Struct specs::storage::RestrictedStorage

pub struct RestrictedStorage<'rf, 'st: 'rf, C, S, B, Restrict> where
    C: Component,
    S: Borrow<C::Storage> + 'rf,
    B: Borrow<BitSet> + 'rf,  { /* fields omitted */ }

Similar to a MaskedStorage and a Storage combined, but restricts usage to only getting and modifying the components. That means it's not possible to modify the inner bitset so the iteration cannot be invalidated. In other words, no insertion or removal is allowed.

Example Usage:

struct SomeComp(u32);
impl Component for SomeComp {
    type Storage = VecStorage<Self>;
}

struct RestrictedSystem;
impl<'a> System<'a> for RestrictedSystem {
    type SystemData = (Entities<'a>, WriteStorage<'a, SomeComp>);

    fn run(&mut self, (entities, mut some_comps): Self::SystemData) {
        for (entity, mut comps) in (&entities, &mut some_comps.restrict_mut()).join() {
            // Check if the reference is fine to mutate.
            if comps.get_unchecked().0 < 5 {
                // Get a mutable reference now.
                let mut mutable = comps.get_mut_unchecked();
                mutable.0 += 1;
            }
        }
    }
}

Trait Implementations

impl<'rf, 'st: 'rf, C, S, B, Restrict> Join for &'rf RestrictedStorage<'rf, 'st, C, S, B, Restrict> where
    C: Component,
    S: Borrow<C::Storage>,
    B: Borrow<BitSet>, 

type Mask = &'rf BitSet

Type of joined bit mask.

type Type = PairedStorage<'rf, 'st, C, &'rf C::Storage, &'rf BitSet, Restrict>

Type of joined components.

type Value = (&'rf C::Storage, &'rf Fetch<'st, EntitiesRes>, &'rf BitSet)

Type of joined storages.

unsafe fn open(self) -> (Self::Mask, Self::Value)

Open this join by returning the mask and the storages.

unsafe fn get(value: &mut Self::Value, id: Index) -> Self::Type

Get a joined component value by a given index.

Important traits for JoinIter<J>

impl<J: Join> Iterator for JoinIter<J> type Item = J::Type;

fn join(self) -> JoinIter<Self> where
    Self: Sized, 

Create a joined iterator over the contents.

fn maybe(self) -> MaybeJoin<Self> where
    Self: Sized, 

Returns a Join-able structure that yields all indices, returning None for all missing elements and Some(T) for found elements.

fn is_unconstrained() -> bool

If this Join typically returns all indices in the mask, then iterating over only it or combined with other joins that are also dangerous will cause the JoinIter/ParJoin to go through all indices which is usually not what is wanted and will kill performance.

impl<'rf, 'st: 'rf, C, S, B, Restrict> Join for &'rf mut RestrictedStorage<'rf, 'st, C, S, B, Restrict> where
    C: Component,
    S: BorrowMut<C::Storage>,
    B: Borrow<BitSet>, 

type Mask = &'rf BitSet

Type of joined bit mask.

type Type = PairedStorage<'rf, 'st, C, &'rf mut C::Storage, &'rf BitSet, Restrict>

Type of joined components.

type Value = (&'rf mut C::Storage, &'rf Fetch<'st, EntitiesRes>, &'rf BitSet)

Type of joined storages.

unsafe fn open(self) -> (Self::Mask, Self::Value)

Open this join by returning the mask and the storages.

unsafe fn get(value: &mut Self::Value, id: Index) -> Self::Type

Get a joined component value by a given index.

Important traits for JoinIter<J>

impl<J: Join> Iterator for JoinIter<J> type Item = J::Type;

fn join(self) -> JoinIter<Self> where
    Self: Sized, 

Create a joined iterator over the contents.

fn maybe(self) -> MaybeJoin<Self> where
    Self: Sized, 

Returns a Join-able structure that yields all indices, returning None for all missing elements and Some(T) for found elements.

fn is_unconstrained() -> bool

If this Join typically returns all indices in the mask, then iterating over only it or combined with other joins that are also dangerous will cause the JoinIter/ParJoin to go through all indices which is usually not what is wanted and will kill performance.

impl<'rf, 'st: 'rf, C, S, B> ParJoin for &'rf mut RestrictedStorage<'rf, 'st, C, S, B, MutableParallelRestriction> where
    C: Component,
    S: BorrowMut<C::Storage> + 'rf,
    B: Borrow<BitSet> + 'rf, 

fn par_join(self) -> JoinParIter<Self> where
    Self: Sized, 

Create a joined parallel iterator over the contents.

impl<'rf, 'st: 'rf, C, S, B, Restrict> ParJoin for &'rf RestrictedStorage<'rf, 'st, C, S, B, Restrict> where
    C: Component,
    S: Borrow<C::Storage> + 'rf,
    B: Borrow<BitSet> + 'rf,
    Restrict: ImmutableAliasing, 

fn par_join(self) -> JoinParIter<Self> where
    Self: Sized, 

Create a joined parallel iterator over the contents.