Trait std::cmp::Eq 1.0.0[−][src]
pub trait Eq: PartialEq<Self> { }
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 == bimpliesb == a; and - transitive:
a == bandb == cimpliesa == 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: &Book) -> bool { self.isbn == other.isbn } } impl Eq for Book {}Run
Implementations on Foreign Types
impl<'a> Eq for Utf8LossyChunk<'a>[src]
impl<'a> Eq for Utf8LossyChunk<'a>Implementors
impl<T> Eq for [T; 25] where
T: Eq,impl Eq for AllocErrimpl<Ret, A, B, C> Eq for extern "C" fn(A, B, C, ...) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for unsafe fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl Eq for CharTryFromErrorimpl<Ret, A, B, C, D, E, F, G, H> Eq for extern "C" fn(A, B, C, D, E, F, G, H) -> Retimpl Eq for Utf8Errorimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl Eq for usizeimpl<T> Eq for Option<T> where
T: Eq,impl<T> Eq for [T] where
T: Eq,impl<Ret, A, B, C, D, E, F, G, H> Eq for extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Retimpl<Ret, A, B, C, D, E, F, G> Eq for fn(A, B, C, D, E, F, G) -> Retimpl Eq for SearchStepimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<Ret, A, B> Eq for fn(A, B) -> Retimpl<Ret, A, B, C, D, E, F, G, H> Eq for fn(A, B, C, D, E, F, G, H) -> Retimpl<H> Eq for BuildHasherDefault<H>impl Eq for NonZeroU16impl Eq for UnicodeVersionimpl<T> Eq for [T; 30] where
T: Eq,impl Eq for TypeIdimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, ...) -> Retimpl<T> Eq for [T; 27] where
T: Eq,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for unsafe fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<T> Eq for [T; 10] where
T: Eq,impl<'a, A> Eq for &'a A where
A: Eq + ?Sized,impl<T> Eq for [T; 21] where
T: Eq,impl<T> Eq for [T; 29] where
T: Eq,impl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H) -> Retimpl<Ret, A, B, C, D, E, F> Eq for unsafe extern "C" fn(A, B, C, D, E, F, ...) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for fn(A, B, C, D, E, F, G, H, I) -> Retimpl Eq for isizeimpl<T> Eq for [T; 16] where
T: Eq,impl<Ret, A, B, C, D, E, F, G, H, I> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, ...) -> Retimpl<Ret, A, B, C, D, E, F> Eq for unsafe fn(A, B, C, D, E, F) -> Retimpl<A, B, C> Eq for (A, B, C) where
A: Eq,
B: Eq,
C: Eq + ?Sized,impl<A, B> Eq for (A, B) where
A: Eq,
B: Eq + ?Sized,impl Eq for NonZeroUsizeimpl<Ret> Eq for extern "C" fn() -> Retimpl Eq for ParseIntErrorimpl<Idx> Eq for RangeFrom<Idx> where
Idx: Eq,impl<T> Eq for [T; 28] where
T: Eq,impl<T> Eq for [T; 23] where
T: Eq,impl Eq for ParseBoolErrorimpl Eq for RangeFullimpl<Ret, A, B, C, D, E> Eq for unsafe fn(A, B, C, D, E) -> Retimpl<Y, R> Eq for GeneratorState<Y, R> where
R: Eq,
Y: Eq,impl Eq for ()impl Eq for Layoutimpl<T> Eq for *const T where
T: ?Sized,impl Eq for ParseCharErrorimpl<T> Eq for Reverse<T> where
T: Eq,impl<T> Eq for [T; 19] where
T: Eq,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<A, B, C, D, E, F, G> Eq for (A, B, C, D, E, F, G) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq + ?Sized,impl<T> Eq for Discriminant<T>impl<Ret, A, B, C> Eq for unsafe extern "C" fn(A, B, C, ...) -> Retimpl<T> Eq for Wrapping<T> where
T: Eq,impl<Ret, A, B> Eq for unsafe extern "C" fn(A, B, ...) -> Retimpl<Ret, A, B, C> Eq for fn(A, B, C) -> Retimpl<T> Eq for [T; 13] where
T: Eq,impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl<Ret, A> Eq for extern "C" fn(A, ...) -> Retimpl<Idx> Eq for Range<Idx> where
Idx: Eq,impl<Ret, A> Eq for unsafe extern "C" fn(A, ...) -> Retimpl<T> Eq for [T; 4] where
T: Eq,impl Eq for LayoutErrimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<Ret, A, B, C, D, E, F, G> Eq for extern "C" fn(A, B, C, D, E, F, G) -> Retimpl<T> Eq for [T; 14] where
