Struct rustc_infer::infer::lub::Lub

pub struct Lub<'combine, 'infcx, 'tcx> {
    fields: &'combine mut CombineFields<'infcx, 'tcx>,
    a_is_expected: bool,
}

“Least upper bound” (common supertype)

Fields

fields: &'combine mut CombineFields<'infcx, 'tcx>

a_is_expected: bool

Implementations

impl<'combine, 'infcx, 'tcx> Lub<'combine, 'infcx, 'tcx>

pub fn new(
    fields: &'combine mut CombineFields<'infcx, 'tcx>,
    a_is_expected: bool
) -> Lub<'combine, 'infcx, 'tcx>

Trait Implementations

impl<'tcx> ConstEquateRelation<'tcx> for Lub<'_, '_, 'tcx>

fn const_equate_obligation(
    &mut self,
    a: &'tcx Const<'tcx>,
    b: &'tcx Const<'tcx>
)

Register an obligation that both constants must be equal to each other.

impl<'combine, 'infcx, 'tcx> LatticeDir<'infcx, 'tcx> for Lub<'combine, 'infcx, 'tcx>

fn infcx(&self) -> &'infcx InferCtxt<'infcx, 'tcx>

fn cause(&self) -> &ObligationCause<'tcx>

fn relate_bound(
    &mut self,
    v: Ty<'tcx>,
    a: Ty<'tcx>,
    b: Ty<'tcx>
) -> RelateResult<'tcx, ()>

impl<'tcx, 'combine, 'infcx> TypeRelation<'tcx> for Lub<'combine, 'infcx, 'tcx>

fn tag(&self) -> &'static str

Returns a static string we can use for printouts.

fn tcx(&self) -> TyCtxt<'tcx>

fn param_env(&self) -> ParamEnv<'tcx>

fn a_is_expected(&self) -> bool

Returns true if the value a is the “expected” type in the relation. Just affects error messages.

fn relate_with_variance<T: Relate<'tcx>>(
    &mut self,
    variance: Variance,
    a: T,
    b: T
) -> RelateResult<'tcx, T>

Switch variance for the purpose of relating a and b.

fn tys(&mut self, a: Ty<'tcx>, b: Ty<'tcx>) -> RelateResult<'tcx, Ty<'tcx>>

fn regions(
    &mut self,
    a: Region<'tcx>,
    b: Region<'tcx>
) -> RelateResult<'tcx, Region<'tcx>>

fn consts(
    &mut self,
    a: &'tcx Const<'tcx>,
    b: &'tcx Const<'tcx>
) -> RelateResult<'tcx, &'tcx Const<'tcx>>

fn binders<T>(
    &mut self,
    a: Binder<'tcx, T>,
    b: Binder<'tcx, T>
) -> RelateResult<'tcx, Binder<'tcx, T>> where
    T: Relate<'tcx>, 

fn with_cause<F, R>(&mut self, _cause: Cause, f: F) -> R where
    F: FnOnce(&mut Self) -> R, 

fn relate<T>(&mut self, a: T, b: T) -> Result<T, TypeError<'tcx>> where
    T: Relate<'tcx>, 

Generic relation routine suitable for most anything.

fn relate_item_substs(
    &mut self,
    item_def_id: DefId,
    a_subst: &'tcx List<GenericArg<'tcx>>,
    b_subst: &'tcx List<GenericArg<'tcx>>
) -> Result<&'tcx List<GenericArg<'tcx>>, TypeError<'tcx>>

Relate the two substitutions for the given item. The default is to look up the variance for the item and proceed accordingly.