Trait rustc_middle::query::Key

pub trait Key: Sized {
    type CacheSelector;

    // Required method
    fn default_span(&self, tcx: TyCtxt<'_>) -> Span;

    // Provided methods
    fn key_as_def_id(&self) -> Option<DefId> { ... }
    fn ty_def_id(&self) -> Option<DefId> { ... }
}

The Key trait controls what types can legally be used as the key for a query.

Required Associated Types

type CacheSelector

Required Methods

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

In the event that a cycle occurs, if no explicit span has been given for a query with key self, what span should we use?

Provided Methods

fn key_as_def_id(&self) -> Option<DefId>

If the key is a DefId or DefId–equivalent, return that DefId. Otherwise, return None.

fn ty_def_id(&self) -> Option<DefId>

Object Safety

This trait is not object safe.

Implementations on Foreign Types

impl Key for (CrateNum, SimplifiedType)

type CacheSelector = DefaultCacheSelector<(CrateNum, SimplifiedType)>

fn default_span(&self, _: TyCtxt<'_>) -> Span

impl Key for (CrateNum, DefId)

type CacheSelector = DefaultCacheSelector<(CrateNum, DefId)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl Key for (DefId, SimplifiedType)

type CacheSelector = DefaultCacheSelector<(DefId, SimplifiedType)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl Key for (DefId, DefId)

type CacheSelector = DefaultCacheSelector<(DefId, DefId)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl Key for (DefId, LocalDefId)

type CacheSelector = DefaultCacheSelector<(DefId, LocalDefId)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl Key for (DefId, Ident)

type CacheSelector = DefaultCacheSelector<(DefId, Ident)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

fn key_as_def_id(&self) -> Option<DefId>

impl Key for (LocalDefId, DefId)

type CacheSelector = DefaultCacheSelector<(LocalDefId, DefId)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl Key for (LocalDefId, LocalDefId)

type CacheSelector = DefaultCacheSelector<(LocalDefId, LocalDefId)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl Key for (LocalDefId, LocalDefId, Ident)

type CacheSelector = DefaultCacheSelector<(LocalDefId, LocalDefId, Ident)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl Key for (Symbol, u32, u32)

type CacheSelector = DefaultCacheSelector<(Symbol, u32, u32)>

fn default_span(&self, _tcx: TyCtxt<'_>) -> Span

impl Key for Option<Symbol>

type CacheSelector = DefaultCacheSelector<Option<Symbol>>

fn default_span(&self, _tcx: TyCtxt<'_>) -> Span

impl Key for ()

type CacheSelector = SingleCacheSelector

fn default_span(&self, _: TyCtxt<'_>) -> Span

impl Key for HirId

type CacheSelector = DefaultCacheSelector<HirId>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

fn key_as_def_id(&self) -> Option<DefId>

impl Key for OwnerId

type CacheSelector = VecCacheSelector<OwnerId>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

fn key_as_def_id(&self) -> Option<DefId>

impl Key for CrateNum

type CacheSelector = VecCacheSelector<CrateNum>

fn default_span(&self, _: TyCtxt<'_>) -> Span

impl Key for DefId

type CacheSelector = DefIdCacheSelector

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

fn key_as_def_id(&self) -> Option<DefId>

impl Key for LocalDefId

type CacheSelector = VecCacheSelector<LocalDefId>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

fn key_as_def_id(&self) -> Option<DefId>

impl Key for LocalModDefId

type CacheSelector = DefaultCacheSelector<LocalModDefId>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

fn key_as_def_id(&self) -> Option<DefId>

impl Key for ModDefId

type CacheSelector = DefaultCacheSelector<ModDefId>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

fn key_as_def_id(&self) -> Option<DefId>

impl Key for Symbol

type CacheSelector = DefaultCacheSelector<Symbol>

fn default_span(&self, _tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (ValidityRequirement, ParamEnvAnd<'tcx, Ty<'tcx>>)

type CacheSelector = DefaultCacheSelector<(ValidityRequirement, ParamEnvAnd<'tcx, Ty<'tcx>>)>

fn default_span(&self, _: TyCtxt<'_>) -> Span

fn ty_def_id(&self) -> Option<DefId>

impl<'tcx> Key for (DefId, Ty<'tcx>, GenericArgsRef<'tcx>, ParamEnv<'tcx>)

type CacheSelector = DefaultCacheSelector<(DefId, Ty<'tcx>, &'tcx List<GenericArg<'tcx>>, ParamEnv<'tcx>)>

fn default_span(&self, _tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (DefId, GenericArgsRef<'tcx>)

type CacheSelector = DefaultCacheSelector<(DefId, &'tcx List<GenericArg<'tcx>>)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (LocalDefId, DefId, GenericArgsRef<'tcx>)

type CacheSelector = DefaultCacheSelector<(LocalDefId, DefId, &'tcx List<GenericArg<'tcx>>)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (UnevaluatedConst<'tcx>, UnevaluatedConst<'tcx>)

