Trait script::dom::bindings::import::module::cmp::Eq

1.0.0 · source ·

pub trait Eq: PartialEq { }

Expand description

Trait for comparisons corresponding to equivalence relations.

This means, that in addition to a == b and a != b being strict inverses, the relation must be (for all a, b and c):

reflexive: a == a;
symmetric: a == b implies b == a (required by PartialEq as well); and
transitive: a == b and b == c implies a == c (required by PartialEq as well).

This property cannot be checked by the compiler, and therefore Eq implies PartialEq, and has no extra methods.

Violating this property 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.

Implement Eq in addition to PartialEq if it’s guaranteed that PartialEq::eq(a, a) always returns true (reflexivity), in addition to the symmetric and transitive properties already required by PartialEq.

§Derivable

This trait can be used with #[derive]. When derived, because Eq has no extra methods, it is only informing the compiler that this is an equivalence relation rather than a partial equivalence relation. Note that the derive strategy requires all fields are Eq, which isn’t always desired.

§How can I implement `Eq`?

If you cannot use the derive strategy, specify that your type implements Eq, which has no methods:

enum BookFormat { Paperback, Hardback, Ebook }
struct Book {
    isbn: i32,
    format: BookFormat,
}
impl PartialEq for Book {
    fn eq(&self, other: &Self) -> bool {
        self.isbn == other.isbn
    }
}
impl Eq for Book {}

Object Safety§

This trait is not object safe.

Trait script::dom::bindings::import::module::cmp::EqCopy item path

§Derivable

§How can I implement Eq?

Object Safety§

Implementors§

impl Eq for AhoCorasickKind

impl Eq for aho_corasick::packed::api::MatchKind

impl Eq for aho_corasick::util::error::MatchErrorKind

impl Eq for aho_corasick::util::search::Anchored

impl Eq for aho_corasick::util::search::MatchKind

impl Eq for StartKind

impl Eq for MonitoredComponentType

impl Eq for PrintFmt

impl Eq for ParseAlphabetError

impl Eq for DecodeError

impl Eq for DecodeSliceError

impl Eq for EncodeSliceError

impl Eq for DecodePaddingMode

impl Eq for Blocklist

impl Eq for byte_slice_cast::Error

impl Eq for CheckedCastError

impl Eq for PodCastError

impl Eq for byteorder::BigEndian

impl Eq for byteorder::LittleEndian

impl Eq for Keviyah

impl Eq for StartOfYear

impl Eq for YearType

impl Eq for AlphaTreatment

impl Eq for TexDataType

impl Eq for TexFormat

impl Eq for WebGLFramebufferBindingRequest

impl Eq for WebGLVersion

impl Eq for YAxisTreatment

impl Eq for Colons

impl Eq for Fixed

impl Eq for chrono::format::Numeric

impl Eq for chrono::format::OffsetPrecision

impl Eq for Pad

impl Eq for ParseErrorKind

impl Eq for SecondsFormat

impl Eq for chrono::month::Month

impl Eq for RoundingError

impl Eq for chrono::weekday::Weekday

impl Eq for LabelStyle

impl Eq for Severity

impl Eq for colored::color::Color

impl Eq for Styles

impl Eq for CheckResult

impl Eq for Destination

impl Eq for content_security_policy::HashAlgorithm

impl Eq for Initiator

impl Eq for InlineCheckType

impl Eq for MatchResult

impl Eq for ParserMetadata

impl Eq for PolicyDisposition

impl Eq for PolicySource

impl Eq for SubresourceIntegrityMetadata

impl Eq for Violates

impl Eq for cookie::draft::SameSite

impl Eq for cookie::expiration::Expiration

impl Eq for cookie::expiration::Expiration

impl Eq for cookie::parse::ParseError

impl Eq for cookie::parse::ParseError

impl Eq for cookie::same_site::SameSite

impl Eq for crossbeam_channel::err::RecvTimeoutError

impl Eq for crossbeam_channel::err::TryRecvError

impl Eq for cssparser::color::PredefinedColorSpace

impl Eq for TokenSerializationType

impl Eq for TimelineMarkerType

impl Eq for embedder_traits::Cursor

impl Eq for CoderResult

impl Eq for DecoderResult

impl Eq for EncoderResult

impl Eq for Latin1Bidi

impl Eq for Blocks

impl Eq for RoundingMode

impl Eq for BlockType

impl Eq for EnvironmentMap

impl Eq for LevelMode

impl Eq for LineOrder

Trait script::dom::bindings::import::module::cmp::Eq

§How can I implement `Eq`?