1 files changed, 10 insertions, 0 deletions
diff --git a/tests/ui/macros/must-use-in-macro-55516.rs b/tests/ui/macros/must-use-in-macro-55516.rs
new file mode 100644
index 000000000..e7c346286
--- /dev/null
+++ b/tests/ui/macros/must-use-in-macro-55516.rs
@@ -0,0 +1,10 @@
+// check-pass
+// compile-flags: -Wunused
+
+// make sure write!() can't hide its unused Result
+
+fn main() {
+    use std::fmt::Write;
+    let mut example = String::new();
+    write!(&mut example, "{}", 42); //~WARN must be used
+}