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<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 Eq for RangeFullimpl Eq for NonZeroUsizeimpl Eq for AllocErrimpl<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 Eq for u16impl<Ret, A, B, C, D, E, F> Eq for unsafe extern "C" fn(A, B, C, D, E, F) -> Retimpl<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<Ret, A> Eq for unsafe extern "C" fn(A) -> Retimpl<T> Eq for [T; 3] where
T: Eq,impl Eq for Errorimpl Eq for TypeIdimpl<Ret, A, B, C, D, E, F> Eq for fn(A, B, C, D, E, F) -> Retimpl Eq for i64impl<T> Eq for [T; 19] 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<T> Eq for [T; 13] where
T: Eq,impl<Ret, A, B, C, D, E> Eq for unsafe extern "C" fn(A, B, C, D, E) -> Retimpl<Ret, A, B, C, D, E, F, G> Eq for extern "C" fn(A, B, C, D, E, F, G) -> Retimpl<Ret, A, B, C, D, E, F, G> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G) -> Retimpl<Ret, A, B, C, D, E> Eq for fn(A, B, C, D, E) -> Retimpl Eq for FpCategoryimpl Eq for NoneErrorimpl<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<A, B, C, D> Eq for (A, B, C, D) where
A: Eq,
B: Eq,
C: Eq,
D: Eq + ?Sized,impl Eq for Utf8Errorimpl<T> Eq for RefCell<T> where
T: Eq + ?Sized,impl<T> Eq for [T; 20] where
T: Eq,impl<Ret, A, B, C, D, E> Eq for unsafe extern "C" fn(A, B, C, D, E, ...) -> Retimpl Eq for i32impl Eq for i8impl<T> Eq for [T; 23] 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> Eq for extern "C" fn(A, B, C, D, E) -> Retimpl<T> Eq for Wrapping<T> where
T: Eq,impl<Ret, A, B, C, D> Eq for unsafe extern "C" fn(A, B, C, D) -> Retimpl<Ret, A> Eq for extern "C" fn(A) -> Retimpl<Ret, A, B, C> Eq for extern "C" fn(A, B, C, ...) -> Retimpl<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, G, H, I, J> Eq for extern "C" fn(A, B, C, D, E, F, G, H, I, J, ...) -> Retimpl<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<Ret, A, B, C> Eq for unsafe fn(A, B, C) -> Retimpl<T> Eq for Discriminant<T>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; 18] where
T: Eq,impl<Ret, A, B> Eq for extern "C" fn(A, B, ...) -> Retimpl<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<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, F, G> Eq for unsafe fn(A, B, C, D, E, F, G) -> Retimpl<T> Eq for [T; 1] where
T: Eq,impl Eq for ParseFloatErrorimpl Eq for u8impl<T> Eq for [T; 14] where
T: Eq,impl<Idx> Eq for RangeToInclusive<Idx> where
Idx: Eq,impl<T> Eq for Reverse<T> where
T: Eq,impl Eq for NonZeroU128impl Eq for usizeimpl<T> Eq for [T] where
T: Eq,impl<Ret, A> Eq for unsafe extern "C" fn(A, ...) -> Retimpl Eq for u32impl<Ret, A, B, C, D, E, F> Eq for extern "C" fn(A, B, C, D, E, F) -> Retimpl<H> Eq for BuildHasherDefault<H>impl<Ret, A, B, C, D, E, F> Eq for extern "C" fn(A, B, C, D, E, F, ...) -> Retimpl Eq for i128impl Eq for NonZeroU32impl Eq for Durationimpl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe 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 Eq for NonZeroU16impl<Idx> Eq for RangeFrom<Idx> where
Idx: Eq,impl<Ret> Eq for unsafe extern "C" fn() -> Retimpl<Ret, A, B> Eq for unsafe extern "C" fn(A, B, ...) -> Retimpl<Ret, A, B, C, D, E, F, G> Eq for fn(A, B, C, D, E, F, G) -> Retimpl<T> Eq for [T; 6] where
T: Eq,impl 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 Eq for charimpl<Ret, A, B, C> Eq for extern "C" fn(A, B, C) -> Retimpl<T> Eq for [T; 27] where
T: Eq,impl<T> Eq for PhantomData<T> where
T: ?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 CharTryFromErrorimpl<Ret, A> Eq for extern "C" fn(A, ...) -> Retimpl<T> Eq for [T; 21] where
T: Eq,impl<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<T> Eq for [T; 22] where
T: Eq,impl<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<T> Eq for Option<T> where
T: Eq,impl<Ret, A, B, C, D> Eq for unsafe extern "C" fn(A, B, C, D, ...) -> Retimpl<T> Eq for Poll<T> where
T: Eq,impl<Ret, A, B, C, D, E, F, G, H> Eq for fn(A, B, C, D, E, F, G, H) -> Retimpl Eq for u128impl<T> Eq for [T; 2] where
T: Eq,impl<Ret, A, B, C> Eq for unsafe extern "C" fn(A, B, C, ...) -> Retimpl<T> Eq for [T; 9] where
T: Eq,impl<T> Eq for [T; 30] where
T: Eq,impl Eq for CannotReallocInPlaceimpl<Ret, A, B, C, D> Eq for extern "C" fn(A, B, C, D, ...) -> Retimpl<T> Eq for [T; 12] where
T: Eq,impl<Ret, A, B> Eq for unsafe extern "C" fn(A, B) -> Retimpl<T> Eq for [T; 7] where
