Rollup merge of #104771 - est31:if_let_chain_broken_mir_test, r=davidtwco

[rust.git] / compiler / rustc_hir_typeck / src / coercion.rs

diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index 3f0d0a76027f45ca49a0bc3473037f465bfe799c..82784bb8a661a61122cf923f7eef8126d064fdd8 100644 (file)
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -588,7 +588,7 @@ fn coerce_unsized(&self, mut source: Ty<'tcx>, mut target: Ty<'tcx>) -> CoerceRe
             }
             _ => None,
         };
-        let coerce_source = reborrow.as_ref().map_or(source, |&(_, ref r)| r.target);
+        let coerce_source = reborrow.as_ref().map_or(source, |(_, r)| r.target);
 
         // Setup either a subtyping or a LUB relationship between
         // the `CoerceUnsized` target type and the expected type.
@@ -755,20 +755,9 @@ fn coerce_dyn_star(
 
         if let ty::Dynamic(a_data, _, _) = a.kind()
             && let ty::Dynamic(b_data, _, _) = b.kind()
+            && a_data.principal_def_id() == b_data.principal_def_id()
         {
-            if a_data.principal_def_id() == b_data.principal_def_id() {
-                return self.unify_and(a, b, |_| vec![]);
-            } else if !self.tcx().features().trait_upcasting {
-                let mut err = feature_err(
-                    &self.tcx.sess.parse_sess,
-                    sym::trait_upcasting,
-                    self.cause.span,
-                    &format!(
-                        "cannot cast `{a}` to `{b}`, trait upcasting coercion is experimental"
-                    ),
-                );
-                err.emit();
-            }
+            return self.unify_and(a, b, |_| vec![]);
         }
 
         // Check the obligations of the cast -- for example, when casting
@@ -796,19 +785,16 @@ fn coerce_dyn_star(
             ])
             .collect();
 
-        // Enforce that the type is `usize`/pointer-sized. For now, only those
-        // can be coerced to `dyn*`, except for `dyn* -> dyn*` upcasts.
-        if !a.is_dyn_star() {
-            obligations.push(Obligation::new(
-                self.tcx,
-                self.cause.clone(),
-                self.param_env,
-                ty::Binder::dummy(
-                    self.tcx.at(self.cause.span).mk_trait_ref(hir::LangItem::PointerSized, [a]),
-                )
-                .to_poly_trait_predicate(),
-            ));
-        }
+        // Enforce that the type is `usize`/pointer-sized.
+        obligations.push(Obligation::new(
+            self.tcx,
+            self.cause.clone(),
+            self.param_env,
+            ty::Binder::dummy(
+                self.tcx.at(self.cause.span).mk_trait_ref(hir::LangItem::PointerSized, [a]),
+            )
+            .to_poly_trait_predicate(),
+        ));
 
         Ok(InferOk {
             value: (vec![Adjustment { kind: Adjust::DynStar, target: b }], b),