Trait frame_support::dispatch::Eq

1.0.0 · source ·

pub trait Eq: PartialEq<Self> { }

Expand description

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 implies b == a; and
transitive: a == b and b == c implies a == 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: &Self) -> bool {
        self.isbn == other.isbn
    }
}
impl Eq for Book {}

Trait frame_support::dispatch::Eq

Derivable

How can I implement Eq?

Implementors§

impl Eq for ArithmeticError

impl Eq for DeriveError

impl Eq for DeriveJunction

impl Eq for PublicError

impl Eq for SecretStringError

impl Eq for Void

impl Eq for HttpError

impl Eq for HttpRequestStatus

impl Eq for OffchainOverlayedChange

impl Eq for StorageKind

impl Eq for CallContext

impl Eq for StorageEntryModifierIR

impl Eq for StorageHasherIR

impl Eq for MultiSignature

impl Eq for MultiSigner

impl Eq for TokenError

impl Eq for TransactionalError

impl Eq for DigestItem

impl Eq for Era

impl Eq for sp_runtime::legacy::byte_sized_error::DispatchError

impl Eq for sp_runtime::offchain::http::Error

impl Eq for Method

impl Eq for StorageRetrievalError

impl Eq for RuntimeString

impl Eq for DisableStrategy

impl Eq for ExecutionError

impl Eq for sp_version::embed::Error

impl Eq for sp_wasm_interface::ValueType

impl Eq for Never

impl Eq for frame_support::pallet_prelude::DispatchError

impl Eq for InvalidTransaction

impl Eq for TransactionSource

impl Eq for TransactionValidityError

impl Eq for UnknownTransaction

impl Eq for ChildInfo

impl Eq for StateVersion

impl Eq for ExecuteOverweightError

impl Eq for ProcessMessageError

impl Eq for frame_support::traits::schedule::LookupError

impl Eq for BalanceStatus

impl Eq for DepositConsequence

impl Eq for ExistenceRequirement

impl Eq for Fortitude

impl Eq for Precision

impl Eq for Preservation

impl Eq for Provenance

impl Eq for Restriction

impl Eq for PaymentStatus

impl Eq for DispatchClass

impl Eq for Pays

impl Eq for frame_support::dispatch::fmt::Alignment

impl Eq for TryReserveErrorKind

impl Eq for core::cmp::Ordering

impl Eq for Infallible

impl Eq for Which

impl Eq for IpAddr

impl Eq for Ipv6MulticastScope

impl Eq for SocketAddr

impl Eq for FpCategory

impl Eq for IntErrorKind

impl Eq for SearchStep

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

impl Eq for proc_macro::Delimiter

impl Eq for proc_macro::Spacing

impl Eq for BacktraceStatus

impl Eq for VarError

impl Eq for std::io::SeekFrom

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

impl Eq for Shutdown

impl Eq for BacktraceStyle

impl Eq for std::sync::mpsc::RecvTimeoutError

impl Eq for std::sync::mpsc::TryRecvError

impl Eq for PrintFmt

impl Eq for SecondsFormat

impl Eq for Fixed

impl Eq for Numeric

How can I implement `Eq`?