Trait sp_std::cmp::Ord1.0.0[−][src]

[+] Show declaration

pub trait Ord: Eq + PartialOrd<Self> {
[+] Expand attributes
#[must_use]    pub fn cmp(&self, other: &Self) -> Ordering;

[+] Expand attributes
#[must_use]    pub fn max(self, other: Self) -> Self { ... }
[+] Expand attributes
#[must_use]    pub fn min(self, other: Self) -> Self { ... }
[+] Expand attributes
#[must_use]    pub fn clamp(self, min: Self, max: Self) -> Self { ... }
}

[−]

Trait for types that form a total order.

An order is a total order if it is (for all a, b and c):

total and asymmetric: exactly one of a < b, a == b or a > b is true; and
transitive, a < b and b < c implies a < c. The same must hold for both == and >.

Derivable

This trait can be used with #[derive]. When derived on structs, it will produce a lexicographic ordering based on the top-to-bottom declaration order of the struct’s members. When derived on enums, variants are ordered by their top-to-bottom discriminant order.

Lexicographical comparison

Lexicographical comparison is an operation with the following properties:

Two sequences are compared element by element.
The first mismatching element defines which sequence is lexicographically less or greater than the other.
If one sequence is a prefix of another, the shorter sequence is lexicographically less than the other.
If two sequence have equivalent elements and are of the same length, then the sequences are lexicographically equal.
An empty sequence is lexicographically less than any non-empty sequence.
Two empty sequences are lexicographically equal.

How can I implement `Ord`?

Ord requires that the type also be PartialOrd and Eq (which requires PartialEq).

Then you must define an implementation for cmp. You may find it useful to use cmp on your type’s fields.

Implementations of PartialEq, PartialOrd, and Ord must agree with each other. That is, a.cmp(b) == Ordering::Equal if and only if a == b and Some(a.cmp(b)) == a.partial_cmp(b) for all a and b. It’s easy to accidentally make them disagree by deriving some of the traits and manually implementing others.

Here’s an example where you want to sort people by height only, disregarding id and name:

use std::cmp::Ordering;

#[derive(Eq)]
struct Person {
    id: u32,
    name: String,
    height: u32,
}

impl Ord for Person {
    fn cmp(&self, other: &Self) -> Ordering {
        self.height.cmp(&other.height)
    }
}

impl PartialOrd for Person {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

impl PartialEq for Person {
    fn eq(&self, other: &Self) -> bool {
        self.height == other.height
    }
}

Required methods

`[+] Expand attributes #[must_use]pub fn cmp(&self, other: &Self) -> Ordering`[src][−]

This method returns an Ordering between self and other.

By convention, self.cmp(&other) returns the ordering matching the expression self <operator> other if true.

Examples

use std::cmp::Ordering;

assert_eq!(5.cmp(&10), Ordering::Less);
assert_eq!(10.cmp(&5), Ordering::Greater);
assert_eq!(5.cmp(&5), Ordering::Equal);

Provided methods

`[+] Expand attributes #[must_use]pub fn max(self, other: Self) -> Self`1.21.0[src][−]

Compares and returns the maximum of two values.

Returns the second argument if the comparison determines them to be equal.

Examples

assert_eq!(2, 1.max(2));
assert_eq!(2, 2.max(2));

`[+] Expand attributes #[must_use]pub fn min(self, other: Self) -> Self`1.21.0[src][−]

Compares and returns the minimum of two values.

Returns the first argument if the comparison determines them to be equal.

Examples

assert_eq!(1, 1.min(2));
assert_eq!(2, 2.min(2));

`[+] Expand attributes #[must_use]pub fn clamp(self, min: Self, max: Self) -> Self`1.50.0[src][−]

Restrict a value to a certain interval.

Returns max if self is greater than max, and min if self is less than min. Otherwise this returns self.

Panics

Panics if min > max.

