pub enum Const<'tcx> {
Ty(Ty<'tcx>, Const<'tcx>),
Unevaluated(UnevaluatedConst<'tcx>, Ty<'tcx>),
Val(ConstValue<'tcx>, Ty<'tcx>),
}
Expand description
Constants
Variants§
Ty(Ty<'tcx>, Const<'tcx>)
This constant came from the type system.
Any way of turning ty::Const
into ConstValue
should go through valtree_to_const_val
;
this ensures that we consistently produce “clean” values without data in the padding or
anything like that.
FIXME(BoxyUwU): We should remove this Ty
and look up the type for params via ParamEnv
Unevaluated(UnevaluatedConst<'tcx>, Ty<'tcx>)
An unevaluated mir constant which is not part of the type system.
Note that Ty(ty::ConstKind::Unevaluated)
and this variant are not identical! Ty
will
always flow through a valtree, so all data not captured in the valtree is lost. This variant
directly uses the evaluated result of the given constant, including e.g. data stored in
padding.
Val(ConstValue<'tcx>, Ty<'tcx>)
This constant cannot go back into the type system, as it represents something the type system cannot handle (e.g. pointers).
Implementations§
Source§impl<'tcx> Const<'tcx>
impl<'tcx> Const<'tcx>
Sourcepub fn from_unevaluated(
tcx: TyCtxt<'tcx>,
def_id: DefId,
) -> EarlyBinder<'tcx, Const<'tcx>>
pub fn from_unevaluated( tcx: TyCtxt<'tcx>, def_id: DefId, ) -> EarlyBinder<'tcx, Const<'tcx>>
Creates an unevaluated const from a DefId
for a const item.
The binders of the const item still need to be instantiated.
pub fn ty(&self) -> Ty<'tcx>
Sourcepub fn is_required_const(&self) -> bool
pub fn is_required_const(&self) -> bool
Determines whether we need to add this const to required_consts
. This is the case if and
only if evaluating it may error.
pub fn try_to_scalar(self) -> Option<Scalar>
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 eval( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, span: Span, ) -> Result<ConstValue<'tcx>, ErrorHandled>
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>
pub fn try_eval_bits( &self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, ) -> Option<u128>
Sourcepub fn eval_bits(self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>) -> u128
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>
Sourcepub fn eval_target_usize(
self,
tcx: TyCtxt<'tcx>,
param_env: ParamEnv<'tcx>,
) -> u64
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 try_eval_bool( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, ) -> Option<bool>
pub fn from_value(val: ConstValue<'tcx>, ty: Ty<'tcx>) -> Self
pub fn from_bits( tcx: TyCtxt<'tcx>, bits: u128, param_env_ty: ParamEnvAnd<'tcx, Ty<'tcx>>, ) -> Self
pub fn from_bool(tcx: TyCtxt<'tcx>, v: bool) -> Self
pub fn zero_sized(ty: Ty<'tcx>) -> Self
pub fn from_usize(tcx: TyCtxt<'tcx>, n: u64) -> Self
pub fn from_scalar(_tcx: TyCtxt<'tcx>, s: Scalar, ty: Ty<'tcx>) -> Self
pub fn from_ty_const(c: Const<'tcx>, ty: Ty<'tcx>, tcx: TyCtxt<'tcx>) -> Self
Sourcepub fn is_deterministic(&self) -> bool
pub fn is_deterministic(&self) -> bool
Return true if any evaluation of this constant always returns the same value, taking into account even pointer identity tests.
Trait Implementations§
Source§impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for Const<'tcx>
impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for Const<'tcx>
fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher, )
Source§impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Const<'tcx>
impl<'tcx> TypeFoldable<TyCtxt<'tcx>> for Const<'tcx>
Source§fn try_fold_with<__F: FallibleTypeFolder<TyCtxt<'tcx>>>(
self,
__folder: &mut __F,
) -> Result<Self, __F::Error>
fn try_fold_with<__F: FallibleTypeFolder<TyCtxt<'tcx>>>( self, __folder: &mut __F, ) -> Result<Self, __F::Error>
Source§fn fold_with<F>(self, folder: &mut F) -> Selfwhere
F: TypeFolder<I>,
fn fold_with<F>(self, folder: &mut F) -> Selfwhere
F: TypeFolder<I>,
try_fold_with
for use with infallible
folders. Do not override this method, to ensure coherence with
try_fold_with
.Source§impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Const<'tcx>
impl<'tcx> TypeVisitable<TyCtxt<'tcx>> for Const<'tcx>
Source§fn visit_with<__V: TypeVisitor<TyCtxt<'tcx>>>(
&self,
__visitor: &mut __V,
) -> __V::Result
fn visit_with<__V: TypeVisitor<TyCtxt<'tcx>>>( &self, __visitor: &mut __V, ) -> __V::Result
impl<'tcx> Copy for Const<'tcx>
impl<'tcx> Eq for Const<'tcx>
impl<'tcx> StructuralPartialEq for Const<'tcx>
Auto Trait Implementations§
impl<'tcx> DynSend for Const<'tcx>
impl<'tcx> DynSync for Const<'tcx>
impl<'tcx> Freeze for Const<'tcx>
impl<'tcx> !RefUnwindSafe for Const<'tcx>
impl<'tcx> Send for Const<'tcx>
impl<'tcx> Sync for Const<'tcx>
impl<'tcx> Unpin for Const<'tcx>
impl<'tcx> !UnwindSafe for Const<'tcx>
Blanket Implementations§
Source§impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
fn allocate_on(self, arena: &'tcx Arena<'tcx>) -> &'tcx mut T
fn allocate_from_iter( arena: &'tcx Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'tcx mut [T]
