Trait cairo_vm::stdlib::prelude::Eq

1.0.0 · source ·

pub trait Eq: PartialEq { }

Expand description

Trait for comparisons corresponding to equivalence relations.

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

reflexive: a == a;
symmetric: a == b implies b == a (required by PartialEq as well); and
transitive: a == b and b == c implies a == c (required by PartialEq as well).

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

Implement Eq in addition to PartialEq if it’s guaranteed that PartialEq::eq(a, a) always returns true (reflexivity), in addition to the symmetric and transitive properties already required by PartialEq.

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 {}

Object Safety§

This trait is not object safe.

Trait cairo_vm::stdlib::prelude::Eq

Derivable

How can I implement Eq?

Object Safety§

Implementors§

impl Eq for Dictionary

impl Eq for BuiltinName

impl Eq for OffsetValue

impl Eq for ApUpdate

impl Eq for FpUpdate

impl Eq for Op1Addr

impl Eq for Opcode

impl Eq for PcUpdate

impl Eq for Register

impl Eq for Res

impl Eq for MaybeRelocatable

impl Eq for ExecScopeError

impl Eq for InsufficientAllocatedCellsError

impl Eq for BuiltinAdditionalData

impl Eq for CairoArg

impl Eq for cairo_vm::with_std::cmp::Ordering

impl Eq for Infallible

impl Eq for cairo_vm::with_std::fmt::Alignment

impl Eq for FpCategory

impl Eq for IntErrorKind

impl Eq for SearchStep

impl Eq for cairo_vm::with_std::sync::atomic::Ordering

impl Eq for RecvTimeoutError

impl Eq for TryRecvError

impl Eq for TryReserveErrorKind

impl Eq for AsciiChar

impl Eq for Which

impl Eq for IpAddr

impl Eq for Ipv6MulticastScope

impl Eq for SocketAddr

impl Eq for BacktraceStatus

impl Eq for VarError

impl Eq for SeekFrom

impl Eq for std::io::error::ErrorKind

impl Eq for Shutdown

impl Eq for BacktraceStyle

impl Eq for AllowedEnumVariants

impl Eq for IntegerType

impl Eq for hashbrown::TryReserveError

impl Eq for nom::error::ErrorKind

impl Eq for Needed

impl Eq for Endianness

impl Eq for Sign

impl Eq for BernoulliError

impl Eq for WeightedError

impl Eq for Category

impl Eq for Value

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 DictManager

impl Eq for DictTracker

impl Eq for HintReference

impl Eq for ApTracking

impl Eq for Attribute

impl Eq for DebugInfo

impl Eq for FlowTrackingData

impl Eq for HintLocation

impl Eq for HintParams

impl Eq for Identifier

impl Eq for InputFile

How can I implement `Eq`?