Remove ProjectionElem::OpaqueCast

Author: flodiebold

crates/hir-ty/src/mir.rs

@@ -181,7 +181,6 @@ pub enum ProjectionElem<V: PartialEq> {
     },
     /// "Downcast" to a variant of an enum or a coroutine.
     Downcast(VariantId),
-    OpaqueCast(std::convert::Infallible), // TODO remove this
 }
 
 impl<V: PartialEq> ProjectionElem<V> {
@@ -195,7 +194,6 @@ impl<V: PartialEq> ProjectionElem<V> {
             }
             ProjectionElem::Subslice { from, to } => ProjectionElem::Subslice { from, to },
             ProjectionElem::Downcast(variant_id) => ProjectionElem::Downcast(variant_id),
-            ProjectionElem::OpaqueCast(ty) => ProjectionElem::OpaqueCast(ty),
         }
     }
 
@@ -212,7 +210,6 @@ impl<V: PartialEq> ProjectionElem<V> {
             }
             ProjectionElem::Subslice { from, to } => ProjectionElem::Subslice { from, to },
             ProjectionElem::Downcast(variant_id) => ProjectionElem::Downcast(variant_id),
-            ProjectionElem::OpaqueCast(ty) => ProjectionElem::OpaqueCast(ty),
         })
     }
 }
@@ -1257,7 +1254,7 @@ impl<'db> PlaceTy<'db> {
                         .instantiate(infcx.interner, args)
                         .skip_norm_wip()
                 }
-                // TODO TyKind::Coroutine...
+                // FIXME TyKind::Coroutine...
                 _ => panic!("can't downcast non-adt non-coroutine type: {self_ty:?}"),
             }
         } else {
@@ -1272,7 +1269,7 @@ impl<'db> PlaceTy<'db> {
                 TyKind::Closure(_, args) => {
                     args.as_closure().tupled_upvars_ty().tuple_fields()[f.0 as usize]
                 }
-                // TODO TyKind::Coroutine / TyKind::CoroutineClosure...
+                // FIXME TyKind::Coroutine / TyKind::CoroutineClosure...
                 TyKind::Tuple(tys) => tys
                     .get(f.0 as usize)
                     .cloned()
@@ -1360,7 +1357,6 @@ impl<'db> PlaceTy<'db> {
                 self.variant_id.clone(),
                 f,
             )),
-            ProjectionElem::OpaqueCast(_ty) => unimplemented!("not emitted, to be removed"),
         };
         answer
     }

crates/hir-ty/src/mir/borrowck.rs

@@ -436,8 +436,7 @@ fn place_case<'db>(
             | ProjectionElem::Index(_) => {
                 is_part_of = true;
             }
-            ProjectionElem::Downcast(_) |
-            ProjectionElem::OpaqueCast(_) => (),
+            ProjectionElem::Downcast(_) => (),
         }
         ty = ty.projection_ty(infcx, proj, env);
     }

crates/hir-ty/src/mir/eval.rs

@@ -852,7 +852,6 @@ impl<'a, 'db: 'a> Evaluator<'a, 'db> {
                 ProjectionElem::Downcast(_) => {
                     // no runtime effect
                 }
-                ProjectionElem::OpaqueCast(_) => not_supported!("opaque cast"),
             }
         }
         Ok((addr, ty.ty, metadata))