Struct oxygengine_core::ecs::shred::Fetch

pub struct Fetch<'a, T> where
    T: 'a + 'a,  { /* fields omitted */ }

Allows to fetch a resource in a system immutably.

If the resource isn't strictly required, you should use Option<Fetch<T>>.

Type parameters

• T: The type of the resource

Trait Implementations

impl<'a, 'b, T> Join for &'a Fetch<'b, T> where
    T: Resource,
    &'a T: Join, 

type Type = <&'a T as Join>::Type

Type of joined components.

type Value = <&'a T as Join>::Value

Type of joined storages.

type Mask = <&'a T as Join>::Mask

Type of joined bit mask.

unsafe fn open(
    self
) -> (<&'a Fetch<'b, T> as Join>::Mask, <&'a Fetch<'b, T> as Join>::Value)

Open this join by returning the mask and the storages.

unsafe fn get(
    v: &mut <&'a Fetch<'b, T> as Join>::Value,
    i: u32
) -> <&'a Fetch<'b, T> as Join>::Type

Get a joined component value by a given index.

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.

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.

impl<'a, T, F> From<Fetch<'a, T>> for Read<'a, T, F>

fn from(inner: Fetch<'a, T>) -> Read<'a, T, F>

Performs the conversion.

impl<'a, T> Deref for Fetch<'a, T> where
    T: Resource, 

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.