Struct rustc_type_ir::ty_kind::AliasTy

pub struct AliasTy<I: Interner> {
    pub args: I::GenericArgs,
    pub def_id: I::DefId,
    pub(crate) _use_alias_ty_new_instead: (),
}

Represents the projection of an associated, opaque, or lazy-type-alias 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: I::GenericArgs

The parameters of the associated or opaque type.

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

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

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

def_id: I::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, interner.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 interner.associated_item(def_id).container, aka. interner.parent(def_id).

_use_alias_ty_new_instead: ()

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

Implementations

impl<I: Interner> AliasTy<I>

pub fn new_from_args( interner: I, def_id: I::DefId, args: I::GenericArgs, ) -> AliasTy<I>

pub fn new( interner: I, def_id: I::DefId, args: impl IntoIterator<Item: Into<I::GenericArg>>, ) -> AliasTy<I>

pub fn kind(self, interner: I) -> AliasTyKind

pub fn is_opaque(self, interner: I) -> bool

Whether this alias type is an opaque.

pub fn to_ty(self, interner: I) -> I::Ty

impl<I: Interner> AliasTy<I>

The following methods work only with (trait) associated type projections.

pub fn self_ty(self) -> I::Ty

pub fn with_self_ty(self, interner: I, self_ty: I::Ty) -> Self

pub fn trait_def_id(self, interner: I) -> I::DefId

pub fn trait_ref_and_own_args( self, interner: I, ) -> (TraitRef<I>, I::GenericArgsSlice)

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, interner: I) -> TraitRef<I>

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<I: Interner> AliasTy<I>

The following methods work only with inherent associated type projections.

pub fn rebase_inherent_args_onto_impl( self, impl_args: I::GenericArgs, interner: I, ) -> I::GenericArgs

Transform the generic parameters 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 args
    P_j GAT args

Trait Implementations

impl<I> Clone for AliasTy<I>

where I: Interner,

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I> Debug for AliasTy<I>

where I: Interner,

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

Formats the value using the given formatter.

impl<I: Interner, __D: TyDecoder<I = I>> Decodable<__D> for AliasTy<I>

where I::GenericArgs: Decodable<__D>, I::DefId: Decodable<__D>,

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

impl<I: Interner> Display for AliasTy<I>

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

Formats the value using the given formatter.

impl<I: Interner, __E: TyEncoder<I = I>> Encodable<__E> for AliasTy<I>

where I::GenericArgs: Encodable<__E>, I::DefId: Encodable<__E>,

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

impl<I: Interner> From<AliasTy<I>> for AliasTerm<I>

fn from(ty: AliasTy<I>) -> Self

Converts to this type from the input type.

impl<I> Hash for AliasTy<I>

where I: Interner,

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<I: Interner, __CTX> HashStable<__CTX> for AliasTy<I>

where I::GenericArgs: HashStable<__CTX>, I::DefId: HashStable<__CTX>,

fn hash_stable(&self, __hcx: &mut __CTX, __hasher: &mut StableHasher)

impl<I, J> Lift<J> for AliasTy<I>

where I: Interner, J: Interner, I::GenericArgs: Lift<J, Lifted = J::GenericArgs>, I::DefId: Lift<J, Lifted = J::DefId>, (): Lift<J, Lifted = ()>,

type Lifted = AliasTy<J>

fn lift_to_interner(self, interner: J) -> Option<Self::Lifted>

impl<I> PartialEq for AliasTy<I>

where I: Interner,

fn eq(&self, __other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

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

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

impl<I: Interner> Relate<I> for AliasTy<I>

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

impl<I> TypeFoldable<I> for AliasTy<I>

where I: Interner, I::GenericArgs: TypeFoldable<I>, I::DefId: TypeFoldable<I>,

fn try_fold_with<__F: FallibleTypeFolder<I>>( 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<I>>(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<I> TypeVisitable<I> for AliasTy<I>

where I: Interner, I::GenericArgs: TypeVisitable<I>, I::DefId: TypeVisitable<I>,

fn visit_with<__V: TypeVisitor<I>>(&self, __visitor: &mut __V) -> __V::Result

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

impl<I> Copy for AliasTy<I>

where I: Interner,

impl<I> Eq for AliasTy<I>

where I: Interner,

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.