Trait Eq 

pub trait Eq: PartialEq { }

Trait for comparisons corresponding to equivalence relations.

The primary difference to PartialEq is the additional requirement for reflexivity. A type that implements PartialEq guarantees that for all a, b and c:

• symmetric: a == b implies b == a and a != b implies !(a == b)
• transitive: a == b and b == c implies a == c

Eq, which builds on top of PartialEq also implies:

• reflexive: a == a

This property cannot be checked by the compiler, and therefore Eq is a trait without 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.

Floating point types such as f32 and f64 implement only PartialEq but not Eq because NaN != NaN.

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 extra 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 {}

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl Eq for AsciiChar

impl Eq for mmcp_server::inventory::core::cmp::Ordering

impl Eq for Infallible

impl Eq for FromBytesWithNulError

impl Eq for mmcp_server::inventory::core::fmt::Alignment

impl Eq for DebugAsHex

impl Eq for Sign

impl Eq for AtomicOrdering

impl Eq for IpAddr

impl Eq for Ipv6MulticastScope

impl Eq for SocketAddr

impl Eq for FpCategory

impl Eq for IntErrorKind

impl Eq for mmcp_server::inventory::core::slice::GetDisjointMutError

impl Eq for SearchStep

impl Eq for mmcp_server::inventory::core::sync::atomic::Ordering

impl Eq for TryReserveErrorKind

impl Eq for BacktraceStatus

impl Eq for VarError

impl Eq for SeekFrom

impl Eq for ErrorKind

impl Eq for Shutdown

impl Eq for BacktraceStyle

impl Eq for RecvTimeoutError

impl Eq for TryRecvError

impl Eq for ParseAlphabetError

impl Eq for DecodeError

impl Eq for DecodeSliceError

impl Eq for EncodeSliceError

impl Eq for DecodePaddingMode

impl Eq for PollNext

impl Eq for hashbrown::TryReserveError

impl Eq for indexmap::GetDisjointMutError

impl Eq for ProtocolVersion

impl Eq for CreateMessageRequestParamsIncludeContext

impl Eq for LoggingLevel

impl Eq for ProgressToken

impl Eq for RequestId

impl Eq for Role

impl Eq for Category

impl Eq for Value

impl Eq for slab::GetDisjointMutError

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 AllocError

impl Eq for Layout

impl Eq for LayoutError

impl Eq for TypeId

impl Eq for CpuidResult

impl Eq for ByteStr

impl Eq for CharTryFromError

impl Eq for DecodeUtf16Error

impl Eq for ParseCharError

impl Eq for TryFromCharError

impl Eq for CStr

impl Eq for FromBytesUntilNulError

impl Eq for Error

impl Eq for FormattingOptions

impl Eq for PhantomPinned

impl Eq for Assume

impl Eq for AddrParseError

impl Eq for Ipv4Addr

impl Eq for Ipv6Addr

impl Eq for SocketAddrV4

impl Eq for SocketAddrV6

impl Eq for ParseFloatError

impl Eq for ParseIntError

impl Eq for TryFromIntError

impl Eq for RangeFull

impl Eq for Location<'_>

impl Eq for mmcp_server::inventory::core::ptr::Alignment

impl Eq for ParseBoolError

impl Eq for Utf8Error

impl Eq for Duration

impl Eq for TryFromFloatSecsError

impl Eq for ByteString

impl Eq for UnorderedKeyError

impl Eq for alloc::collections::TryReserveError

impl Eq for CString

impl Eq for FromVecWithNulError

impl Eq for IntoStringError

impl Eq for NulError

impl Eq for FromUtf8Error

impl Eq for String

impl Eq for OsStr

impl Eq for OsString

impl Eq for FileType

impl Eq for Permissions

impl Eq for UCred

impl Eq for Components<'_>

impl Eq for Path

impl Eq for PathBuf

impl Eq for StripPrefixError

impl Eq for ExitStatus

