Struct NodeId 

pub struct NodeId { /* private fields */ }

A unique, generation-checked identifier for an item in an Arena.

NodeId is Copy and can be freely stored, passed around, and compared. It becomes invalid after the corresponding item is deallocated — accessing it will return None rather than corrupted data.

Safety

NodeId provides logical safety (stale IDs are detected) without requiring unsafe code. The generation check prevents use-after-free at the logical level, though it cannot prevent a malicious caller from constructing arbitrary IDs.

Implementations

impl NodeId

pub const fn from_raw_parts(index: u32, generation: u32) -> Self

Creates a NodeId from raw index and generation values.

This is primarily intended for FFI boundaries where node IDs need to be converted to/from C-compatible representations.

Correctness

The caller is responsible for providing valid index/generation pairs that were originally obtained from the arena. Using arbitrary values may result in accessing wrong nodes or getting None from arena lookups.

pub const fn raw_parts(self) -> (u32, u32)

Returns the raw index and generation values of this NodeId.

This is primarily intended for FFI boundaries where node IDs need to be converted to C-compatible representations.

Trait Implementations

impl Clone for NodeId

fn clone(&self) -> NodeId

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for NodeId

impl Debug for NodeId

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

Formats the value using the given formatter.

impl Eq for NodeId

impl Hash for NodeId

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 PartialEq for NodeId

fn eq(&self, other: &NodeId) -> 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 StructuralPartialEq for NodeId