1 files changed, 27 insertions, 0 deletions
diff --git a/tests/ui/unboxed-closures/unboxed-closures-blanket-fn-mut.rs b/tests/ui/unboxed-closures/unboxed-closures-blanket-fn-mut.rs
new file mode 100644
index 000000000..a10016735
--- /dev/null
+++ b/tests/ui/unboxed-closures/unboxed-closures-blanket-fn-mut.rs
@@ -0,0 +1,27 @@
+// run-pass
+#![allow(unused_variables)]
+// Test that you can supply `&F` where `F: FnMut()`.
+
+#![feature(lang_items)]
+
+fn a<F:FnMut() -> i32>(mut f: F) -> i32 {
+    f()
+}
+
+fn b(f: &mut dyn FnMut() -> i32) -> i32 {
+    a(f)
+}
+
+fn c<F:FnMut() -> i32>(f: &mut F) -> i32 {
+    a(f)
+}
+
+fn main() {
+    let z: isize = 7;
+
+    let x = b(&mut || 22);
+    assert_eq!(x, 22);
+
+    let x = c(&mut || 22);
+    assert_eq!(x, 22);
+}