Trait ibc::core::primitives::prelude::Ord

1.0.0 · source ·

pub trait Ord: Eq + PartialOrd {
    // Required method
    fn cmp(&self, other: &Self) -> Ordering;

    // Provided methods
    fn max(self, other: Self) -> Self
       where Self: Sized { ... }
    fn min(self, other: Self) -> Self
       where Self: Sized { ... }
    fn clamp(self, min: Self, max: Self) -> Self
       where Self: Sized + PartialOrd { ... }
}

Expand description

Trait for types that form a total order.

Implementations must be consistent with the PartialOrd implementation, and ensure max, min, and clamp are consistent with cmp:

partial_cmp(a, b) == Some(cmp(a, b)).
max(a, b) == max_by(a, b, cmp) (ensured by the default implementation).
min(a, b) == min_by(a, b, cmp) (ensured by the default implementation).
For a.clamp(min, max), see the method docs (ensured by the default implementation).

It’s easy to accidentally make cmp and partial_cmp disagree by deriving some of the traits and manually implementing others.

Violating these requirements is a logic error. The behavior resulting from a logic error is not specified, but users of the trait must ensure that such logic errors do not result in undefined behavior. This means that unsafe code must not rely on the correctness of these methods.

§Corollaries

From the above and the requirements of PartialOrd, it follows that for all a, b and c:

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

Mathematically speaking, the < operator defines a strict weak order. In cases where == conforms to mathematical equality, it also defines a strict total order.

§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 primarily by their discriminants. Secondarily, they are ordered by their fields. By default, the discriminant is smallest for variants at the top, and largest for variants at the bottom. Here’s an example:

#[derive(PartialEq, Eq, PartialOrd, Ord)]
enum E {
    Top,
    Bottom,
}

assert!(E::Top < E::Bottom);

However, manually setting the discriminants can override this default behavior:

#[derive(PartialEq, Eq, PartialOrd, Ord)]
enum E {
    Top = 2,
    Bottom = 1,
}

assert!(E::Bottom < E::Top);

§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 sequences 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.

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§

1.0.0 · source

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

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§

1.21.0 · source

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

Compares and returns the maximum of two values.

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

§Examples

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

1.21.0 · source

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

Compares and returns the minimum of two values.

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

§Examples

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

1.50.0 · source

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

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_eq!((-3).clamp(-2, 1), -2);
assert_eq!(0.clamp(-2, 1), 0);
assert_eq!(2.clamp(-2, 1), 1);

Object Safety§

This trait is not object safe.

Trait ibc::core::primitives::prelude::OrdCopy item path

§Corollaries

§Derivable

§Lexicographical comparison

§How can I implement Ord?

Required Methods§

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

§Examples

Provided Methods§

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

§Examples

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

§Examples

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

§Panics

§Examples

Object Safety§

Implementors§

impl Ord for Order

impl Ord for ResponseResultType

impl Ord for ibc::core::channel::types::proto::v1::State

impl Ord for HashOp

impl Ord for LengthOp

impl Ord for ibc::core::connection::types::proto::v1::State

impl Ord for ibc::core::host::types::path::Path

impl Ord for UpgradeClientPath

impl Ord for AsciiChar

impl Ord for Ordering

impl Ord for Infallible

impl Ord for IpAddr

impl Ord for SocketAddr

impl Ord for std::io::error::ErrorKind

impl Ord for borsh::nostd_io::ErrorKind

impl Ord for BigEndian

impl Ord for LittleEndian

impl Ord for ibc_proto::cosmos::gov::v1::ProposalStatus

impl Ord for ibc_proto::cosmos::gov::v1::VoteOption

impl Ord for ibc_proto::cosmos::gov::v1beta1::ProposalStatus

impl Ord for ibc_proto::cosmos::gov::v1beta1::VoteOption

impl Ord for AuthorizationType

impl Ord for BondStatus

impl Ord for Infraction

impl Ord for ibc_proto::cosmos::staking::v1beta1::InfractionType

impl Ord for SignMode

impl Ord for BroadcastMode

impl Ord for OrderBy

impl Ord for Edition

impl Ord for VerificationState

impl Ord for EnumType

impl Ord for FieldPresence

impl Ord for JsonFormat

impl Ord for MessageEncoding

impl Ord for RepeatedFieldEncoding

impl Ord for Utf8Validation

impl Ord for Label

impl Ord for ibc_proto::google::protobuf::field_descriptor_proto::Type

impl Ord for CType

impl Ord for JsType

impl Ord for OptionRetention

impl Ord for OptionTargetType

impl Ord for OptimizeMode

impl Ord for Semantic

impl Ord for IdempotencyLevel

impl Ord for ibc_proto::ibc::applications::interchain_accounts::v1::Type

impl Ord for ConsumerPacketDataType

impl Ord for ibc_proto::interchain_security::ccv::v1::InfractionType

impl Ord for MetaForm

impl Ord for PortableForm

impl Ord for TypeDefPrimitive

impl Ord for InstanceType

impl Ord for Status

impl Ord for tendermint_proto::tendermint::v0_34::abci::CheckTxType

impl Ord for EvidenceType

impl Ord for tendermint_proto::tendermint::v0_34::abci::response_apply_snapshot_chunk::Result

impl Ord for tendermint_proto::tendermint::v0_34::abci::response_offer_snapshot::Result

impl Ord for tendermint_proto::tendermint::v0_34::privval::Errors

impl Ord for tendermint_proto::tendermint::v0_34::types::BlockIdFlag

impl Ord for tendermint_proto::tendermint::v0_34::types::SignedMsgType

impl Ord for tendermint_proto::tendermint::v0_37::abci::CheckTxType

impl Ord for tendermint_proto::tendermint::v0_37::abci::MisbehaviorType

Trait ibc::core::primitives::prelude::Ord

§How can I implement `Ord`?

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

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

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