std::cmp::Eq
Trait std::cmp::Eq
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 == b
impliesb == a
; and - transitive:
a == b
andb == c
impliesa == 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 derive
d, 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 {}
Implementors
impl<K, V> Eq for BTreeMap<K, V> where
K: Eq,
V: Eq,impl<'a, B> Eq for Cow<'a, B> where
B: Eq + ToOwned + ?Sized,impl<T> Eq for LinkedList<T> where
T: Eq,impl Eq for ParseError
impl<T> Eq for Vec<T> where
T: Eq,impl<A> Eq for VecDeque<A> where
A: Eq,impl<T> Eq for BTreeSet<T> where
T: Eq,impl Eq for String
impl<T> Eq for Bound<T> where
T: Eq,impl<T> Eq for Box<T> where
T: Eq + ?Sized,impl<T> Eq for Arc<T> where
T: Eq + ?Sized,impl<T> Eq for Rc<T> where
T: Eq + ?Sized,impl<T> Eq for Discriminant<T>
impl<T> Eq for *const T where
T: ?Sized,impl<T> Eq for *mut T where
T: ?Sized,impl Eq for Ordering
impl Eq for !
impl<'a, A> Eq for &'a A where
A: Eq + ?Sized,impl<'a, A> Eq for &'a mut A where
A: Eq + ?Sized,impl<T> Eq for Cell<T> where
T: Copy + Eq,impl<T> Eq for RefCell<T> where
T: Eq + ?Sized,impl<T> Eq for [T] where
T: Eq,impl Eq for str
impl<T> Eq for Wrapping<T> where
T: Eq,impl Eq for ParseFloatError
impl Eq for FpCategory
impl Eq for ParseIntError
impl<T> Eq for NonZero<T> where
T: Zeroable + Eq,impl<Ret> Eq for fn() -> Ret
impl<Ret> Eq for extern fn() -> Ret
impl<Ret> Eq for unsafe fn() -> Ret
impl<Ret> Eq for unsafe extern fn() -> Ret
impl<Ret, A> Eq for fn(A) -> Ret
impl<Ret, A> Eq for extern fn(A) -> Ret
impl<Ret, A> Eq for extern fn(A, ...) -> Ret
impl<Ret, A> Eq for unsafe fn(A) -> Ret
impl<Ret, A> Eq for unsafe extern fn(A) -> Ret
impl<Ret, A> Eq for unsafe extern fn(A, ...) -> Ret
impl<Ret, A, B> Eq for fn(A, B) -> Ret
impl<Ret, A, B> Eq for extern fn(A, B) -> Ret
impl<Ret, A, B> Eq for extern fn(A, B, ...) -> Ret
impl<Ret, A, B> Eq for unsafe fn(A, B) -> Ret
impl<Ret, A, B> Eq for unsafe extern fn(A, B) -> Ret
impl<Ret, A, B> Eq for unsafe extern fn(A, B, ...) -> Ret
impl<Ret, A, B, C> Eq for fn(A, B, C) -> Ret
impl<Ret, A, B, C> Eq for extern fn(A, B, C) -> Ret
impl<Ret, A, B, C> Eq for extern fn(A, B, C, ...) -> Ret
impl<Ret, A, B, C> Eq for unsafe fn(A, B, C) -> Ret
impl<Ret, A, B, C> Eq for unsafe extern fn(A, B, C) -> Ret
impl<Ret, A, B, C> Eq for unsafe extern fn(A, B, C, ...) -> Ret
impl<Ret, A, B, C, D> Eq for fn(A, B, C, D) -> Ret
impl<Ret, A, B, C, D> Eq for extern fn(A, B, C, D) -> Ret
impl<Ret, A, B, C, D> Eq for extern fn(A, B, C, D, ...) -> Ret
impl<Ret, A, B, C, D> Eq for unsafe fn(A, B, C, D) -> Ret
impl<Ret, A, B, C, D> Eq for unsafe extern fn(A, B, C, D) -> Ret
impl<Ret, A, B, C, D> Eq for unsafe extern fn(A, B, C, D, ...) -> Ret
impl<Ret, A, B, C, D, E> Eq for fn(A, B, C, D, E) -> Ret
impl<Ret, A, B, C, D, E> Eq for extern fn(A, B, C, D, E) -> Ret
impl<Ret, A, B, C, D, E> Eq for extern fn(A, B, C, D, E, ...) -> Ret
impl<Ret, A, B, C, D, E> Eq for unsafe fn(A, B, C, D, E) -> Ret
impl<Ret, A, B, C, D, E> Eq for unsafe extern fn(A, B, C, D, E) -> Ret
impl<Ret, A, B, C, D, E> Eq for unsafe extern fn(A, B, C, D, E, ...) -> Ret
impl<Ret, A, B, C, D, E, F> Eq for fn(A, B, C, D, E, F) -> Ret
impl<Ret, A, B, C, D, E, F> Eq for extern fn(A, B, C, D, E, F) -> Ret
impl<Ret, A, B, C, D, E, F> Eq for extern fn(A, B, C, D, E, F, ...) -> Ret
impl<Ret, A, B, C, D, E, F> Eq for unsafe fn(A, B, C, D, E, F) -> Ret
impl<Ret, A, B, C, D, E, F> Eq for unsafe extern fn(A, B, C, D, E, F) -> Ret
impl<Ret, A, B, C, D, E, F> Eq for unsafe extern fn(A, B, C, D, E, F, ...) -> Ret
