Struct rustc_trait_selection::infer::region_constraints::RegionConstraintStorage

pub struct RegionConstraintStorage<'tcx> {
    var_infos: IndexVec<RegionVid, RegionVariableInfo>,
    data: RegionConstraintData<'tcx>,
    lubs: HashMap<TwoRegions<'tcx>, RegionVid, BuildHasherDefault<FxHasher>>,
    glbs: HashMap<TwoRegions<'tcx>, RegionVid, BuildHasherDefault<FxHasher>>,
    pub(super) unification_table: UnificationTable<InPlace<RegionVidKey<'tcx>, Vec<VarValue<RegionVidKey<'tcx>>, Global>, ()>>,
    any_unifications: bool,
}

Fields

var_infos: IndexVec<RegionVid, RegionVariableInfo>

For each RegionVid, the corresponding RegionVariableOrigin.

data: RegionConstraintData<'tcx>

lubs: HashMap<TwoRegions<'tcx>, RegionVid, BuildHasherDefault<FxHasher>>

For a given pair of regions (R1, R2), maps to a region R3 that is designated as their LUB (edges R1 <= R3 and R2 <= R3 exist). This prevents us from making many such regions.

glbs: HashMap<TwoRegions<'tcx>, RegionVid, BuildHasherDefault<FxHasher>>

For a given pair of regions (R1, R2), maps to a region R3 that is designated as their GLB (edges R3 <= R1 and R3 <= R2 exist). This prevents us from making many such regions.

unification_table: UnificationTable<InPlace<RegionVidKey<'tcx>, Vec<VarValue<RegionVidKey<'tcx>>, Global>, ()>>

When we add a R1 == R2 constraint, we currently add (a) edges R1 <= R2 and R2 <= R1 and (b) we unify the two regions in this table. You can then call opportunistic_resolve_var early which will map R1 and R2 to some common region (i.e., either R1 or R2). This is important when fulfillment, dropck and other such code is iterating to a fixed point, because otherwise we sometimes would wind up with a fresh stream of region variables that have been equated but appear distinct.

any_unifications: bool

a flag set to true when we perform any unifications; this is used to micro-optimize take_and_reset_data

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: 224 bytes