Trait std::cmp::Eq

1.0.0 · source ·
pub trait Eq: PartialEq<Self> {
    // Provided method
    fn assert_receiver_is_total_eq(&self) { ... }
}
Expand description

Trait for equality comparisons which are equivalence relations.

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

  • reflexive: a == a;
  • symmetric: a == b implies b == a; and
  • transitive: a == b and b == c implies a == c.

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

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 {}
Run

Provided Methods§

Implementors§

source§

impl Eq for hashbrown::TryReserveError

source§

impl Eq for AsciiChar

1.65.0 · source§

impl Eq for BacktraceStatus

source§

impl Eq for PrintFmt

source§

impl Eq for TryReserveErrorKind

1.34.0 · source§

impl Eq for Infallible

source§

impl Eq for VarError

1.28.0 · source§

impl Eq for std::fmt::Alignment

source§

impl Eq for SeekFrom

source§

impl Eq for ErrorKind

1.7.0 · source§

impl Eq for IpAddr

source§

impl Eq for Ipv6MulticastScope

source§

impl Eq for Shutdown

source§

impl Eq for SocketAddr

source§

impl Eq for FpCategory

1.55.0 · source§

impl Eq for IntErrorKind

source§

impl Eq for BacktraceStyle

source§

impl Eq for Which

source§

impl Eq for SearchStep

source§

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

source§

impl Eq for Selected

1.12.0 · source§

impl Eq for RecvTimeoutError

source§

impl Eq for TryRecvError

source§

impl Eq for ReparsePoint

source§

impl Eq for std::cmp::Ordering

source§

impl Eq for bool

source§

impl Eq for char

source§

impl Eq for i8

source§

impl Eq for i16

source§

impl Eq for i32

source§

impl Eq for i64

source§

impl Eq for i128

source§

impl Eq for isize

source§

impl Eq for !

source§

impl Eq for str

source§

impl Eq for u8

source§

impl Eq for u16

source§

impl Eq for u32

source§

impl Eq for u64

source§

impl Eq for u128

source§

impl Eq for ()

