2 files changed, 10 insertions, 0 deletions
diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index 5566835d..a2323898 100644
--- a/src/rt/rust_builtin.cpp
+++ b/src/rt/rust_builtin.cpp
@@ -178,6 +178,15 @@ vec_from_vbuf(rust_task *task, type_desc *ty, void *vbuf, size_t n_elts)
                                vbuf);
 }
 
+extern "C" CDECL rust_vec*
+unsafe_vec_to_mut(rust_task *task, type_desc *ty, rust_vec *v)
+{
+    if (v->ref_count != CONST_REFCOUNT) {
+        v->ref();
+    }
+    return v;
+}
+
 extern "C" CDECL rust_str*
 str_alloc(rust_task *task, size_t n_bytes)
 {
diff --git a/src/rt/rustrt.def.in b/src/rt/rustrt.def.in
index e378fa8d..d30c146e 100644
--- a/src/rt/rustrt.def.in
+++ b/src/rt/rustrt.def.in
@@ -33,6 +33,7 @@ str_from_vec
 str_push_byte
 str_vec
 task_sleep
+unsafe_vec_to_mut
 unsupervise
 upcall_clone_chan
 upcall_del_chan