type CacheSelector = DefaultCacheSelector<(UnevaluatedConst<'tcx>, UnevaluatedConst<'tcx>)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (Instance<'tcx>, &'tcx List<Ty<'tcx>>)

type CacheSelector = DefaultCacheSelector<(Instance<'tcx>, &'tcx List<Ty<'tcx>>)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (Instance<'tcx>, LocalDefId)

type CacheSelector = DefaultCacheSelector<(Instance<'tcx>, LocalDefId)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (Predicate<'tcx>, WellFormedLoc)

type CacheSelector = DefaultCacheSelector<(Predicate<'tcx>, WellFormedLoc)>

fn default_span(&self, _tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (ParamEnv<'tcx>, TraitRef<'tcx>)

type CacheSelector = DefaultCacheSelector<(ParamEnv<'tcx>, TraitRef<'tcx>)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (Ty<'tcx>, ValTree<'tcx>)

type CacheSelector = DefaultCacheSelector<(Ty<'tcx>, ValTree<'tcx>)>

fn default_span(&self, _: TyCtxt<'_>) -> Span

impl<'tcx> Key for (Ty<'tcx>, Option<PolyExistentialTraitRef<'tcx>>)

type CacheSelector = DefaultCacheSelector<(Ty<'tcx>, Option<Binder<'tcx, ExistentialTraitRef<'tcx>>>)>

fn default_span(&self, _: TyCtxt<'_>) -> Span

impl<'tcx> Key for (Ty<'tcx>, Ty<'tcx>)

type CacheSelector = DefaultCacheSelector<(Ty<'tcx>, Ty<'tcx>)>

fn default_span(&self, _: TyCtxt<'_>) -> Span

impl<'tcx> Key for (PolyTraitRef<'tcx>, PolyTraitRef<'tcx>)

type CacheSelector = DefaultCacheSelector<(Binder<'tcx, TraitRef<'tcx>>, Binder<'tcx, TraitRef<'tcx>>)>

fn default_span(&self, tcx: TyCtxt<'_>) -> Span

impl<'tcx> Key for (PolyFnSig<'tcx>, &'tcx List<Ty<'tcx>>)

type CacheSelector = DefaultCacheSelector<(Binder<'tcx, FnSig<'tcx>>, &'tcx List<Ty<'tcx>>)>

fn default_span(&self, _: TyCtxt<'_>) -> Span

Implementors

impl Key for SimplifiedType

type CacheSelector = DefaultCacheSelector<SimplifiedType>

impl<'tcx> Key for &'tcx List<Clause<'tcx>>

type CacheSelector = DefaultCacheSelector<&'tcx List<Clause<'tcx>>>

impl<'tcx> Key for InstanceDef<'tcx>

type CacheSelector = DefaultCacheSelector<InstanceDef<'tcx>>

impl<'tcx> Key for GlobalId<'tcx>

type CacheSelector = DefaultCacheSelector<GlobalId<'tcx>>

impl<'tcx> Key for LitToConstInput<'tcx>

type CacheSelector = DefaultCacheSelector<LitToConstInput<'tcx>>

impl<'tcx> Key for Const<'tcx>

type CacheSelector = DefaultCacheSelector<Const<'tcx>>

impl<'tcx> Key for GenericArg<'tcx>

type CacheSelector = DefaultCacheSelector<GenericArg<'tcx>>

impl<'tcx> Key for Instance<'tcx>

type CacheSelector = DefaultCacheSelector<Instance<'tcx>>

impl<'tcx> Key for ParamEnv<'tcx>

type CacheSelector = DefaultCacheSelector<ParamEnv<'tcx>>

impl<'tcx> Key for Ty<'tcx>

type CacheSelector = DefaultCacheSelector<Ty<'tcx>>

impl<'tcx> Key for GenericArgsRef<'tcx>

type CacheSelector = DefaultCacheSelector<&'tcx List<GenericArg<'tcx>>>

impl<'tcx> Key for TyAndLayout<'tcx>

type CacheSelector = DefaultCacheSelector<TyAndLayout<'tcx, Ty<'tcx>>>

impl<'tcx> Key for PolyExistentialTraitRef<'tcx>

type CacheSelector = DefaultCacheSelector<Binder<'tcx, ExistentialTraitRef<'tcx>>>

impl<'tcx> Key for PolyTraitRef<'tcx>

type CacheSelector = DefaultCacheSelector<Binder<'tcx, TraitRef<'tcx>>>

impl<'tcx, T: Clone> Key for Canonical<'tcx, T>

Canonical query goals correspond to abstract trait operations that are not tied to any crate in particular.

type CacheSelector = DefaultCacheSelector<Canonical<TyCtxt<'tcx>, T>>

impl<'tcx, T: Key> Key for ParamEnvAnd<'tcx, T>

type CacheSelector = DefaultCacheSelector<ParamEnvAnd<'tcx, T>>