Struct LayerHandle 

pub struct LayerHandle { /* private fields */ }

Opaque, generation-tagged identity for a scene layer.

The scene recycles table slots, so a bare index would let a handle to a removed layer address whatever took its place. The generation counter makes that impossible: a stale handle no longer matches, and layer returns None.

Implementations

impl LayerHandle

pub const fn is_valid(self) -> bool

Whether this is not the default sentinel.

Says nothing about liveness — a valid handle can still be stale. Resolve with LayerScene::layer.

pub const fn layer_id(self) -> LayerId

A stable identity for the allocator.

Packs slot and generation, so a recycled slot yields a different id. That is what the allocator’s warm-start state needs: a new layer must never be able to masquerade as the removed one whose place it took.

Trait Implementations

impl Clone for LayerHandle

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for LayerHandle

impl Debug for LayerHandle

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

Formats the value using the given formatter.

impl Default for LayerHandle

fn default() -> Self

Returns the “default value” for a type.

impl Eq for LayerHandle

impl From<LayerHandle> for LayerId

fn from(handle: LayerHandle) -> Self

The same packing LayerHandle::layer_id does.

Here as well so anything taking a layer’s identity can accept either, which is what lets a report be queried with a handle by a caller and with a bare id by a test that has no scene to get a handle from.

impl Hash for LayerHandle

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 Ord for LayerHandle

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.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

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

Restrict a value to a certain range.

impl PartialEq for LayerHandle

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for LayerHandle

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 StructuralPartialEq for LayerHandle