Recognize mutable slice argument as permitting mutable return

dtolnay · Mar 28, 2021 · ffd6f84 · ffd6f84
1 parent b7a48dd
commit ffd6f84
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/syntax/check.rs b/syntax/check.rs
@@ -539,6 +539,7 @@ fn check_mut_return_restriction(cx: &mut Check, efn: &ExternFn) {
         fn visit_type(&mut self, ty: &'t Type) {
             self.found |= match ty {
                 Type::Ref(ty) => ty.mutable,
+                Type::SliceRef(slice) => slice.mutable,
                 Type::Ident(ident) if Atom::from(&ident.rust).is_none() => {
                     match self.cx.types.try_resolve(ident) {
                         Some(resolve) => !resolve.generics.lifetimes.is_empty(),