pub struct Reverse<T>(pub T);
Expand description
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.
Examples
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]);
Tuple Fields§
§0: T
Trait Implementations§
source§impl<T> Ord for Reverse<T>where
T: Ord,
impl<T> Ord for Reverse<T>where T: Ord,
1.21.0 · source§fn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere Self: Sized,
Compares and returns the maximum of two values. Read more
source§impl<T> PartialEq<Reverse<T>> for Reverse<T>where
T: PartialEq<T>,
impl<T> PartialEq<Reverse<T>> for Reverse<T>where T: PartialEq<T>,
source§impl<T> PartialOrd<Reverse<T>> for Reverse<T>where
T: PartialOrd<T>,
impl<T> PartialOrd<Reverse<T>> for Reverse<T>where T: PartialOrd<T>,
source§fn le(&self, other: &Reverse<T>) -> bool
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. Read moreimpl<T> Copy for Reverse<T>where T: Copy,
impl<T> Eq for Reverse<T>where T: Eq,
impl<T> StructuralEq for Reverse<T>
impl<T> StructuralPartialEq for Reverse<T>
Auto Trait Implementations§
impl<T> RefUnwindSafe for Reverse<T>where T: RefUnwindSafe,
impl<T> Send for Reverse<T>where T: Send,
impl<T> Sync for Reverse<T>where T: Sync,
impl<T> Unpin for Reverse<T>where T: Unpin,
impl<T> UnwindSafe for Reverse<T>where T: UnwindSafe,
Blanket Implementations§
source§impl<T> ArchivePointee for T
impl<T> ArchivePointee for T
§type ArchivedMetadata = ()
type ArchivedMetadata = ()
The archived version of the pointer metadata for this type.
source§fn pointer_metadata(
_: &<T as ArchivePointee>::ArchivedMetadata
) -> <T as Pointee>::Metadata
fn pointer_metadata( _: &<T as ArchivePointee>::ArchivedMetadata ) -> <T as Pointee>::Metadata
Converts some archived metadata to the pointer metadata for itself.
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
source§impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere
W: DeserializeWith<F, T, D>,
D: Fallible + ?Sized,
F: ?Sized,
impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere W: DeserializeWith<F, T, D>, D: Fallible + ?Sized, F: ?Sized,
source§impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,
source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
Compare self to
key
and return true
if they are equal.source§impl<T> LayoutRaw for T
impl<T> LayoutRaw for T
source§fn layout_raw(_: <T as Pointee>::Metadata) -> Result<Layout, LayoutError>
fn layout_raw(_: <T as Pointee>::Metadata) -> Result<Layout, LayoutError>
Gets the layout of the type.