Trait System

pub trait System<'a> {
    type SystemData: DynamicSystemData<'a>;

    // Required method
    fn run(&mut self, data: Self::SystemData);

    // Provided methods
    fn running_time(&self) -> RunningTime { ... }
    fn accessor<'b>(&'b self) -> AccessorCow<'a, 'b, Self> { ... }
    fn setup(&mut self, world: &mut World) { ... }
    fn dispose(self, world: &mut World)
       where Self: Sized { ... }
}

A System, executed with a set of required Resources.

Required Associated Types

type SystemData: DynamicSystemData<'a>

The resource bundle required to execute this system.

You will mostly use a tuple of system data (which also implements SystemData). You can also create such a resource bundle by simply deriving SystemData for a struct.

Every SystemData is also a DynamicSystemData.

Required Methods

fn run(&mut self, data: Self::SystemData)

Executes the system with the required system data.

Provided Methods

fn running_time(&self) -> RunningTime

Returns a hint how long the system needs for running. This is used to optimize the way they’re executed (might allow more parallelization).

Defaults to RunningTime::Average.

fn accessor<'b>(&'b self) -> AccessorCow<'a, 'b, Self>

Return the accessor from the SystemData.

fn setup(&mut self, world: &mut World)

Sets up the World using Self::SystemData::setup.

fn dispose(self, world: &mut World)

where Self: Sized,

Performs clean up that requires resources from the World. This commonly removes components from world which depend on external resources.

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