pub struct Res<'w, T: ?Sized + Resource> { /* private fields */ }
Expand description
Shared borrow of a Resource
.
See the Resource
documentation for usage.
If you need a unique mutable borrow, use ResMut
instead.
This SystemParam
fails validation if resource doesn’t exist.
This will cause a panic, but can be configured to do nothing or warn once.
Use Option<Res<T>>
instead if the resource might not always exist.
Implementations§
Source§impl<'w, T: Resource> Res<'w, T>
impl<'w, T: Resource> Res<'w, T>
Sourcepub fn clone(this: &Self) -> Self
pub fn clone(this: &Self) -> Self
Copies a reference to a resource.
Note that unless you actually need an instance of Res<T>
, you should
prefer to just convert it to &T
which can be freely copied.
Sourcepub fn into_inner(self) -> &'w T
pub fn into_inner(self) -> &'w T
Due to lifetime limitations of the Deref
trait, this method can be used to obtain a
reference of the Resource
with a lifetime bound to 'w
instead of the lifetime of the
struct itself.
Trait Implementations§
Source§impl<'w, T: ?Sized + Resource> DetectChanges for Res<'w, T>
impl<'w, T: ?Sized + Resource> DetectChanges for Res<'w, T>
Source§fn is_changed(&self) -> bool
fn is_changed(&self) -> bool
Returns
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
Returns the change tick recording the time this data was most recently changed. Read more
Source§fn changed_by(&self) -> MaybeLocation
fn changed_by(&self) -> MaybeLocation
The location that last caused this to change.
Source§impl<'w, 'a, T: Resource> IntoIterator for &'a Res<'w, T>where
&'a T: IntoIterator,
impl<'w, 'a, T: Resource> IntoIterator for &'a Res<'w, T>where
&'a T: IntoIterator,
Source§impl<'a, T: Resource> SystemParam for Res<'a, T>
impl<'a, T: Resource> SystemParam for Res<'a, T>
Source§type State = ComponentId
type State = ComponentId
Used to store data which persists across invocations of a system.
Source§type Item<'w, 's> = Res<'w, T>
type Item<'w, 's> = Res<'w, T>
The item type returned when constructing this system param.
The value of this associated type should be
Self
, instantiated with new lifetimes. Read moreSource§fn init_access(
component_id: &Self::State,
system_meta: &mut SystemMeta,
component_access_set: &mut FilteredAccessSet,
_world: &mut World,
)
fn init_access( component_id: &Self::State, system_meta: &mut SystemMeta, component_access_set: &mut FilteredAccessSet, _world: &mut World, )
Registers any
World
access used by this SystemParam
Source§unsafe fn validate_param(
component_id: &mut Self::State,
_system_meta: &SystemMeta,
world: UnsafeWorldCell<'_>,
) -> Result<(), SystemParamValidationError>
unsafe fn validate_param( component_id: &mut Self::State, _system_meta: &SystemMeta, world: UnsafeWorldCell<'_>, ) -> Result<(), SystemParamValidationError>
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>
Creates a parameter to be passed into a
SystemParamFunction
. 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)
Applies any deferred mutations stored in this
SystemParam
’s state.
This is used to apply Commands
during ApplyDeferred
.Source§fn queue(
state: &mut Self::State,
system_meta: &SystemMeta,
world: DeferredWorld<'_>,
)
fn queue( state: &mut Self::State, system_meta: &SystemMeta, world: DeferredWorld<'_>, )
Queues any deferred mutations to be applied at the next
ApplyDeferred
.impl<'a, T: Resource> ReadOnlySystemParam for Res<'a, T>
Auto Trait Implementations§
impl<'w, T> Freeze for Res<'w, T>where
T: ?Sized,
impl<'w, T> RefUnwindSafe for Res<'w, T>where
T: RefUnwindSafe + ?Sized,
impl<'w, T> Send for Res<'w, T>where
T: ?Sized,
impl<'w, T> Sync for Res<'w, T>where
T: ?Sized,
impl<'w, T> Unpin for Res<'w, T>where
T: ?Sized,
impl<'w, T> UnwindSafe for Res<'w, T>where
T: RefUnwindSafe + ?Sized,
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
Mutably borrows from an owned value. Read more
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>
Converts
Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
, which can then be
downcast
into Box<dyn 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>
Converts
Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
, which 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)
Converts
&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)
Converts
&mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s.Source§impl<T> DowncastSend for T
impl<T> DowncastSend for T
Source§impl<T> Instrument for T
impl<T> Instrument for T
Source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
Source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
Source§impl<T> IntoResult<T> for T
impl<T> IntoResult<T> for T
Source§fn into_result(self) -> Result<T, RunSystemError>
fn into_result(self) -> Result<T, RunSystemError>
Converts this type into the system output type.