Struct rustc_infer::infer::combine::CombineFields
source · pub struct CombineFields<'infcx, 'tcx> {
pub infcx: &'infcx InferCtxt<'tcx>,
pub trace: TypeTrace<'tcx>,
pub cause: Option<Cause>,
pub param_env: ParamEnv<'tcx>,
pub obligations: PredicateObligations<'tcx>,
pub define_opaque_types: DefineOpaqueTypes,
}
Fields§
§infcx: &'infcx InferCtxt<'tcx>
§trace: TypeTrace<'tcx>
§cause: Option<Cause>
§param_env: ParamEnv<'tcx>
§obligations: PredicateObligations<'tcx>
§define_opaque_types: DefineOpaqueTypes
Implementations§
source§impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx>
impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx>
pub fn tcx(&self) -> TyCtxt<'tcx>
pub fn equate<'a>(&'a mut self, a_is_expected: bool) -> Equate<'a, 'infcx, 'tcx>
pub fn sub<'a>(&'a mut self, a_is_expected: bool) -> Sub<'a, 'infcx, 'tcx>
pub fn lub<'a>(&'a mut self, a_is_expected: bool) -> Lub<'a, 'infcx, 'tcx>
pub fn glb<'a>(&'a mut self, a_is_expected: bool) -> Glb<'a, 'infcx, 'tcx>
sourcepub fn instantiate(
&mut self,
a_ty: Ty<'tcx>,
ambient_variance: Variance,
b_vid: TyVid,
a_is_expected: bool
) -> RelateResult<'tcx, ()>
pub fn instantiate( &mut self, a_ty: Ty<'tcx>, ambient_variance: Variance, b_vid: TyVid, a_is_expected: bool ) -> RelateResult<'tcx, ()>
Here, dir
is either EqTo
, SubtypeOf
, or SupertypeOf
.
The idea is that we should ensure that the type a_ty
is equal
to, a subtype of, or a supertype of (respectively) the type
to which b_vid
is bound.
Since b_vid
has not yet been instantiated with a type, we
will first instantiate b_vid
with a generalized version
of a_ty
. Generalization introduces other inference
variables wherever subtyping could occur.
pub fn register_obligations(&mut self, obligations: PredicateObligations<'tcx>)
pub fn register_predicates( &mut self, obligations: impl IntoIterator<Item: ToPredicate<'tcx>> )
source§impl<'a, 'tcx> CombineFields<'a, 'tcx>
impl<'a, 'tcx> CombineFields<'a, 'tcx>
sourcepub fn higher_ranked_sub<T>(
&mut self,
sub: Binder<'tcx, T>,
sup: Binder<'tcx, T>,
sub_is_expected: bool
) -> RelateResult<'tcx, ()>where
T: Relate<'tcx>,
pub fn higher_ranked_sub<T>( &mut self, sub: Binder<'tcx, T>, sup: Binder<'tcx, T>, sub_is_expected: bool ) -> RelateResult<'tcx, ()>where T: Relate<'tcx>,
Checks whether for<..> sub <: for<..> sup
holds.
For this to hold, all instantiations of the super type have to be a super type of at least one instantiation of the subtype.
This is implemented by first entering a new universe.
We then replace all bound variables in sup
with placeholders,
and all bound variables in sub
with inference vars.
We can then just relate the two resulting types as normal.
Note: this is a subtle algorithm. For a full explanation, please see the rustc dev guide
Trait Implementations§
source§impl<'infcx, 'tcx> Clone for CombineFields<'infcx, 'tcx>
impl<'infcx, 'tcx> Clone for CombineFields<'infcx, 'tcx>
source§fn clone(&self) -> CombineFields<'infcx, 'tcx>
fn clone(&self) -> CombineFields<'infcx, 'tcx>
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moreAuto Trait Implementations§
impl<'infcx, 'tcx> !RefUnwindSafe for CombineFields<'infcx, 'tcx>
impl<'infcx, 'tcx> !Send for CombineFields<'infcx, 'tcx>
impl<'infcx, 'tcx> !Sync for CombineFields<'infcx, 'tcx>
impl<'infcx, 'tcx> Unpin for CombineFields<'infcx, 'tcx>
impl<'infcx, 'tcx> !UnwindSafe for CombineFields<'infcx, 'tcx>
Blanket Implementations§
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
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: 136 bytes