1 files changed, 10 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-4333.rs b/src/test/ui/issues/issue-4333.rs
new file mode 100644
index 000000000..3df319b68
--- /dev/null
+++ b/src/test/ui/issues/issue-4333.rs
@@ -0,0 +1,10 @@
+// run-pass
+#![allow(unused_must_use)]
+// pretty-expanded FIXME #23616
+
+use std::io;
+
+pub fn main() {
+    let stdout = &mut io::stdout() as &mut dyn io::Write;
+    stdout.write(b"Hello!");
+}