Trait kvarn_async::prelude::compact_str::core::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.

Implementors§

1.7.0 · source§

Trait kvarn_async::prelude::compact_str::core::cmp::Eq

§Derivable

§How can I implement Eq?

Object Safety§

Implementors§

impl Eq for IpAddr

impl Eq for SocketAddr

impl Eq for kvarn_async::prelude::fmt::Alignment

impl Eq for ErrorKind

impl Eq for SeekFrom

impl Eq for Ipv6MulticastScope

impl Eq for Shutdown

impl Eq for CacheControlError

impl Eq for RequestParseStage

impl Eq for SanitizeError

impl Eq for AsciiChar

impl Eq for Infallible

impl Eq for FpCategory

impl Eq for IntErrorKind

impl Eq for SearchStep

impl Eq for kvarn_async::prelude::compact_str::core::sync::atomic::Ordering

impl Eq for kvarn_async::prelude::compact_str::core::cmp::Ordering

impl Eq for TryReserveErrorKind

impl Eq for BacktraceStatus

impl Eq for VarError

impl Eq for BacktraceStyle

impl Eq for RecvTimeoutError

impl Eq for std::sync::mpsc::TryRecvError

impl Eq for Level

impl Eq for LevelFilter

impl Eq for RuntimeFlavor

impl Eq for TryAcquireError

impl Eq for tokio::sync::broadcast::error::RecvError

impl Eq for tokio::sync::broadcast::error::TryRecvError

impl Eq for tokio::sync::mpsc::error::TryRecvError

impl Eq for tokio::sync::oneshot::error::TryRecvError

impl Eq for MissedTickBehavior

impl Eq for bool

impl Eq for char

impl Eq for i8

impl Eq for i16

impl Eq for i32

impl Eq for i64

impl Eq for i128

impl Eq for isize

impl Eq for !

impl Eq for str

impl Eq for u8

impl Eq for u16

impl Eq for u32

impl Eq for u64

impl Eq for u128

impl Eq for ()

impl Eq for usize

impl Eq for Error

impl Eq for AddrParseError

impl Eq for Ipv4Addr

impl Eq for Ipv6Addr

impl Eq for SocketAddrV4

impl Eq for SocketAddrV6

impl Eq for CriticalRequestComponents

impl Eq for ParseBoolError

impl Eq for Utf8Error

impl Eq for Bytes

impl Eq for BytesMut

impl Eq for CompactString

impl Eq for Duration

impl Eq for HeaderName

impl Eq for HeaderValue

impl Eq for kvarn_async::prelude::Instant

impl Eq for Method

impl Eq for Path

impl Eq for PathBuf

impl Eq for StatusCode

impl Eq for Uri

impl Eq for Version

impl Eq for Authority

impl Eq for PathAndQuery

impl Eq for Scheme

impl Eq for AllocError

§How can I implement `Eq`?