Struct Local 

pub struct Local<'a, T: Default + Send + Sync + 'static> { /* private fields */ }

Per-system persistent local state.

Unlike Res/ResMut, a Local<T> is not shared through Resources — each system gets its own private T, initialized with Default::default the first time the system is registered, and preserved across every subsequent run of that system.

Useful for counters, caches, or any state a single system needs to remember without polluting the global resource set.

Trait Implementations

impl<'a, T: Default + Send + Sync + 'static> Deref for Local<'a, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'a, T: Default + Send + Sync + 'static> DerefMut for Local<'a, T>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<T> SystemParam for Local<'static, T>

where T: Default + Send + Sync + 'static,

type Item<'a> = Local<'a, T>

type State = T

fn fetch<'a>( state: &'a mut Self::State, _world: &'a World, _resources: &'a Resources, ) -> Self::Item<'a>

fn requires() -> Vec<RequiredResource>

Resource types this parameter unconditionally needs present to avoid panicking. Used by App to validate — before running a non-convergent stage’s systems — that every hard requirement is already satisfied, failing fast with a clear message instead of panicking deep inside whichever system happens to run first.