Struct RuntimeCell 

pub struct RuntimeCell<T: 'static> { /* private fields */ }

A value kept in a runtime, reached through a handle that copies like a MutableState.

A state holder that is Copy keeps its shared, interior-mutable parts here: a read finds the value in the runtime’s cells, with no snapshot records to walk and no scope subscribed. Nothing recomposes when the value changes, so what a composition reads goes in a MutableState instead.

The value is owned as a state is: made while a remember builds its value, it belongs to that slot and goes with it; made anywhere else, it lives as long as the runtime.

use std::cell::Cell;

use cranpose_core::{DefaultScheduler, Runtime, RuntimeCell, scheduler_ref};

let runtime = Runtime::new(scheduler_ref(DefaultScheduler));
let count = RuntimeCell::with_runtime(Cell::new(0), runtime.handle());
let copy = count;
copy.with(|count| count.set(count.get() + 1));
assert_eq!(count.with(Cell::get), 1);

Implementations

impl<T: 'static> RuntimeCell<T>

pub fn new(value: T) -> Self

Keeps value in the current runtime. Panics without one.

pub fn with_runtime(value: T, runtime: RuntimeHandle) -> Self

Keeps value in runtime.

pub fn is_alive(&self) -> bool

Whether the value still lives: its owner and its runtime keep it.

pub fn try_get(&self) -> Option<Rc<T>>

A handle to the value, or None once it is gone. The handle keeps the value alive.

pub fn get(&self) -> Rc<T>

A handle to the value. Panics once it is gone.

pub fn try_with<R>(&self, f: impl FnOnce(&T) -> R) -> Option<R>

Runs f on the value, or returns None once it is gone.

pub fn with<R>(&self, f: impl FnOnce(&T) -> R) -> R

Runs f on the value. Panics once it is gone.

Trait Implementations

impl<T: 'static> Clone for RuntimeCell<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: 'static> Copy for RuntimeCell<T>

impl<T: 'static> Debug for RuntimeCell<T>

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

Formats the value using the given formatter.

impl<T: 'static> Eq for RuntimeCell<T>

impl<T: 'static> Hash for RuntimeCell<T>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: 'static> PartialEq for RuntimeCell<T>

fn eq(&self, other: &Self) -> bool

Equality operator ==.

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

Inequality operator !=.