#[repr(i8)]pub enum Ordering {
Less = -1,
Equal = 0,
Greater = 1,
}
Expand description
Variants§
Less = -1
An ordering where a compared value is less than another.
Equal = 0
An ordering where a compared value is equal to another.
Greater = 1
An ordering where a compared value is greater than another.
Implementations§
source§impl Ordering
impl Ordering
const: 1.48.0 · sourcepub const fn reverse(self) -> Ordering
pub const fn reverse(self) -> Ordering
Reverses the Ordering
.
Less
becomesGreater
.Greater
becomesLess
.Equal
becomesEqual
.
§Examples
Basic behavior:
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);
RunThis method can be used to reverse a comparison:
let 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);
Run1.17.0 (const: 1.48.0) · sourcepub const fn then(self, other: Ordering) -> Ordering
pub const fn then(self, other: Ordering) -> Ordering
Chains two orderings.
Returns self
when it’s not Equal
. Otherwise returns other
.
§Examples
use std::cmp::Ordering;
let result = Ordering::Equal.then(Ordering::Less);
assert_eq!(result, Ordering::Less);
let result = Ordering::Less.then(Ordering::Equal);
assert_eq!(result, Ordering::Less);
let result = Ordering::Less.then(Ordering::Greater);
assert_eq!(result, Ordering::Less);
let result = Ordering::Equal.then(Ordering::Equal);
assert_eq!(result, Ordering::Equal);
let x: (i64, i64, i64) = (1, 2, 7);
let y: (i64, i64, i64) = (1, 5, 3);
let result = x.0.cmp(&y.0).then(x.1.cmp(&y.1)).then(x.2.cmp(&y.2));
assert_eq!(result, Ordering::Less);
Run1.17.0 · sourcepub fn then_with<F>(self, f: F) -> Ordering
pub fn then_with<F>(self, f: F) -> Ordering
Chains the ordering with the given function.
Returns self
when it’s not Equal
. Otherwise calls f
and returns
the result.
§Examples
use std::cmp::Ordering;
let result = Ordering::Equal.then_with(|| Ordering::Less);
assert_eq!(result, Ordering::Less);
let result = Ordering::Less.then_with(|| Ordering::Equal);
assert_eq!(result, Ordering::Less);
let result = Ordering::Less.then_with(|| Ordering::Greater);
assert_eq!(result, Ordering::Less);
let result = Ordering::Equal.then_with(|| Ordering::Equal);
assert_eq!(result, Ordering::Equal);
let x: (i64, i64, i64) = (1, 2, 7);
let y: (i64, i64, i64) = (1, 5, 3);
let result = x.0.cmp(&y.0).then_with(|| x.1.cmp(&y.1)).then_with(|| x.2.cmp(&y.2));
assert_eq!(result, Ordering::Less);
RunTrait Implementations§
source§impl Ord for Ordering
impl Ord for Ordering
source§impl PartialOrd for Ordering
impl PartialOrd for Ordering
impl Copy for Ordering
impl Eq for Ordering
impl StructuralPartialEq for Ordering
Auto Trait Implementations§
impl RefUnwindSafe for Ordering
impl Send for Ordering
impl Sync for Ordering
impl Unpin for Ordering
impl UnwindSafe for Ordering
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more