Enum core::cmp::Ordering

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 Hash for Ordering

fn hash<__H: Hasher>(&self, __arg_0: &mut __H)

fn hash_slice<H: Hasher>(data: &[Self], state: &mut H) where Self: Sized

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, other: &Rhs) -> bool

impl Copy for Ordering

impl Clone for Ordering

fn clone(&self) -> Ordering

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