Struct ComponentId

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

A value which uniquely identifies the type of a Component of Resource within a World.

Each time a new Component type is registered within a World using e.g. World::init_component or World::init_component_with_descriptor or a Resource with e.g. World::init_resource, a corresponding ComponentId is created to track it.

While the distinction between ComponentId and TypeId may seem superficial, breaking them into two separate but related concepts allows components to exist outside of Rust’s type system. Each Rust type registered as a Component will have a corresponding ComponentId, but additional ComponentIds may exist in a World to track components which cannot be represented as Rust types for scripting or other advanced use-cases.

A ComponentId is tightly coupled to its parent World. Attempting to use a ComponentId from one World to access the metadata of a Component in a different World is undefined behavior and must not be attempted.

Given a type T which implements Component, the ComponentId for T can be retrieved from a World using World::component_id() or via Components::component_id(). Access to the ComponentId for a Resource is available via Components::resource_id().

Implementations

impl ComponentId

pub const fn new(index: usize) -> ComponentId

Creates a new ComponentId.

The index is a unique value associated with each type of component in a given world. Usually, this value is taken from a counter incremented for each type of component registered with the world.

pub fn index(self) -> usize

Returns the index of the current component.

Trait Implementations

impl Clone for ComponentId

fn clone(&self) -> ComponentId

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ComponentId

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

Formats the value using the given formatter.

impl<T: Component> From<ComponentIdFor<'_, T>> for ComponentId

fn from(to_component_id: ComponentIdFor<'_, T>) -> ComponentId

Converts to this type from the input type.

impl Hash for ComponentId

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 ComponentId

fn cmp(&self, other: &ComponentId) -> 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 ComponentId

fn eq(&self, other: &ComponentId) -> 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 ComponentId

fn partial_cmp(&self, other: &ComponentId) -> 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 SparseSetIndex for ComponentId

fn sparse_set_index(&self) -> usize

Gets the sparse set index corresponding to this instance.

fn get_sparse_set_index(value: usize) -> Self

Creates a new instance of this type with the specified index.

impl TriggerTargets for ComponentId

fn components(&self) -> impl ExactSizeIterator<Item = ComponentId>

The components the trigger should target.

fn entities(&self) -> impl ExactSizeIterator<Item = Entity>

The entities the trigger should target.

impl Copy for ComponentId

impl Eq for ComponentId

impl StructuralPartialEq for ComponentId