Struct rustc_infer::traits::Obligation
source · [−]pub struct Obligation<'tcx, T> {
pub cause: ObligationCause<'tcx>,
pub param_env: ParamEnv<'tcx>,
pub predicate: T,
pub recursion_depth: usize,
}
Expand description
An Obligation
represents some trait reference (e.g., i32: Eq
) for
which the “impl_source” must be found. The process of finding an “impl_source” is
called “resolving” the Obligation
. This process consists of
either identifying an impl
(e.g., impl Eq for i32
) that
satisfies the obligation, or else finding a bound that is in
scope. The eventual result is usually a Selection
(defined below).
Fields
cause: ObligationCause<'tcx>
The reason we have to prove this thing.
param_env: ParamEnv<'tcx>
The environment in which we should prove this thing.
predicate: T
The thing we are trying to prove.
recursion_depth: usize
If we started proving this as a result of trying to prove something else, track the total depth to ensure termination. If this goes over a certain threshold, we abort compilation – in such cases, we can not say whether or not the predicate holds for certain. Stupid halting problem; such a drag.
Implementations
sourceimpl<'tcx> Obligation<'tcx, Predicate<'tcx>>
impl<'tcx> Obligation<'tcx, Predicate<'tcx>>
sourcepub fn flip_polarity(
&self,
tcx: TyCtxt<'tcx>
) -> Option<PredicateObligation<'tcx>>
pub fn flip_polarity(
&self,
tcx: TyCtxt<'tcx>
) -> Option<PredicateObligation<'tcx>>
Flips the polarity of the inner predicate.
Given T: Trait
predicate it returns T: !Trait
and given T: !Trait
returns T: Trait
.
sourceimpl Obligation<'tcx, Binder<'tcx, TraitPredicate<'tcx>>>
impl Obligation<'tcx, Binder<'tcx, TraitPredicate<'tcx>>>
sourceimpl<'tcx, O> Obligation<'tcx, O>
impl<'tcx, O> Obligation<'tcx, O>
pub fn new(
cause: ObligationCause<'tcx>,
param_env: ParamEnv<'tcx>,
predicate: O
) -> Obligation<'tcx, O>
pub fn with_depth(
cause: ObligationCause<'tcx>,
recursion_depth: usize,
param_env: ParamEnv<'tcx>,
predicate: O
) -> Obligation<'tcx, O>
pub fn misc(
span: Span,
body_id: HirId,
param_env: ParamEnv<'tcx>,
trait_ref: O
) -> Obligation<'tcx, O>
pub fn with<P>(&self, value: P) -> Obligation<'tcx, P>
sourceimpl<'tcx> Obligation<'tcx, Binder<'tcx, TraitPredicate<'tcx>>>
impl<'tcx> Obligation<'tcx, Binder<'tcx, TraitPredicate<'tcx>>>
Trait Implementations
sourceimpl<'tcx, T: Clone> Clone for Obligation<'tcx, T>
impl<'tcx, T: Clone> Clone for Obligation<'tcx, T>
sourcefn clone(&self) -> Obligation<'tcx, T>
fn clone(&self) -> Obligation<'tcx, T>
Returns a copy of the value. Read more
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
sourceimpl<'tcx, O: Debug> Debug for Obligation<'tcx, O>
impl<'tcx, O: Debug> Debug for Obligation<'tcx, O>
sourceimpl<'tcx, T: Hash> Hash for Obligation<'tcx, T>
impl<'tcx, T: Hash> Hash for Obligation<'tcx, T>
sourceimpl<'tcx, T: PartialEq> PartialEq<Obligation<'tcx, T>> for Obligation<'tcx, T>
impl<'tcx, T: PartialEq> PartialEq<Obligation<'tcx, T>> for Obligation<'tcx, T>
sourcefn eq(&self, other: &Obligation<'tcx, T>) -> bool
fn eq(&self, other: &Obligation<'tcx, T>) -> bool
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
sourcefn ne(&self, other: &Obligation<'tcx, T>) -> bool
fn ne(&self, other: &Obligation<'tcx, T>) -> bool
This method tests for !=
.
