1 files changed, 12 insertions, 0 deletions
diff --git a/library/core/benches/any.rs b/library/core/benches/any.rs
new file mode 100644
index 000000000..53099b782
--- /dev/null
+++ b/library/core/benches/any.rs
@@ -0,0 +1,12 @@
+use core::any::*;
+use test::{black_box, Bencher};
+
+#[bench]
+fn bench_downcast_ref(b: &mut Bencher) {
+    b.iter(|| {
+        let mut x = 0;
+        let mut y = &mut x as &mut dyn Any;
+        black_box(&mut y);
+        black_box(y.downcast_ref::<isize>() == Some(&0));
+    });
+}