# Struct core::cell::Cell 1.0.0 [−] [src]

    pub struct Cell<T> { /* fields omitted */ }

A mutable memory location.

# Examples

Here you can see how using `Cell<T>` allows to use mutable field inside immutable struct (which is also called '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, because my_struct is immutable
    // my_struct.regular_field = new_value;

    // WORKS, although `my_struct` is immutable, field `special_field` is mutable because it is Cell
    my_struct.special_field.set(new_value);
    assert_eq!(my_struct.special_field.get(), new_value);Run

See the module-level documentation for more.

## Methods

### `impl<T: Copy> Cell<T>`
[src]

#### `fn get(&self) -> T`
[src]

Returns a copy of the contained value.

# Examples

    use std::cell::Cell;

    let c = Cell::new(5);

    let five = c.get();Run

### `impl<T> Cell<T>`
[src]

#### `const fn new(value: T) -> Cell<T>`
[src]

Creates a new `Cell` containing the given value.

# Examples

    use std::cell::Cell;

    let c = Cell::new(5);Run

#### `fn as_ptr(&self) -> *mut T`
1.12.0
[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

#### `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

#### `fn set(&self, val: T)`
[src]

Sets the contained value.

# Examples

    use std::cell::Cell;

    let c = Cell::new(5);

    c.set(10);Run

#### `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

#### `fn replace(&self, val: T) -> T`
1.17.0
[src]

Replaces the contained value, and returns it.

# 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

#### `fn into_inner(self) -> T`
1.17.0
[src]

Unwraps the value.

# Examples

    use std::cell::Cell;

    let c = Cell::new(5);
    let five = c.into_inner();

    assert_eq!(five, 5);Run

### `impl<T: Default> Cell<T>`
[src]

#### `fn take(&self) -> T`
1.17.0
[src]

Takes the value of the cell, leaving `Default::default()` in its place.

# Examples

    use std::cell::Cell;

    let c = Cell::new(5);
    let five = c.take();

    assert_eq!(five, 5);
    assert_eq!(c.into_inner(), 0);Run

## Trait Implementations

### `impl<T> Send for Cell<T> where
T: Send,`
[src]

### `impl<T> !Sync for Cell<T>`
[src]

### `impl<T: Copy> Clone for Cell<T>`
[src]

#### `fn clone(&self) -> Cell<T>`
[src]

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`
[src]

Performs copy-assignment from `source`. Read more

### `impl<T: Default> Default for Cell<T>`
[src]

#### `fn default() -> Cell<T>`
[src]

Creates a `Cell<T>`, with the `Default` value for T.

### `impl<T: PartialEq + Copy> PartialEq for Cell<T>`
[src]

#### `fn eq(&self, other: &Cell<T>) -> bool`
[src]

This method tests for `self` and `other` values to be equal, and is used by `==`. Read more

#### `fn ne(&self, other: &Rhs) -> bool`
[src]

This method tests for `!=`.

### `impl<T: Eq + Copy> Eq for Cell<T>`
1.2.0
[src]

### `impl<T: PartialOrd + Copy> PartialOrd for Cell<T>`
1.10.0
[src]

#### `fn partial_cmp(&self, other: &Cell<T>) -> Option<Ordering>`
[src]

This method returns an ordering between `self` and `other` values if one exists. Read more

#### `fn lt(&self, other: &Cell<T>) -> bool`
[src]

This method tests less than (for `self` and `other`) and is used by the `<` operator. Read more

#### `fn le(&self, other: &Cell<T>) -> bool`
[src]

This method tests less than or equal to (for `self` and `other`) and is used by the `<=` operator. Read more

#### `fn gt(&self, other: &Cell<T>) -> bool`
[src]

This method tests greater than (for `self` and `other`) and is used by the `>` operator. Read more

#### `fn ge(&self, other: &Cell<T>) -> bool`
[src]

This method tests greater than or equal to (for `self` and `other`) and is used by the `>=` operator. Read more

### `impl<T: Ord + Copy> Ord for Cell<T>`
1.10.0
[src]

#### `fn cmp(&self, other: &Cell<T>) -> Ordering`
[src]

This method returns an `Ordering` between `self` and `other`. Read more

#### `fn max(self, other: Self) -> Self where
Self: Sized,`
1.21.0
[src]

Compares and returns the maximum of two values. Read more

#### `fn min(self, other: Self) -> Self where
Self: Sized,`
1.21.0
[src]

Compares and returns the minimum of two values. Read more

### `impl<T> From<T> for Cell<T>`
1.12.0
[src]

#### `fn from(t: T) -> Cell<T>`
[src]

Performs the conversion.

### `impl<T: CoerceUnsized<U>, U> CoerceUnsized<Cell<U>> for Cell<T>`
[src]

### `impl<T: Copy + Debug> Debug for Cell<T>`
[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result`
[src]

Formats the value using the given formatter.

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