Struct rustc_trait_selection::infer::free_regions::FreeRegionMap

pub struct FreeRegionMap<'tcx> {
    relation: TransitiveRelation<&'tcx RegionKind>,
}

Fields

relation: TransitiveRelation<&'tcx RegionKind>

Implementations

impl<'tcx> FreeRegionMap<'tcx>

pub fn elements(&self) -> impl Iterator<Item = &&'tcx RegionKind>

pub fn is_empty(&self) -> bool

pub fn relate_regions(&mut self, sub: &'tcx RegionKind, sup: &'tcx RegionKind)

pub fn sub_free_regions(
    &self,
    tcx: TyCtxt<'tcx>,
    r_a: &'tcx RegionKind,
    r_b: &'tcx RegionKind
) -> bool

Tests whether r_a <= r_b.

Both regions must meet is_free_or_static.

Subtle: one tricky case that this code gets correct is as follows. If we know that r_b: 'static, then this function will return true, even though we don't know anything that directly relates r_a and r_b.

Also available through the FreeRegionRelations trait below.

pub fn is_free(&self, r: &RegionKind) -> bool

True for free regions other than 'static.

pub fn is_free_or_static(&self, r: &RegionKind) -> bool

True if r is a free region or static of the sort that this free region map can be used with.

pub fn lub_free_regions(
    &self,
    tcx: TyCtxt<'tcx>,
    r_a: &'tcx RegionKind,
    r_b: &'tcx RegionKind
) -> &'tcx RegionKind

Computes the least-upper-bound of two free regions. In some cases, this is more conservative than necessary, in order to avoid making arbitrary choices. See TransitiveRelation::postdom_upper_bound for more details.

Trait Implementations

impl<'tcx> Clone for FreeRegionMap<'tcx>

fn clone(&self) -> FreeRegionMap<'tcx>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'tcx> Debug for FreeRegionMap<'tcx>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'tcx> Default for FreeRegionMap<'tcx>

fn default() -> FreeRegionMap<'tcx>

Returns the "default value" for a type.