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);
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.
impl Ordering
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pub fn reverse(self) -> Ordering
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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]; // 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);
pub fn then(self, other: Ordering) -> Ordering
[src]1.17.0
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);
pub fn then_with<F>(self, f: F) -> Ordering where
F: FnOnce() -> Ordering,
[src]1.17.0
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);
impl Copy for Ordering
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impl Hash for Ordering
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fn hash<__H>(&self, state: &mut __H) where
__H: Hasher,
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fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,
[src]1.3.0
Feeds a slice of this type into the given [Hasher
]. Read more
impl Clone for Ordering
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fn clone(&self) -> Ordering
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fn clone_from(&mut self, source: &Self)
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Performs copy-assignment from source
. Read more
impl Eq for Ordering
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impl PartialOrd<Ordering> for Ordering
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fn partial_cmp(&self, other: &Ordering) -> Option<Ordering>
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fn lt(&self, other: &Rhs) -> bool
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This method tests less than (for self
and other
) and is used by the <
operator. Read more
fn le(&self, other: &Rhs) -> bool
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This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
fn gt(&self, other: &Rhs) -> bool
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This method tests greater than (for self
and other
) and is used by the >
operator. Read more
fn ge(&self, other: &Rhs) -> bool
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This method tests greater than or equal to (for self
and other
) and is used by the >=
operator. Read more
impl Ord for Ordering
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fn cmp(&self, other: &Ordering) -> Ordering
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fn max(self, other: Self) -> Self
[src]1.21.0
Compares and returns the maximum of two values. Read more
fn min(self, other: Self) -> Self
[src]1.21.0
Compares and returns the minimum of two values. Read more
fn clamp(self, min: Self, max: Self) -> Self
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Restrict a value to a certain interval. Read more
impl Debug for Ordering
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impl PartialEq<Ordering> for Ordering
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impl UnwindSafe for Ordering
impl RefUnwindSafe for Ordering
impl Unpin for Ordering
impl Send for Ordering
impl Sync for Ordering
impl<T, U> TryFrom<U> for T where
U: Into<T>,
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type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> Into<U> for T where
U: From<T>,
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impl<T> From<T> for T
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
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impl<T> Borrow<T> for T where
T: ?Sized,
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fn borrow(&self) -> &T
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impl<'_, F> Future for &'_ mut F where F: Unpin + Future + ?Sized, type Output = <F as Future>::Output; impl<'_, I> Iterator for &'_ mut I where I: Iterator + ?Sized, type Item = <I as Iterator>::Item; impl<'_, R: Read + ?Sized> Read for &'_ mut R impl<'_, W: Write + ?Sized> Write for &'_ mut W
impl<T> BorrowMut<T> for T where
T: ?Sized,
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fn borrow_mut(&mut self) -> &mut T
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impl<'_, F> Future for &'_ mut F where F: Unpin + Future + ?Sized, type Output = <F as Future>::Output; impl<'_, I> Iterator for &'_ mut I where I: Iterator + ?Sized, type Item = <I as Iterator>::Item; impl<'_, R: Read + ?Sized> Read for &'_ mut R impl<'_, W: Write + ?Sized> Write for &'_ mut W
impl<T> Any for T where
T: 'static + ?Sized,
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impl<T> ToOwned for T where
T: Clone,
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© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/cmp/enum.Ordering.html