# Enum core::cmp::Ordering [−] [src]

    pub enum Ordering {
        Less,
        Equal,
        Greater,
    }

An `Ordering` is the result of a comparison between two values.

# Examples

fn main() { use std::cmp::Ordering; let result = 1.cmp(&2); assert_eq!(Ordering::Less, result); let result = 1.cmp(&1); assert_eq!(Ordering::Equal, result); let result = 2.cmp(&1); assert_eq!(Ordering::Greater, result); }

    use std::cmp::Ordering;

    let result = 1.cmp(&2);
    assert_eq!(Ordering::Less, result);

    let result = 1.cmp(&1);
    assert_eq!(Ordering::Equal, result);

    let result = 2.cmp(&1);
    assert_eq!(Ordering::Greater, result);

## Variants

`Less` | An ordering where a compared value is less [than another].
`Equal` | An ordering where a compared value is equal [to another].
`Greater` | An ordering where a compared value is greater [than another].

## Methods

### `impl Ordering`

#### `fn reverse(self) -> Ordering`

Reverse the `Ordering`.

- `Less` becomes `Greater`.
- `Greater` becomes `Less`.
- `Equal` becomes `Equal`.

# Examples

Basic behavior:

fn main() { use std::cmp::Ordering; assert_eq!(Ordering::Less.reverse(), Ordering::Greater); assert_eq!(Ordering::Equal.reverse(), Ordering::Equal); assert_eq!(Ordering::Greater.reverse(), Ordering::Less); }

    use std::cmp::Ordering;

    assert_eq!(Ordering::Less.reverse(), Ordering::Greater);
    assert_eq!(Ordering::Equal.reverse(), Ordering::Equal);
    assert_eq!(Ordering::Greater.reverse(), Ordering::Less);

This method can be used to reverse a comparison:

fn main() { let mut data: &mut [_] = &mut [2, 10, 5, 8]; // sort the array from largest to smallest. data.sort_by(|a, b| a.cmp(b).reverse()); let b: &mut [_] = &mut [10, 8, 5, 2]; assert!(data == b); }

    let mut data: &mut [_] = &mut [2, 10, 5, 8];

    // sort the array from largest to smallest.
    data.sort_by(|a, b| a.cmp(b).reverse());

    let b: &mut [_] = &mut [10, 8, 5, 2];
    assert!(data == b);

## Trait Implementations

### `impl Eq for Ordering`

### `impl Ord for Ordering`

#### `fn cmp(&self, other: &Ordering) -> Ordering`

### `impl PartialOrd for Ordering`

#### `fn partial_cmp(&self, other: &Ordering) -> Option<Ordering>`

#### `fn lt(&self, other: &Rhs) -> bool`

#### `fn le(&self, other: &Rhs) -> bool`

#### `fn gt(&self, other: &Rhs) -> bool`

#### `fn ge(&self, other: &Rhs) -> bool`

### Derived Implementations

### `impl Debug for Ordering`

#### `fn fmt(&self, __arg_0: &mut Formatter) -> Result`

### `impl PartialEq for Ordering`

#### `fn eq(&self, __arg_0: &Ordering) -> bool`

#### `fn ne(&self, __arg_0: &Ordering) -> bool`

### `impl Copy for Ordering`

### `impl Clone for Ordering`

#### `fn clone(&self) -> Ordering`

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

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