impl<Ret, A, B, C, D, E, F, G> Eq for fn(A, B, C, D, E, F, G) -> Ret
impl<Ret, A, B, C, D, E, F, G> Eq for extern fn(A, B, C, D, E, F, G) -> Ret
impl<Ret, A, B, C, D, E, F, G> Eq for extern fn(A, B, C, D, E, F, G, ...) -> Ret
impl<Ret, A, B, C, D, E, F, G> Eq for unsafe fn(A, B, C, D, E, F, G) -> Ret
impl<Ret, A, B, C, D, E, F, G> Eq for unsafe extern fn(A, B, C, D, E, F, G) -> Ret
impl<Ret, A, B, C, D, E, F, G> Eq for unsafe extern fn(A, B, C, D, E, F, G, ...) -> Ret
impl<Ret, A, B, C, D, E, F, G, H> Eq for fn(A, B, C, D, E, F, G, H) -> Ret
impl<Ret, A, B, C, D, E, F, G, H> Eq for extern fn(A, B, C, D, E, F, G, H) -> Ret
impl<Ret, A, B, C, D, E, F, G, H> Eq for extern fn(A, B, C, D, E, F, G, H, ...) -> Ret
impl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe fn(A, B, C, D, E, F, G, H) -> Ret
impl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe extern fn(A, B, C, D, E, F, G, H) -> Ret
impl<Ret, A, B, C, D, E, F, G, H> Eq for unsafe extern fn(A, B, C, D, E, F, G, H, ...) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I> Eq for fn(A, B, C, D, E, F, G, H, I) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I> Eq for extern fn(A, B, C, D, E, F, G, H, I) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I> Eq for extern fn(A, B, C, D, E, F, G, H, I, ...) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe fn(A, B, C, D, E, F, G, H, I) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe extern fn(A, B, C, D, E, F, G, H, I) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I> Eq for unsafe extern fn(A, B, C, D, E, F, G, H, I, ...) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for fn(A, B, C, D, E, F, G, H, I, J) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for extern fn(A, B, C, D, E, F, G, H, I, J) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for extern fn(A, B, C, D, E, F, G, H, I, J, ...) -> Ret
impl<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) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for unsafe extern fn(A, B, C, D, E, F, G, H, I, J) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J> Eq for unsafe extern fn(A, B, C, D, E, F, G, H, I, J, ...) -> Ret
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) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for extern fn(A, B, C, D, E, F, G, H, I, J, K) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for extern fn(A, B, C, D, E, F, G, H, I, J, K, ...) -> Ret
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) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for unsafe extern fn(A, B, C, D, E, F, G, H, I, J, K) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J, K> Eq for unsafe extern fn(A, B, C, D, E, F, G, H, I, J, K, ...) -> Ret
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) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for extern fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for extern fn(A, B, C, D, E, F, G, H, I, J, K, L, ...) -> Ret
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) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for unsafe extern fn(A, B, C, D, E, F, G, H, I, J, K, L) -> Ret
impl<Ret, A, B, C, D, E, F, G, H, I, J, K, L> Eq for unsafe extern fn(A, B, C, D, E, F, G, H, I, J, K, L, ...) -> Ret
impl<T> Eq for PhantomData<T> where
T: ?Sized,impl Eq for RangeFull
impl<Idx> Eq for Range<Idx> where
Idx: Eq,impl<Idx> Eq for RangeFrom<Idx> where
Idx: Eq,impl<Idx> Eq for RangeTo<Idx> where
Idx: Eq,impl<Idx> Eq for RangeInclusive<Idx> where
