Struct EntityId

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

Lightweight identifier for an entity.

Entity identifiers are implemented using an index and a generation count. The generation count ensures that IDs from despawned entities are not reused by new entities.

An entity identifier is only meaningful in the World it was created from. Attempting to use an entity ID in a different world will have unexpected results.

Implementations

impl EntityId

pub const NULL: EntityId

The entity ID which never identifies a live entity. This is the default value for EntityId.

pub const fn new(index: u32, generation: u32) -> Option<EntityId>

Creates a new entity ID from an index and generation count. Returns None if a valid ID is not formed.

pub const fn index(self) -> EntityIdx

Returns the index of this ID.

pub const fn generation(self) -> u32

Returns the generation count of this ID.

Trait Implementations

impl Clone for EntityId

fn clone(&self) -> EntityId

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EntityId

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

Formats the value using the given formatter.

impl Default for EntityId

fn default() -> EntityId

Returns the “default value” for a type.

impl Hash for EntityId

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

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 EntityId

fn cmp(&self, other: &EntityId) -> 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 PartialEq for EntityId

fn eq(&self, other: &EntityId) -> 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 PartialOrd for EntityId

fn partial_cmp(&self, other: &EntityId) -> 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 Query for EntityId

Returns the EntityId of the matched entity.

type Item<'a> = EntityId

The item returned by this query. This is usually the same type as Self, but with a modified lifetime.

type ArchState = ColumnPtr<EntityId>

Per-archetype state, e.g. pointers to archetype columns.

type State = ()

Cached data for fetch initialization, e.g. component indices.

fn init( _world: &mut World, _config: &mut HandlerConfig, ) -> Result<(ComponentAccess, <EntityId as Query>::State), InitError>

Initialize the query. Returns an expression describing the components accessed by the query and a new instance of Self::State.

fn new_state(_world: &mut World) -> <EntityId as Query>::State

Returns a new Self::State instance.

fn new_arch_state( arch: &Archetype, _: &mut <EntityId as Query>::State, ) -> Option<<EntityId as Query>::ArchState>

Returns a new Self::ArchState instance.

unsafe fn get<'a>( state: &<EntityId as Query>::ArchState, row: ArchetypeRow, ) -> <EntityId as Query>::Item<'a>

Gets the query item at the given row in the archetype.

impl Copy for EntityId

impl Eq for EntityId

impl ReadOnlyQuery for EntityId

impl StructuralPartialEq for EntityId