Trait specs::join::Join[][src]

pub trait Join {
    type Type;
    type Value;
    type Mask: BitSetLike;
    unsafe fn open(self) -> (Self::Mask, Self::Value);
unsafe fn get(value: &mut Self::Value, id: Index) -> Self::Type; fn join(self) -> JoinIter<Self>
    where
        Self: Sized
, { ... } }

The purpose of the Join trait is to provide a way to access multiple storages at the same time with the merged bit set.

Joining component storages means that you'll only get values where for a given entity every storage has an associated component.

Example

let mut world = World::new();

world.register::<Pos>();
world.register::<Vel>();

{
    let pos = world.read_storage::<Pos>();
    let vel = world.read_storage::<Vel>();

    // There are no entities yet, so no pair will be returned.
    let joined: Vec<_> = (&pos, &vel).join().collect();
    assert_eq!(joined, vec![]);
}

world
    .create_entity()
    .with(Pos)
    .build();

{
    let pos = world.read_storage::<Pos>();
    let vel = world.read_storage::<Vel>();

    // Although there is an entity, it only has `Pos`.
    let joined: Vec<_> = (&pos, &vel).join().collect();
    assert_eq!(joined, vec![]);
}

let ent = world.create_entity()
    .with(Pos)
    .with(Vel)
    .build();

{
    let pos = world.read_storage::<Pos>();
    let vel = world.read_storage::<Vel>();

    // Now there is one entity that has both a `Vel` and a `Pos`.
    let joined: Vec<_> = (&pos, &vel).join().collect();
    assert_eq!(joined, vec![(&Pos, &Vel)]);

    // If we want to get the entity the components are associated to,
    // we need to join over `Entities`:

    let entities = world.read_resource::<EntitiesRes>();
    // note: `EntitiesRes` is the fetched resource; we get back
    // `Read<EntitiesRes>`.
    // `Read<EntitiesRes>` can also be referred to by `Entities` which
    // is a shorthand type definition to the former type.

    let joined: Vec<_> = (&*entities, &pos, &vel).join().collect(); // note the `&*entities`
    assert_eq!(joined, vec![(ent, &Pos, &Vel)]);
}

Iterating over a single storage

Join can also be used to iterate over a single storage, just by writing (&storage).join().

Associated Types

Type of joined components.

Type of joined storages.

Type of joined bit mask.

Required Methods

Open this join by returning the mask and the storages.

This is unsafe because implementations of this trait can permit the Value to be mutated independently of the Mask. If the Mask does not correctly report the status of the Value then illegal memory access can occur.

Get a joined component value by a given index.

Provided Methods

Important traits for JoinIter<J>

Create a joined iterator over the contents.

Implementations on Foreign Types

impl Join for AtomicBitSet
[src]

Important traits for JoinIter<J>

impl<'a> Join for &'a AtomicBitSet
[src]

Important traits for JoinIter<J>

impl<A> Join for BitSetNot<A> where
    A: BitSetLike
[src]

Important traits for JoinIter<J>

impl<'a, A> Join for &'a BitSetNot<A> where
    A: BitSetLike
[src]

Important traits for JoinIter<J>

impl<A, B> Join for BitSetAnd<A, B> where
    A: BitSetLike,
    B: BitSetLike
[src]

Important traits for JoinIter<J>

impl<'a, A, B> Join for &'a BitSetAnd<A, B> where
    A: BitSetLike,
    B: BitSetLike
[src]

Important traits for JoinIter<J>

impl<A, B> Join for BitSetOr<A, B> where
    A: BitSetLike,
    B: BitSetLike
[src]

Important traits for JoinIter<J>

impl<'a, A, B> Join for &'a BitSetOr<A, B> where
    A: BitSetLike,
    B: BitSetLike
[src]

Important traits for JoinIter<J>

impl<A, B> Join for BitSetXor<A, B> where
    A: BitSetLike,
    B: BitSetLike
[src]

Important traits for JoinIter<J>

impl<A> Join for (A,) where
    A: Join,
    (<A as Join>::Mask,): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B> Join for (A, B) where
    A: Join,
    B: Join,
    (<A as Join>::Mask, <B as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C> Join for (A, B, C) where
    A: Join,
    B: Join,
    C: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D> Join for (A, B, C, D) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E> Join for (A, B, C, D, E) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F> Join for (A, B, C, D, E, F) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G> Join for (A, B, C, D, E, F, G) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H> Join for (A, B, C, D, E, F, G, H) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I> Join for (A, B, C, D, E, F, G, H, I) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I, J> Join for (A, B, C, D, E, F, G, H, I, J) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    J: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask, <J as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I, J, K> Join for (A, B, C, D, E, F, G, H, I, J, K) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    J: Join,
    K: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask, <J as Join>::Mask, <K as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I, J, K, L> Join for (A, B, C, D, E, F, G, H, I, J, K, L) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    J: Join,
    K: Join,
    L: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask, <J as Join>::Mask, <K as Join>::Mask, <L as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I, J, K, L, M> Join for (A, B, C, D, E, F, G, H, I, J, K, L, M) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    J: Join,
    K: Join,
    L: Join,
    M: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask, <J as Join>::Mask, <K as Join>::Mask, <L as Join>::Mask, <M as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I, J, K, L, M, N> Join for (A, B, C, D, E, F, G, H, I, J, K, L, M, N) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    J: Join,
    K: Join,
    L: Join,
    M: Join,
    N: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask, <J as Join>::Mask, <K as Join>::Mask, <L as Join>::Mask, <M as Join>::Mask, <N as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I, J, K, L, M, N, O> Join for (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    J: Join,
    K: Join,
    L: Join,
    M: Join,
    N: Join,
    O: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask, <J as Join>::Mask, <K as Join>::Mask, <L as Join>::Mask, <M as Join>::Mask, <N as Join>::Mask, <O as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P> Join for (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    J: Join,
    K: Join,
    L: Join,
    M: Join,
    N: Join,
    O: Join,
    P: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask, <J as Join>::Mask, <K as Join>::Mask, <L as Join>::Mask, <M as Join>::Mask, <N as Join>::Mask, <O as Join>::Mask, <P as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q> Join for (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    J: Join,
    K: Join,
    L: Join,
    M: Join,
    N: Join,
    O: Join,
    P: Join,
    Q: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask, <J as Join>::Mask, <K as Join>::Mask, <L as Join>::Mask, <M as Join>::Mask, <N as Join>::Mask, <O as Join>::Mask, <P as Join>::Mask, <Q as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

impl<A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R> Join for (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R) where
    A: Join,
    B: Join,
    C: Join,
    D: Join,
    E: Join,
    F: Join,
    G: Join,
    H: Join,
    I: Join,
    J: Join,
    K: Join,
    L: Join,
    M: Join,
    N: Join,
    O: Join,
    P: Join,
    Q: Join,
    R: Join,
    (<A as Join>::Mask, <B as Join>::Mask, <C as Join>::Mask, <D as Join>::Mask, <E as Join>::Mask, <F as Join>::Mask, <G as Join>::Mask, <H as Join>::Mask, <I as Join>::Mask, <J as Join>::Mask, <K as Join>::Mask, <L as Join>::Mask, <M as Join>::Mask, <N as Join>::Mask, <O as Join>::Mask, <P as Join>::Mask, <Q as Join>::Mask, <R as Join>::Mask): BitAnd
[src]

Important traits for JoinIter<J>

Implementors