T: Eq,impl<T> Eq for Bound<T> where
T: Eq,impl<T> Eq for [T; 17] where
T: Eq,impl<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 Eq for NonZeroU64impl Eq for ()impl Eq for InvalidSequenceimpl<'a, A> Eq for &'a A where
A: Eq + ?Sized,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<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 Eq for UnicodeVersionimpl<Y, R> Eq for GeneratorState<Y, R> where
R: Eq,
Y: 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<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, 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, D, E, F, G> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, ...) -> 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 Eq for isizeimpl<Ret, A, B> Eq for extern "C" fn(A, B) -> Retimpl<Ret, A, B, C, D, E> Eq for extern "C" fn(A, B, C, D, E, ...) -> Retimpl<A> Eq for (A,) where
A: Eq + ?Sized,impl<Ret> Eq for unsafe fn() -> Retimpl<Ret, A, B, C, D> Eq for extern "C" fn(A, B, C, D) -> Retimpl Eq for !impl<T> Eq for *mut T where
T: ?Sized,impl<Ret, A, B, C, D, E, F> Eq for unsafe fn(A, B, C, D, E, F) -> Retimpl Eq for ParseBoolErrorimpl<T> Eq for [T; 25] where
T: Eq,impl<Ret, A, B, C> Eq for unsafe extern "C" fn(A, B, C) -> Retimpl<T> Eq for [T; 24] where
T: Eq,impl<Idx> Eq for RangeTo<Idx> where
Idx: Eq,impl<T> Eq for [T; 8] where
T: Eq,impl<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<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, H, I, J, K, L> Eq for fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Retimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for fn(A, B, C, D, E, F, G, H, I) -> Retimpl<Ret> Eq for fn() -> Retimpl<'a, A> Eq for &'a mut A where
A: Eq + ?Sized,impl Eq for ParseCharErrorimpl<T> Eq for *const T where
T: ?Sized,impl<Ret, A> Eq for unsafe fn(A) -> 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 Eq for boolimpl Eq for Layoutimpl<T> Eq for [T; 5] where
T: Eq,impl<T> Eq for [T; 4] where
T: Eq,impl Eq for LayoutErrimpl Eq for DecodeUtf16Errorimpl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe fn(A, B, C, D, E, F, G, H, I) -> Retimpl<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, I, J, K> Eq for unsafe extern "C" fn(A, B, C, D, E, F, G, H, I, J, K, ...) -> Retimpl Eq for Pinnedimpl Eq for strimpl<Ret, A, B, C, D> Eq for unsafe fn(A, B, C, D) -> Retimpl<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 Eq for NonZeroU8impl Eq for ParseIntErrorimpl<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<A, B> Eq for (A, B) where
A: Eq,
B: Eq + ?Sized,impl<Idx> Eq for Range<Idx> where
Idx: Eq,impl<T> Eq for [T; 32] where
T: Eq,impl<Ret, A, B, C> Eq for fn(A, B, C) -> Retimpl<Ret, A, B, C, D, E, F, G> Eq for extern "C" fn(A, B, C, D, E, F, G, ...) -> Retimpl Eq for Orderingimpl Eq for u64impl<T> Eq for [T; 29] where
T: Eq,impl<T> Eq for NonNull<T> where
T: ?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 Eq for SearchStepimpl<T> Eq for [T; 16] where
T: Eq,impl<T> Eq for ManuallyDrop<T> where
T: Eq,impl<Ret, A, B, C, D, E> Eq for unsafe fn(A, B, C, D, E) -> Retimpl<T> Eq for [T; 26] where
T: Eq,impl<Ret, A, B> Eq for unsafe fn(A, B) -> Retimpl<Ret, A, B, C, D> Eq for fn(A, B, C, D) -> Retimpl<T> Eq for [T; 0] where
T: Eq,impl<T> Eq for [T; 15] where
T: Eq,impl<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<Ret, A> Eq for fn(A) -> Retimpl<T> Eq for [T; 28] where
T: Eq,impl<T> Eq for [T; 11] where
T: Eq,impl<T, E> Eq for Result<T, E> where
E: Eq,
T: Eq,impl<T> Eq for [T; 31] where
T: Eq,impl<T> Eq for Cell<T> where
T: Copy + Eq,impl<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; 10] where
T: Eq,impl<Idx> Eq for RangeInclusive<Idx> where
Idx: Eq,impl<A, B, C> Eq for (A, B, C) where
A: Eq,
B: Eq,
C: Eq + ?Sized,impl<Ret> Eq for extern "C" fn() -> Retimpl<'a, B> Eq for Cow<'a, B> where
B: Eq + ToOwned + ?Sized,impl<T> Eq for BTreeSet<T> where
T: Eq,impl Eq for CollectionAllocErrimpl<T> Eq for Box<T> where
T: Eq + ?Sized,impl Eq for ParseErrorimpl Eq for Stringimpl<T> Eq for Rc<T> where
T: Eq + ?Sized,impl<A> Eq for VecDeque<A> where
A: Eq,impl<T> Eq for Vec<T> where
T: Eq,impl<T> Eq for Arc<T> where
T: Eq + ?Sized,impl<K, V> Eq for BTreeMap<K, V> where
K: Eq,
V: Eq,impl<T> Eq for LinkedList<T> where
T: 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