Struct std::cmp::Reverse

pub struct Reverse<T>(pub T);

A helper struct for reverse ordering.

This struct is a helper to be used with functions like Vec::sort_by_key and can be used to reverse order a part of a key.

Example usage:

use std::cmp::Reverse;

let mut v = vec![1, 2, 3, 4, 5, 6];
v.sort_by_key(|&num| (num > 3, Reverse(num)));
assert_eq!(v, vec![3, 2, 1, 6, 5, 4]);

Trait Implementations

impl<T> PartialOrd<Reverse<T>> for Reverse<T> where
    T: PartialOrd<T>, 

fn partial_cmp(&self, other: &Reverse<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Reverse<T>) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Reverse<T>) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn ge(&self, other: &Reverse<T>) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

fn gt(&self, other: &Reverse<T>) -> bool

This method tests greater than (for self and other) and is used by the > operator.

impl<T> Hash for Reverse<T> where
    T: Hash, 

fn hash<__HT>(&self, state: &mut __HT) where
    __HT: Hasher, 

Feeds this value into the given [Hasher].

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

Feeds a slice of this type into the given [Hasher].

impl<T> Default for Reverse<T> where
    T: Default, 

fn default() -> Reverse<T>

Returns the "default value" for a type.

impl<T> Eq for Reverse<T> where
    T: Eq, 

impl<T> Clone for Reverse<T> where
    T: Clone, 

fn clone(&self) -> Reverse<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Debug for Reverse<T> where
    T: Debug, 

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.

impl<T> Copy for Reverse<T> where
    T: Copy, 

impl<T> Ord for Reverse<T> where
    T: Ord, 

fn cmp(&self, other: &Reverse<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp #44095)

Restrict a value to a certain interval.

impl<T> PartialEq<Reverse<T>> for Reverse<T> where
    T: PartialEq<T>, 

fn eq(&self, other: &Reverse<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Reverse<T>) -> bool

This method tests for !=.