Struct rustc_mir::borrow_check::type_check::free_region_relations::UniversalRegionRelations[][src]

pub(crate) struct UniversalRegionRelations<'tcx> {
    universal_regions: Rc<UniversalRegions<'tcx>>,
    outlives: TransitiveRelation<RegionVid>,
    inverse_outlives: TransitiveRelation<RegionVid>,
}

Fields

universal_regions: Rc<UniversalRegions<'tcx>>outlives: TransitiveRelation<RegionVid>

Stores the outlives relations that are known to hold from the implied bounds, in-scope where-clauses, and that sort of thing.

inverse_outlives: TransitiveRelation<RegionVid>

This is the <= relation; that is, if a: b, then b <= a, and we store that here. This is useful when figuring out how to express some local region in terms of external regions our caller will understand.

Implementations

impl<'tcx> UniversalRegionRelations<'tcx>[src]

fn relate_universal_regions(&mut self, fr_a: RegionVid, fr_b: RegionVid)[src]

Records in the outlives_relation (and inverse_outlives_relation) that fr_a: fr_b. Invoked by the builder below.

pub(crate) fn postdom_upper_bound(
    &self,
    fr1: RegionVid,
    fr2: RegionVid
) -> RegionVid
[src]

Given two universal regions, returns the postdominating upper-bound (effectively the least upper bound).

(See TransitiveRelation::postdom_upper_bound for details on the postdominating upper bound in general.)

pub(crate) fn non_local_upper_bounds<'a>(
    &'a self,
    fr: &'a RegionVid
) -> Vec<&'a RegionVid>
[src]

Finds an “upper bound” for fr that is not local. In other words, returns the smallest (*) known region fr1 that (a) outlives fr and (b) is not local.

(*) If there are multiple competing choices, we return all of them.

pub(crate) fn non_local_upper_bound(&self, fr: RegionVid) -> RegionVid[src]

Returns the “postdominating” bound of the set of non_local_upper_bounds for the given region.

pub(crate) fn non_local_lower_bound(&self, fr: RegionVid) -> Option<RegionVid>[src]

Finds a “lower bound” for fr that is not local. In other words, returns the largest (*) known region fr1 that (a) is outlived by fr and (b) is not local.

(*) If there are multiple competing choices, we pick the “postdominating” one. See TransitiveRelation::postdom_upper_bound for details.

fn non_local_bounds<'a>(
    &self,
    relation: &'a TransitiveRelation<RegionVid>,
    fr0: &'a RegionVid
) -> Vec<&'a RegionVid>
[src]

Helper for non_local_upper_bounds and non_local_lower_bounds. Repeatedly invokes postdom_parent until we find something that is not local. Returns None if we never do so.

pub(crate) fn outlives(&self, fr1: RegionVid, fr2: RegionVid) -> bool[src]

Returns true if fr1 is known to outlive fr2.

This will only ever be true for universally quantified regions.

pub(crate) fn regions_outlived_by(&self, fr1: RegionVid) -> Vec<&RegionVid>[src]

Returns a vector of free regions x such that fr1: x is known to hold.

pub(crate) fn known_outlives(
    &self
) -> impl Iterator<Item = (&RegionVid, &RegionVid)>
[src]

Returns the non-transitive set of known outlives constraints between free regions.

Trait Implementations

impl<'tcx> Debug for UniversalRegionRelations<'tcx>[src]

impl<'tcx> FreeRegionRelations<'tcx> for UniversalRegionRelations<'tcx>[src]

This trait is used by the impl-trait constraint code to abstract over the FreeRegionMap from lexical regions and UniversalRegions (from NLL)`.

Auto Trait Implementations

impl<'tcx> !RefUnwindSafe for UniversalRegionRelations<'tcx>

impl<'tcx> !Send for UniversalRegionRelations<'tcx>

impl<'tcx> !Sync for UniversalRegionRelations<'tcx>

impl<'tcx> Unpin for UniversalRegionRelations<'tcx>

impl<'tcx> !UnwindSafe for UniversalRegionRelations<'tcx>

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<T> WithConstness for T[src]