T: Eq,impl Eq for i128impl<A, B, C, D, E, F, G, H> Eq for (A, B, C, D, E, F, G, H) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq + ?Sized,impl<T> Eq for [T; 26] where
T: Eq,impl<Ret, A, B, C, D, E> Eq for fn(A, B, C, D, E) -> Retimpl<A, B, C, D, E, F, G, H, I, J, K, L> Eq for (A, B, C, D, E, F, G, H, I, J, K, L) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq,
I: Eq,
J: Eq,
K: Eq,
L: Eq + ?Sized,impl<Ret, A, B, C> Eq for unsafe fn(A, B, C) -> Retimpl<Ret, A, B> Eq for extern "C" fn(A, B) -> Retimpl Eq for i16impl<A, B, C, D, E> Eq for (A, B, C, D, E) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq + ?Sized,impl<Ret, A, B> Eq for extern "C" fn(A, B, ...) -> Retimpl Eq for u64impl<T> Eq for [T; 6] where
T: Eq,impl<Ret, A, B, C, D> Eq for fn(A, B, C, D) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, ...) -> Retimpl<Ret, A, B, C, D, E, F, G> Eq for extern "C" fn(A, B, C, D, E, F, G, ...) -> Retimpl<A, B, C, D, E, F, G, H, I> Eq for (A, B, C, D, E, F, G, H, I) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq,
I: Eq + ?Sized,impl Eq for Errorimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe fn(A, B, C, D, E, F, G, H, I) -> Retimpl Eq for i32impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl<'a, A> Eq for &'a mut A where
A: Eq + ?Sized,impl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, ...) -> Retimpl Eq for Pinnedimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for unsafe fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<A, B, C, D, E, F, G, H, I, J, K> Eq for (A, B, C, D, E, F, G, H, I, J, K) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq,
I: Eq,
J: Eq,
K: Eq + ?Sized,impl Eq for Orderingimpl<Ret, A, B, C, D, E, F> Eq for unsafe extern "C" fn(A, B, C, D, E, F) -> Retimpl<Ret, A, B, C, D, E, F, G> Eq for unsafe fn(A, B, C, D, E, F, G) -> Retimpl Eq for FpCategoryimpl<T> Eq for Bound<T> where
T: Eq,impl<Idx> Eq for RangeTo<Idx> where
Idx: Eq,impl<T> Eq for [T; 9] where
T: Eq,impl<T> Eq for RefCell<T> where
T: Eq + ?Sized,impl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, ...) -> Retimpl<Ret, A, B, C, D, E> Eq for unsafe extern "C" fn(A, B, C, D, E, ...) -> Retimpl<T> Eq for [T; 32] where
T: Eq,impl<T> Eq for [T; 8] where
T: Eq,impl Eq for u16impl Eq for i8impl Eq for NonZeroU128impl Eq for Durationimpl Eq for u128impl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe fn(A, B, C, D, E, F, G, H) -> Retimpl<T> Eq for [T; 17] where
T: Eq,impl<A, B, C, D> Eq for (A, B, C, D) where
A: Eq,
B: Eq,
C: Eq,
D: Eq + ?Sized,impl<Ret, A, B, C, D, E, F, G> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G) -> Retimpl<A, B, C, D, E, F> Eq for (A, B, C, D, E, F) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq + ?Sized,impl Eq for InvalidSequenceimpl Eq for NonZeroU32impl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I) -> Retimpl<T> Eq for PhantomData<T> where
T: ?Sized,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L, ...) -> Retimpl<T> Eq for [T; 24] where
T: Eq,impl<T> Eq for [T; 22] where
T: Eq,impl Eq for NonZeroU64impl<Idx> Eq for RangeInclusive<Idx> where
Idx: Eq,impl<T> Eq for [T; 2] where
T: Eq,impl<Ret> Eq for unsafe fn() -> Retimpl<T> Eq for [T; 3] where
T: Eq,impl Eq for ParseFloatErrorimpl<T> Eq for [T; 0] where
T: Eq,impl Eq for CannotReallocInPlaceimpl<T> Eq for [T; 15] where
T: Eq,impl<A, B, C, D, E, F, G, H, I, J> Eq for (A, B, C, D, E, F, G, H, I, J) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: Eq,
F: Eq,
G: Eq,
H: Eq,
I: Eq,
J: Eq + ?Sized,impl<Ret, A, B, C> Eq for unsafe extern "C" fn(A, B, C) -> Retimpl Eq for i64impl<Ret, A, B, C, D, E, F> Eq for fn(A, B, C, D, E, F) -> Retimpl<Ret, A, B> Eq for unsafe fn(A, B) -> Retimpl<Ret, A, B, C, D, E, F, G> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, ...) -> Retimpl Eq for strimpl<T> Eq for [T; 18] where
