Type Definition specs::WriteStorage
source · pub type WriteStorage<'a, T> = Storage<'a, T, FetchMut<'a, MaskedStorage<T>>>;
Expand description
A storage with read and write access.
Additionally to what ReadStorage
can do a storage with mutable access allows:
Aliasing
It is strictly disallowed to fetch both a ReadStorage
and a WriteStorage
of the same component.
Because Specs uses interior mutability for its resources, we can’t check
this at compile time. If you try to do this, you will get a panic.
It is also disallowed to fetch multiple WriteStorage
s for the same
component.
Retrieve components mutably
This works just like Storage::get
, but returns a mutable reference:
let entity = world.create_entity()
.with(Pos(2.0))
.build();
assert_eq!(pos_storage.get_mut(entity), Some(&mut Pos(2.0)));
if let Some(pos) = pos_storage.get_mut(entity) {
*pos = Pos(4.5);
}
assert_eq!(pos_storage.get(entity), Some(&Pos(4.5)));
Inserting and removing components
You can insert components using Storage::insert
and remove them
again with Storage::remove
.
let entity = world.create_entity()
.with(Pos(0.1))
.build();
if let Ok(Some(p)) = pos_storage.insert(entity, Pos(4.0)) {
println!("Overwrote {:?} with a new position", p);
}
There’s also an Entry-API similar to the one provided by
std::collections::HashMap
.
Trait Implementations
sourceimpl<'a: 'b, 'b, T> GenericReadStorage for &'b WriteStorage<'a, T>where
T: Component,
impl<'a: 'b, 'b, T> GenericReadStorage for &'b WriteStorage<'a, T>where
T: Component,
sourceimpl<'a, T> GenericReadStorage for WriteStorage<'a, T>where
T: Component,
impl<'a, T> GenericReadStorage for WriteStorage<'a, T>where
T: Component,
sourceimpl<'a: 'b, 'b, T> GenericWriteStorage for &'b mut WriteStorage<'a, T>where
T: Component,
impl<'a: 'b, 'b, T> GenericWriteStorage for &'b mut WriteStorage<'a, T>where
T: Component,
sourceimpl<'a, T> GenericWriteStorage for WriteStorage<'a, T>where
T: Component,
impl<'a, T> GenericWriteStorage for WriteStorage<'a, T>where
T: Component,
sourceimpl<'a, T> SystemData<'a> for WriteStorage<'a, T>where
T: Component,
impl<'a, T> SystemData<'a> for WriteStorage<'a, T>where
T: Component,
sourcefn fetch(res: &'a Resources) -> Self
fn fetch(res: &'a Resources) -> Self
Fetches the system data from
Resources
. Note that this is only specified for one concrete
lifetime 'a
, you need to implement the SystemData
trait for every possible
lifetime. Read moresourcefn reads() -> Vec<ResourceId>
fn reads() -> Vec<ResourceId>
Returns all read dependencies as fetched from
Self::fetch
. Read moresourcefn writes() -> Vec<ResourceId>
fn writes() -> Vec<ResourceId>
Returns all write dependencies as fetched from
Self::fetch
. Read more