Struct KeyCell

pub struct KeyCell<T: Meta>(/* private fields */);

A RefCell-like wrapper that can only be accessed via Key.

Implementations

impl<T: Meta> KeyCell<T>

pub fn new(item: T, attached: T::Data) -> Self

Creates a new KeyCell from an object and its associated metadata.

Examples

use mutcy::KeyCell;

let kc = KeyCell::new(123, ());

pub fn borrow<'a>(&'a self, _key: &'a Key) -> KeyCellRef<'a, T>

Immutably borrows the wrapped value.

Examples

use mutcy::{Key, KeyCell};

let key = Key::acquire();
let kc = KeyCell::new(123, ());

let borrowed1 = kc.borrow(&key);
let borrowed2 = kc.borrow(&key);

pub fn borrow_mut<'a>(&'a self, key: &'a mut Key) -> KeyCellMut<'a, T>

Mutably borrows the wrapped value.

Requires a &mut Key that ensures that no other borrows exist simultaneously.

Examples

use mutcy::{Key, KeyCell};

let mut key = Key::acquire();
let kc = KeyCell::new(123, ());

let borrowed1 = kc.borrow_mut(&mut key);

let borrowed2 = kc.borrow(&key);

// This does not compile.
// let _ = *borrowed1;

pub fn meta(&self) -> &T::Data

Acquire metadata. See Meta.

Examples

use mutcy::{KeyCell, Meta};
struct A;

impl Meta for A {
    type Data = i32;
}

let kc = KeyCell::new(A, 123);

assert_eq!(*kc.meta(), 123);