Trait Accessor

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

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.

Provided Methods

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).

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.

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.

Implementors

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

where T: SystemData<'a>,