Struct specs::Read

pub struct Read<'a, T, F = DefaultProvider> where
    T: 'a,  { /* fields omitted */ }

Allows to fetch a resource in a system immutably.

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

Type parameters

• T: The type of the resource
• F: The setup handler (default: DefaultProvider)

Trait Implementations

impl<'a, T, F> SystemData<'a> for Read<'a, T, F> where     F: SetupHandler<T>,     T: Resource,

fn setup(res: &mut Resources)

Sets up the system data for fetching it from the Resources.

fn fetch(res: &'a Resources) -> Read<'a, T, F>

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.

Important traits for Vec<u8>

impl Write for Vec<u8>

fn reads() -> Vec<ResourceId>

Returns all read dependencies as fetched from Self::fetch.

Important traits for Vec<u8>

impl Write for Vec<u8>

fn writes() -> Vec<ResourceId>

Returns all write dependencies as fetched from Self::fetch.

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

type Target = T

The resulting type after dereferencing.

Important traits for &'a mut R

impl<'a, R> Read for &'a mut R where
    R: Read + ?Sized, impl<'a, W> Write for &'a mut W where
    W: Write + ?Sized, impl<'a, I> Iterator for &'a mut I where
    I: Iterator + ?Sized,  type Item = <I as Iterator>::Item;

fn deref(&self) -> &T

Dereferences the value.

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

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) -> (Self::Mask, Self::Value)

Open this join by returning the mask and the storages.

unsafe fn get(v: &mut Self::Value, i: Index) -> Self::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: 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.

impl<'a, 'b, T> ParJoin for &'a Read<'b, T> where     &'a T: ParJoin,     T: Resource,

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

Create a joined parallel iterator over the contents.