Enum rustc_middle::ty::ConstKind

pub enum ConstKind<'tcx> {
    Param(ParamConst),
    Infer(InferConst<'tcx>),
    Bound(DebruijnIndex, BoundVar),
    Placeholder(PlaceholderConst<'tcx>),
    Unevaluated(Unevaluated<'tcx>),
    Value(ValTree<'tcx>),
    Error(DelaySpanBugEmitted),
}

Represents a constant in Rust.

Variants

Param(ParamConst)

A const generic parameter.

Infer(InferConst<'tcx>)

Infer the value of the const.

Bound(DebruijnIndex, BoundVar)

Bound const variable, used only when preparing a trait query.

Placeholder(PlaceholderConst<'tcx>)

A placeholder const - universally quantified higher-ranked const.

Unevaluated(Unevaluated<'tcx>)

Used in the HIR by using Unevaluated everywhere and later normalizing to one of the other variants when the code is monomorphic enough for that.

Value(ValTree<'tcx>)

Used to hold computed value.

Error(DelaySpanBugEmitted)

A placeholder for a const which could not be computed; this is propagated to avoid useless error messages.

Implementations

impl<'tcx> ConstKind<'tcx>

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

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

pub fn try_to_scalar_int(self) -> Option<ScalarInt>

pub fn try_to_bits(self, size: Size) -> Option<u128>

pub fn try_to_bool(self) -> Option<bool>

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

impl<'tcx> ConstKind<'tcx>

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

Tries to evaluate the constant if it is Unevaluated. If that doesn’t succeed, return the unevaluated constant.

pub fn try_eval_for_mir(
    self,
    tcx: TyCtxt<'tcx>,
    param_env: ParamEnv<'tcx>
) -> Option<Result<ConstValue<'tcx>, ErrorGuaranteed>>

Tries to evaluate the constant if it is Unevaluated. If that isn’t possible or necessary return None.

pub fn try_eval_for_typeck(
    self,
    tcx: TyCtxt<'tcx>,
    param_env: ParamEnv<'tcx>
) -> Option<Result<ValTree<'tcx>, ErrorGuaranteed>>

Tries to evaluate the constant if it is Unevaluated. If that isn’t possible or necessary return None.

fn try_eval_inner(
    self,
    tcx: TyCtxt<'tcx>,
    param_env: ParamEnv<'tcx>,
    eval_mode: EvalMode
) -> Option<Result<EvalResult<'tcx>, ErrorGuaranteed>>

Trait Implementations

impl<'tcx> Clone for ConstKind<'tcx>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx> Debug for ConstKind<'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 ConstKind<'tcx>

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

impl<'tcx, __E: TyEncoder<I = TyCtxt<'tcx>>> Encodable<__E> for ConstKind<'tcx>

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

impl<'tcx> Hash for ConstKind<'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, 

Feeds a slice of this type into the given Hasher.

impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for ConstKind<'tcx>

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

impl<'tcx> Ord for ConstKind<'tcx>

fn cmp(&self, other: &ConstKind<'tcx>) -> Ordering

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

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

Restrict a value to a certain interval.

impl<'tcx> PartialEq<ConstKind<'tcx>> for ConstKind<'tcx>

fn eq(&self, other: &ConstKind<'tcx>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &ConstKind<'tcx>) -> bool

This method tests for !=.

impl<'tcx> PartialOrd<ConstKind<'tcx>> for ConstKind<'tcx>

fn partial_cmp(&self, other: &ConstKind<'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> TypeFoldable<'tcx> for ConstKind<'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 ConstKind<'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 self has any regions that escape binder (and hence are not bound by it).

fn has_escaping_bound_vars(&self) -> bool

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) -> Option<ErrorGuaranteed>

fn has_param_types_or_consts(&self) -> bool

fn has_infer_regions(&self) -> bool

fn has_infer_types(&self) -> bool

fn has_infer_types_or_consts(&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 ConstKind<'tcx>

impl<'tcx> Eq for ConstKind<'tcx>

impl<'tcx> StructuralEq for ConstKind<'tcx>

impl<'tcx> StructuralPartialEq for ConstKind<'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: 40 bytes

Size for each variant:

• Param: 8 bytes
• Infer: 8 bytes
• Bound: 8 bytes
• Placeholder: 28 bytes
• Unevaluated: 36 bytes
• Value: 28 bytes
• Error: 0 bytes