Struct rustc_infer::infer::sub::Sub

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

Ensures a is made a subtype of b. Returns a on success.

Fields

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

a_is_expected: bool

Implementations

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

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

pub(in infer::sub) fn with_expected_switched<R, F: FnOnce(&mut Self) -> R>(
    &mut self,
    f: F
) -> R

Trait Implementations

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

pub 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<'tcx, 'combine, 'infcx> TypeRelation<'tcx> for Sub<'combine, 'infcx, 'tcx>

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

Returns a static string we can use for printouts.

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

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

pub fn a_is_expected(&self) -> bool

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

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

pub 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.

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

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

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

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

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

Generic relation routine suitable for most anything.

pub 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.