Trait frame_support::dispatch::marker::StructuralEq[−][src]

pub trait StructuralEq { }

🔬 This is a nightly-only experimental API. (structural_match)

Expand description

Required trait for constants used in pattern matches.

Any type that derives Eq automatically implements this trait, regardless of whether its type parameters implement Eq.

This is a hack to work around a limitation in our type system.

Background

We want to require that types of consts used in pattern matches have the attribute #[derive(PartialEq, Eq)].

In a more ideal world, we could check that requirement by just checking that the given type implements both the StructuralPartialEq trait and the Eq trait. However, you can have ADTs that do derive(PartialEq, Eq), and be a case that we want the compiler to accept, and yet the constant’s type fails to implement Eq.

Namely, a case like this:

#[derive(PartialEq, Eq)]
struct Wrap<X>(X);

fn higher_order(_: &()) { }

const CFN: Wrap<fn(&())> = Wrap(higher_order);

fn main() {
    match CFN {
        CFN => {}
        _ => {}
    }
}

(The problem in the above code is that Wrap<fn(&())> does not implement PartialEq, nor Eq, because for<'a> fn(&'a _) does not implement those traits.)

Therefore, we cannot rely on naive check for StructuralPartialEq and mere Eq.

As a hack to work around this, we use two separate traits injected by each of the two derives (#[derive(PartialEq)] and #[derive(Eq)]) and check that both of them are present as part of structural-match checking.

Implementations on Foreign Types

1.0.0[src]

impl StructuralEq for SocketAddr

Trait frame_support::dispatch::marker::StructuralEq[−][src]

Background

Implementations on Foreign Types

Implementors

impl StructuralEq for Error

impl StructuralEq for FunctionMetadata

impl StructuralEq for FunctionArgumentMetadata

impl<E> StructuralEq for FnEncode<E> where E: Encode + 'static,

impl StructuralEq for OuterEventMetadata

impl StructuralEq for EventMetadata

impl StructuralEq for StorageEntryMetadata

impl StructuralEq for ModuleConstantMetadata

impl StructuralEq for ErrorMetadata

impl StructuralEq for StorageHasher

impl StructuralEq for StorageEntryType

impl StructuralEq for StorageEntryModifier

impl StructuralEq for StorageMetadata

impl StructuralEq for RuntimeMetadataPrefixed

impl StructuralEq for ExtrinsicMetadata

impl StructuralEq for RuntimeMetadata

impl StructuralEq for RuntimeMetadataDeprecated

impl StructuralEq for RuntimeMetadataV13

impl StructuralEq for ModuleMetadata

impl<T: Config> StructuralEq for Module<T>

impl<T: Config + Send + Sync> StructuralEq for CheckGenesis<T>

impl<T: Config + Send + Sync> StructuralEq for CheckMortality<T>

impl<T: Config> StructuralEq for CheckNonce<T>

impl<T: Config + Send + Sync> StructuralEq for CheckSpecVersion<T>

impl<T: Config + Send + Sync> StructuralEq for CheckTxVersion<T>

impl<T: Config + Send + Sync> StructuralEq for CheckWeight<T>

impl StructuralEq for Phase

impl<E: Parameter + Member, T> StructuralEq for EventRecord<E, T>

impl<AccountId> StructuralEq for RawOrigin<AccountId>

impl<Index, AccountData> StructuralEq for AccountInfo<Index, AccountData>

impl StructuralEq for IncRefStatus

impl StructuralEq for DecRefStatus

impl StructuralEq for ProxyType

impl StructuralEq for SessionKeys

impl StructuralEq for NposSolution16

impl StructuralEq for Runtime

impl StructuralEq for Event

impl StructuralEq for OriginCaller

impl StructuralEq for Call

impl StructuralEq for SessionKeys

impl StructuralEq for Runtime

impl StructuralEq for Event

impl StructuralEq for OriginCaller

impl StructuralEq for Call

impl<Balance, AccountId, DepositBalance> StructuralEq for AssetDetails<Balance, AccountId, DepositBalance>

impl<Balance, DepositBalance> StructuralEq for Approval<Balance, DepositBalance>

impl<Balance, Extra> StructuralEq for AssetBalance<Balance, Extra>

impl<DepositBalance, BoundedString> StructuralEq for AssetMetadata<DepositBalance, BoundedString>

impl StructuralEq for DestroyWitness

impl StructuralEq for ConversionError

impl<T: Config> StructuralEq for PendingSwap<T>

impl<AccountId, C: ReservableCurrency<AccountId>> StructuralEq for BalanceSwapAction<AccountId, C>

impl StructuralEq for Reasons

impl<Balance> StructuralEq for BalanceLock<Balance>

impl<ReserveIdentifier, Balance> StructuralEq for ReserveData<ReserveIdentifier, Balance>

impl<Balance> StructuralEq for AccountData<Balance>

impl<T: Config<I>, I: 'static> StructuralEq for PositiveImbalance<T, I>

impl<T: Config<I>, I: 'static> StructuralEq for NegativeImbalance<T, I>

impl<AccountId, Balance, BlockNumber> StructuralEq for Bounty<AccountId, Balance, BlockNumber>

impl<AccountId, BlockNumber> StructuralEq for BountyStatus<AccountId, BlockNumber>