Examples

assert!((-3).clamp(-2, 1) == -2);
assert!(0.clamp(-2, 1) == 0);
assert!(2.clamp(-2, 1) == 1);

Trait sp_std::cmp::Ord1.0.0[−][src]

Required methods

[+] Expand attributes#[must_use]pub fn cmp(&self, other: &Self) -> Ordering[src][−]

Provided methods

[+] Expand attributes#[must_use]pub fn max(self, other: Self) -> Self1.21.0[src][−]

[+] Expand attributes#[must_use]pub fn min(self, other: Self) -> Self1.21.0[src][−]

[+] Expand attributes#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self1.50.0[src][−]

Implementations on Foreign Types

impl<'_> Ord for PrefixComponent<'_>[src][−]

pub fn cmp(&self, other: &PrefixComponent<'_>) -> Ordering[src]

impl Ord for PathBuf[src][−]

pub fn cmp(&self, other: &PathBuf) -> Ordering[src]

impl Ord for SocketAddrV6[src][−]

pub fn cmp(&self, other: &SocketAddrV6) -> Ordering[src]

impl Ord for SocketAddrV4[src][−]

pub fn cmp(&self, other: &SocketAddrV4) -> Ordering[src]

impl Ord for OsString[src][−]

pub fn cmp(&self, other: &OsString) -> Ordering[src]

impl Ord for CString[src][−]

pub fn cmp(&self, other: &CString) -> Ordering[src]

impl<'a> Ord for Component<'a>[src][−]

pub fn cmp(&self, other: &Component<'a>) -> Ordering[src]

impl Ord for Instant[src][−]

pub fn cmp(&self, other: &Instant) -> Ordering[src]

impl Ord for SocketAddr[src][−]

pub fn cmp(&self, other: &SocketAddr) -> Ordering[src]

impl Ord for Path[src][−]

pub fn cmp(&self, other: &Path) -> Ordering[src]

impl<'_> Ord for Components<'_>[src][−]

pub fn cmp(&self, other: &Components<'_>) -> Ordering[src]

impl<'a> Ord for Prefix<'a>[src][−]

pub fn cmp(&self, other: &Prefix<'a>) -> Ordering[src]

impl Ord for Ipv6Addr[src][−]

pub fn cmp(&self, other: &Ipv6Addr) -> Ordering[src]

impl Ord for CStr[src][−]

pub fn cmp(&self, other: &CStr) -> Ordering[src]

impl Ord for SystemTime[src][−]

pub fn cmp(&self, other: &SystemTime) -> Ordering[src]

impl Ord for IpAddr[src][−]

pub fn cmp(&self, other: &IpAddr) -> Ordering[src]

impl Ord for OsStr[src][−]

pub fn cmp(&self, other: &OsStr) -> Ordering[src]

impl Ord for ErrorKind[src][−]

pub fn cmp(&self, other: &ErrorKind) -> Ordering[src]

impl Ord for Ipv4Addr[src][−]

pub fn cmp(&self, other: &Ipv4Addr) -> Ordering[src]

impl<Ret, A, B, C, D, E, F, G, H, I, J> Ord for fn(A, B, C, D, E, F, G, H, I, J) -> Ret[src][−]

pub fn cmp(&self, other: &fn(A, B, C, D, E, F, G, H, I, J) -> Ret) -> Ordering[src]

impl<Ret, A, B, C, D, E, F, G> Ord for unsafe extern "C" fn(A, B, C, D, E, F, G, ...) -> Ret[src][−]

pub fn cmp( &self, other: &unsafe extern "C" fn(A, B, C, D, E, F, G, ...) -> Ret) -> Ordering[src]

impl<T, const N: usize> Ord for [T; N] where T: Ord, [src][−]

pub fn cmp(&self, other: &[T; N]) -> Ordering[src]

impl<Ret, A, B, C, D, E, F, G, H, I, J> Ord for extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Ret[src][−]

pub fn cmp( &self, other: &extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Ret) -> Ordering[src]

impl<Ret, A, B, C> Ord for extern "C" fn(A, B, C, ...) -> Ret[src][−]

pub fn cmp(&self, other: &extern "C" fn(A, B, C, ...) -> Ret) -> Ordering[src]

impl<Ret, A, B> Ord for unsafe fn(A, B) -> Ret[src][−]

pub fn cmp(&self, other: &unsafe fn(A, B) -> Ret) -> Ordering[src]

impl<A, B, C, D, E> Ord for (A, B, C, D, E) where C: Ord, A: Ord, E: Ord + ?Sized, B: Ord, D: Ord, [src][−]

pub fn cmp(&self, other: &(A, B, C, D, E)) -> Ordering[src]

impl Ord for char[src][−]

pub fn cmp(&self, other: &char) -> Ordering[src]

impl Ord for i8[src][−]

pub fn cmp(&self, other: &i8) -> Ordering[src]