impl Eq for ExitStatusError

impl Eq for Output

impl Eq for RecvError

impl Eq for WaitTimeoutResult

impl Eq for AccessError

impl Eq for ThreadId

impl Eq for Instant

impl Eq for SystemTime

impl Eq for Alphabet

impl Eq for DecodeMetadata

impl Eq for futures_channel::mpsc::SendError

impl Eq for Canceled

impl Eq for Aborted

impl Eq for indexmap::TryReserveError

impl Eq for ClientCapabilitiesRoots

impl Eq for CompleteRequestParamsArgument

impl Eq for mmcp_protocol::mcp::Cursor

impl Eq for Implementation

impl Eq for ListPromptsRequestParams

impl Eq for ListResourceTemplatesRequestParams

impl Eq for ListResourcesRequestParams

impl Eq for ListToolsRequestParams

impl Eq for ModelHint

impl Eq for PaginatedRequestParams

impl Eq for PromptArgument

impl Eq for PromptReference

impl Eq for ReadResourceRequestParams

impl Eq for ResourceContents

impl Eq for ResourceReference

impl Eq for ResourceUpdatedNotificationParams

impl Eq for Root

impl Eq for ServerCapabilitiesPrompts

impl Eq for ServerCapabilitiesResources

impl Eq for ServerCapabilitiesTools

impl Eq for SubscribeRequestParams

impl Eq for TextResourceContents

impl Eq for ToolAnnotations

impl Eq for UnsubscribeRequestParams

impl Eq for Map<String, Value>

impl Eq for Number

impl<'a> Eq for Utf8Pattern<'a>

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

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

impl<'a> Eq for PhantomContravariantLifetime<'a>

impl<'a> Eq for PhantomCovariantLifetime<'a>

impl<'a> Eq for PhantomInvariantLifetime<'a>

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

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

impl<A> Eq for &A

where A: Eq + ?Sized,

impl<A> Eq for &mut A

where A: Eq + ?Sized,

impl<B> Eq for Cow<'_, B>

where B: Eq + ToOwned + ?Sized,

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

where B: Eq, C: Eq,

impl<Dyn> Eq for DynMetadata<Dyn>

where Dyn: ?Sized,

impl<F> Eq for F

where F: FnPtr,

impl<H> Eq for BuildHasherDefault<H>

impl<Idx> Eq for mmcp_server::inventory::core::ops::Range<Idx>

where Idx: Eq,

impl<Idx> Eq for mmcp_server::inventory::core::ops::RangeFrom<Idx>

where Idx: Eq,

impl<Idx> Eq for mmcp_server::inventory::core::ops::RangeInclusive<Idx>

where Idx: Eq,

impl<Idx> Eq for RangeTo<Idx>

where Idx: Eq,

impl<Idx> Eq for RangeToInclusive<Idx>

where Idx: Eq,

impl<Idx> Eq for mmcp_server::inventory::core::range::Range<Idx>

where Idx: Eq,

impl<Idx> Eq for mmcp_server::inventory::core::range::RangeFrom<Idx>

where Idx: Eq,

impl<Idx> Eq for mmcp_server::inventory::core::range::RangeInclusive<Idx>

where Idx: Eq,

impl<K, V> Eq for indexmap::map::slice::Slice<K, V>

where K: Eq, V: Eq,

impl<K, V, A> Eq for BTreeMap<K, V, A>

where K: Eq, V: Eq, A: Allocator + Clone,

impl<K, V, S> Eq for std::collections::hash::map::HashMap<K, V, S>

where K: Eq + Hash, V: Eq, S: BuildHasher,

impl<K, V, S> Eq for IndexMap<K, V, S>

where K: Eq + Hash, V: Eq, S: BuildHasher,

impl<K, V, S, A> Eq for hashbrown::map::HashMap<K, V, S, A>

where K: Eq + Hash, V: Eq, S: BuildHasher, A: Allocator,

impl<Ptr> Eq for Pin<Ptr>

where Ptr: Deref, <Ptr as Deref>::Target: Eq,

impl<T> Eq for Bound<T>

where T: Eq,

impl<T> Eq for Option<T>

where T: Eq,

impl<T> Eq for Poll<T>

where T: Eq,

impl<T> Eq for SendTimeoutError<T>

where T: Eq,

impl<T> Eq for std::sync::mpsc::TrySendError<T>

where T: Eq,

impl<T> Eq for *const T

where T: ?Sized,

Pointer equality is an equivalence relation.

