Struct bevy_ecs::system::RemovedComponents
source · pub struct RemovedComponents<'a, T: Component> { /* private fields */ }
Expand description
A SystemParam
that grants access to the entities that had their T
Component
removed.
Note that this does not allow you to see which data existed before removal.
If you need this, you will need to track the component data value on your own,
using a regularly scheduled system that requests Query<(Entity, &T), Changed<T>>
and stores the data somewhere safe to later cross-reference.
If you are using bevy_ecs
as a standalone crate,
note that the RemovedComponents
list will not be automatically cleared for you,
and will need to be manually flushed using World::clear_trackers
For users of bevy
itself, this is automatically done in a system added by MinimalPlugins
or DefaultPlugins
at the end of each pass of the game loop during the CoreStage::Last
stage. As such RemovedComponents
systems should be scheduled after the stage where
removal occurs but before CoreStage::Last
.
Examples
Basic usage:
fn react_on_removal(removed: RemovedComponents<MyComponent>) {
removed.iter().for_each(|removed_entity| println!("{:?}", removed_entity));
}
Implementations§
Trait Implementations§
source§impl<'a, T: Component> IntoIterator for &'a RemovedComponents<'a, T>
impl<'a, T: Component> IntoIterator for &'a RemovedComponents<'a, T>
source§impl<'a, T: Component> SystemParam for RemovedComponents<'a, T>
impl<'a, T: Component> SystemParam for RemovedComponents<'a, T>
Auto Trait Implementations§
impl<'a, T> !RefUnwindSafe for RemovedComponents<'a, T>
impl<'a, T> Send for RemovedComponents<'a, T>
impl<'a, T> Sync for RemovedComponents<'a, T>
impl<'a, T> Unpin for RemovedComponents<'a, T>where
T: Unpin,
impl<'a, T> !UnwindSafe for RemovedComponents<'a, T>
Blanket Implementations§
source§impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
source§fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>
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
. Read moresource§fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>
Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
. Read moresource§fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
&Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s. Read moresource§fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
&mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s. Read more