Trait Eq

1.0.0 · Source

pub trait Eq: PartialEq { }

Expand description

Trait for comparisons corresponding to equivalence relations.

The primary difference to PartialEq is the additional requirement for reflexivity. A type that implements PartialEq guarantees that for all a, b and c:

symmetric: a == b implies b == a and a != b implies !(a == b)
transitive: a == b and b == c implies a == c

Eq, which builds on top of PartialEq also implies:

reflexive: a == a

This property cannot be checked by the compiler, and therefore Eq is a trait without 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.

Floating point types such as f32 and f64 implement only PartialEq but not Eq because NaN != NaN.

§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 extra 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 {}

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Eq

Trait Eq Copy item path

§Derivable

§How can I implement Eq?

Dyn Compatibility§

Implementors§

impl Eq for AddressBech32DecodeError

impl Eq for AddressBech32EncodeError

impl Eq for AlwaysVisibleGlobalNodesVersion

impl Eq for ParseBlsPublicKeyError

impl Eq for ParseBlsSignatureError

impl Eq for ParseEd25519PublicKeyError

impl Eq for ParseEd25519SignatureError

impl Eq for ParseHashError

impl Eq for ParseSecp256k1PublicKeyError

impl Eq for ParseSecp256k1SignatureError

impl Eq for radix_common::crypto::PublicKey

impl Eq for PublicKeyHash

impl Eq for ManifestCustomExtension

impl Eq for ManifestCustomTraversal

impl Eq for ManifestCustomValue

impl Eq for ManifestCustomValueKind

impl Eq for ManifestToRustValueError

impl Eq for RustToManifestValueError

impl Eq for AllowedIds

impl Eq for LowerBound

impl Eq for ManifestAddress

impl Eq for ManifestBucketBatch

impl Eq for ManifestComponentAddress

impl Eq for ManifestExpression

impl Eq for ManifestGlobalAddress

impl Eq for ManifestNonFungibleLocalId

impl Eq for ManifestNonFungibleLocalIdValidationError

impl Eq for ManifestPackageAddress

impl Eq for ManifestProofBatch

impl Eq for ManifestResourceAddress

impl Eq for ManifestResourceConstraint

impl Eq for ParseManifestAddressReservationError

impl Eq for ParseManifestBlobRefError

impl Eq for ParseManifestBucketError

impl Eq for ParseManifestDecimalError

impl Eq for ParseManifestExpressionError

impl Eq for ParseManifestPreciseDecimalError

impl Eq for ParseManifestProofError

impl Eq for ResourceConstraintError

impl Eq for ResourceConstraintsError

impl Eq for UpperBound

impl Eq for OwnValidation

impl Eq for ReferenceValidation

impl Eq for ScryptoCustomTraversal

impl Eq for ScryptoCustomTypeKind

impl Eq for ScryptoCustomTypeKindLabel

impl Eq for ScryptoCustomTypeValidation

impl Eq for ScryptoCustomValue

impl Eq for ScryptoCustomValueKind

impl Eq for ContentValidationError

impl Eq for NonFungibleIdType

impl Eq for NonFungibleLocalId

impl Eq for ParseNonFungibleLocalIdError

impl Eq for ParseOwnError

impl Eq for ParseReferenceError

impl Eq for ParseI192Error

impl Eq for ParseI256Error

impl Eq for ParseI320Error

impl Eq for ParseI384Error

impl Eq for ParseI448Error

impl Eq for ParseI512Error

impl Eq for ParseI768Error

impl Eq for ParseU192Error

impl Eq for ParseU256Error

impl Eq for ParseU320Error

impl Eq for ParseU384Error

impl Eq for ParseU448Error

impl Eq for ParseU512Error

impl Eq for ParseU768Error

impl Eq for ParseDecimalError

impl Eq for ParsePreciseDecimalError

impl Eq for RoundingMode

impl Eq for BatchPartitionStateUpdate

impl Eq for DatabaseUpdate

Trait Eq

§How can I implement `Eq`?