut self)

Transition: Reserved -> Vacant (Next Generation)

Used when releasing a handle. Increases value by 3 (0bXX01 -> 0bYY00), handles generation wrap

状态转换：预留 -> 空闲（下一代）

用于释放 handle 时。 值增加 3 (0bXX01 -> 0bYY00)，处理代数回绕

Trait Implementations

impl Clone for Version

fn clone(&self) -> Version

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Version

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

Formats the value using the given formatter.

impl PartialEq for Version

fn eq(&self, other: &Version) -> 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 Copy for Version

impl Eq for Version

impl StructuralPartialEq for Version