Struct Registry 

pub struct Registry { /* private fields */ }

Type-to-index mapping shared between WorldBuilder and World.

Contains only the type registry — no storage, no pointers. Passed to IntoSystem::into_system and SystemParam::init so systems can resolve ResourceIds during driver setup.

Obtained via WorldBuilder::registry() or World::registry().

Implementations

impl Registry

pub fn id<T: 'static>(&self) -> ResourceId

Resolve the ResourceId for a type. Cold path — uses HashMap lookup.

Panics

Panics if the resource type was not registered.

pub fn try_id<T: 'static>(&self) -> Option<ResourceId>

Try to resolve the ResourceId for a type. Returns None if the type was not registered.

pub fn contains<T: 'static>(&self) -> bool

Returns true if a resource of type T has been registered.

pub fn len(&self) -> usize

Returns the number of registered resources.

pub fn is_empty(&self) -> bool

Returns true if no resources have been registered.

pub fn check_access(&mut self, accesses: &[(Option<ResourceId>, &str)])

Validate that a set of parameter accesses don’t conflict.

Two accesses conflict when they target the same ResourceId. Called at construction time by into_system, into_callback, and into_stage.

Fast path (≤128 resources): single u128 on the stack, zero heap. Slow path (>128 resources): reusable Vec<u64> owned by Registry — allocated once on first use, then cleared and reused.

Panics

Panics if any resource is accessed by more than one parameter.