Idx: Eq,impl<Idx> Eq for RangeToInclusive<Idx> where
Idx: Eq,impl<T> Eq for Reverse<T> where
T: Eq,impl Eq for ()
impl Eq for bool
impl Eq for char
impl Eq for usize
impl Eq for u8
impl Eq for u16
impl Eq for u32
impl Eq for u64
impl Eq for u128
impl Eq for isize
impl Eq for i8
impl Eq for i16
impl Eq for i32
impl Eq for i64
impl Eq for i128
impl Eq for TypeId
impl<T> Eq for [T; 0] where
T: Eq,impl<T> Eq for [T; 1] where
T: Eq,impl<T> Eq for [T; 2] where
T: Eq,impl<T> Eq for [T; 3] where
T: Eq,impl<T> Eq for [T; 4] where
T: Eq,impl<T> Eq for [T; 5] where
T: Eq,impl<T> Eq for [T; 6] where
T: Eq,impl<T> Eq for [T; 7] where
T: Eq,impl<T> Eq for [T; 8] where
T: Eq,impl<T> Eq for [T; 9] where
T: Eq,impl<T> Eq for [T; 10] where
T: Eq,impl<T> Eq for [T; 11] where
T: Eq,impl<T> Eq for [T; 12] where
T: Eq,impl<T> Eq for [T; 13] where
T: Eq,impl<T> Eq for [T; 14] where
T: Eq,impl<T> Eq for [T; 15] where
T: Eq,impl<T> Eq for [T; 16] where
T: Eq,impl<T> Eq for [T; 17] where
T: Eq,impl<T> Eq for [T; 18] where
T: Eq,impl<T> Eq for [T; 19] where
T: Eq,impl<T> Eq for [T; 20] where
T: Eq,impl<T> Eq for [T; 21] where
T: Eq,impl<T> Eq for [T; 22] where
T: Eq,impl<T> Eq for [T; 23] where
T: Eq,impl<T> Eq for [T; 24] where
T: Eq,impl<T> Eq for [T; 25] where
T: Eq,impl<T> Eq for [T; 26] where
T: Eq,impl<T> Eq for [T; 27] where
T: Eq,impl<T> Eq for [T; 28] where
T: Eq,impl<T> Eq for [T; 29] where
T: Eq,impl<T> Eq for [T; 30] where
T: Eq,impl<T> Eq for [T; 31] where
T: Eq,impl<T> Eq for [T; 32] where
T: Eq,impl Eq for CharTryFromError
impl Eq for InvalidSequence
impl<T> Eq for Option<T> where
T: Eq,impl<T, E> Eq for Result<T, E> where
E: Eq,
T: Eq,impl Eq for SearchStep
impl Eq for ParseBoolError
impl Eq for Utf8Error
impl Eq for Error
impl<A> Eq for (A,) where
A: Eq,impl<A, B> Eq for (A, B) where
A: Eq,
B: Eq,impl<A, B, C> Eq for (A, B, C) where
A: Eq,
B: Eq,
C: Eq,impl<A, B, C, D> Eq for (A, B, C, D) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,impl<A, B, C, D, E> Eq for (A, B, C, D, E) where
A: Eq,
B: Eq,
C: Eq,
D: Eq,
E: 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,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,impl<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,impl<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,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,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,impl<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,impl Eq for DecodeUtf16Error
impl Eq for LocalKeyState
impl Eq for ThreadId
impl<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 VarError
impl Eq for CString
impl Eq for NulError
impl Eq for FromBytesWithNulError
impl Eq for IntoStringError
impl Eq for CStr
impl Eq for OsString
impl Eq for OsStr
impl Eq for Permissions
impl Eq for FileType
impl Eq for ErrorKind
impl Eq for SeekFrom
impl Eq for IpAddr
impl Eq for Ipv6MulticastScope
impl Eq for Ipv4Addr
impl Eq for Ipv6Addr
impl Eq for SocketAddr
impl Eq for SocketAddrV4
impl Eq for SocketAddrV6
impl Eq for AddrParseError
impl Eq for Shutdown
impl<'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 PathBuf
impl Eq for StripPrefixError
impl Eq for Path
impl Eq for Output
impl Eq for ExitStatus
impl<T: Eq> Eq for SendError<T>
impl Eq for RecvError
impl Eq for TryRecvError
impl Eq for RecvTimeoutError
impl<T: Eq> Eq for TrySendError<T>
impl Eq for WaitTimeoutResult
impl Eq for Duration
impl Eq for Instant
impl Eq for SystemTime
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/cmp/trait.Eq.html