impl<Balance, AccountId> StructuralEq for RawEvent<Balance, AccountId>

impl<T: Config> StructuralEq for Module<T>

impl<AccountId, I> StructuralEq for RawOrigin<AccountId, I>

impl<AccountId, BlockNumber> StructuralEq for Votes<AccountId, BlockNumber>

impl StructuralEq for Instance1

impl StructuralEq for Instance2

impl StructuralEq for Instance3

impl StructuralEq for Instance4

impl StructuralEq for Instance5

impl StructuralEq for Instance6

impl StructuralEq for Instance7

impl StructuralEq for Instance8

impl StructuralEq for Instance9

impl StructuralEq for Instance10

impl StructuralEq for Instance11

impl StructuralEq for Instance12

`impl StructuralEq for Error`

`impl StructuralEq for FunctionMetadata`

`impl StructuralEq for FunctionArgumentMetadata`

`impl<E> StructuralEq for FnEncode<E> where E: Encode + 'static,`

`impl StructuralEq for OuterEventMetadata`

`impl StructuralEq for EventMetadata`

`impl StructuralEq for StorageEntryMetadata`

`impl StructuralEq for ModuleConstantMetadata`

`impl StructuralEq for ErrorMetadata`

`impl StructuralEq for StorageHasher`

`impl StructuralEq for StorageEntryType`

`impl StructuralEq for StorageEntryModifier`

`impl StructuralEq for StorageMetadata`

`impl StructuralEq for RuntimeMetadataPrefixed`

`impl StructuralEq for ExtrinsicMetadata`

`impl StructuralEq for RuntimeMetadata`

`impl StructuralEq for RuntimeMetadataDeprecated`

`impl StructuralEq for RuntimeMetadataV13`

`impl StructuralEq for ModuleMetadata`

`impl<T: Config> StructuralEq for Module<T>`

`impl<T: Config + Send + Sync> StructuralEq for CheckGenesis<T>`

`impl<T: Config + Send + Sync> StructuralEq for CheckMortality<T>`

`impl<T: Config> StructuralEq for CheckNonce<T>`

`impl<T: Config + Send + Sync> StructuralEq for CheckSpecVersion<T>`

`impl<T: Config + Send + Sync> StructuralEq for CheckTxVersion<T>`

`impl<T: Config + Send + Sync> StructuralEq for CheckWeight<T>`

`impl StructuralEq for Phase`

`impl<E: Parameter + Member, T> StructuralEq for EventRecord<E, T>`

`impl<AccountId> StructuralEq for RawOrigin<AccountId>`

`impl<Index, AccountData> StructuralEq for AccountInfo<Index, AccountData>`

`impl StructuralEq for IncRefStatus`

`impl StructuralEq for DecRefStatus`

`impl StructuralEq for ProxyType`

`impl StructuralEq for SessionKeys`

`impl StructuralEq for NposSolution16`

`impl StructuralEq for Runtime`

`impl StructuralEq for Event`

`impl StructuralEq for OriginCaller`

`impl StructuralEq for Call`

`impl StructuralEq for SessionKeys`

`impl StructuralEq for Runtime`

`impl StructuralEq for Event`

`impl StructuralEq for OriginCaller`

`impl StructuralEq for Call`

`impl<Balance, AccountId, DepositBalance> StructuralEq for AssetDetails<Balance, AccountId, DepositBalance>`

`impl<Balance, DepositBalance> StructuralEq for Approval<Balance, DepositBalance>`

`impl<Balance, Extra> StructuralEq for AssetBalance<Balance, Extra>`

`impl<DepositBalance, BoundedString> StructuralEq for AssetMetadata<DepositBalance, BoundedString>`

`impl StructuralEq for DestroyWitness`

`impl StructuralEq for ConversionError`

`impl<T: Config> StructuralEq for PendingSwap<T>`

`impl<AccountId, C: ReservableCurrency<AccountId>> StructuralEq for BalanceSwapAction<AccountId, C>`

`impl StructuralEq for Reasons`

`impl<Balance> StructuralEq for BalanceLock<Balance>`

`impl<ReserveIdentifier, Balance> StructuralEq for ReserveData<ReserveIdentifier, Balance>`

`impl<Balance> StructuralEq for AccountData<Balance>`

`impl<T: Config<I>, I: 'static> StructuralEq for PositiveImbalance<T, I>`

`impl<T: Config<I>, I: 'static> StructuralEq for NegativeImbalance<T, I>`

`impl<AccountId, Balance, BlockNumber> StructuralEq for Bounty<AccountId, Balance, BlockNumber>`

`impl<AccountId, BlockNumber> StructuralEq for BountyStatus<AccountId, BlockNumber>`

`impl<Balance, AccountId> StructuralEq for RawEvent<Balance, AccountId>`

`impl<T: Config> StructuralEq for Module<T>`

`impl<AccountId, I> StructuralEq for RawOrigin<AccountId, I>`

`impl<AccountId, BlockNumber> StructuralEq for Votes<AccountId, BlockNumber>`

`impl StructuralEq for Instance1`

`impl StructuralEq for Instance2`

`impl StructuralEq for Instance3`

`impl StructuralEq for Instance4`

`impl StructuralEq for Instance5`

`impl StructuralEq for Instance6`

`impl StructuralEq for Instance7`

`impl StructuralEq for Instance8`

`impl StructuralEq for Instance9`

`impl StructuralEq for Instance10`

`impl StructuralEq for Instance11`

`impl StructuralEq for Instance12`

`impl StructuralEq for Instance13`

`impl StructuralEq for Instance14`

`impl StructuralEq for Instance15`

`impl StructuralEq for Instance16`