Struct State 

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

Handle to memoized state created by remember and remember_with_key.

State<T> is Copy + Send + Sync and provides with, with_mut, get, set, and cloned to read or update the stored value.

Component factories such as remember run only during a Tessera build. Remembered state survives recomposition while its slot is used; retain also keeps unused slots until the component unmounts. StateOwner provides a controller or route lifetime independent of component mounting.

Access rejects stale handles and handles owned by another UI session.

Examples

use tessera_ui::{remember, tessera};

#[tessera]
fn counter() {
    let count = remember(|| 0usize);
    count.with_mut(|c| *c += 1);
    let current = count.get();
    assert!(current >= 1);
}

Implementations

impl<T> State<T>

where T: Send + Sync + 'static,

pub fn is_alive(&self) -> bool

Returns whether this handle still refers to a live state slot.

Remembered state can expire when its component leaves the tree; retained state remains alive until the runtime is reset.

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

Execute a closure with a shared reference to the stored value.

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

Execute a closure with a mutable reference to the stored value.

pub fn get(&self) -> T

where T: Clone,

Get a cloned value. Requires T: Clone.

pub fn set_if_changed(&self, value: T) -> bool

where T: PartialEq,

Replaces the value and invalidates readers only when it differs.

The comparison does not subscribe the caller to the state. This permits publishing derived geometry without making its publisher a reader.

pub fn set(&self, value: T)

Replace the stored value.

Trait Implementations

impl<T> Clone for State<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> Copy for State<T>

impl<T> Eq for State<T>

impl<T> Hash for State<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> PartialEq for State<T>

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

Equality operator ==.

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

Inequality operator !=.