Struct oxygengine_core::ecs::storage::RestrictedStorage

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

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

Type of joined components.

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

Type of joined storages.

type Mask = &'rf BitSet

Type of joined bit mask.

unsafe fn open(
    self
) -> (<&'rf RestrictedStorage<'rf, 'st, C, S, B, Restrict> as Join>::Mask, <&'rf RestrictedStorage<'rf, 'st, C, S, B, Restrict> as Join>::Value)

Open this join by returning the mask and the storages.

unsafe fn get(
    value: &mut <&'rf RestrictedStorage<'rf, 'st, C, S, B, Restrict> as Join>::Value,
    id: u32
) -> <&'rf RestrictedStorage<'rf, 'st, C, S, B, Restrict> as Join>::Type

Get a joined component value by a given index.

Important traits for JoinIter<J>

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

fn join(self) -> JoinIter<Self>

Create a joined iterator over the contents.

fn maybe(self) -> MaybeJoin<Self>

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

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

Type of joined components.

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

Type of joined storages.

type Mask = &'rf BitSet

Type of joined bit mask.

unsafe fn open(
    self
) -> (<&'rf mut RestrictedStorage<'rf, 'st, C, S, B, Restrict> as Join>::Mask, <&'rf mut RestrictedStorage<'rf, 'st, C, S, B, Restrict> as Join>::Value)

Open this join by returning the mask and the storages.

unsafe fn get(
    value: &mut <&'rf mut RestrictedStorage<'rf, 'st, C, S, B, Restrict> as Join>::Value,
    id: u32
) -> <&'rf mut RestrictedStorage<'rf, 'st, C, S, B, Restrict> as Join>::Type

Get a joined component value by a given index.

Important traits for JoinIter<J>

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

fn join(self) -> JoinIter<Self>

Create a joined iterator over the contents.

fn maybe(self) -> MaybeJoin<Self>

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.