impl<T> Eq for *mut T

where T: ?Sized,

Pointer equality is an equivalence relation.

impl<T> Eq for [T]

where T: Eq,

impl<T> Eq for (T₁, T₂, …, Tₙ)

where T: Eq,

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

impl<T> Eq for Cell<T>

where T: Eq + Copy,

impl<T> Eq for OnceCell<T>

where T: Eq,

impl<T> Eq for RefCell<T>

where T: Eq + ?Sized,

impl<T> Eq for Reverse<T>

where T: Eq,

impl<T> Eq for PhantomContravariant<T>

where T: ?Sized,

impl<T> Eq for PhantomCovariant<T>

where T: ?Sized,

impl<T> Eq for PhantomData<T>

where T: ?Sized,

impl<T> Eq for PhantomInvariant<T>

where T: ?Sized,

impl<T> Eq for Discriminant<T>

impl<T> Eq for ManuallyDrop<T>

where T: Eq + ?Sized,

impl<T> Eq for NonZero<T>

where T: ZeroablePrimitive + Eq,

impl<T> Eq for Saturating<T>

where T: Eq,

impl<T> Eq for Wrapping<T>

where T: Eq,

impl<T> Eq for NonNull<T>

where T: ?Sized,

impl<T> Eq for std::io::cursor::Cursor<T>

where T: Eq,

impl<T> Eq for std::sync::mpsc::SendError<T>

where T: Eq,

impl<T> Eq for OnceLock<T>

where T: Eq,

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

where T: Eq,

impl<T> Eq for AllowStdIo<T>

where T: Eq,

impl<T> Eq for indexmap::set::slice::Slice<T>

where T: Eq,

impl<T, A> Eq for Box<T, A>

where T: Eq + ?Sized, A: Allocator,

impl<T, A> Eq for BTreeSet<T, A>

where T: Eq, A: Allocator + Clone,

impl<T, A> Eq for LinkedList<T, A>

where T: Eq, A: Allocator,

impl<T, A> Eq for VecDeque<T, A>

where T: Eq, A: Allocator,

impl<T, A> Eq for Rc<T, A>

where T: Eq + ?Sized, A: Allocator,

impl<T, A> Eq for UniqueRc<T, A>

where T: Eq + ?Sized, A: Allocator,

impl<T, A> Eq for Arc<T, A>

where T: Eq + ?Sized, A: Allocator,

impl<T, A> Eq for UniqueArc<T, A>

where T: Eq + ?Sized, A: Allocator,

impl<T, A> Eq for Vec<T, A>

where T: Eq, A: Allocator,

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

where T: Eq, E: Eq,

impl<T, E> Eq for TryChunksError<T, E>

where T: Eq, E: Eq,

impl<T, E> Eq for TryReadyChunksError<T, E>

where T: Eq, E: Eq,

impl<T, S> Eq for std::collections::hash::set::HashSet<T, S>

where T: Eq + Hash, S: BuildHasher,

impl<T, S> Eq for IndexSet<T, S>

where T: Eq + Hash, S: BuildHasher,

impl<T, S, A> Eq for hashbrown::set::HashSet<T, S, A>

where T: Eq + Hash, S: BuildHasher, A: Allocator,

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

where T: Eq,

impl<T, const N: usize> Eq for Simd<T, N>

where LaneCount<N>: SupportedLaneCount, T: SimdElement + Eq,

impl<Y, R> Eq for CoroutineState<Y, R>

where Y: Eq, R: Eq,