misc

Author: BoxyUwU

compiler/rustc_hir_typeck/src/coercion.rs

@@ -177,7 +177,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         })
     }
 
-    #[instrument(skip(self))]
+    #[instrument(skip(self), ret)]
     fn coerce(&self, a: Ty<'tcx>, b: Ty<'tcx>) -> CoerceResult<'tcx> {
         // First, remove any resolved type variables (at the top level, at least):
         let a = self.shallow_resolve(a);
@@ -324,11 +324,10 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         debug_assert!(self.shallow_resolve(a) == a);
         debug_assert!(self.shallow_resolve(b) == b);
 
-        let (r_a, mt_a) = match *a.kind() {
-            ty::Ref(r_a, ty, mutbl) => {
-                let mt_a = ty::TypeAndMut { ty, mutbl };
-                coerce_mutbls(mt_a.mutbl, mutbl_b)?;
-                (r_a, mt_a)
+        let mt_a = match *a.kind() {
+            ty::Ref(_, ty, mutbl) => {
+                coerce_mutbls(mutbl, mutbl_b)?;
+                ty::TypeAndMut { ty, mutbl }
             }
             _ => return self.unify(a, b),
         };
@@ -412,8 +411,7 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         obligations.extend(o);
         obligations.extend(autoderef.into_obligations());
 
-        // Now apply the autoref. We have to extract the region out of
-        // the final ref type we got.
+        // Now apply the autoref
         let ty::Ref(..) = coerced_a.kind() else {
             span_bug!(self.cause.span, "expected a ref type, got {:?}", coerced_a);
         };