impl<A, B, C, D, E, F> Ord for (A, B, C, D, E, F) where C: Ord, A: Ord, E: Ord, F: Ord + ?Sized, B: Ord, D: Ord, [src][−]

pub fn cmp(&self, other: &(A, B, C, D, E, F)) -> Ordering[src]

impl<Ret, A, B, C, D, E, F, G, H> Ord for unsafe extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret[src][−]

pub fn cmp( &self, other: &unsafe extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret) -> Ordering[src]

impl<Ret, A, B> Ord for unsafe extern "C" fn(A, B, ...) -> Ret[src][−]

pub fn cmp(&self, other: &unsafe extern "C" fn(A, B, ...) -> Ret) -> Ordering[src]

impl<Ret, A, B, C, D, E, F> Ord for extern "C" fn(A, B, C, D, E, F) -> Ret[src][−]

pub fn cmp(&self, other: &extern "C" fn(A, B, C, D, E, F) -> Ret) -> Ordering[src]

impl<Ret, A> Ord for unsafe extern "C" fn(A, ...) -> Ret[src][−]

pub fn cmp(&self, other: &unsafe extern "C" fn(A, ...) -> Ret) -> Ordering[src]

impl<Ret, A, B, C, D> Ord for unsafe extern "C" fn(A, B, C, D) -> Ret[src][−]

pub fn cmp(&self, other: &unsafe extern "C" fn(A, B, C, D) -> Ret) -> Ordering[src]

impl<Ret, A, B, C> Ord for unsafe fn(A, B, C) -> Ret[src][−]

pub fn cmp(&self, other: &unsafe fn(A, B, C) -> Ret) -> Ordering[src]

impl Ord for str[src][−]

pub fn cmp(&self, other: &str) -> Ordering[src]

`[+] Expand attributes #[must_use]pub fn cmp(&self, other: &Self) -> Ordering`[src][−]

`[+] Expand attributes #[must_use]pub fn max(self, other: Self) -> Self`1.21.0[src][−]

`[+] Expand attributes #[must_use]pub fn min(self, other: Self) -> Self`1.21.0[src][−]

`[+] Expand attributes #[must_use]pub fn clamp(self, min: Self, max: Self) -> Self`1.50.0[src][−]

`impl<'_> Ord for PrefixComponent<'_>`[src][−]

`pub fn cmp(&self, other: &PrefixComponent<'_>) -> Ordering`[src]

`impl Ord for PathBuf`[src][−]

`pub fn cmp(&self, other: &PathBuf) -> Ordering`[src]

`impl Ord for SocketAddrV6`[src][−]

`pub fn cmp(&self, other: &SocketAddrV6) -> Ordering`[src]

`impl Ord for SocketAddrV4`[src][−]

`pub fn cmp(&self, other: &SocketAddrV4) -> Ordering`[src]

`impl Ord for OsString`[src][−]

`pub fn cmp(&self, other: &OsString) -> Ordering`[src]

`impl Ord for CString`[src][−]

`pub fn cmp(&self, other: &CString) -> Ordering`[src]

`impl<'a> Ord for Component<'a>`[src][−]

`pub fn cmp(&self, other: &Component<'a>) -> Ordering`[src]

`impl Ord for Instant`[src][−]

`pub fn cmp(&self, other: &Instant) -> Ordering`[src]

`impl Ord for SocketAddr`[src][−]

`pub fn cmp(&self, other: &SocketAddr) -> Ordering`[src]

`impl Ord for Path`[src][−]

`pub fn cmp(&self, other: &Path) -> Ordering`[src]

`impl<'_> Ord for Components<'_>`[src][−]

`pub fn cmp(&self, other: &Components<'_>) -> Ordering`[src]

`impl<'a> Ord for Prefix<'a>`[src][−]

`pub fn cmp(&self, other: &Prefix<'a>) -> Ordering`[src]

`impl Ord for Ipv6Addr`[src][−]

`pub fn cmp(&self, other: &Ipv6Addr) -> Ordering`[src]

`impl Ord for CStr`[src][−]

`pub fn cmp(&self, other: &CStr) -> Ordering`[src]

`impl Ord for SystemTime`[src][−]

`pub fn cmp(&self, other: &SystemTime) -> Ordering`[src]

`impl Ord for IpAddr`[src][−]

`pub fn cmp(&self, other: &IpAddr) -> Ordering`[src]

`impl Ord for OsStr`[src][−]

`pub fn cmp(&self, other: &OsStr) -> Ordering`[src]

