Struct bevy_internal::ecs::change_detection::MutUntyped

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

Unique mutable borrow of resources or an entity’s component.

Similar to Mut, but not generic over the component type, instead exposing the raw pointer as a *mut ().

Usually you don’t need to use this and can instead use the APIs returning a Mut, but in situations where the types are not known at compile time or are defined outside of rust this can be used.

Implementations

impl<'w> MutUntyped<'w>

pub fn into_inner(self) -> PtrMut<'w>

Returns the pointer to the value, marking it as changed.

In order to avoid marking the value as changed, you need to call bypass_change_detection.

pub fn reborrow(&mut self) -> MutUntyped<'_>

Returns a MutUntyped with a smaller lifetime. This is useful if you have &mut MutUntyped, but you need a MutUntyped.

pub fn as_mut(&mut self) -> PtrMut<'_>

Returns a pointer to the value without taking ownership of this smart pointer, marking it as changed.

In order to avoid marking the value as changed, you need to call bypass_change_detection.

pub fn as_ref(&self) -> Ptr<'_>

Returns an immutable pointer to the value without taking ownership.

pub fn map_unchanged<T>( self, f: impl FnOnce(PtrMut<'w>) -> &'w mut T ) -> Mut<'w, T>

where T: ?Sized,

Turn this MutUntyped into a Mut by mapping the inner PtrMut to another value, without flagging a change. This function is the untyped equivalent of Mut::map_unchanged.

You should never modify the argument passed to the closure – if you want to modify the data without flagging a change, consider using bypass_change_detection to make your intent explicit.

If you know the type of the value you can do

// SAFETY: ptr is of type `u8`
mut_untyped.map_unchanged(|ptr| unsafe { ptr.deref_mut::<u8>() });

If you have a ReflectFromPtr that you know belongs to this MutUntyped, you can do

// SAFETY: from the context it is known that `ReflectFromPtr` was made for the type of the `MutUntyped`
mut_untyped.map_unchanged(|ptr| unsafe { reflect_from_ptr.as_reflect_mut(ptr) });

pub unsafe fn with_type<T>(self) -> Mut<'w, T>

Transforms this MutUntyped into a Mut<T> with the same lifetime.

Safety

• T must be the erased pointee type for this MutUntyped.

Trait Implementations

impl Debug for MutUntyped<'_>

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

Formats the value using the given formatter.

impl<'w> DetectChanges for MutUntyped<'w>

fn is_added(&self) -> bool

Returns true if this value was added after the system last ran.

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.

fn last_changed(&self) -> Tick

Returns the change tick recording the time this data was most recently changed.

impl<'w> DetectChangesMut for MutUntyped<'w>

type Inner = PtrMut<'w>

The type contained within this smart pointer

fn set_changed(&mut self)

Flags this value as having been changed.

fn set_last_changed(&mut self, last_changed: Tick)

Manually sets the change tick recording the time when this data was last mutated.

fn bypass_change_detection( &mut self ) -> &mut <MutUntyped<'w> as DetectChangesMut>::Inner

Manually bypasses change detection, allowing you to mutate the underlying value without updating the change tick.