Struct ResMut 

pub struct ResMut<'w, T: Resource> { /* private fields */ }

Mutable reference to a resource in World.

Analogous to Bevy’s ResMut<T>.

Appears in handler function signatures to declare a write dependency. Derefs to the inner value transparently.

Passing by value

ResMut<T> cannot be Copy (exclusive borrow). To pass the wrapper to inner functions without moving, call reborrow() — analogous to the &mut *x pattern for &mut T.

For shared read access, use Res<T>. For optional write access (no panic if unregistered), use Option<ResMut<T>>.

Construction is pub(crate) — only the dispatch layer creates these.

Implementations

impl<'w, T: Resource> ResMut<'w, T>

pub fn reborrow(&mut self) -> ResMut<'_, T>

Reborrow as a ResMut<'_, T> with a shorter lifetime.

The original is frozen for the duration of the reborrow, then usable again. Lets you pass ResMut<T> to inner functions without moving — analogous to the &mut *x reborrow pattern for &mut T.

ResMut<T> cannot be Copy (exclusive borrow), so this is the counterpart to Res<T>’s Copy impl when the inner function signature takes the wrapper itself rather than &mut T.

Trait Implementations

impl<T: Debug + Resource> Debug for ResMut<'_, T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Resource> Deref for ResMut<'_, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<T: Resource> DerefMut for ResMut<'_, T>

fn deref_mut(&mut self) -> &mut T

Mutably dereferences the value.

impl<T: Resource> Param for ResMut<'_, T>

type State = ResourceId

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

type Item<'w> = ResMut<'w, T>

The item produced at dispatch time.

fn init(registry: &Registry) -> ResourceId

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

unsafe fn fetch<'w>( world: &'w World, state: &'w mut ResourceId, ) -> ResMut<'w, T>

Fetch the item using cached state.

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

The ResourceId this param accesses, if any.