Struct ndarray::MathCell

pub struct MathCell<T>(/* private fields */);

A transparent wrapper of Cell<T> which is identical in every way, except it will implement arithmetic operators as well.

The purpose of MathCell is to be used from .cell_view(). The MathCell derefs to Cell, so all the cell’s methods are available.

Implementations

impl<T> MathCell<T>

pub const fn new(value: T) -> Self

Create a new cell with the given value

pub fn into_inner(self) -> T

Return the inner value

pub fn swap(&self, other: &Self)

Swap value with another cell

Methods from Deref<Target = Cell<T>>

pub fn set(&self, val: T)

Sets the contained value.

Examples

use std::cell::Cell;

let c = Cell::new(5);

c.set(10);

pub fn swap(&self, other: &Cell<T>)

Swaps the values of two Cells.

The difference with std::mem::swap is that this function doesn’t require a &mut reference.

Panics

This function will panic if self and other are different Cells that partially overlap. (Using just standard library methods, it is impossible to create such partially overlapping Cells. However, unsafe code is allowed to e.g. create two &Cell<[i32; 2]> that partially overlap.)

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());

pub fn replace(&self, val: T) -> T

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);

pub fn get(&self) -> T

Returns a copy of the contained value.

Examples

use std::cell::Cell;

let c = Cell::new(5);

let five = c.get();

pub fn update<F>(&self, f: F) -> T

where F: FnOnce(T) -> T,

🔬This is a nightly-only experimental API. (cell_update)

Updates the contained value using a function and returns the new value.

Examples

#![feature(cell_update)]

use std::cell::Cell;

let c = Cell::new(5);
let new = c.update(|x| x + 1);

assert_eq!(new, 6);
assert_eq!(c.get(), 6);

pub fn as_ptr(&self) -> *mut T

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();

pub fn get_mut(&mut self) -> &mut T

Returns a mutable reference to the underlying data.

This call borrows Cell mutably (at compile-time) which guarantees that we possess the only reference.

However be cautious: this method expects self to be mutable, which is generally not the case when using a Cell. If you require interior mutability by reference, consider using RefCell which provides run-time checked mutable borrows through its borrow_mut method.

Examples

use std::cell::Cell;

let mut c = Cell::new(5);
*c.get_mut() += 1;

assert_eq!(c.get(), 6);

pub fn take(&self) -> T

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);

pub fn as_slice_of_cells(&self) -> &[Cell<T>]

Returns a &[Cell<T>] from a &Cell<[T]>

Examples

use std::cell::Cell;

let slice: &mut [i32] = &mut [1, 2, 3];
let cell_slice: &Cell<[i32]> = Cell::from_mut(slice);
let slice_cell: &[Cell<i32>] = cell_slice.as_slice_of_cells();

assert_eq!(slice_cell.len(), 3);

pub fn as_array_of_cells(&self) -> &[Cell<T>; N]

🔬This is a nightly-only experimental API. (as_array_of_cells)

Returns a &[Cell<T>; N] from a &Cell<[T; N]>

Examples

#![feature(as_array_of_cells)]
use std::cell::Cell;

let mut array: [i32; 3] = [1, 2, 3];
let cell_array: &Cell<[i32; 3]> = Cell::from_mut(&mut array);
let array_cell: &[Cell<i32>; 3] = cell_array.as_array_of_cells();

Trait Implementations

impl<'a, T> AssignElem<T> for &'a MathCell<T>

Assignable element, simply self.set(input).

fn assign_elem(self, input: T)

Assign the value input to the element that self represents.

impl<T> Clone for MathCell<T>

where T: Copy,

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Debug for MathCell<T>

where T: Copy + Debug,

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

Formats the value using the given formatter.

impl<T: Default> Default for MathCell<T>

fn default() -> MathCell<T>

Returns the “default value” for a type.

impl<T> Deref for MathCell<T>

type Target = Cell<T>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T> DerefMut for MathCell<T>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<T> Ord for MathCell<T>

where T: Copy + Ord,

fn cmp(&self, rhs: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<T> PartialEq for MathCell<T>

where T: Copy + PartialEq,

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> PartialOrd for MathCell<T>

where T: Copy + PartialOrd,

fn partial_cmp(&self, rhs: &Self) -> Option<Ordering>

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

fn lt(&self, rhs: &Self) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, rhs: &Self) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, rhs: &Self) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, rhs: &Self) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> Eq for MathCell<T>

where T: Copy + Eq,