Struct rustc_middle::ty::AliasTy

pub struct AliasTy<'tcx> {
    pub args: GenericArgsRef<'tcx>,
    pub def_id: DefId,
    pub(super) _use_mk_alias_ty_instead: (),
}

Represents the projection of an associated type.

• For a projection, this would be <Ty as Trait<...>>::N<...>.
• For an inherent projection, this would be Ty::N<...>.
• For an opaque type, there is no explicit syntax.

Fields

args: GenericArgsRef<'tcx>

The parameters of the associated or opaque item.

For a projection, these are the substitutions for the trait and the GAT substitutions, if there are any.

For an inherent projection, they consist of the self type and the GAT substitutions, if there are any.

For RPIT the substitutions are for the generics of the function, while for TAIT it is used for the generic parameters of the alias.

def_id: DefId

The DefId of the TraitItem or ImplItem for the associated type N depending on whether this is a projection or an inherent projection or the DefId of the OpaqueType item if this is an opaque.

During codegen, tcx.type_of(def_id) can be used to get the type of the underlying type if the type is an opaque.

Note that if this is an associated type, this is not the DefId of the TraitRef containing this associated type, which is in tcx.associated_item(def_id).container, aka. tcx.parent(def_id).

_use_mk_alias_ty_instead: ()

This field exists to prevent the creation of AliasTy without using TyCtxt::mk_alias_ty.

Implementations

impl<'tcx> AliasTy<'tcx>

pub fn kind(self, tcx: TyCtxt<'tcx>) -> AliasKind

pub fn to_ty(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx>

impl<'tcx> AliasTy<'tcx>

The following methods work only with associated type projections.

pub fn self_ty(self) -> Ty<'tcx>

pub fn with_self_ty(self, tcx: TyCtxt<'tcx>, self_ty: Ty<'tcx>) -> Self

impl<'tcx> AliasTy<'tcx>

The following methods work only with trait associated type projections.

pub fn trait_def_id(self, tcx: TyCtxt<'tcx>) -> DefId

pub fn trait_ref_and_own_args( self, tcx: TyCtxt<'tcx> ) -> (TraitRef<'tcx>, &'tcx [GenericArg<'tcx>])

Extracts the underlying trait reference and own args from this projection. For example, if this is a projection of <T as StreamingIterator>::Item<'a>, then this function would return a T: StreamingIterator trait reference and ['a] as the own args

pub fn trait_ref(self, tcx: TyCtxt<'tcx>) -> TraitRef<'tcx>

Extracts the underlying trait reference from this projection. For example, if this is a projection of <T as Iterator>::Item, then this function would return a T: Iterator trait reference.

WARNING: This will drop the args for generic associated types consider calling Self::trait_ref_and_own_args to get those as well.

impl<'tcx> AliasTy<'tcx>

The following methods work only with inherent associated type projections.

pub fn rebase_inherent_args_onto_impl( self, impl_args: GenericArgsRef<'tcx>, tcx: TyCtxt<'tcx> ) -> GenericArgsRef<'tcx>

Transform the substitutions to have the given impl args as the base and the GAT args on top of that.

Does the following transformation:

[Self, P_0...P_m] -> [I_0...I_n, P_0...P_m]

    I_i impl subst
    P_j GAT subst

Trait Implementations

impl<'tcx> Clone for AliasTy<'tcx>

fn clone(&self) -> AliasTy<'tcx>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'tcx> Debug for AliasTy<'tcx>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for AliasTy<'tcx>

fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>( this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>, f: &mut Formatter<'_> ) -> Result

impl<'tcx, __D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<__D> for AliasTy<'tcx>

fn decode(__decoder: &mut __D) -> Self

impl<'tcx> Display for AliasTy<'tcx>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'tcx, __E: TyEncoder<I = TyCtxt<'tcx>>> Encodable<__E> for AliasTy<'tcx>

fn encode(&self, __encoder: &mut __E)

impl<'tcx> EraseType for AliasTy<'tcx>

type Result = [u8; 16]

impl<'tcx> Hash for AliasTy<'tcx>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for AliasTy<'tcx>

fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher )

impl<'tcx, '__lifted> Lift<'__lifted> for AliasTy<'tcx>

type Lifted = AliasTy<'__lifted>

fn lift_to_tcx(self, __tcx: TyCtxt<'__lifted>) -> Option<AliasTy<'__lifted>>

impl<'tcx> Ord for AliasTy<'tcx>

fn cmp(&self, other: &AliasTy<'tcx>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Selfwhere Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl<'tcx> PartialEq<AliasTy<'tcx>> for AliasTy<'tcx>

fn eq(&self, other: &AliasTy<'tcx>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'tcx> PartialOrd<AliasTy<'tcx>> for AliasTy<'tcx>

fn partial_cmp(&self, other: &AliasTy<'tcx>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'tcx, P: PrettyPrinter<'tcx>> Print<'tcx, P> for AliasTy<'tcx>

type Output = P

type Error = Error

fn print(&self, cx: P) -> Result<Self::Output, Self::Error>

impl<'tcx> Relate<'tcx> for AliasTy<'tcx>

fn relate<R: TypeRelation<'tcx>>( relation: &mut R, a: AliasTy<'tcx>, b: AliasTy<'tcx> ) -> RelateResult<'tcx, AliasTy<'tcx>>

impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for AliasTy<'tcx>

fn try_fold_with<__F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, __folder: &mut __F ) -> Result<Self, __F::Error>

The entry point for folding. To fold a value t with a folder f call: t.try_fold_with(f).

fn fold_with<F>(self, folder: &mut F) -> Selfwhere F: TypeFolder<I>,

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.

impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for AliasTy<'tcx>

fn visit_with<__V: TypeVisitor<TyCtxt<'tcx>>>( &self, __visitor: &mut __V ) -> ControlFlow<__V::BreakTy>

The entry point for visiting. To visit a value t with a visitor v call: t.visit_with(v).

impl<'tcx> Copy for AliasTy<'tcx>

impl<'tcx> Eq for AliasTy<'tcx>

impl<'tcx> StructuralEq for AliasTy<'tcx>

impl<'tcx> StructuralPartialEq for AliasTy<'tcx>

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 16 bytes