Struct FieldStorage 

pub struct FieldStorage<T>
where
    T: Clone,
{
    pub inner: FieldStorageInner<T>,
}

Generic storage for PyBevy field types (non-Copy types like TextureAtlas)

Supports two modes:

• Owned: Python-created value, stored in Box
• Borrowed: Reference to field in a component (e.g., sprite.texture_atlas)

Type Parameters

• T: The field type (does not need to implement Copy)

Safety

Borrowed variant contains a raw pointer to value data in a component. The ValidityFlagWithMode ensures this pointer is only dereferenced during system execution when the pointer is guaranteed to be valid.

Fields

inner: FieldStorageInner<T>

Implementations

impl<T> FieldStorage<T>

where T: Clone,

pub fn owned(value: T) -> FieldStorage<T>

Create owned field storage with validity tracking

pub fn as_ref(&self) -> Result<&T, StorageError>

Get immutable reference to the value, checking validity

pub fn as_mut(&mut self) -> Result<&mut T, StorageError>

Get mutable reference to the value, checking validity and write permission

pub fn get(&self) -> Result<T, StorageError>

Get the current value (returns a clone)

pub fn borrow_field<F, S>( &self, field_accessor: impl Fn(&T) -> &F, ) -> Result<S, StorageError>

where F: Clone, S: BorrowableStorage<F>,

Borrow a field from the stored value

Returns a borrowed reference to a nested field that can be mutated and have changes persist back to the original storage.

Example

Prefer using borrow_field_as for simpler syntax:

#[getter]
pub fn physical_position(&self) -> PyResult<PyUVec2> {
    self.storage.borrow_field_as(|v| &v.physical_position)
}

Or use borrow_field directly when more control is needed:

let storage = self.storage.borrow_field(|v| &v.physical_position)?;
Ok(PyUVec2::from_borrowed(storage))

pub fn borrow_field_as<F, S, W>( &self, field_accessor: impl Fn(&T) -> &F, ) -> Result<W, StorageError>

where F: Clone, S: BorrowableStorage<F>, W: FromBorrowedStorage<S>,

Helper to borrow a field and wrap it in the final Python type

Combines borrow_field with FromBorrowedStorage::from_borrowed to reduce boilerplate.

Example

#[getter]
pub fn physical_position(&self) -> PyResult<PyUVec2> {
    self.storage.borrow_field_as(|v| &v.physical_position)
}

Trait Implementations

impl<T> BorrowableStorage<T> for FieldStorage<T>

where T: Clone,

unsafe fn borrowed( ptr: *mut T, validity: ValidityFlagWithMode, ) -> FieldStorage<T>

Create a borrowed storage from a raw pointer and validity flag

fn snapshot(value: &T) -> FieldStorage<T>

Create a read-only owned snapshot (copy) of the given value.

impl<T> Clone for FieldStorage<T>

where T: Clone,

fn clone(&self) -> FieldStorage<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for FieldStorage<T>

where T: Debug + Clone,

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

Formats the value using the given formatter.

impl<T> Drop for FieldStorage<T>

where T: Clone,

fn drop(&mut self)

Executes the destructor for this type.

impl<T> PartialEq for FieldStorage<T>

where T: Clone + PartialEq,

fn eq(&self, other: &FieldStorage<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> Send for FieldStorage<T>

where T: Clone + Send,

impl<T> Sync for FieldStorage<T>

where T: Clone + Sync,