Struct gdnative_core::export::user_data::LocalCellData

pub struct LocalCellData<T> { /* private fields */ }

User-data wrapper analogous to a Arc<RefCell<T>>, that is restricted to the thread where it was originally created. The destructor of T is not guaranteed to be run if this is actually shared across multiple threads.

This works by checking ThreadId before touching the underlying reference. If the id doesn’t match the original thread, map and map_mut will return an error.

Since it isn’t possible to control where the last reference is dropped, the destructor isn’t run if the last reference is dropped on a different thread than the one where the wrapper was originally created. To ensure that values are cleaned up properly, keep the game single-threaded, or use a real thread-safe wrapper such as MutexData instead.

Trait Implementations

impl<T> Clone for LocalCellData<T>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for LocalCellData<T>

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

Formats the value using the given formatter.

impl<T> Map for LocalCellData<T> where
    T: NativeClass, 

type Err = LocalCellError

fn map<F, U>(&self, op: F) -> Result<U, Self::Err> where
    F: FnOnce(&Self::Target) -> U, 

Maps a &T to U. Called for methods that take &self.

impl<T> MapMut for LocalCellData<T> where
    T: NativeClass, 

type Err = LocalCellError

fn map_mut<F, U>(&self, op: F) -> Result<U, Self::Err> where
    F: FnOnce(&mut Self::Target) -> U, 

Maps a &mut T to U. Called for methods that take &mut self.

impl<T> UserData for LocalCellData<T> where
    T: NativeClass, 

type Target = T

fn new(val: Self::Target) -> Self

Creates a new owned wrapper from a NativeClass instance.

fn into_user_data(self) -> *const c_void

Takes a native instance and returns an opaque pointer that can be used to recover it.

unsafe fn consume_user_data_unchecked(ptr: *const c_void) -> Self

Takes an opaque pointer produced by into_user_data and “consumes” it to produce the original instance, keeping the reference count.

unsafe fn clone_from_user_data_unchecked(ptr: *const c_void) -> Self

Takes an opaque pointer produced by into_user_data and “clones” it to produce the original instance, increasing the reference count.