Enum SystemHandle 

pub enum SystemHandle<I = (), O = ()>
where
    I: SystemInput,
{
    Strong(Arc<StrongSystemHandle>),
    Weak(SystemId<I, O>),
}

A maybe-strong handle to an entity acting as a registered system. Strong handles are created by World::register_tracked_system or World::register_tracked_boxed_system.

Strong handles provide automatic cleanup of registered systems once all clones of the handle are dropped, while weak handles do not. However, the existence of a strong handle does not prevent the registered system entity from being despawned manually, like with World::unregister_system or World::unregister_system_cached.

Cleanup

Registered system entities are cleaned up by the despawn_unused_registered_systems system, which is automatically added to the default app by the bevy_app crate when the “std” feature is enabled. If not using the default app, the “std” feature, or bevy_app in general, consider running this system yourself to ensure proper cleanup of registered systems.

Variants

Strong(Arc<StrongSystemHandle>)

A strong handle keeps the system entity alive as long as the handle (and any clones of it) exist, as long as the system entity isn’t manually despawned.

Weak(SystemId<I, O>)

A weak handle does not keep the system entity alive.

Implementations

impl<I, O> SystemHandle<I, O>

where I: SystemInput,

pub fn entity(&self) -> Entity

Returns the Entity of the registered system associated with this handle.

Trait Implementations

impl<I, O> Clone for SystemHandle<I, O>

where I: SystemInput,

fn clone(&self) -> SystemHandle<I, O>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<I, O> Debug for SystemHandle<I, O>

where I: SystemInput,

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

Formats the value using the given formatter.

impl<I, O> From<&SystemHandle<I, O>> for SystemId<I, O>

where I: SystemInput,

fn from(handle: &SystemHandle<I, O>) -> SystemId<I, O>

Converts to this type from the input type.

impl<I, O> From<SystemHandle<I, O>> for SystemHandleTemplate<I, O>

where I: SystemInput + 'static, O: 'static,

fn from(handle: SystemHandle<I, O>) -> SystemHandleTemplate<I, O>

Converts to this type from the input type.

impl<I, O> From<SystemHandle<I, O>> for SystemId<I, O>

where I: SystemInput,

fn from(handle: SystemHandle<I, O>) -> SystemId<I, O>

Converts to this type from the input type.

impl<I, O> From<SystemId<I, O>> for SystemHandle<I, O>

where I: SystemInput,

fn from(id: SystemId<I, O>) -> SystemHandle<I, O>

Converts to this type from the input type.

impl<I, O> FromTemplate for SystemHandle<I, O>

where I: SystemInput + 'static, O: 'static,

type Template = SystemHandleTemplate<I, O>

The Template for this type.

impl<I, O> Hash for SystemHandle<I, O>

where I: SystemInput,

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<I, O> PartialEq<SystemId<I, O>> for SystemHandle<I, O>

where I: SystemInput,

fn eq(&self, other: &SystemId<I, O>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<I, O> PartialEq for SystemHandle<I, O>

where I: SystemInput,

fn eq(&self, other: &SystemHandle<I, O>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<I, O> Eq for SystemHandle<I, O>

where I: SystemInput,