sourceimpl<'tcx, O: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Obligation<'tcx, O>
impl<'tcx, O: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Obligation<'tcx, O>
sourcefn try_super_fold_with<F: FallibleTypeFolder<'tcx>>(
self,
folder: &mut F
) -> Result<Self, F::Error>
fn try_super_fold_with<F: FallibleTypeFolder<'tcx>>(
self,
folder: &mut F
) -> Result<Self, F::Error>
Traverses the type in question, typically by calling try_fold_with
on
each field/element. This is true even for types of interest such as
Ty
. This should only be called within TypeFolder
methods, when
non-custom traversals are desired for types of interest. Read more
sourcefn super_visit_with<V: TypeVisitor<'tcx>>(
&self,
visitor: &mut V
) -> ControlFlow<V::BreakTy>
fn super_visit_with<V: TypeVisitor<'tcx>>(
&self,
visitor: &mut V
) -> ControlFlow<V::BreakTy>
Traverses the type in question, typically by calling visit_with
on
each field/element. This is true even for types of interest such as
Ty
. This should only be called within TypeVisitor
methods, when
non-custom traversals are desired for types of interest. Read more
sourcefn try_fold_with<F>(
self,
folder: &mut F
) -> Result<Self, <F as TypeFolder<'tcx>>::Error> where
F: FallibleTypeFolder<'tcx>,
fn try_fold_with<F>(
self,
folder: &mut F
) -> Result<Self, <F as TypeFolder<'tcx>>::Error> where
F: FallibleTypeFolder<'tcx>,
The main entry point for folding. To fold a value t
with a folder f
call: t.try_fold_with(f)
. Read more
sourcefn fold_with<F>(self, folder: &mut F) -> Self where
F: TypeFolder<'tcx, Error = !>,
fn fold_with<F>(self, folder: &mut F) -> Self where
F: TypeFolder<'tcx, Error = !>,
A convenient alternative to try_fold_with
for use with infallible
folders. Do not override this method, to ensure coherence with
try_fold_with
. Read more
sourcefn super_fold_with<F>(self, folder: &mut F) -> Self where
F: TypeFolder<'tcx, Error = !>,
fn super_fold_with<F>(self, folder: &mut F) -> Self where
F: TypeFolder<'tcx, Error = !>,
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
. Read more
sourcefn visit_with<V>(
&self,
visitor: &mut V
) -> ControlFlow<<V as TypeVisitor<'tcx>>::BreakTy, ()> where
V: TypeVisitor<'tcx>,
fn visit_with<V>(
&self,
visitor: &mut V
) -> ControlFlow<<V as TypeVisitor<'tcx>>::BreakTy, ()> where
V: TypeVisitor<'tcx>,
The entry point for visiting. To visit a value t
with a visitor v
call: t.visit_with(v)
. Read more
sourcefn has_vars_bound_at_or_above(&self, binder: DebruijnIndex) -> bool
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. Read more
sourcefn has_vars_bound_above(&self, binder: DebruijnIndex) -> bool
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). Read more
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 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
sourcefn has_free_regions(&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. Read more
fn has_erased_regions(&self) -> bool
sourcefn has_erasable_regions(&self) -> bool
fn has_erasable_regions(&self) -> bool
True if there are any un-erased free regions.
sourcefn is_global(&self) -> bool
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. Read more
sourcefn has_late_bound_regions(&self) -> bool
fn has_late_bound_regions(&self) -> bool
True if there are any late-bound regions
sourcefn still_further_specializable(&self) -> bool
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. Read more
impl<'tcx, T: Eq> Eq for Obligation<'tcx, T>
impl<'tcx, T> StructuralEq for Obligation<'tcx, T>
impl<'tcx, T> StructuralPartialEq for Obligation<'tcx, T>
Auto Trait Implementations
impl<'tcx, T> !RefUnwindSafe for Obligation<'tcx, T>
impl<'tcx, T> !Send for Obligation<'tcx, T>
impl<'tcx, T> !Sync for Obligation<'tcx, T>
impl<'tcx, T> Unpin for Obligation<'tcx, T> where
T: Unpin,
impl<'tcx, T> !UnwindSafe for Obligation<'tcx, T>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcepub fn borrow_mut(&mut self) -> &mut T
pub fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<'tcx, T> Subst<'tcx> for T where
T: TypeFoldable<'tcx>,
impl<'tcx, T> Subst<'tcx> for T where
T: TypeFoldable<'tcx>,
pub fn subst_spanned(
self,
tcx: TyCtxt<'tcx>,
substs: &[GenericArg<'tcx>],
span: Option<Span>
) -> T
fn subst(self, tcx: TyCtxt<'tcx>, substs: &[GenericArg<'tcx>]) -> Self
sourceimpl<T> ToOwned for T where
T: Clone,
impl<T> ToOwned for T where
T: Clone,
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
sourcepub fn to_owned(&self) -> T
pub fn to_owned(&self) -> T
Creates owned data from borrowed data, usually by cloning. Read more
sourcepub fn clone_into(&self, target: &mut T)
pub fn clone_into(&self, target: &mut T)
toowned_clone_into
)Uses borrowed data to replace owned data, usually by cloning. Read more
impl<'a, T> Captures<'a> for T where
T: ?Sized,
Layout
Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.