Struct bevy_ecs::query::NopWorldQuery

pub struct NopWorldQuery<D: QueryData>(/* private fields */);

WorldQuery used to nullify queries by turning Query<D> into Query<NopWorldQuery<D>>

This will rarely be useful to consumers of bevy_ecs.

Trait Implementations

impl<D: QueryData> QueryData for NopWorldQuery<D>

SAFETY: Self::ReadOnly is Self

type ReadOnly = NopWorldQuery<D>

The read-only variant of this QueryData, which satisfies the ReadOnlyQueryData trait.

impl<D: QueryData> WorldQuery for NopWorldQuery<D>

SAFETY: update_component_access and update_archetype_component_access do nothing. This is sound because fetch does not access components.

type Item<'w> = ()

The item returned by this WorldQuery For QueryData this will be the item returned by the query. For QueryFilter this will be either (), or a bool indicating whether the entity should be included or a tuple of such things.

type Fetch<'w> = ()

Per archetype/table state used by this WorldQuery to fetch Self::Item

type State = <D as WorldQuery>::State

State used to construct a Self::Fetch. This will be cached inside QueryState, so it is best to move as much data / computation here as possible to reduce the cost of constructing Self::Fetch.

fn shrink<'wlong: 'wshort, 'wshort>(_: ())

This function manually implements subtyping for the query items.

unsafe fn init_fetch( _world: UnsafeWorldCell<'_>, _state: &D::State, _last_run: Tick, _this_run: Tick )

Creates a new instance of this fetch.

const IS_DENSE: bool = D::IS_DENSE

Returns true if (and only if) every table of every archetype matched by this fetch contains all of the matched components. This is used to select a more efficient “table iterator” for “dense” queries. If this returns true, WorldQuery::set_table must be used before WorldQuery::fetch can be called for iterators. If this returns false, WorldQuery::set_archetype must be used before WorldQuery::fetch can be called for iterators.

unsafe fn set_archetype( _fetch: &mut (), _state: &D::State, _archetype: &Archetype, _tables: &Table )

Adjusts internal state to account for the next Archetype. This will always be called on archetypes that match this WorldQuery.

unsafe fn set_table<'w>(_fetch: &mut (), _state: &D::State, _table: &Table)

Adjusts internal state to account for the next Table. This will always be called on tables that match this WorldQuery.

unsafe fn fetch<'w>( _fetch: &mut Self::Fetch<'w>, _entity: Entity, _table_row: TableRow ) -> Self::Item<'w>

Fetch Self::Item for either the given entity in the current Table, or for the given entity in the current Archetype. This must always be called after WorldQuery::set_table with a table_row in the range of the current Table or after WorldQuery::set_archetype with a entity in the current archetype.

fn update_component_access( _state: &D::State, _access: &mut FilteredAccess<ComponentId> )

Adds any component accesses used by this WorldQuery to access.

fn init_state(world: &mut World) -> Self::State

Creates and initializes a State for this WorldQuery type.

fn get_state(world: &World) -> Option<Self::State>

Attempts to initializes a State for this WorldQuery type.

fn matches_component_set( state: &Self::State, set_contains_id: &impl Fn(ComponentId) -> bool ) -> bool

Returns true if this query matches a set of components. Otherwise, returns false.

fn set_access(_state: &mut Self::State, _access: &FilteredAccess<ComponentId>)

Sets available accesses for implementors with dynamic access such as FilteredEntityRef or FilteredEntityMut.

impl<D: QueryData> ReadOnlyQueryData for NopWorldQuery<D>

SAFETY: NopFetch never accesses any data