Struct RegistryRef 

pub struct RegistryRef<'w> { /* private fields */ }

Read-only access to the Registry during handler dispatch.

Allows handlers to create new handlers at runtime by calling into_handler or into_callback on the borrowed registry.

No ResourceId needed — the registry is part of World’s structure, not a registered resource.

Methods from Deref<Target = Registry>

pub fn id<T: Resource>(&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: Resource>(&self) -> Option<ResourceId>

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

pub fn contains<T: Resource>(&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(&self, accesses: &[(Option<ResourceId>, &str)])

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

Two accesses conflict when they target the same ResourceId (same pointer). O(n²) pairwise comparison — handler arity is 1-8, so this is trivially fast at build time.

Panics

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

Trait Implementations

impl Deref for RegistryRef<'_>

type Target = Registry

The resulting type after dereferencing.

fn deref(&self) -> &Registry

Dereferences the value.

impl Param for RegistryRef<'_>

type State = ()

Opaque state cached at build time (e.g. ResourceId).

type Item<'w> = RegistryRef<'w>

The item produced at dispatch time.

fn init(_registry: &Registry)

Resolve state from the registry. Called once at build time.

unsafe fn fetch<'w>(world: &'w World, _state: &'w mut ()) -> RegistryRef<'w>

Fetch the item using cached state.

fn resource_id(state: &Self::State) -> Option<ResourceId>

The ResourceId this param accesses, if any.