#[repr(i8)]
pub enum Ordering {
Less,
Equal,
Greater,
}
Expand description
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.
Implementations
sourceimpl 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) -> Orderingwhere
F: FnOnce() -> Ordering,
pub fn then_with<F>(self, f: F) -> Orderingwhere
F: FnOnce() -> 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
const: unstable · sourceimpl Ord for Ordering
impl Ord for Ordering
1.21.0 · sourceconst fn max(self, other: Self) -> Self
const fn max(self, other: Self) -> Self
Compares and returns the maximum of two values. Read more
1.21.0 · sourceconst fn min(self, other: Self) -> Self
const fn min(self, other: Self) -> Self
Compares and returns the minimum of two values. Read more
1.50.0 · sourceconst fn clamp(self, min: Self, max: Self) -> Selfwhere
Self: PartialOrd<Self>,
const fn clamp(self, min: Self, max: Self) -> Selfwhere
Self: PartialOrd<Self>,
Restrict a value to a certain interval. Read more
const: unstable · sourceimpl PartialEq<Ordering> for Ordering
impl PartialEq<Ordering> for Ordering
const: unstable · sourceimpl PartialOrd<Ordering> for Ordering
impl PartialOrd<Ordering> for Ordering
sourceconst fn le(&self, other: &Rhs) -> bool
const fn le(&self, other: &Rhs) -> bool
This method tests less than or equal to (for
self
and other
) and is used by the <=
operator. Read moreimpl Copy for Ordering
impl Eq for Ordering
impl StructuralEq 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
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more