Struct With 

pub struct With<T>(/* private fields */);

Query filter that matches entities that have a component.

With<T> is a filter, not a data fetch. It filters entities to only those that have component T, but doesn’t actually retrieve the component data.

Use With<T> when you need to ensure an entity has a component but don’t need to access its data.

Example

use goud_engine::ecs::{Component, World};
use goud_engine::ecs::query::With;

struct Player;
impl Component for Player {}

struct Health(f32);
impl Component for Health {}

// Query for Health, but only for entities that also have Player
// (Health, With<Player>) - fetches Health data, filters by Player

Implementations

impl<T> With<T>

pub fn new() -> Self

Creates a new With filter.

Trait Implementations

impl<T: Clone> Clone for With<T>

fn clone(&self) -> With<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for With<T>

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

Formats the value using the given formatter.

impl<T: Default> Default for With<T>

fn default() -> With<T>

Returns the “default value” for a type.

impl<T: Component> WorldQuery for With<T>

type Item<'w> = ()

The type of data this query fetches.

type State = ComponentId

The cached state for this query.

fn init_state(_world: &World) -> Self::State

Initializes the query state from the world.

fn component_access(_state: &Self::State) -> BTreeSet<ComponentId>

Returns the set of component IDs this query reads.

fn matches_archetype(state: &Self::State, archetype: &Archetype) -> bool

Checks whether this query matches the given archetype.

fn fetch<'w>( state: &Self::State, world: &'w World, entity: Entity, ) -> Option<Self::Item<'w>>

Fetches data for a specific entity from the world.

fn fetch_mut<'w>( state: &Self::State, world: &'w mut World, entity: Entity, ) -> Option<Self::Item<'w>>

Fetches data for a specific entity from a mutable world reference.

impl<T: Copy> Copy for With<T>

impl<T: Component> ReadOnlyWorldQuery for With<T>