Struct bevy_ecs::change_detection::ResMut
source · pub struct ResMut<'w, T: ?Sized + Resource> { /* private fields */ }
Expand description
Unique mutable borrow of a Resource
.
See the Resource
documentation for usage.
If you need a shared borrow, use Res
instead.
§Panics
Panics when used as a SystemParam
if the resource does not exist.
Use Option<ResMut<T>>
instead if the resource might not always exist.
Implementations§
source§impl<'w, T: ?Sized + Resource> ResMut<'w, T>
impl<'w, T: ?Sized + Resource> ResMut<'w, T>
sourcepub fn into_inner(self) -> &'w mut T
pub fn into_inner(self) -> &'w mut T
Consume self
and return a mutable reference to the
contained value while marking self
as “changed”.
sourcepub fn reborrow(&mut self) -> Mut<'_, T>
pub fn reborrow(&mut self) -> Mut<'_, T>
Returns a Mut<>
with a smaller lifetime.
This is useful if you have &mut ResMut <T>
, but you need a Mut<T>
.
sourcepub fn map_unchanged<U: ?Sized>(
self,
f: impl FnOnce(&mut T) -> &mut U
) -> Mut<'w, U>
pub fn map_unchanged<U: ?Sized>( self, f: impl FnOnce(&mut T) -> &mut U ) -> Mut<'w, U>
Maps to an inner value by applying a function to the contained reference, without flagging a change.
You should never modify the argument passed to the closure – if you want to modify the data
without flagging a change, consider using DetectChangesMut::bypass_change_detection
to make your intent explicit.
// When run, zeroes the translation of every entity.
fn reset_positions(mut transforms: Query<&mut Transform>) {
for transform in &mut transforms {
// We pinky promise not to modify `t` within the closure.
// Breaking this promise will result in logic errors, but will never cause undefined behavior.
let mut translation = transform.map_unchanged(|t| &mut t.translation);
// Only reset the translation if it isn't already zero;
translation.set_if_neq(Vec2::ZERO);
}
}
Trait Implementations§
source§impl<'w, T: ?Sized + Resource> DetectChanges for ResMut<'w, T>
impl<'w, T: ?Sized + Resource> DetectChanges for ResMut<'w, T>
source§fn is_changed(&self) -> bool
fn is_changed(&self) -> bool
true
if this value was added or mutably dereferenced
either since the last time the system ran or, if the system never ran,
since the beginning of the program. Read moresource§fn last_changed(&self) -> Tick
fn last_changed(&self) -> Tick
source§impl<'w, T: ?Sized + Resource> DetectChangesMut for ResMut<'w, T>
impl<'w, T: ?Sized + Resource> DetectChangesMut for ResMut<'w, T>
source§fn set_changed(&mut self)
fn set_changed(&mut self)
source§fn set_last_changed(&mut self, last_changed: Tick)
fn set_last_changed(&mut self, last_changed: Tick)
source§fn bypass_change_detection(&mut self) -> &mut Self::Inner
fn bypass_change_detection(&mut self) -> &mut Self::Inner
source§impl<'w, 'a, T: Resource> IntoIterator for &'a ResMut<'w, T>where
&'a T: IntoIterator,
impl<'w, 'a, T: Resource> IntoIterator for &'a ResMut<'w, T>where
&'a T: IntoIterator,
source§impl<'w, 'a, T: Resource> IntoIterator for &'a mut ResMut<'w, T>where
&'a mut T: IntoIterator,
impl<'w, 'a, T: Resource> IntoIterator for &'a mut ResMut<'w, T>where
&'a mut T: IntoIterator,
source§impl<'a, T: Resource> SystemParam for ResMut<'a, T>
impl<'a, T: Resource> SystemParam for ResMut<'a, T>
§type State = ComponentId
type State = ComponentId
§type Item<'w, 's> = ResMut<'w, T>
type Item<'w, 's> = ResMut<'w, T>
Self
, instantiated with new lifetimes. Read moresource§fn init_state(world: &mut World, system_meta: &mut SystemMeta) -> Self::State
fn init_state(world: &mut World, system_meta: &mut SystemMeta) -> Self::State
World
access used by this SystemParam
and creates a new instance of this param’s State
.source§unsafe fn get_param<'w, 's>(
component_id: &'s mut Self::State,
system_meta: &SystemMeta,
world: UnsafeWorldCell<'w>,
change_tick: Tick
) -> Self::Item<'w, 's>
unsafe fn get_param<'w, 's>( component_id: &'s mut Self::State, system_meta: &SystemMeta, world: UnsafeWorldCell<'w>, change_tick: Tick ) -> Self::Item<'w, 's>
SystemParamFunction
. Read moresource§unsafe fn new_archetype(
state: &mut Self::State,
archetype: &Archetype,
system_meta: &mut SystemMeta
)
unsafe fn new_archetype( state: &mut Self::State, archetype: &Archetype, system_meta: &mut SystemMeta )
Archetype
, registers the components accessed by this SystemParam
(if applicable).a Read moresource§fn apply(state: &mut Self::State, system_meta: &SystemMeta, world: &mut World)
fn apply(state: &mut Self::State, system_meta: &SystemMeta, world: &mut World)
SystemParam
’s state.
This is used to apply Commands
during apply_deferred
.source§fn queue(
state: &mut Self::State,
system_meta: &SystemMeta,
world: DeferredWorld<'_>
)
fn queue( state: &mut Self::State, system_meta: &SystemMeta, world: DeferredWorld<'_> )
apply_deferred
.Auto Trait Implementations§
impl<'w, T> Freeze for ResMut<'w, T>where
T: ?Sized,
impl<'w, T> RefUnwindSafe for ResMut<'w, T>where
T: RefUnwindSafe + ?Sized,
impl<'w, T> Send for ResMut<'w, T>where
T: ?Sized,
impl<'w, T> Sync for ResMut<'w, T>where
T: ?Sized,
impl<'w, T> Unpin for ResMut<'w, T>where
T: ?Sized,
impl<'w, T> !UnwindSafe for ResMut<'w, T>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
source§fn into_any(self: Box<T>) -> Box<dyn Any>
fn into_any(self: Box<T>) -> Box<dyn Any>
Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
. Box<dyn Any>
can
then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
.source§fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
.source§fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
&Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s.source§fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
&mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s.