Enum bevy_ecs::world::Entry

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pub enum Entry<'w, 'a, T: Component> {
    Occupied(OccupiedEntry<'w, 'a, T>),
    Vacant(VacantEntry<'w, 'a, T>),
}
Expand description

A view into a single entity and component in a world, which may either be vacant or occupied.

This enum can only be constructed from the entry method on EntityWorldMut.

Variants§

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Occupied(OccupiedEntry<'w, 'a, T>)

An occupied entry.

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Vacant(VacantEntry<'w, 'a, T>)

A vacant entry.

Implementations§

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impl<'w, 'a, T: Component> Entry<'w, 'a, T>

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pub fn and_modify<F: FnOnce(Mut<'_, T>)>(self, f: F) -> Self

Provides in-place mutable access to an occupied entry.

Examples
#[derive(Component, Default, Clone, Copy, Debug, PartialEq)]
struct Comp(u32);

let mut entity = world.spawn(Comp(0));

entity.entry::<Comp>().and_modify(|mut c| c.0 += 1);
assert_eq!(world.query::<&Comp>().single(&world).0, 1);
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pub fn insert_entry(self, component: T) -> OccupiedEntry<'w, 'a, T>

Replaces the component of the entry, and returns an OccupiedEntry.

Examples
#[derive(Component, Default, Clone, Copy, Debug, PartialEq)]
struct Comp(u32);

let mut entity = world.spawn_empty();

let entry = entity.entry().insert_entry(Comp(4));
assert_eq!(entry.get(), &Comp(4));

let entry = entity.entry().insert_entry(Comp(2));
assert_eq!(entry.get(), &Comp(2));
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pub fn or_insert(self, default: T) -> Mut<'a, T>

Ensures the entry has this component by inserting the given default if empty, and returns a mutable reference to this component in the entry.

Examples
#[derive(Component, Default, Clone, Copy, Debug, PartialEq)]
struct Comp(u32);

let mut entity = world.spawn_empty();

entity.entry().or_insert(Comp(4));
assert_eq!(world.query::<&Comp>().single(&world).0, 4);

entity.entry().or_insert(Comp(15)).0 *= 2;
assert_eq!(world.query::<&Comp>().single(&world).0, 8);
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pub fn or_insert_with<F: FnOnce() -> T>(self, default: F) -> Mut<'a, T>

Ensures the entry has this component by inserting the result of the default function if empty, and returns a mutable reference to this component in the entry.

Examples
#[derive(Component, Default, Clone, Copy, Debug, PartialEq)]
struct Comp(u32);

let mut entity = world.spawn_empty();

entity.entry().or_insert_with(|| Comp(4));
assert_eq!(world.query::<&Comp>().single(&world).0, 4);
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impl<'w, 'a, T: Component + Default> Entry<'w, 'a, T>

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pub fn or_default(self) -> Mut<'a, T>

Ensures the entry has this component by inserting the default value if empty, and returns a mutable reference to this component in the entry.

Examples
#[derive(Component, Default, Clone, Copy, Debug, PartialEq)]
struct Comp(u32);

let mut entity = world.spawn_empty();

entity.entry::<Comp>().or_default();
assert_eq!(world.query::<&Comp>().single(&world).0, 0);

Auto Trait Implementations§

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impl<'w, 'a, T> !RefUnwindSafe for Entry<'w, 'a, T>

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impl<'w, 'a, T> Send for Entry<'w, 'a, T>

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impl<'w, 'a, T> Sync for Entry<'w, 'a, T>

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impl<'w, 'a, T> Unpin for Entry<'w, 'a, T>
where T: Unpin,

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impl<'w, 'a, T> !UnwindSafe for Entry<'w, 'a, T>

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> Downcast for T
where T: Any,

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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.
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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.
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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.
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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.
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impl<T> DowncastSync for T
where T: Any + Send + Sync,

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fn into_any_arc(self: Arc<T>) -> Arc<dyn Any + Send + Sync>

Convert Arc<Trait> (where Trait: Downcast) to Arc<Any>. Arc<Any> can then be further downcast into Arc<ConcreteType> where ConcreteType implements Trait.
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more