Struct rustc_trait_selection::infer::canonical::ir::EarlyBinder

pub struct EarlyBinder<I, T>
where
    I: Interner,
{
    value: T,
    _tcx: PhantomData<I>,
}

Similar to super::Binder except that it tracks early bound generics, i.e. struct Foo<T>(T) needs T instantiated immediately. This type primarily exists to avoid forgetting to call instantiate.

If you don’t have anything to instantiate, you may be looking for instantiate_identity or skip_binder.

Fields

value: T

_tcx: PhantomData<I>

Implementations

impl<I, T> EarlyBinder<I, T>

where I: Interner,

pub fn bind(value: T) -> EarlyBinder<I, T>

pub fn as_ref(&self) -> EarlyBinder<I, &T>

pub fn map_bound_ref<F, U>(&self, f: F) -> EarlyBinder<I, U>

where F: FnOnce(&T) -> U,

pub fn map_bound<F, U>(self, f: F) -> EarlyBinder<I, U>

where F: FnOnce(T) -> U,

pub fn try_map_bound<F, U, E>(self, f: F) -> Result<EarlyBinder<I, U>, E>

where F: FnOnce(T) -> Result<U, E>,

pub fn rebind<U>(&self, value: U) -> EarlyBinder<I, U>

pub fn skip_binder(self) -> T

Skips the binder and returns the “bound” value. This can be used to extract data that does not depend on generic parameters (e.g., getting the DefId of the inner value or getting the number of arguments of an FnSig). Otherwise, consider using instantiate_identity.

To skip the binder on x: &EarlyBinder<I, T> to obtain &T, leverage EarlyBinder::as_ref: x.as_ref().skip_binder().

See also Binder::skip_binder, which is the analogous operation on super::Binder.

impl<I, T> EarlyBinder<I, Option<T>>

where I: Interner,

pub fn transpose(self) -> Option<EarlyBinder<I, T>>

impl<I, Iter> EarlyBinder<I, Iter>

where I: Interner, Iter: IntoIterator, <Iter as IntoIterator>::Item: TypeFoldable<I>,

pub fn iter_instantiated<A>( self, cx: I, args: A, ) -> IterInstantiated<I, Iter, A>

where A: SliceLike<Item = <I as Interner>::GenericArg>,

pub fn iter_identity(self) -> <Iter as IntoIterator>::IntoIter

Similar to instantiate_identity, but on an iterator of TypeFoldable values.

impl<'s, I, Iter> EarlyBinder<I, Iter>

where I: Interner, Iter: IntoIterator, <Iter as IntoIterator>::Item: Deref, <<Iter as IntoIterator>::Item as Deref>::Target: Copy + TypeFoldable<I>,

pub fn iter_instantiated_copied( self, cx: I, args: &'s [<I as Interner>::GenericArg], ) -> IterInstantiatedCopied<'s, I, Iter>

pub fn iter_identity_copied( self, ) -> impl Iterator<Item = <<Iter as IntoIterator>::Item as Deref>::Target>

Similar to instantiate_identity, but on an iterator of values that deref to a TypeFoldable.

impl<I, T> EarlyBinder<I, T>

where I: Interner, T: IntoIterator,

pub fn transpose_iter(self) -> EarlyBinderIter<I, <T as IntoIterator>::IntoIter>

impl<I, T> EarlyBinder<I, T>

where I: Interner, T: TypeFoldable<I>,

pub fn instantiate<A>(self, cx: I, args: A) -> T

where A: SliceLike<Item = <I as Interner>::GenericArg>,

pub fn instantiate_identity(self) -> T

Makes the identity replacement T0 => T0, ..., TN => TN. Conceptually, this converts universally bound variables into placeholders when inside of a given item.

For example, consider for<T> fn foo<T>(){ .. }:

• Outside of foo, T is bound (represented by the presence of EarlyBinder).
• Inside of the body of foo, we treat T as a placeholder by calling instantiate_identity to discharge the EarlyBinder.

pub fn no_bound_vars(self) -> Option<T>

Returns the inner value, but only if it contains no bound vars.

Trait Implementations

impl<I, T> Clone for EarlyBinder<I, T>

where I: Interner, T: Clone,

fn clone(&self) -> EarlyBinder<I, T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I, T> Debug for EarlyBinder<I, T>

where I: Interner, T: Debug,

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

Formats the value using the given formatter.

impl<I, T, __D> Decodable<__D> for EarlyBinder<I, T>

where I: Interner, __D: TyDecoder<I = I>, T: Decodable<__D>, PhantomData<I>: Decodable<__D>,

fn decode(__decoder: &mut __D) -> EarlyBinder<I, T>

impl<I, T, __E> Encodable<__E> for EarlyBinder<I, T>

where I: Interner, __E: TyEncoder<I = I>, T: Encodable<__E>, PhantomData<I>: Encodable<__E>,

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

impl<T> EraseType for EarlyBinder<TyCtxt<'_>, T>

where T: EraseType,

type Result = <T as EraseType>::Result

impl<I, T> Hash for EarlyBinder<I, T>

where I: Interner, T: Hash,

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

where __HIT: 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, T, __CTX> HashStable<__CTX> for EarlyBinder<I, T>

where I: Interner, T: HashStable<__CTX>, PhantomData<I>: HashStable<__CTX>,

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

impl<I, T> Ord for EarlyBinder<I, T>

where I: Interner, T: Ord,

fn cmp(&self, other: &EarlyBinder<I, T>) -> Ordering

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<T> ParameterizedOverTcx for EarlyBinder<TyCtxt<'static>, T>

where T: ParameterizedOverTcx,

type Value<'tcx> = EarlyBinder<TyCtxt<'tcx>, <T as ParameterizedOverTcx>::Value<'tcx>>

impl<I, T> PartialEq for EarlyBinder<I, T>

where I: Interner, T: PartialEq,

fn eq(&self, other: &EarlyBinder<I, T>) -> 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<I, T> PartialOrd for EarlyBinder<I, T>

where I: Interner, T: Ord,

fn partial_cmp(&self, other: &EarlyBinder<I, T>) -> 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<I, T> !TypeFoldable<I> for EarlyBinder<I, T>

where I: Interner,

For early binders, you should first call instantiate before using any visitors.

fn try_fold_with<F>( self, folder: &mut F, ) -> Result<Self, <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, T> !TypeVisitable<I> for EarlyBinder<I, T>

where I: Interner,

For early binders, you should first call instantiate before using any visitors.

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<'tcx> Value<TyCtxt<'tcx>> for EarlyBinder<TyCtxt<'_>, Binder<TyCtxt<'_>, FnSig<TyCtxt<'_>>>>

fn from_cycle_error( tcx: TyCtxt<'tcx>, cycle_error: &CycleError, guar: ErrorGuaranteed, ) -> EarlyBinder<TyCtxt<'_>, Binder<TyCtxt<'_>, FnSig<TyCtxt<'_>>>>

impl<'tcx> Value<TyCtxt<'tcx>> for EarlyBinder<TyCtxt<'_>, Ty<'_>>

fn from_cycle_error( tcx: TyCtxt<'tcx>, cycle_error: &CycleError, guar: ErrorGuaranteed, ) -> EarlyBinder<TyCtxt<'_>, Ty<'_>>

impl<I, T> Copy for EarlyBinder<I, T>

where I: Interner, T: Copy,

impl<I, T> Eq for EarlyBinder<I, T>

where I: Interner, T: 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.