source§

impl Eq for usize

1.27.0 · source§

impl Eq for CpuidResult

1.69.0 · source§

impl Eq for FromBytesUntilNulError

source§

impl Eq for AllocError

1.28.0 · source§

impl Eq for Layout

1.50.0 · source§

impl Eq for LayoutError

source§

impl Eq for TypeId

1.34.0 · source§

impl Eq for CharTryFromError

1.9.0 · source§

impl Eq for DecodeUtf16Error

1.20.0 · source§

impl Eq for ParseCharError

1.59.0 · source§

impl Eq for TryFromCharError

1.57.0 · source§

impl Eq for std::collections::TryReserveError

source§

impl Eq for OsStr

source§

impl Eq for OsString

source§

impl Eq for CStr

1.64.0 · source§

impl Eq for CString

1.64.0 · source§

impl Eq for FromBytesWithNulError

1.64.0 · source§

impl Eq for FromVecWithNulError

1.64.0 · source§

impl Eq for IntoStringError

1.64.0 · source§

impl Eq for NulError

source§

impl Eq for Error

1.1.0 · source§

impl Eq for std::fs::FileType

source§

impl Eq for Permissions

1.33.0 · source§

impl Eq for PhantomPinned

source§

impl Eq for Assume

source§

impl Eq for AddrParseError

source§

impl Eq for Ipv4Addr

source§

impl Eq for Ipv6Addr

source§

impl Eq for SocketAddrV4

source§

impl Eq for SocketAddrV6

1.34.0 · source§

impl Eq for NonZeroI8

1.34.0 · source§

impl Eq for NonZeroI16

1.34.0 · source§

impl Eq for NonZeroI32

1.34.0 · source§

impl Eq for NonZeroI64

1.34.0 · source§

impl Eq for NonZeroI128

1.34.0 · source§

impl Eq for NonZeroIsize

1.28.0 · source§

impl Eq for NonZeroU8

1.28.0 · source§

impl Eq for NonZeroU16

1.28.0 · source§

impl Eq for NonZeroU32

1.28.0 · source§

impl Eq for NonZeroU64

1.28.0 · source§

impl Eq for NonZeroU128

1.28.0 · source§

impl Eq for NonZeroUsize

source§

impl Eq for ParseFloatError

source§

impl Eq for ParseIntError

1.34.0 · source§

impl Eq for TryFromIntError

source§

impl Eq for RangeFull

1.63.0 · source§

impl Eq for InvalidHandleError

Available on Windows only.
1.63.0 · source§

impl Eq for NullHandleError

Available on Windows only.
source§

impl Eq for Components<'_>

source§

impl Eq for Path

source§

impl Eq for PathBuf

1.7.0 · source§

impl Eq for StripPrefixError

source§

impl Eq for std::process::ExitStatus

source§

impl Eq for std::process::ExitStatusError

source§

impl Eq for Output

source§

impl Eq for std::ptr::Alignment

source§

impl Eq for ParseBoolError

source§

impl Eq for Utf8Error

source§

impl Eq for FromUtf8Error

source§

impl Eq for String

1.5.0 · source§

impl Eq for WaitTimeoutResult

source§

impl Eq for Operation

source§

impl Eq for RecvError

source§

impl Eq for FilePermissions

source§

impl Eq for std::sys::windows::fs::FileType

source§

impl Eq for ExitCode

source§

impl Eq for std::sys::windows::process::ExitStatus

source§

impl Eq for std::sys::windows::process::ExitStatusError

source§

impl Eq for std::sys::windows::time::Instant

source§

impl Eq for std::sys::windows::time::SystemTime

source§

impl Eq for CodePoint

source§

impl Eq for Wtf8

source§

impl Eq for Wtf8Buf

1.26.0 · source§

impl Eq for AccessError

1.19.0 · source§

impl Eq for ThreadId

1.3.0 · source§

impl Eq for Duration

1.8.0 · source§

impl Eq for std::time::Instant

1.8.0 · source§

impl Eq for std::time::SystemTime

1.66.0 · source§

impl Eq for TryFromFloatSecsError

source§

impl<'a> Eq for Component<'a>

source§

impl<'a> Eq for Prefix<'a>

1.10.0 · source§

impl<'a> Eq for Location<'a>

source§

impl<'a> Eq for PrefixComponent<'a>

source§

impl<'a> Eq for Utf8Chunk<'a>

source§

impl<A> Eq for &Awhere A: Eq + ?Sized,

source§

impl<A> Eq for &mut Awhere A: Eq + ?Sized,

source§

impl<A, Z, Y, X, W, V, U, T> Eq for (A, Z, Y, X, W, V, U, T)where A: Eq, Z: Eq, Y: Eq, X: Eq, W: Eq, V: Eq, U: Eq, T: Eq + ?Sized,

source§

impl<B> Eq for Cow<'_, B>where B: Eq + ToOwned + ?Sized,

source§

impl<B, A, Z, Y, X, W, V, U, T> Eq for (B, A, Z, Y, X, W, V, U, T)where B: Eq, A: Eq, Z: Eq, Y: Eq, X: Eq, W: Eq, V: Eq, U: Eq, T: Eq + ?Sized,

1.55.0 · source§

impl<B, C> Eq for ControlFlow<B, C>where B: Eq, C: Eq,

source§

impl<C, B, A, Z, Y, X, W, V, U, T> Eq for (C, B, A, Z, Y, X, W, V, U, T)where C: Eq, B: Eq, A: Eq, Z: Eq, Y: Eq, X: Eq, W: Eq, V: Eq, U: Eq, T: Eq + ?Sized,

source§

impl<D, C, B, A, Z, Y, X, W, V, U, T> Eq for (D, C, B, A, Z, Y, X, W, V, U, T)where D: Eq, C: Eq, B: Eq, A: Eq, Z: Eq, Y: Eq, X: Eq, W: Eq, V: Eq, U: Eq, T: Eq + ?Sized,

source§

impl<Dyn> Eq for DynMetadata<Dyn>where Dyn: ?Sized,

source§

impl<E, D, C, B, A, Z, Y, X, W, V, U, T> Eq for (E, D, C, B, A, Z, Y, X, W, V, U, T)where E: Eq, D: Eq, C: Eq, B: Eq, A: Eq, Z: Eq, Y: Eq, X: Eq, W: Eq, V: Eq, U: Eq, T: Eq + ?Sized,

1.4.0 · source§

impl<F> Eq for Fwhere F: FnPtr,

1.29.0 · source§

impl<H> Eq for BuildHasherDefault<H>

source§

impl<Idx> Eq for Range<Idx>where Idx: Eq,

source§

impl<Idx> Eq for RangeFrom<Idx>where Idx: Eq,

1.26.0 · source§

impl<Idx> Eq for RangeInclusive<Idx>where Idx: Eq,

source§

impl<Idx> Eq for RangeTo<Idx>where Idx: Eq,

1.26.0 · source§

impl<Idx> Eq for RangeToInclusive<Idx>where Idx: Eq,

source§

impl<K, V, A> Eq for BTreeMap<K, V, A>where K: Eq, V: Eq, A: Allocator + Clone,

source§

impl<K, V, S> Eq for std::collections::hash::map::HashMap<K, V, S>where K: Eq + Hash, V: Eq, S: BuildHasher,

source§

impl<K, V, S, A> Eq for hashbrown::map::HashMap<K, V, S, A>where K: Eq + Hash, V: Eq, S: BuildHasher, A: Allocator + Clone,