`impl Ord for ErrorKind`[src][−]

`pub fn cmp(&self, other: &ErrorKind) -> Ordering`[src]

`impl Ord for Ipv4Addr`[src][−]

`pub fn cmp(&self, other: &Ipv4Addr) -> Ordering`[src]

`impl<Ret, A, B, C, D, E, F, G, H, I, J> Ord for fn(A, B, C, D, E, F, G, H, I, J) -> Ret`[src][−]

`pub fn cmp(&self, other: &fn(A, B, C, D, E, F, G, H, I, J) -> Ret) -> Ordering`[src]

`impl<Ret, A, B, C, D, E, F, G> Ord for unsafe extern "C" fn(A, B, C, D, E, F, G, ...) -> Ret`[src][−]

`pub fn cmp( &self, other: &unsafe extern "C" fn(A, B, C, D, E, F, G, ...) -> Ret ) -> Ordering`[src]

`impl<T, const N: usize> Ord for [T; N] where T: Ord,` [src][−]

`pub fn cmp(&self, other: &[T; N]) -> Ordering`[src]

`impl<Ret, A, B, C, D, E, F, G, H, I, J> Ord for extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Ret`[src][−]

`pub fn cmp( &self, other: &extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Ret ) -> Ordering`[src]

`impl<Ret, A, B, C> Ord for extern "C" fn(A, B, C, ...) -> Ret`[src][−]

`pub fn cmp(&self, other: &extern "C" fn(A, B, C, ...) -> Ret) -> Ordering`[src]

`impl<Ret, A, B> Ord for unsafe fn(A, B) -> Ret`[src][−]

`pub fn cmp(&self, other: &unsafe fn(A, B) -> Ret) -> Ordering`[src]

`impl<A, B, C, D, E> Ord for (A, B, C, D, E) where C: Ord, A: Ord, E: Ord + ?Sized, B: Ord, D: Ord,` [src][−]

`pub fn cmp(&self, other: &(A, B, C, D, E)) -> Ordering`[src]

`impl Ord for char`[src][−]

`pub fn cmp(&self, other: &char) -> Ordering`[src]

`impl Ord for i8`[src][−]

`pub fn cmp(&self, other: &i8) -> Ordering`[src]

`impl<A, B, C, D, E, F> Ord for (A, B, C, D, E, F) where C: Ord, A: Ord, E: Ord, F: Ord + ?Sized, B: Ord, D: Ord,` [src][−]

`pub fn cmp(&self, other: &(A, B, C, D, E, F)) -> Ordering`[src]

`impl<Ret, A, B, C, D, E, F, G, H> Ord for unsafe extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret`[src][−]

`pub fn cmp( &self, other: &unsafe extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret ) -> Ordering`[src]

`impl<Ret, A, B> Ord for unsafe extern "C" fn(A, B, ...) -> Ret`[src][−]

`pub fn cmp(&self, other: &unsafe extern "C" fn(A, B, ...) -> Ret) -> Ordering`[src]

`impl<Ret, A, B, C, D, E, F> Ord for extern "C" fn(A, B, C, D, E, F) -> Ret`[src][−]

`pub fn cmp(&self, other: &extern "C" fn(A, B, C, D, E, F) -> Ret) -> Ordering`[src]

`impl<Ret, A> Ord for unsafe extern "C" fn(A, ...) -> Ret`[src][−]

`pub fn cmp(&self, other: &unsafe extern "C" fn(A, ...) -> Ret) -> Ordering`[src]

`impl<Ret, A, B, C, D> Ord for unsafe extern "C" fn(A, B, C, D) -> Ret`[src][−]

`pub fn cmp(&self, other: &unsafe extern "C" fn(A, B, C, D) -> Ret) -> Ordering`[src]

`impl<Ret, A, B, C> Ord for unsafe fn(A, B, C) -> Ret`[src][−]

`pub fn cmp(&self, other: &unsafe fn(A, B, C) -> Ret) -> Ordering`[src]

`impl Ord for str`[src][−]

`pub fn cmp(&self, other: &str) -> Ordering`[src]

`impl Ord for u32`[src][−]

`pub fn cmp(&self, other: &u32) -> Ordering`[src]

`impl<Ret, A, B, C, D, E, F, G, H> Ord for extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret`[src][−]

`pub fn cmp( &self, other: &extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Ret ) -> Ordering`[src]