gamer

Author: lcnr

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -36,7 +36,6 @@ use crate::type_check::{Locations, MirTypeckRegionConstraints};
 use crate::universal_regions::{RegionClassification, UniversalRegions};
 use crate::{BorrowCheckRootCtxt, BorrowckInferCtxt, BorrowckState};
 
-#[allow(unused)] // TODO
 pub(crate) enum DeferredOpaqueTypeError<'tcx> {
     UnexpectedHiddenRegion {
         /// The opaque type.
@@ -593,7 +592,7 @@ fn apply_defining_uses<'tcx>(
         });
 
         let locations = Locations::All(hidden_type.span);
-        fully_perform_op_raw(
+        if let Err(guar) = fully_perform_op_raw(
             infcx,
             body,
             universal_regions,
@@ -614,8 +613,9 @@ fn apply_defining_uses<'tcx>(
                 },
                 "equating opaque types",
             ),
-        )
-        .expect("failed to relate opaque types");
+        ) {
+            root_cx.add_concrete_opaque_type(key.def_id, OpaqueHiddenType::new_error(tcx, guar));
+        }
     }
 }