pub enum Ordering {
    Less,
    Equal,
    Greater,
}
Available on non-crate feature miri-test-libstd only.
Expand description

An Ordering is the result of a comparison between two values.

Examples

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);

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§

source§

impl Ordering

1.53.0 (const: 1.53.0) · source

pub const fn is_eq(self) -> bool

Returns true if the ordering is the Equal variant.

Examples
use std::cmp::Ordering;

assert_eq!(Ordering::Less.is_eq(), false);
assert_eq!(Ordering::Equal.is_eq(), true);
assert_eq!(Ordering::Greater.is_eq(), false);
1.53.0 (const: 1.53.0) · source

pub const fn is_ne(self) -> bool

Returns true if the ordering is not the Equal variant.

Examples
use std::cmp::Ordering;

assert_eq!(Ordering::Less.is_ne(), true);
assert_eq!(Ordering::Equal.is_ne(), false);
assert_eq!(Ordering::Greater.is_ne(), true);
1.53.0 (const: 1.53.0) · source

pub const fn is_lt(self) -> bool

Returns true if the ordering is the Less variant.

Examples
use std::cmp::Ordering;

assert_eq!(Ordering::Less.is_lt(), true);
assert_eq!(Ordering::Equal.is_lt(), false);
assert_eq!(Ordering::Greater.is_lt(), false);
1.53.0 (const: 1.53.0) · source

pub const fn is_gt(self) -> bool

Returns true if the ordering is the Greater variant.

Examples
use std::cmp::Ordering;

assert_eq!(Ordering::Less.is_gt(), false);
assert_eq!(Ordering::Equal.is_gt(), false);
assert_eq!(Ordering::Greater.is_gt(), true);
1.53.0 (const: 1.53.0) · source

pub const fn is_le(self) -> bool

Returns true if the ordering is either the Less or Equal variant.

Examples
use std::cmp::Ordering;

assert_eq!(Ordering::Less.is_le(), true);
assert_eq!(Ordering::Equal.is_le(), true);
assert_eq!(Ordering::Greater.is_le(), false);
1.53.0 (const: 1.53.0) · source

pub const fn is_ge(self) -> bool

Returns true if the ordering is either the Greater or Equal variant.

Examples
use std::cmp::Ordering;

assert_eq!(Ordering::Less.is_ge(), false);
assert_eq!(Ordering::Equal.is_ge(), true);
assert_eq!(Ordering::Greater.is_ge(), true);
const: 1.48.0 · source

pub const fn reverse(self) -> Ordering

Reverses the Ordering.

  • Less becomes Greater.
  • Greater becomes Less.
  • Equal becomes Equal.
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);

This 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);
1.17.0 (const: 1.48.0) · source

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);
1.17.0 · source

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);

Trait Implementations§

source§

impl Clone for Ordering

source§

fn clone(&self) -> Ordering

Returns a copy of the value. Read more
source§

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

Performs copy-assignment from source. Read more
source§

impl Debug for Ordering

source§

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

Formats the value using the given formatter. Read more
source§

impl Hash for Ordering

source§

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

Feeds this value into the given Hasher. Read more
1.3.0 · source§

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

Feeds a slice of this type into the given Hasher. Read more
source§

impl Ord for Ordering

source§

const fn cmp(&self, other: &Ordering) -> Ordering

This method returns an Ordering between self and other. Read more
1.21.0 · source§

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

Compares and returns the maximum of two values. Read more
1.21.0 · source§

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

Compares and returns the minimum of two values. Read more
1.50.0 · source§

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval. Read more
source§

impl PartialEq<Ordering> for Ordering

source§

const fn eq(&self, other: &Ordering) -> bool

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

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
source§

impl PartialOrd<Ordering> for Ordering

source§

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

This method returns an ordering between self and other values if one exists. Read more
source§

fn lt(&self, other: &Rhs) -> bool

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

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 more
source§

fn gt(&self, other: &Rhs) -> bool

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

fn ge(&self, other: &Rhs) -> bool

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

impl Copy for Ordering

source§

impl Eq for Ordering

source§

impl StructuralEq for Ordering

source§

impl StructuralPartialEq for Ordering

Auto Trait Implementations§

Blanket Implementations§

source§

impl<T> Any for Twhere T: 'static + ?Sized,

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
§

impl<'a, T, E> AsTaggedExplicit<'a, E> for Twhere T: 'a,

§

fn explicit(self, class: Class, tag: u32) -> TaggedParser<'a, Explicit, Self, E>

§

impl<'a, T, E> AsTaggedImplicit<'a, E> for Twhere T: 'a,

§

fn implicit( self, class: Class, constructed: bool, tag: u32 ) -> TaggedParser<'a, Implicit, Self, E>

source§

impl<T> Borrow<T> for Twhere T: ?Sized,

const: unstable · source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for Twhere T: ?Sized,

const: unstable · source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
source§

impl<Q, K> Equivalent<K> for Qwhere Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

source§

fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
§

impl<Q, K> Equivalent<K> for Qwhere Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

§

fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
source§

impl<T> From<T> for T

const: unstable · source§

fn from(t: T) -> T

Returns the argument unchanged.

§

impl<T> Instrument for T

§

fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
§

fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
source§

impl<T, U> Into<U> for Twhere U: From<T>,

const: unstable · source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

§

impl<T> Pointable for T

§

const ALIGN: usize = mem::align_of::<T>()

The alignment of pointer.
§

type Init = T

The type for initializers.
§

unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
§

unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
§

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
§

unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
source§

impl<T> Same<T> for T

§

type Output = T

Should always be Self
source§

impl<T> ToOwned for Twhere T: Clone,

§

type Owned = T

The resulting type after obtaining ownership.
source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
source§

impl<T, U> TryFrom<U> for Twhere U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
const: unstable · source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
§

impl<V, T> VZip<V> for Twhere V: MultiLane<T>,

§

fn vzip(self) -> V

§

impl<T> WithSubscriber for T

§

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self> where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a [WithDispatch] wrapper. Read more
§

fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a [WithDispatch] wrapper. Read more
source§

impl<N> NodeTrait for Nwhere N: Copy + Ord + Hash,