pub struct With<T>(/* private fields */);
Expand description
Filter that selects entities with a component T
.
This can be used in a Query
if entities are required to have the
component T
but you don’t actually care about components value.
This is the negation of Without
.
§Examples
fn compliment_entity_system(query: Query<&Name, With<IsBeautiful>>) {
for name in &query {
println!("{} is looking lovely today!", name.name);
}
}
Trait Implementations§
source§impl<T: Component> QueryFilter for With<T>
impl<T: Component> QueryFilter for With<T>
source§const IS_ARCHETYPAL: bool = true
const IS_ARCHETYPAL: bool = true
Returns true if (and only if) this Filter relies strictly on archetypes to limit which
components are accessed by the Query. Read more
source§impl<T: Component> WorldQuery for With<T>
impl<T: Component> WorldQuery for With<T>
SAFETY:
update_component_access
does not add any accesses.
This is sound because fetch
does not access any components.
update_component_access
adds a With
filter for T
.
This is sound because matches_component_set
returns whether the set contains the component.
§type Item<'w> = ()
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> = ()
type Fetch<'w> = ()
Per archetype/table state used by this
WorldQuery
to fetch Self::Item
§type State = ComponentId
type State = ComponentId
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
.source§fn shrink<'wlong: 'wshort, 'wshort>(
_: Self::Item<'wlong>
) -> Self::Item<'wshort>
fn shrink<'wlong: 'wshort, 'wshort>( _: Self::Item<'wlong> ) -> Self::Item<'wshort>
This function manually implements subtyping for the query items.
source§unsafe fn init_fetch(
_world: UnsafeWorldCell<'_>,
_state: &ComponentId,
_last_run: Tick,
_this_run: Tick
)
unsafe fn init_fetch( _world: UnsafeWorldCell<'_>, _state: &ComponentId, _last_run: Tick, _this_run: Tick )
Creates a new instance of this fetch. Read more
source§const IS_DENSE: bool = _
const IS_DENSE: bool = _
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.source§unsafe fn set_archetype(
_fetch: &mut (),
_state: &ComponentId,
_archetype: &Archetype,
_table: &Table
)
unsafe fn set_archetype( _fetch: &mut (), _state: &ComponentId, _archetype: &Archetype, _table: &Table )
Adjusts internal state to account for the next
Archetype
. This will always be called on
archetypes that match this WorldQuery
. Read moresource§unsafe fn set_table(_fetch: &mut (), _state: &ComponentId, _table: &Table)
unsafe fn set_table(_fetch: &mut (), _state: &ComponentId, _table: &Table)
Adjusts internal state to account for the next
Table
. This will always be called on tables
that match this WorldQuery
. Read moresource§unsafe fn fetch<'w>(
_fetch: &mut Self::Fetch<'w>,
_entity: Entity,
_table_row: TableRow
) -> Self::Item<'w>
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. Read moresource§fn update_component_access(
id: &ComponentId,
access: &mut FilteredAccess<ComponentId>
)
fn update_component_access( id: &ComponentId, access: &mut FilteredAccess<ComponentId> )
source§fn init_state(world: &mut World) -> ComponentId
fn init_state(world: &mut World) -> ComponentId
Creates and initializes a
State
for this WorldQuery
type.source§fn matches_component_set(
id: &ComponentId,
set_contains_id: &impl Fn(ComponentId) -> bool
) -> bool
fn matches_component_set( id: &ComponentId, set_contains_id: &impl Fn(ComponentId) -> bool ) -> bool
source§fn set_access(_state: &mut Self::State, _access: &FilteredAccess<ComponentId>)
fn set_access(_state: &mut Self::State, _access: &FilteredAccess<ComponentId>)
Sets available accesses for implementors with dynamic access such as
FilteredEntityRef
or FilteredEntityMut
. Read moreimpl<T: Component> ArchetypeFilter for With<T>
Auto Trait Implementations§
impl<T> Freeze for With<T>
impl<T> RefUnwindSafe for With<T>where
T: RefUnwindSafe,
impl<T> Send for With<T>where
T: Send,
impl<T> Sync for With<T>where
T: Sync,
impl<T> Unpin for With<T>where
T: Unpin,
impl<T> UnwindSafe for With<T>where
T: UnwindSafe,
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
source§impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
source§fn into_any(self: Box<T>) -> Box<dyn Any>
fn into_any(self: Box<T>) -> Box<dyn Any>
Convert
Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
. Box<dyn Any>
can
then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
.source§fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
Convert
Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
.source§fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
Convert
&Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s.source§fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
Convert
&mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s.