commit ffd6f84833465a47dbd4a5254e5a0aed30db6735
author David Tolnay <dtolnay@gmail.com> Sun Mar 28 04:14:12 2021 -0400
committer David Tolnay <dtolnay@gmail.com> Sun Mar 28 04:17:56 2021 -0400
tree c3a14a08eb785c408077f8d432c6180636c5fdb1
parent b7a48dd75aafe5eb0c590109bea531a6e40e3d52

Recognize mutable slice argument as permitting mutable return

syntax/check.rs

diff --git a/syntax/check.rs b/syntax/check.rs
index b9c5370..10025ac 100644
--- a/syntax/check.rs
+++ b/syntax/check.rs
@@ -539,6 +539,7 @@
         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(),