1.41.0 · source§

impl<P> Eq for Pin<P>where P: Deref, <P as Deref>::Target: Eq,

1.17.0 · source§

impl<T> Eq for Bound<T>where T: Eq,

source§

impl<T> Eq for Option<T>where T: Eq,

1.36.0 · source§

impl<T> Eq for Poll<T>where T: Eq,

source§

impl<T> Eq for *const Twhere T: ?Sized,

source§

impl<T> Eq for *mut Twhere T: ?Sized,

source§

impl<T> Eq for [T]where T: Eq,

source§

impl<T> Eq for (T₁, T₂, …, Tₙ)where T: Eq + ?Sized,

This trait is implemented for tuples up to twelve items long.

1.2.0 · source§

impl<T> Eq for Cell<T>where T: Eq + Copy,

1.70.0 · source§

impl<T> Eq for OnceCell<T>where T: Eq,

1.2.0 · source§

impl<T> Eq for RefCell<T>where T: Eq + ?Sized,

source§

impl<T> Eq for PhantomData<T>where T: ?Sized,

1.21.0 · source§

impl<T> Eq for Discriminant<T>

1.20.0 · source§

impl<T> Eq for ManuallyDrop<T>where T: Eq + ?Sized,

source§

impl<T> Eq for Saturating<T>where T: Eq,

source§

impl<T> Eq for Wrapping<T>where T: Eq,

1.25.0 · source§

impl<T> Eq for NonNull<T>where T: ?Sized,

source§

impl<T> Eq for Rc<T>where T: Eq + ?Sized,

source§

impl<T> Eq for Arc<T>where T: Eq + ?Sized,

1.19.0 · source§

impl<T> Eq for Reverse<T>where T: Eq,

source§

impl<T, A> Eq for Box<T, A>where T: Eq + ?Sized, A: Allocator,

source§

impl<T, A> Eq for BTreeSet<T, A>where T: Eq, A: Allocator + Clone,

source§

impl<T, A> Eq for LinkedList<T, A>where T: Eq, A: Allocator,

source§

impl<T, A> Eq for VecDeque<T, A>where T: Eq, A: Allocator,

source§

impl<T, A> Eq for Vec<T, A>where T: Eq, A: Allocator,

source§

impl<T, E> Eq for Result<T, E>where T: Eq, E: Eq,

source§

impl<T, S> Eq for std::collections::hash::set::HashSet<T, S>where T: Eq + Hash, S: BuildHasher,

source§

impl<T, S, A> Eq for hashbrown::set::HashSet<T, S, A>where T: Eq + Hash, S: BuildHasher, A: Allocator + Clone,

source§

impl<T, const N: usize> Eq for [T; N]where T: Eq,

source§

impl<T, const N: usize> Eq for Simd<T, N>where LaneCount<N>: SupportedLaneCount, T: SimdElement + Eq,

source§

impl<T: Eq> Eq for SendTimeoutError<T>

source§

impl<T: Eq> Eq for TrySendError<T>

source§

impl<T: Eq> Eq for Cursor<T>

source§

impl<T: Eq> Eq for CachePadded<T>

source§

impl<T: Eq> Eq for SendError<T>

1.70.0 · source§

impl<T: Eq> Eq for OnceLock<T>

source§

impl<U, T> Eq for (U, T)where U: Eq, T: Eq + ?Sized,

source§

impl<V, U, T> Eq for (V, U, T)where V: Eq, U: Eq, T: Eq + ?Sized,

source§

impl<W, V, U, T> Eq for (W, V, U, T)where W: Eq, V: Eq, U: Eq, T: Eq + ?Sized,

source§

impl<X, W, V, U, T> Eq for (X, W, V, U, T)where X: Eq, W: Eq, V: Eq, U: Eq, T: Eq + ?Sized,

source§

impl<Y, R> Eq for GeneratorState<Y, R>where Y: Eq, R: Eq,

source§

impl<Y, X, W, V, U, T> Eq for (Y, X, W, V, U, T)where Y: Eq, X: Eq, W: Eq, V: Eq, U: Eq, T: Eq + ?Sized,

source§

impl<Z, Y, X, W, V, U, T> Eq for (Z, Y, X, W, V, U, T)where Z: Eq, Y: Eq, X: Eq, W: Eq, V: Eq, U: Eq, T: Eq + ?Sized,