pub enum Ordering {
Less,
Equal,
Greater,
}
An Ordering
is the result of a comparison between two values.
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);
An ordering where a compared value is less [than another].
An ordering where a compared value is equal [to another].
An ordering where a compared value is greater [than another].
Reverses the Ordering
.
Less
becomes Greater
.
Greater
becomes Less
.
Equal
becomes Equal
.
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);
This method can be used to reverse a comparison:
let mut data: &mut [_] = &mut [2, 10, 5, 8];
data.sort_by(|a, b| a.cmp(b).reverse());
let b: &mut [_] = &mut [10, 8, 5, 2];
assert!(data == b);
Chains two orderings.
Returns self
when it's not Equal
. Otherwise returns other
.
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);
Chains the ordering with the given function.
Returns self
when it's not Equal
. Otherwise calls f
and returns
the result.
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);
Performs copy-assignment from source
. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method tests greater than or equal to (for self
and other
) and is used by the >=
operator. Read more
This method returns an Ordering
between self
and other
. Read more
fn max(self, other: Self) -> Self | 1.21.0 [src] |
Compares and returns the maximum of two values. Read more
fn min(self, other: Self) -> Self | 1.21.0 [src] |
Compares and returns the minimum of two values. Read more
Feeds this value into the given [Hasher
]. Read more
Feeds a slice of this type into the given [Hasher
]. Read more
This method tests for self
and other
values to be equal, and is used by ==
. Read more
This method tests for !=
.
Formats the value using the given formatter. Read more