T: Eq,impl<T> Eq for [T; 12] where
T: Eq,impl<Ret, A, B, C, D, E> Eq for extern "C" fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C, D, E> Eq for unsafe extern "C" fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C> Eq for extern "C" fn(A, B, C) -> Retimpl<T> Eq for [T; 31] where
T: Eq,impl<Ret> Eq for fn() -> Retimpl<Ret, A, B, C, D, E> Eq for extern "C" fn(A, B, C, D, E, ...) -> Retimpl<T> Eq for Cell<T> where
T: Copy + Eq,impl Eq for charimpl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, L, ...) -> Retimpl<Ret, A, B, C, D> Eq for unsafe fn(A, B, C, D) -> Retimpl Eq for !impl<T> Eq for ManuallyDrop<T> where
T: Eq,impl<Ret, A, B, C, D, E, F> Eq for extern "C" fn(A, B, C, D, E, F) -> Retimpl Eq for NonZeroU8impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for fn(A, B, C, D, E, F, G, H, I, J, K) -> Retimpl<Ret, A> Eq for unsafe extern "C" fn(A) -> Retimpl<T> Eq for [T; 7] where
T: Eq,impl<T> Eq for [T; 5] where
T: Eq,impl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Retimpl<T> Eq for *mut T where
T: ?Sized,impl Eq for u32impl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for fn(A, B, C, D, E, F, G, H, I, J) -> Retimpl<Idx> Eq for RangeToInclusive<Idx> where
Idx: Eq,impl<Ret> Eq for unsafe extern "C" fn() -> Retimpl<Ret, A, B, C, D> Eq for extern "C" fn(A, B, C, D) -> Retimpl<Ret, A, B, C, D> Eq for unsafe extern "C" fn(A, B, C, D, ...) -> Retimpl Eq for u8impl<Ret, A> Eq for fn(A) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I) -> Retimpl<Ret, A, B> Eq for unsafe extern "C" fn(A, B) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Retimpl<T, E> Eq for Result<T, E> where
E: Eq,
T: Eq,impl<Ret, A, B, C, D> Eq for unsafe extern "C" fn(A, B, C, D) -> Retimpl<A> Eq for (A,) where
A: Eq + ?Sized,impl<Ret, A, B, C, D> Eq for extern "C" fn(A, B, C, D, ...) -> Retimpl Eq for NoneErrorimpl<Ret, A, B, C, D, E, F> Eq for extern "C" fn(A, B, C, D, E, F, ...) -> Retimpl<Ret, A> Eq for extern "C" fn(A) -> Retimpl<T> Eq for [T; 20] where
T: Eq,impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<T> Eq for Poll<T> where
T: Eq,impl Eq for boolimpl<T> Eq for [T; 1] where
T: Eq,impl<T> Eq for NonNull<T> where
T: ?Sized,impl Eq for DecodeUtf16Errorimpl<T> Eq for [T; 11] where
T: Eq,impl<Ret, A> Eq for unsafe fn(A) -> Retimpl Eq for ParseErrorimpl Eq for CollectionAllocErrimpl<A> Eq for VecDeque<A> where
A: Eq,impl<T> Eq for LinkedList<T> where
T: Eq,impl<'a, B> Eq for Cow<'a, B> where
B: Eq + ToOwned + ?Sized,impl<T> Eq for Box<T> where
T: Eq + ?Sized,impl Eq for Stringimpl<T> Eq for Arc<T> where
T: Eq + ?Sized,impl<T> Eq for BTreeSet<T> where
T: Eq,impl<T> Eq for Rc<T> where
T: Eq + ?Sized,impl<T> Eq for Vec<T> where
T: Eq,impl<K, V> Eq for BTreeMap<K, V> where
K: Eq,
V: Eq,impl Eq for ThreadIdimpl<K, V, S> Eq for HashMap<K, V, S> where
K: Eq + Hash,
V: Eq,
S: BuildHasher,impl<T, S> Eq for HashSet<T, S> where
T: Eq + Hash,
S: BuildHasher,impl Eq for VarErrorimpl Eq for CStringimpl Eq for NulErrorimpl Eq for FromBytesWithNulErrorimpl Eq for IntoStringErrorimpl Eq for CStrimpl Eq for OsStringimpl Eq for OsStrimpl Eq for Permissionsimpl Eq for FileTypeimpl Eq for ErrorKindimpl Eq for SeekFromimpl Eq for IpAddrimpl Eq for Ipv6MulticastScopeimpl Eq for Ipv4Addrimpl Eq for Ipv6Addrimpl Eq for SocketAddrimpl Eq for SocketAddrV4impl Eq for SocketAddrV6impl Eq for AddrParseErrorimpl Eq for Shutdownimpl<'a> Eq for Prefix<'a>impl<'a> Eq for PrefixComponent<'a>impl<'a> Eq for Component<'a>impl<'a> Eq for Components<'a>impl Eq for PathBufimpl Eq for StripPrefixErrorimpl Eq for Pathimpl Eq for Outputimpl Eq for ExitStatusimpl<T: Eq> Eq for SendError<T>impl Eq for RecvErrorimpl Eq for TryRecvErrorimpl Eq for RecvTimeoutErrorimpl<T: Eq> Eq for TrySendError<T>impl Eq for WaitTimeoutResultimpl Eq for Instantimpl Eq for SystemTime