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§
Occupied(OccupiedEntry<'w, 'a, T>)
An occupied entry.
Vacant(VacantEntry<'w, 'a, T>)
A vacant entry.
Implementations§
Source§impl<'w, 'a, T: Component> Entry<'w, 'a, T>
impl<'w, 'a, T: Component> Entry<'w, 'a, T>
Sourcepub fn and_modify<F: FnOnce(Mut<'_, T>)>(self, f: F) -> Self
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);
Sourcepub fn insert_entry(self, component: T) -> OccupiedEntry<'w, 'a, T>
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));
Sourcepub fn or_insert(self, default: T) -> Mut<'a, T>
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);
Sourcepub fn or_insert_with<F: FnOnce() -> T>(self, default: F) -> Mut<'a, T>
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);
Source§impl<'w, 'a, T: Component + Default> Entry<'w, 'a, T>
impl<'w, 'a, T: Component + Default> Entry<'w, 'a, T>
Sourcepub fn or_default(self) -> Mut<'a, T>
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);