Source§impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere
T: Copy,
fn allocate_on(self, arena: &'tcx Arena<'tcx>) -> &'tcx mut T
fn allocate_from_iter( arena: &'tcx Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'tcx mut [T]
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
Source§unsafe fn clone_to_uninit(&self, dst: *mut T)
unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)Source§impl<T, R> CollectAndApply<T, R> for T
impl<T, R> CollectAndApply<T, R> for T
Source§impl<Tcx, T> DepNodeParams<Tcx> for T
impl<Tcx, T> DepNodeParams<Tcx> for T
default fn fingerprint_style() -> FingerprintStyle
Source§default fn to_fingerprint(&self, tcx: Tcx) -> Fingerprint
default fn to_fingerprint(&self, tcx: Tcx) -> Fingerprint
default fn to_debug_str(&self, _: Tcx) -> String
Source§default fn recover(_: Tcx, _: &DepNode) -> Option<T>
default fn recover(_: Tcx, _: &DepNode) -> Option<T>
DepNode
,
something which is needed when forcing DepNode
s during red-green
evaluation. The query system will only call this method if
fingerprint_style()
is not FingerprintStyle::Opaque
.
It is always valid to return None
here, in which case incremental
compilation will treat the query as having changed instead of forcing it.Source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
Source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
Source§impl<Q, K> Equivalent<K> for Q
impl<Q, K> Equivalent<K> for Q
Source§fn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
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and return true
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Source§fn filterable(
self,
filter_name: &'static str,
) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>
fn filterable( self, filter_name: &'static str, ) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>
Source§impl<T> Instrument for T
impl<T> Instrument for T
Source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
Source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
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into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
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otherwise. Read moreSource§impl<P> IntoQueryParam<P> for P
impl<P> IntoQueryParam<P> for P
fn into_query_param(self) -> P
Source§impl<'tcx, T> IsSuggestable<'tcx> for T
impl<'tcx, T> IsSuggestable<'tcx> for T
Source§impl<T> MaybeResult<T> for T
impl<T> MaybeResult<T> for T
Source§impl<T> Pointable for T
impl<T> Pointable for T
Source§impl<I, T> TypeVisitableExt<I> for Twhere
I: Interner,
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fn has_type_flags(&self, flags: TypeFlags) -> bool
Source§fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool
fn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool
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if self
has any late-bound regions that are either
bound by binder
or bound by some binder outside of binder
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Source§fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool
fn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool
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fn has_escaping_bound_vars(&self) -> bool
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. Read morefn has_aliases(&self) -> bool
fn has_opaque_types(&self) -> bool
fn has_coroutines(&self) -> bool
fn references_error(&self) -> bool
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 has_infer(&self) -> bool
fn has_placeholders(&self) -> bool
fn has_non_region_placeholders(&self) -> bool
fn has_param(&self) -> bool
Source§fn has_free_regions(&self) -> bool
fn has_free_regions(&self) -> bool
fn has_erased_regions(&self) -> bool
Source§fn has_erasable_regions(&self) -> bool
fn has_erasable_regions(&self) -> bool
Source§fn is_global(&self) -> bool
fn is_global(&self) -> bool
Source§fn has_bound_regions(&self) -> bool
fn has_bound_regions(&self) -> bool
Source§fn has_non_region_bound_vars(&self) -> bool
fn has_non_region_bound_vars(&self) -> bool
Source§fn has_bound_vars(&self) -> bool
fn has_bound_vars(&self) -> bool
Source§fn still_further_specializable(&self) -> bool
fn still_further_specializable(&self) -> bool
impl
specialization.Source§impl<I, T, U> Upcast<I, U> for Twhere
U: UpcastFrom<I, T>,
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U: UpcastFrom<I, T>,
Source§impl<I, T> UpcastFrom<I, T> for T
impl<I, T> UpcastFrom<I, T> for T
fn upcast_from(from: T, _tcx: I) -> T
Source§impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
impl<Tcx, T> Value<Tcx> for Twhere
Tcx: DepContext,
default fn from_cycle_error( tcx: Tcx, cycle_error: &CycleError, _guar: ErrorGuaranteed, ) -> T
Source§impl<T> WithSubscriber for T
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Source§fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
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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:
Ty
: 16 bytesUnevaluated
: 32 bytesVal
: 32 bytes