Struct rustc_middle::ty::Const

pub struct Const<'tcx>(pub(super) Interned<'tcx, ConstData<'tcx>>);

Use this rather than ConstData, whenever possible.

Tuple Fields

0: Interned<'tcx, ConstData<'tcx>>

Implementations

impl<'tcx> Const<'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 }

impl<'tcx> Const<'tcx>

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

pub fn kind(self) -> ConstKind<'tcx>

pub fn new( tcx: TyCtxt<'tcx>, kind: ConstKind<'tcx>, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_param( tcx: TyCtxt<'tcx>, param: ParamConst, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_var( tcx: TyCtxt<'tcx>, infer: ConstVid<'tcx>, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_fresh(tcx: TyCtxt<'tcx>, fresh: u32, ty: Ty<'tcx>) -> Const<'tcx>

pub fn new_infer( tcx: TyCtxt<'tcx>, infer: InferConst<'tcx>, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_bound( tcx: TyCtxt<'tcx>, debruijn: DebruijnIndex, var: BoundVar, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_placeholder( tcx: TyCtxt<'tcx>, placeholder: PlaceholderConst<'tcx>, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_unevaluated( tcx: TyCtxt<'tcx>, uv: UnevaluatedConst<'tcx>, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_value( tcx: TyCtxt<'tcx>, val: ValTree<'tcx>, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_expr( tcx: TyCtxt<'tcx>, expr: Expr<'tcx>, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_error( tcx: TyCtxt<'tcx>, e: ErrorGuaranteed, ty: Ty<'tcx> ) -> Const<'tcx>

pub fn new_misc_error(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Const<'tcx>

Like Ty::new_error but for constants.

pub fn new_error_with_message<S: Into<MultiSpan>>( tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, span: S, msg: &'static str ) -> Const<'tcx>

Like Ty::new_error_with_message but for constants.

pub fn from_anon_const(tcx: TyCtxt<'tcx>, def: LocalDefId) -> Self

Literals and const generic parameters are eagerly converted to a constant, everything else becomes Unevaluated.

fn try_from_lit_or_param( tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, expr: &'tcx Expr<'tcx> ) -> Option<Self>

pub fn from_bits( tcx: TyCtxt<'tcx>, bits: u128, ty: ParamEnvAnd<'tcx, Ty<'tcx>> ) -> Self

Creates a constant with the given integer value and interns it.

pub fn zero_sized(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Self

Creates an interned zst constant.

pub fn from_bool(tcx: TyCtxt<'tcx>, v: bool) -> Self

Creates an interned bool constant.

pub fn from_target_usize(tcx: TyCtxt<'tcx>, n: u64) -> Self

Creates an interned usize constant.

pub fn eval( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, span: Option<Span> ) -> Result<ValTree<'tcx>, ErrorHandled>

Returns the evaluated constant

pub fn normalize(self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>) -> Self

Normalizes the constant to a value or an error if possible.

pub fn try_eval_scalar( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx> ) -> Option<Scalar>

pub fn try_eval_scalar_int( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx> ) -> Option<ScalarInt>

Attempts to evaluate the given constant to bits. Can fail to evaluate in the presence of generics (or erroneous code) or if the value can’t be represented as bits (e.g. because it contains const generic parameters or pointers).

pub fn try_eval_bits( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx> ) -> Option<u128>

Attempts to evaluate the given constant to bits. Can fail to evaluate in the presence of generics (or erroneous code) or if the value can’t be represented as bits (e.g. because it contains const generic parameters or pointers).

pub fn eval_bits(self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>) -> u128

Panics if the value cannot be evaluated or doesn’t contain a valid integer of the given type.

pub fn try_eval_target_usize( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx> ) -> Option<u64>

pub fn try_eval_bool( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx> ) -> Option<bool>

pub fn eval_target_usize( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx> ) -> u64

Panics if the value cannot be evaluated or doesn’t contain a valid usize.

pub fn to_valtree(self) -> ValTree<'tcx>

Panics if self.kind != ty::ConstKind::Value

pub fn try_to_valtree(self) -> Option<ValTree<'tcx>>

Attempts to convert to a ValTree

pub fn try_to_scalar(self) -> Option<Scalar<AllocId>>

pub fn try_to_target_usize(self, tcx: TyCtxt<'tcx>) -> Option<u64>

pub fn is_ct_infer(self) -> bool

Trait Implementations

impl<'tcx> Clone for Const<'tcx>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx> Debug for Const<'tcx>

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

Formats the value using the given formatter.

impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for Const<'tcx>

fn fmt<InfCtx: InferCtxtLike<TyCtxt<'tcx>>>( this: OptWithInfcx<'_, TyCtxt<'tcx>, InfCtx, &Self>, f: &mut Formatter<'_> ) -> Result

impl<'tcx, D: TyDecoder<I = TyCtxt<'tcx>>> Decodable<D> for Const<'tcx>

fn decode(decoder: &mut D) -> Self

impl<'tcx> Display for Const<'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 Const<'tcx>

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

impl<'tcx> EraseType for Const<'tcx>

type Result = [u8; 8]

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<Const<'tcx>> for Term<'tcx>

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

Converts to this type from the input type.

impl<'tcx> Hash for Const<'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<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for Const<'tcx>

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

impl<'tcx> Key for Const<'tcx>

type CacheSelector = DefaultCacheSelector<Const<'tcx>>

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?

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 Const<'a>

type Lifted = Const<'tcx>

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

impl<'tcx> Ord for Const<'tcx>

fn cmp(&self, other: &Const<'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 ParameterizedOverTcx for Const<'static>

type Value<'tcx> = Const<'tcx>

impl<'tcx> PartialEq<Const<'tcx>> for Const<'tcx>

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

fn partial_cmp(&self, other: &Const<'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: Printer<'tcx>> Print<'tcx, P> for Const<'tcx>

type Output = <P as Printer<'tcx>>::Const

type Error = <P as Printer<'tcx>>::Error

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

impl<'tcx> Relate<'tcx> for Const<'tcx>

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

impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Const<'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> TypeSuperFoldable<TyCtxt<'tcx>> for Const<'tcx>

fn try_super_fold_with<F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, folder: &mut F ) -> Result<Self, F::Error>

Provides a default fold for a recursive type of interest. This should only be called within TypeFolder methods, when a non-custom traversal is desired for the value of the type of interest passed to that method. For example, in MyFolder::try_fold_ty(ty), it is valid to call ty.try_super_fold_with(self), but any other folding should be done with xyz.try_fold_with(self).

fn super_fold_with<F>(self, folder: &mut F) -> Selfwhere F: TypeFolder<I>,

A convenient alternative to try_super_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_super_fold_with.

impl<'tcx> TypeSuperVisitable<TyCtxt<'tcx>> for Const<'tcx>

fn super_visit_with<V: TypeVisitor<TyCtxt<'tcx>>>( &self, visitor: &mut V ) -> ControlFlow<V::BreakTy>

Provides a default visit for a recursive type of interest. This should only be called within TypeVisitor methods, when a non-custom traversal is desired for the value of the type of interest passed to that method. For example, in MyVisitor::visit_ty(ty), it is valid to call ty.super_visit_with(self), but any other visiting should be done with xyz.visit_with(self).

impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Const<'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> Copy for Const<'tcx>

impl<'tcx> Eq for Const<'tcx>

impl<'tcx> StructuralEq for Const<'tcx>

impl<'tcx> StructuralPartialEq for Const<'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