Trait Accessor

pub trait Accessor: Sized {
    // Required methods
    fn try_new() -> Option<Self>;
    fn reads(&self) -> Vec<ResourceId>;
    fn writes(&self) -> Vec<ResourceId>;
}

A trait for accessing read/write multiple resources from a system. This can be used to create dynamic systems that don’t specify what they fetch at compile-time.

For compile-time system data this will all be done for you using StaticAccessor.

Required Methods

fn try_new() -> Option<Self>

Tries to create a new instance of this type. This one returns Some in case there is a default, otherwise the system needs to override System::accessor.

fn reads(&self) -> Vec<ResourceId>

A list of ResourceIds the bundle needs read access to in order to build the target resource bundle.

Contract

Exactly return the dependencies you’re going to fetch! Doing otherwise will cause a panic.

This method is only executed once, thus the returned value may never change (otherwise it has no effect).

fn writes(&self) -> Vec<ResourceId>

A list of ResourceIds the bundle needs write access to in order to build the target resource bundle.

Contract

Exactly return the dependencies you’re going to fetch! Doing otherwise will cause a panic.

This method is only executed once, thus the returned value may never change (otherwise it has no effect).

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl Accessor for ()

fn try_new() -> Option<()>

fn reads(&self) -> Vec<ResourceId>

fn writes(&self) -> Vec<ResourceId>

impl<T> Accessor for PhantomData<T>

where T: ?Sized,

fn try_new() -> Option<PhantomData<T>>

fn reads(&self) -> Vec<ResourceId>

fn writes(&self) -> Vec<ResourceId>

Implementors

impl Accessor for BatchAccessor

impl<'a, T> Accessor for StaticAccessor<T>

where T: SystemData<'a>,