Struct rustc_middle::ty::Canonical

pub struct Canonical<I, V>
where
    I: Interner,
{
    pub value: V,
    pub max_universe: UniverseIndex,
    pub defining_opaque_types: <I as Interner>::DefiningOpaqueTypes,
    pub variables: <I as Interner>::CanonicalVars,
}

A “canonicalized” type V is one where all free inference variables have been rewritten to “canonical vars”. These are numbered starting from 0 in order of first appearance.

Fields

value: V

max_universe: UniverseIndex

defining_opaque_types: <I as Interner>::DefiningOpaqueTypes

variables: <I as Interner>::CanonicalVars

Implementations

impl<I, V> Canonical<I, V>

where I: Interner,

pub fn unchecked_map<W>(self, map_op: impl FnOnce(V) -> W) -> Canonical<I, 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<I, T> = ...;
let b: Canonical<I, (T,)> = a.unchecked_map(|v| (v, ));

An example of an incorrect use of this:

let a: Canonical<I, T> = ...;
let ty: Ty<I> = ...;
let b: Canonical<I, (T, Ty<I>)> = a.unchecked_map(|v| (v, ty));

pub fn unchecked_rebind<W>(self, value: W) -> Canonical<I, 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<I, V> Clone for Canonical<I, V>

where I: Interner, V: Clone,

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I, V> Debug for Canonical<I, V>

where I: Interner, V: Debug,

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

Formats the value using the given formatter.

impl<I, V, __D> Decodable<__D> for Canonical<I, V>

where I: Interner, __D: TyDecoder<I = I>, V: Decodable<__D>, <I as Interner>::DefiningOpaqueTypes: Decodable<__D>, <I as Interner>::CanonicalVars: Decodable<__D>,

fn decode(__decoder: &mut __D) -> Canonical<I, V>

impl<I, V> Display for Canonical<I, V>

where I: Interner, V: Display,

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

Formats the value using the given formatter.

impl<I, V, __E> Encodable<__E> for Canonical<I, V>

where I: Interner, __E: TyEncoder<I = I>, V: Encodable<__E>, <I as Interner>::DefiningOpaqueTypes: Encodable<__E>, <I as Interner>::CanonicalVars: Encodable<__E>,

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

impl<I, V> Hash for Canonical<I, V>

where I: Interner, V: Hash,

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

where __H: Hasher,

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, V, __CTX> HashStable<__CTX> for Canonical<I, V>

where I: Interner, V: HashStable<__CTX>, <I as Interner>::DefiningOpaqueTypes: HashStable<__CTX>, <I as Interner>::CanonicalVars: HashStable<__CTX>,

fn hash_stable( &self, __hcx: &mut __CTX, __hasher: &mut StableHasher<SipHasher128>, )

impl<I, V> PartialEq for Canonical<I, V>

where I: Interner, V: PartialEq,

fn eq(&self, __other: &Canonical<I, V>) -> 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, V> TypeFoldable<I> for Canonical<I, V>

where I: Interner, V: TypeFoldable<I>, <I as Interner>::DefiningOpaqueTypes: TypeFoldable<I>, <I as Interner>::CanonicalVars: TypeFoldable<I>,

fn try_fold_with<__F>( self, __folder: &mut __F, ) -> Result<Canonical<I, V>, <__F as FallibleTypeFolder<I>>::Error>

where __F: FallibleTypeFolder<I>,

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) -> Self

where 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<I, V> TypeVisitable<I> for Canonical<I, V>

where I: Interner, V: TypeVisitable<I>, <I as Interner>::DefiningOpaqueTypes: TypeVisitable<I>, <I as Interner>::CanonicalVars: TypeVisitable<I>,

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

where __V: TypeVisitor<I>,

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

impl<I, V> Copy for Canonical<I, V>

where I: Interner, V: Copy,

impl<I, V> Eq for Canonical<I, V>

where I: Interner, V: Eq,

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.