Trait wasmer_types::lib::std::cmp::Eq

1.0.0 · source ·

pub trait Eq: PartialEq { }

Available on crate feature std only.

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 wasmer_types::lib::std::cmp::EqCopy item path

§Derivable

§How can I implement Eq?

Object Safety§

Implementors§

impl Eq for RelocationKind

impl Eq for RelocationTarget

impl Eq for CustomSectionProtection

impl Eq for Symbol

impl Eq for CpuFeature

impl Eq for CompiledFunctionUnwindInfo

impl Eq for Aarch64Architecture

impl Eq for Architecture

impl Eq for BinaryFormat

impl Eq for CallingConvention

impl Eq for wasmer_types::Endianness

impl Eq for Environment

impl Eq for ExportIndex

impl Eq for ExternType

impl Eq for HashAlgorithm

impl Eq for ImportIndex

impl Eq for LibCall

impl Eq for MemoryStyle

impl Eq for ModuleHash

impl Eq for Mutability

impl Eq for OperatingSystem

impl Eq for PointerWidth

impl Eq for TableStyle

impl Eq for TrapCode

impl Eq for Type

impl Eq for Vendor

impl Eq for MemoryError

impl Eq for Infallible

impl Eq for wasmer_types::lib::std::fmt::Alignment

impl Eq for wasmer_types::lib::std::sync::atomic::Ordering

impl Eq for RecvTimeoutError

impl Eq for TryRecvError

impl Eq for wasmer_types::lib::std::cmp::Ordering

impl Eq for TryReserveErrorKind

impl Eq for AsciiChar

impl Eq for IpAddr

impl Eq for Ipv6MulticastScope

impl Eq for SocketAddr

impl Eq for FpCategory

impl Eq for IntErrorKind

impl Eq for SearchStep

impl Eq for BacktraceStatus

impl Eq for VarError

impl Eq for std::io::SeekFrom

impl Eq for std::io::error::ErrorKind

impl Eq for Shutdown

impl Eq for BacktraceStyle

impl Eq for ParseAlphabetError

impl Eq for DecodeError

impl Eq for DecodeSliceError

impl Eq for EncodeSliceError

impl Eq for DecodePaddingMode

impl Eq for FlushCompress

impl Eq for FlushDecompress

impl Eq for Status

impl Eq for hashbrown::TryReserveError

impl Eq for hashbrown::TryReserveError

impl Eq for TrieType

impl Eq for ExtensionType

impl Eq for icu_locid_transform::directionality::Direction

impl Eq for Decomposed

impl Eq for BidiPairingProperties

impl Eq for PropertiesError

impl Eq for GeneralCategory

impl Eq for CheckedBidiPairedBracketType

impl Eq for BufferFormat

impl Eq for DataErrorKind

impl Eq for LocaleFallbackPriority

impl Eq for LocaleFallbackSupplement

impl Eq for DnsLength

impl Eq for ErrorPolicy

impl Eq for Hyphens

impl Eq for ProcessingError

impl Eq for ProcessingSuccess

impl Eq for Advice

Trait wasmer_types::lib::std::cmp::Eq

§How can I implement `Eq`?