diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src')
| -rw-r--r-- | compiler/rustc_trait_selection/src/solve/canonicalize.rs | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/compiler/rustc_trait_selection/src/solve/canonicalize.rs b/compiler/rustc_trait_selection/src/solve/canonicalize.rs index 19f0c9fe826..377ae1b4e85 100644 --- a/compiler/rustc_trait_selection/src/solve/canonicalize.rs +++ b/compiler/rustc_trait_selection/src/solve/canonicalize.rs @@ -224,12 +224,20 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for Canonicalizer<'_, 'tcx> { let kind = match *r { ty::ReLateBound(..) => return r, - ty::ReStatic => match self.canonicalize_mode { + // We may encounter `ReStatic` in item signatures or the hidden type + // of an opaque. `ReErased` should only be encountered in the hidden + // type of an opaque for regions that are ignored for the purposes of + // captures. + // + // FIXME: We should investigate the perf implications of not uniquifying + // `ReErased`. We may be able to short-circuit registering region + // obligations if we encounter a `ReErased` on one side, for example. + ty::ReStatic | ty::ReErased => match self.canonicalize_mode { CanonicalizeMode::Input => CanonicalVarKind::Region(ty::UniverseIndex::ROOT), CanonicalizeMode::Response { .. } => return r, }, - ty::ReErased | ty::ReFree(_) | ty::ReEarlyBound(_) => match self.canonicalize_mode { + ty::ReFree(_) | ty::ReEarlyBound(_) => match self.canonicalize_mode { CanonicalizeMode::Input => CanonicalVarKind::Region(ty::UniverseIndex::ROOT), CanonicalizeMode::Response { .. } => bug!("unexpected region in response: {r:?}"), }, |