Type Alias rustc_middle::ty::CanonicalUserType

pub type CanonicalUserType<'tcx> = Canonical<'tcx, UserType<'tcx>>;

Canonical user type annotation.

Aliased Type

struct CanonicalUserType<'tcx> {
    pub value: UserType<'tcx>,
    pub max_universe: UniverseIndex,
    pub variables: &'tcx List<CanonicalVarInfo<'tcx>>,
}

Fields

value: UserType<'tcx>

max_universe: UniverseIndex

variables: &'tcx List<CanonicalVarInfo<'tcx>>

Implementations

impl<'tcx> CanonicalUserType<'tcx>

pub fn is_identity(&self) -> bool

Returns true if this represents a substitution of the form [?0, ?1, ?2], i.e., each thing is mapped to a canonical variable with the same index.

impl<'tcx, V> Canonical<'tcx, V>

pub fn unchecked_map<W>(self, map_op: impl FnOnce(V) -> W) -> Canonical<'tcx, W>

Allows you to map the value of a canonical while keeping the same set of bound variables.

WARNING: This function is very easy to mis-use, hence the name! In particular, the new value W must use all the same type/region variables in precisely the same order as the original! (The ordering is defined by the TypeFoldable implementation of the type in question.)

An example of a correct use of this:

let a: Canonical<'_, T> = ...;
let b: Canonical<'_, (T,)> = a.unchecked_map(|v| (v, ));

An example of an incorrect use of this:

let a: Canonical<'tcx, T> = ...;
let ty: Ty<'tcx> = ...;
let b: Canonical<'tcx, (T, Ty<'tcx>)> = a.unchecked_map(|v| (v, ty));

pub fn unchecked_rebind<W>(self, value: W) -> Canonical<'tcx, W>

Allows you to map the value of a canonical while keeping the same set of bound variables.

WARNING: This function is very easy to mis-use, hence the name! See the comment of Canonical::unchecked_map for more details.

Trait Implementations

impl<'tcx, V: Clone> Clone for Canonical<'tcx, V>

fn clone(&self) -> Canonical<'tcx, V>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx, V: Debug> Debug for Canonical<'tcx, V>

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

Formats the value using the given formatter.

impl<'tcx, V, __D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<__D> for Canonical<'tcx, V>where V: Decodable<__D>,

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

impl<'tcx, V: Display> Display for Canonical<'tcx, V>

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

Formats the value using the given formatter.

impl<'tcx, V, __E: TyEncoder<I = TyCtxt<'tcx>>> Encodable<__E> for Canonical<'tcx, V>where V: Encodable<__E>,

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

impl<'tcx, V: Hash> Hash for Canonical<'tcx, V>

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, V> HashStable<StableHashingContext<'__ctx>> for Canonical<'tcx, V>where V: HashStable<StableHashingContext<'__ctx>>,

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

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<'tcx, T>>

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?

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_adt_id(&self) -> Option<DefId>

impl<'tcx, V: PartialEq> PartialEq<Canonical<'tcx, V>> for Canonical<'tcx, V>

fn eq(&self, other: &Canonical<'tcx, V>) -> 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, V> TypeFoldable<TyCtxt<'tcx>> for Canonical<'tcx, V>where V: TypeFoldable<TyCtxt<'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, V> TypeVisitable<TyCtxt<'tcx>> for Canonical<'tcx, V>where V: TypeVisitable<TyCtxt<'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, V: Copy> Copy for Canonical<'tcx, V>

impl<'tcx, V: Eq> Eq for Canonical<'tcx, V>

impl<'tcx, V> StructuralEq for Canonical<'tcx, V>

impl<'tcx, V> StructuralPartialEq for Canonical<'tcx, V>

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: 48 bytes