Struct LayerId 

pub struct LayerId(pub u64);

Stable identity for a layer across frames.

Deviation: identity by value, not by address

The C++ allocator remembers const Layer* and therefore needs forget_layer(), which the header explains must run before a Layer is destroyed:

without invalidation, heap reuse can give a freshly-added layer the same address, fool the diff path into treating the two as the same logical layer, and silently skip property writes the kernel needs.

Keying on a caller-assigned id removes that hazard rather than mitigating it: a recycled allocation cannot masquerade as a previous layer, provided the caller never reuses an id (Output and the scene never do). Allocator::forget_layer is still worth calling, to keep the fast path warm and to force a full write on the plane the layer leaves.

Tuple Fields

0: u64

Trait Implementations

impl Clone for LayerId

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 LayerId

impl Debug for LayerId

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

Formats the value using the given formatter.

impl Eq for LayerId

impl Hash for LayerId

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 LayerId

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 LayerId

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for LayerId

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 LayerId