Fix incorrect use mut diagnostics

[rust.git] / compiler / rustc_mir / src / borrow_check / path_utils.rs

diff --git a/compiler/rustc_mir/src/borrow_check/path_utils.rs b/compiler/rustc_mir/src/borrow_check/path_utils.rs
index 934729553a73be6588cc0f34b4b444cfd89d157e..80de3b4e363bfb369a40b701ff9cf944e43df84a 100644 (file)
--- a/compiler/rustc_mir/src/borrow_check/path_utils.rs
+++ b/compiler/rustc_mir/src/borrow_check/path_utils.rs
@@ -143,31 +143,29 @@ pub(super) fn borrow_of_local_data(place: Place<'_>) -> bool {
 /// of a closure type.
 pub(crate) fn is_upvar_field_projection(
     tcx: TyCtxt<'tcx>,
-    upvars: &[Upvar],
+    upvars: &[Upvar<'tcx>],
     place_ref: PlaceRef<'tcx>,
     body: &Body<'tcx>,
 ) -> Option<Field> {
-    let mut place_projection = place_ref.projection;
+    let mut place_ref = place_ref;
     let mut by_ref = false;
 
-    if let [proj_base @ .., ProjectionElem::Deref] = place_projection {
-        place_projection = proj_base;
+    if let Some((place_base, ProjectionElem::Deref)) = place_ref.last_projection() {
+        place_ref = place_base;
         by_ref = true;
     }
 
-    match place_projection {
-        [base @ .., ProjectionElem::Field(field, _ty)] => {
-            let base_ty = Place::ty_from(place_ref.local, base, body, tcx).ty;
-
+    match place_ref.last_projection() {
+        Some((place_base, ProjectionElem::Field(field, _ty))) => {
+            let base_ty = place_base.ty(body, tcx).ty;
             if (base_ty.is_closure() || base_ty.is_generator())
                 && (!by_ref || upvars[field.index()].by_ref)
             {
-                Some(*field)
+                Some(field)
             } else {
                 None
             }
         }
-
         _ => None,
     }
 }