1 files changed, 31 insertions, 0 deletions
diff --git a/src/test/ui/unboxed-closures/unboxed-closures-manual-impl.rs b/src/test/ui/unboxed-closures/unboxed-closures-manual-impl.rs
new file mode 100644
index 000000000..df60b42ab
--- /dev/null
+++ b/src/test/ui/unboxed-closures/unboxed-closures-manual-impl.rs
@@ -0,0 +1,31 @@
+// run-pass
+#![feature(unboxed_closures, fn_traits)]
+
+struct S;
+
+impl FnMut<(i32,)> for S {
+    extern "rust-call" fn call_mut(&mut self, (x,): (i32,)) -> i32 {
+        x * x
+    }
+}
+
+impl FnOnce<(i32,)> for S {
+    type Output = i32;
+
+    extern "rust-call" fn call_once(mut self, args: (i32,)) -> i32 { self.call_mut(args) }
+}
+
+fn call_it<F:FnMut(i32)->i32>(mut f: F, x: i32) -> i32 {
+    f(x) + 3
+}
+
+fn call_box(f: &mut dyn FnMut(i32) -> i32, x: i32) -> i32 {
+    f(x) + 3
+}
+
+fn main() {
+    let x = call_it(S, 1);
+    let y = call_box(&mut S, 1);
+    assert_eq!(x, 4);
+    assert_eq!(y, 4);
+}