Struct rustc_trait_selection::infer::InferCtxtInner
source · pub struct InferCtxtInner<'tcx> {
pub projection_cache: ProjectionCacheStorage<'tcx>,
type_variable_storage: TypeVariableStorage<'tcx>,
const_unification_storage: UnificationTable<InPlace<ConstVid<'tcx>, Vec<VarValue<ConstVid<'tcx>>, Global>, ()>>,
int_unification_storage: UnificationTable<InPlace<IntVid, Vec<VarValue<IntVid>, Global>, ()>>,
float_unification_storage: UnificationTable<InPlace<FloatVid, Vec<VarValue<FloatVid>, Global>, ()>>,
region_constraint_storage: Option<RegionConstraintStorage<'tcx>>,
region_obligations: Vec<RegionObligation<'tcx>, Global>,
undo_log: InferCtxtUndoLogs<'tcx>,
pub opaque_type_storage: OpaqueTypeStorage<'tcx>,
}
Expand description
This type contains all the things within InferCtxt
that sit within a
RefCell
and are involved with taking/rolling back snapshots. Snapshot
operations are hot enough that we want only one call to borrow_mut
per
call to start_snapshot
and rollback_to
.
Fields
projection_cache: ProjectionCacheStorage<'tcx>
Cache for projections. This cache is snapshotted along with the infcx.
Public so that traits::project
can use it.
type_variable_storage: TypeVariableStorage<'tcx>
We instantiate UnificationTable
with bounds<Ty>
because the types
that might instantiate a general type variable have an order,
represented by its upper and lower bounds.
const_unification_storage: UnificationTable<InPlace<ConstVid<'tcx>, Vec<VarValue<ConstVid<'tcx>>, Global>, ()>>
Map from const parameter variable to the kind of const it represents.
int_unification_storage: UnificationTable<InPlace<IntVid, Vec<VarValue<IntVid>, Global>, ()>>
Map from integral variable to the kind of integer it represents.
float_unification_storage: UnificationTable<InPlace<FloatVid, Vec<VarValue<FloatVid>, Global>, ()>>
Map from floating variable to the kind of float it represents.
region_constraint_storage: Option<RegionConstraintStorage<'tcx>>
Tracks the set of region variables and the constraints between them.
This is initially Some(_)
but when
resolve_regions_and_report_errors
is invoked, this gets set to None
– further attempts to perform unification, etc., may fail if new
region constraints would’ve been added.
region_obligations: Vec<RegionObligation<'tcx>, Global>
A set of constraints that regionck must validate. Each
constraint has the form T:'a
, meaning “some type T
must
outlive the lifetime ’a”. These constraints derive from
instantiated type parameters. So if you had a struct defined
like
struct Foo<T:'static> { ... }
then in some expression let x = Foo { ... }
it will
instantiate the type parameter T
with a fresh type $0
. At
the same time, it will record a region obligation of
$0:'static
. This will get checked later by regionck. (We
can’t generally check these things right away because we have
to wait until types are resolved.)
These are stored in a map keyed to the id of the innermost enclosing fn body / static initializer expression. This is because the location where the obligation was incurred can be relevant with respect to which sublifetime assumptions are in place. The reason that we store under the fn-id, and not something more fine-grained, is so that it is easier for regionck to be sure that it has found all the region obligations (otherwise, it’s easy to fail to walk to a particular node-id).
Before running resolve_regions_and_report_errors
, the creator
of the inference context is expected to invoke
InferCtxt::process_registered_region_obligations
for each body-id in this map, which will process the
obligations within. This is expected to be done ‘late enough’
that all type inference variables have been bound and so forth.
undo_log: InferCtxtUndoLogs<'tcx>
opaque_type_storage: OpaqueTypeStorage<'tcx>
Caches for opaque type inference.
Auto Trait Implementations
impl<'tcx> !RefUnwindSafe for InferCtxtInner<'tcx>
impl<'tcx> !Send for InferCtxtInner<'tcx>
impl<'tcx> !Sync for InferCtxtInner<'tcx>
impl<'tcx> Unpin for InferCtxtInner<'tcx>
impl<'tcx> !UnwindSafe for InferCtxtInner<'tcx>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut 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: 480 bytes