Struct rustc_middle::ty::AliasTy

pub struct AliasTy<'tcx> {
    pub substs: SubstsRef<'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 opaque type, there is no explicit syntax.

Fields

substs: SubstsRef<'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 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 for the associated type N if this is a projection, or 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 ProjectionTy without using TyCtxt::mk_alias_ty.

Implementations

impl<'tcx> AliasTy<'tcx>

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

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

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

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 substs for generic associated types consider calling Self::trait_ref_and_own_substs to get those as well.

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

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, __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> 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<'tcx> for AliasTy<'tcx>

fn try_fold_with<__F: FallibleTypeFolder<'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: TypeFolder<'tcx>>(self, folder: &mut F) -> Self

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<'tcx> for AliasTy<'tcx>

fn visit_with<__V: TypeVisitor<'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).

fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool

Returns true if self has any late-bound regions that are either bound by binder or bound by some binder outside of binder. If binder is ty::INNERMOST, this indicates whether there are any late-bound regions that appear free.

fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool

Returns true if this type has any regions that escape binder (and hence are not bound by it).

fn has_escaping_bound_vars(&self) -> bool

Return true if this type has regions that are not a part of the type. For example, for<'a> fn(&'a i32) return false, while fn(&'a i32) would return true. The latter can occur when traversing through the former.

fn has_type_flags(&self, flags: TypeFlags) -> bool

fn has_projections(&self) -> bool

fn has_opaque_types(&self) -> bool

fn references_error(&self) -> bool

fn error_reported(&self) -> Result<(), ErrorGuaranteed>

fn has_non_region_param(&self) -> bool

fn has_infer_regions(&self) -> bool

fn has_infer_types(&self) -> bool

fn has_non_region_infer(&self) -> bool

fn needs_infer(&self) -> bool

fn has_placeholders(&self) -> bool

fn needs_subst(&self) -> bool

fn has_free_regions(&self) -> bool

“Free” regions in this context means that it has any region that is not (a) erased or (b) late-bound.

fn has_erased_regions(&self) -> bool

fn has_erasable_regions(&self) -> bool

True if there are any un-erased free regions.

fn is_global(&self) -> bool

Indicates whether this value references only ‘global’ generic parameters that are the same regardless of what fn we are in. This is used for caching.

fn has_late_bound_regions(&self) -> bool

True if there are any late-bound regions

fn still_further_specializable(&self) -> bool

Indicates whether this value still has parameters/placeholders/inference variables which could be replaced later, in a way that would change the results of impl specialization.

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