pub enum InhabitedPredicate<'tcx> {
True,
False,
ConstIsZero(Const<'tcx>),
NotInModule(DefId),
GenericType(Ty<'tcx>),
And(&'tcx [InhabitedPredicate<'tcx>; 2]),
Or(&'tcx [InhabitedPredicate<'tcx>; 2]),
}
Expand description
Represents whether some type is inhabited in a given context.
Examples of uninhabited types are !
, enum Void {}
, or a struct
containing either of those types.
A type’s inhabitedness may depend on the ParamEnv
as well as what types
are visible in the current module.
Variants§
True
Inhabited
False
Uninhabited
ConstIsZero(Const<'tcx>)
Uninhabited when a const value is non-zero. This occurs when there is an array of uninhabited items, but the array is inhabited if it is empty.
NotInModule(DefId)
Uninhabited if within a certain module. This occurs when an uninhabited type has restricted visibility.
GenericType(Ty<'tcx>)
Inhabited if some generic type is inhabited.
These are replaced by calling Self::instantiate
.
And(&'tcx [InhabitedPredicate<'tcx>; 2])
A AND B
Or(&'tcx [InhabitedPredicate<'tcx>; 2])
A OR B
Implementations§
source§impl<'tcx> InhabitedPredicate<'tcx>
impl<'tcx> InhabitedPredicate<'tcx>
sourcepub fn apply(
self,
tcx: TyCtxt<'tcx>,
param_env: ParamEnv<'tcx>,
module_def_id: DefId
) -> bool
pub fn apply( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, module_def_id: DefId ) -> bool
Returns true if the corresponding type is inhabited in the given
ParamEnv
and module
sourcepub fn apply_any_module(
self,
tcx: TyCtxt<'tcx>,
param_env: ParamEnv<'tcx>
) -> Option<bool>
pub fn apply_any_module( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx> ) -> Option<bool>
Same as apply
, but returns None
if self contains a module predicate
sourcepub fn apply_ignore_module(
self,
tcx: TyCtxt<'tcx>,
param_env: ParamEnv<'tcx>
) -> bool
pub fn apply_ignore_module( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx> ) -> bool
Same as apply
, but NotInModule(_)
predicates yield false
. That is,
privately uninhabited types are considered always uninhabited.
fn apply_inner<E>( self, tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, in_module: &impl Fn(DefId) -> Result<bool, E> ) -> Result<bool, E>
pub fn and(self, tcx: TyCtxt<'tcx>, other: Self) -> Self
pub fn or(self, tcx: TyCtxt<'tcx>, other: Self) -> Self
pub fn all(tcx: TyCtxt<'tcx>, iter: impl IntoIterator<Item = Self>) -> Self
pub fn any(tcx: TyCtxt<'tcx>, iter: impl IntoIterator<Item = Self>) -> Self
fn reduce_and(self, tcx: TyCtxt<'tcx>, other: Self) -> Option<Self>
fn reduce_or(self, tcx: TyCtxt<'tcx>, other: Self) -> Option<Self>
sourcepub fn instantiate(self, tcx: TyCtxt<'tcx>, args: GenericArgsRef<'tcx>) -> Self
pub fn instantiate(self, tcx: TyCtxt<'tcx>, args: GenericArgsRef<'tcx>) -> Self
Replaces generic types with its corresponding predicate
fn instantiate_opt( self, tcx: TyCtxt<'tcx>, args: GenericArgsRef<'tcx> ) -> Option<Self>
Trait Implementations§
source§impl<'tcx> Clone for InhabitedPredicate<'tcx>
impl<'tcx> Clone for InhabitedPredicate<'tcx>
source§fn clone(&self) -> InhabitedPredicate<'tcx>
fn clone(&self) -> InhabitedPredicate<'tcx>
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moresource§impl<'tcx> Debug for InhabitedPredicate<'tcx>
impl<'tcx> Debug for InhabitedPredicate<'tcx>
source§impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for InhabitedPredicate<'tcx>
impl<'tcx, '__ctx> HashStable<StableHashingContext<'__ctx>> for InhabitedPredicate<'tcx>
fn hash_stable( &self, __hcx: &mut StableHashingContext<'__ctx>, __hasher: &mut StableHasher )
source§impl<'tcx> PartialEq<InhabitedPredicate<'tcx>> for InhabitedPredicate<'tcx>
impl<'tcx> PartialEq<InhabitedPredicate<'tcx>> for InhabitedPredicate<'tcx>
source§fn eq(&self, other: &InhabitedPredicate<'tcx>) -> bool
fn eq(&self, other: &InhabitedPredicate<'tcx>) -> bool
self
and other
values to be equal, and is used
by ==
.impl<'tcx> Copy for InhabitedPredicate<'tcx>
impl<'tcx> StructuralPartialEq for InhabitedPredicate<'tcx>
Auto Trait Implementations§
impl<'tcx> !RefUnwindSafe for InhabitedPredicate<'tcx>
impl<'tcx> Send for InhabitedPredicate<'tcx>
impl<'tcx> Sync for InhabitedPredicate<'tcx>
impl<'tcx> Unpin for InhabitedPredicate<'tcx>
impl<'tcx> !UnwindSafe for InhabitedPredicate<'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<'a>(self, arena: &'a Arena<'tcx>) -> &'a mut T
fn allocate_from_iter<'a>( arena: &'a Arena<'tcx>, iter: impl IntoIterator<Item = T> ) -> &'a 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, R> CollectAndApply<T, R> for T
impl<T, R> CollectAndApply<T, R> for T
source§impl<Tcx, T> DepNodeParams<Tcx> for Twhere
Tcx: DepContext,
T: for<'a> HashStable<StableHashingContext<'a>> + Debug,
impl<Tcx, T> DepNodeParams<Tcx> for Twhere Tcx: DepContext, T: for<'a> HashStable<StableHashingContext<'a>> + Debug,
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<P> IntoQueryParam<P> for P
impl<P> IntoQueryParam<P> for P
fn into_query_param(self) -> P
source§impl<T> MaybeResult<T> for T
impl<T> MaybeResult<T> for T
source§impl<'tcx, T> ToPredicate<'tcx, T> for T
impl<'tcx, T> ToPredicate<'tcx, T> for T
fn to_predicate(self, _tcx: TyCtxt<'tcx>) -> 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: &[QueryInfo], _guar: ErrorGuaranteed ) -> T
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: 16 bytes
Size for each variant:
True
: 0 bytesFalse
: 0 bytesConstIsZero
: 12 bytesNotInModule
: 8 bytesGenericType
: 12 bytesAnd
: 12 bytesOr
: 12 bytes