Struct core::cell::Cell 1.0.0[−][src]
#[repr(transparent)]pub struct Cell<T: ?Sized> { /* fields omitted */ }
A mutable memory location.
Examples
In this example, you can see that Cell<T>
enables mutation inside an
immutable struct. In other words, it enables “interior mutability”.
use std::cell::Cell; struct SomeStruct { regular_field: u8, special_field: Cell<u8>, } let my_struct = SomeStruct { regular_field: 0, special_field: Cell::new(1), }; let new_value = 100; // ERROR: `my_struct` is immutable // my_struct.regular_field = new_value; // WORKS: although `my_struct` is immutable, `special_field` is a `Cell`, // which can always be mutated my_struct.special_field.set(new_value); assert_eq!(my_struct.special_field.get(), new_value);Run
See the module-level documentation for more.
Implementations
impl<T> Cell<T>
[src]
impl<T> Cell<T>
[src]pub const fn new(value: T) -> Cell<T>
1.0.0 (const: 1.24.0)[src]
Creates a new Cell
containing the given value.
Examples
use std::cell::Cell; let c = Cell::new(5);Run
pub fn set(&self, val: T)
[src]
pub fn swap(&self, other: &Self)
1.17.0[src]
Swaps the values of two Cells.
Difference with std::mem::swap
is that this function doesn’t require &mut
reference.
Examples
use std::cell::Cell; let c1 = Cell::new(5i32); let c2 = Cell::new(10i32); c1.swap(&c2); assert_eq!(10, c1.get()); assert_eq!(5, c2.get());Run
pub fn replace(&self, val: T) -> T
1.17.0[src]
Replaces the contained value with val
, and returns the old contained value.
Examples
use std::cell::Cell; let cell = Cell::new(5); assert_eq!(cell.get(), 5); assert_eq!(cell.replace(10), 5); assert_eq!(cell.get(), 10);Run
pub fn into_inner(self) -> T
1.17.0[src]
impl<T: Copy> Cell<T>
[src]
impl<T: Copy> Cell<T>
[src]impl<T: ?Sized> Cell<T>
[src]
impl<T: ?Sized> Cell<T>
[src]pub const fn as_ptr(&self) -> *mut T
1.12.0 (const: 1.32.0)[src]
Returns a raw pointer to the underlying data in this cell.
Examples
use std::cell::Cell; let c = Cell::new(5); let ptr = c.as_ptr();Run
pub fn get_mut(&mut self) -> &mut T
1.11.0[src]
Returns a mutable reference to the underlying data.
This call borrows Cell
mutably (at compile-time) which guarantees
that we possess the only reference.
Examples
use std::cell::Cell; let mut c = Cell::new(5); *c.get_mut() += 1; assert_eq!(c.get(), 6);Run
pub fn from_mut(t: &mut T) -> &Cell<T>
1.37.0[src]
impl<T: Default> Cell<T>
[src]
impl<T: Default> Cell<T>
[src]impl<T> Cell<[T]>
[src]
impl<T> Cell<[T]>
[src]pub fn as_slice_of_cells(&self) -> &[Cell<T>]
1.37.0[src]
Trait Implementations
impl<T: Copy> Clone for Cell<T>
[src]
impl<T: Copy> Clone for Cell<T>
[src]fn clone(&self) -> Cell<T>
[src]
fn clone_from(&mut self, source: &Self)
[src]
impl<T: PartialOrd + Copy> PartialOrd<Cell<T>> for Cell<T>
1.10.0[src]
impl<T: PartialOrd + Copy> PartialOrd<Cell<T>> for Cell<T>
1.10.0[src]impl<T: CoerceUnsized<U>, U> CoerceUnsized<Cell<U>> for Cell<T>
[src]
impl<T: Eq + Copy> Eq for Cell<T>
1.2.0[src]
impl<T: ?Sized> Send for Cell<T> where
T: Send,
[src]
T: Send,