Enum rustc::infer::region_inference::UndoLogEntry

pub enum UndoLogEntry<'tcx> {
    OpenSnapshot,
    CommitedSnapshot,
    AddVar(RegionVid),
    AddConstraint(Constraint<'tcx>),
    AddVerify(usize),
    AddGiven(FreeRegion, RegionVid),
    AddCombination(CombineMapType, TwoRegions<'tcx>),
    Purged,
}

🔬 This is a nightly-only experimental API. (rustc_private)

Variants

OpenSnapshot

🔬 This is a nightly-only experimental API. (rustc_private)

Pushed when we start a snapshot.

CommitedSnapshot

🔬 This is a nightly-only experimental API. (rustc_private)

Replaces an OpenSnapshot when a snapshot is committed, but that snapshot is not the root. If the root snapshot is unrolled, all nested snapshots must be committed.

AddVar(RegionVid)

🔬 This is a nightly-only experimental API. (rustc_private)

We added RegionVid

AddConstraint(Constraint<'tcx>)

🔬 This is a nightly-only experimental API. (rustc_private)

We added the given constraint

AddVerify(usize)

🔬 This is a nightly-only experimental API. (rustc_private)

We added the given verify

AddGiven(FreeRegion, RegionVid)

🔬 This is a nightly-only experimental API. (rustc_private)

We added the given given

AddCombination(CombineMapType, TwoRegions<'tcx>)

🔬 This is a nightly-only experimental API. (rustc_private)

We added a GLB/LUB "combinaton variable"

Purged

🔬 This is a nightly-only experimental API. (rustc_private)

During skolemization, we sometimes purge entries from the undo log in a kind of minisnapshot (unlike other snapshots, this purging actually takes place on success). In that case, we replace the corresponding entry with Noop so as to avoid the need to do a bunch of swapping. (We can't use swap_remove as the order of the vector is important.)

Trait Implementations

impl<'tcx> Copy for UndoLogEntry<'tcx>

impl<'tcx> Clone for UndoLogEntry<'tcx>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'tcx> PartialEq for UndoLogEntry<'tcx>

fn eq(&self, __arg_0: &UndoLogEntry<'tcx>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, __arg_0: &UndoLogEntry<'tcx>) -> bool

This method tests for !=.