Struct bevy::ecs::query::NopWorldQuery

pub struct NopWorldQuery<Q>(_)
where
         Q: WorldQuery;

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

This will rarely be useful to consumers of bevy_ecs.

Trait Implementations

impl<Q> WorldQuery for NopWorldQuery<Q>where Q: WorldQuery,

SAFETY: Self::ReadOnly is Self

type Fetch = ()

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

type Item = ()

The item returned by this WorldQuery

type ReadOnly = NopWorldQuery<Q>

The read-only variant of this WorldQuery, which satisfies the ReadOnlyWorldQuery trait.

type State = <Q 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>(_: ())where 'wlong: 'wshort,

This function manually implements subtyping for the query items.

const IS_DENSE: bool = Q::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.

const IS_ARCHETYPAL: bool = true

Returns true if (and only if) this Fetch relies strictly on archetypes to limit which components are accessed by the Query.

unsafe fn init_fetch( _world: &World, _state: &<Q as WorldQuery>::State, _last_change_tick: u32, _change_tick: u32 )

Creates a new instance of this fetch.

unsafe fn clone_fetch<'w>( _fetch: &<NopWorldQuery<Q> as WorldQuery>::Fetch<'w> ) -> <NopWorldQuery<Q> as WorldQuery>::Fetch<'w>

While this function can be called for any query, it is always safe to call if Self: ReadOnlyWorldQuery holds.

unsafe fn set_archetype( _fetch: &mut (), _state: &<Q as WorldQuery>::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: &<Q as WorldQuery>::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 <NopWorldQuery<Q> as WorldQuery>::Fetch<'w>, _entity: Entity, _table_row: TableRow ) -> <NopWorldQuery<Q> as WorldQuery>::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: &<Q as WorldQuery>::State, _access: &mut FilteredAccess<ComponentId> )

fn update_archetype_component_access( _state: &<Q as WorldQuery>::State, _archetype: &Archetype, _access: &mut Access<ArchetypeComponentId> )

fn init_state(world: &mut World) -> <NopWorldQuery<Q> as WorldQuery>::State

fn matches_component_set( state: &<NopWorldQuery<Q> as WorldQuery>::State, set_contains_id: &impl Fn(ComponentId) -> bool ) -> bool

unsafe fn filter_fetch( fetch: &mut Self::Fetch<'_>, entity: Entity, table_row: TableRow ) -> bool

Safety

impl<Q> ReadOnlyWorldQuery for NopWorldQuery<Q>where Q: WorldQuery,

SAFETY: NopFetch never accesses any data