Struct rustc_middle::ty::subst::GenericArg

pub struct GenericArg<'tcx> {
    ptr: NonZeroUsize,
    marker: PhantomData<(Ty<'tcx>, Region<'tcx>, Const<'tcx>)>,
}

An entity in the Rust type system, which can be one of several kinds (types, lifetimes, and consts). To reduce memory usage, a GenericArg is an interned pointer, with the lowest 2 bits being reserved for a tag to indicate the type (Ty, Region, or Const) it points to.

Note: the PartialEq, Eq and Hash derives are only valid because Ty, Region and Const are all interned.

Fields

ptr: NonZeroUsize

marker: PhantomData<(Ty<'tcx>, Region<'tcx>, Const<'tcx>)>

Implementations

impl<'tcx> GenericArg<'tcx>

pub fn unpack(self) -> GenericArgKind<'tcx>

pub fn expect_region(self) -> Region<'tcx>

Unpack the GenericArg as a region when it is known certainly to be a region.

pub fn expect_ty(self) -> Ty<'tcx>

Unpack the GenericArg as a type when it is known certainly to be a type. This is true in cases where Substs is used in places where the kinds are known to be limited (e.g. in tuples, where the only parameters are type parameters).

pub fn expect_const(self) -> Const<'tcx>

Unpack the GenericArg as a const when it is known certainly to be a const.

pub fn is_non_region_infer(self) -> bool

impl<'tcx> GenericArg<'tcx>

pub fn walk(self) -> TypeWalker<'tcx>

Iterator that walks self and any types reachable from self, in depth-first order. Note that just walks the types that appear in self, it does not descend into the fields of structs or variants. For example:

isize => { isize }
Foo<Bar<isize>> => { Foo<Bar<isize>>, Bar<isize>, isize }
[isize] => { [isize], isize }

pub fn walk_shallow(
    self,
    visited: &mut SsoHashSet<GenericArg<'tcx>>
) -> impl Iterator<Item = GenericArg<'tcx>>

Iterator that walks the immediate children of self. Hence Foo<Bar<i32>, u32> yields the sequence [Bar<i32>, u32] (but not i32, like walk).

Iterator only walks items once. It accepts visited set, updates it with all visited types and skips any types that are already there.

Trait Implementations

impl<'tcx> Clone for GenericArg<'tcx>

fn clone(&self) -> GenericArg<'tcx>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx> Debug for GenericArg<'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 GenericArg<'tcx>

fn decode(d: &mut D) -> GenericArg<'tcx>

impl<'tcx> Display for GenericArg<'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 GenericArg<'tcx>

fn encode(&self, e: &mut E)

impl<'tcx> From<Const<'tcx>> for GenericArg<'tcx>

fn from(c: Const<'tcx>) -> GenericArg<'tcx>

Converts to this type from the input type.

impl<'tcx> From<Region<'tcx>> for GenericArg<'tcx>

fn from(r: Region<'tcx>) -> GenericArg<'tcx>

Converts to this type from the input type.

impl<'tcx> From<Term<'tcx>> for GenericArg<'tcx>

fn from(value: Term<'tcx>) -> Self

Converts to this type from the input type.

impl<'tcx> From<Ty<'tcx>> for GenericArg<'tcx>

fn from(ty: Ty<'tcx>) -> GenericArg<'tcx>

Converts to this type from the input type.

impl<'tcx> Hash for GenericArg<'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<'a, 'tcx> HashStable<StableHashingContext<'a>> for GenericArg<'tcx>

fn hash_stable(
    &self,
    hcx: &mut StableHashingContext<'a>,
    hasher: &mut StableHasher
)

impl<'tcx> Key for GenericArg<'tcx>

fn query_crate_is_local(&self) -> bool

Given an instance of this key, what crate is it referring to? This is used to find the provider.

fn default_span(&self, _: 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?

type CacheSelector = DefaultCacheSelector<Self>

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<'a, 'tcx> Lift<'tcx> for GenericArg<'a>

type Lifted = GenericArg<'tcx>

fn lift_to_tcx(self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted>

impl<'tcx> Ord for GenericArg<'tcx>

fn cmp(&self, other: &GenericArg<'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<GenericArg<'tcx>> for GenericArg<'tcx>

fn eq(&self, other: &GenericArg<'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<GenericArg<'tcx>> for GenericArg<'tcx>

fn partial_cmp(&self, other: &GenericArg<'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 GenericArg<'tcx>

type Output = P

type Error = Error

fn print(&self, cx: P) -> Result<Self::Output, Self::Error>

impl<'tcx> Relate<'tcx> for GenericArg<'tcx>

fn relate<R: TypeRelation<'tcx>>(
    relation: &mut R,
    a: GenericArg<'tcx>,
    b: GenericArg<'tcx>
) -> RelateResult<'tcx, GenericArg<'tcx>>

impl<'tcx> TypeFoldable<'tcx> for GenericArg<'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 GenericArg<'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 GenericArg<'tcx>

impl<'tcx> Eq for GenericArg<'tcx>

impl<'tcx> StructuralEq for GenericArg<'tcx>

impl<'tcx> StructuralPartialEq for GenericArg<'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: 8 bytes