1 files changed, 25 insertions, 0 deletions
diff --git a/tests/ui/macros/rfc-2011-nicer-assert-messages/auxiliary/common.rs b/tests/ui/macros/rfc-2011-nicer-assert-messages/auxiliary/common.rs
new file mode 100644
index 00000000000..903ed507c2e
--- /dev/null
+++ b/tests/ui/macros/rfc-2011-nicer-assert-messages/auxiliary/common.rs
@@ -0,0 +1,25 @@
+#[macro_export]
+macro_rules! test {
+  (
+    let mut $elem_ident:ident = $elem_expr:expr;
+    [ $($assert:tt)* ] => $msg:literal
+  ) => {
+    {
+      #[allow(unused_assignments, unused_mut, unused_variables)]
+      let rslt = std::panic::catch_unwind(|| {
+        let mut $elem_ident = $elem_expr;
+        assert!($($assert)*);
+      });
+      let err = rslt.unwrap_err();
+      if let Some(elem) = err.downcast_ref::<String>() {
+        assert_eq!(elem, &$msg);
+      }
+      else if let Some(elem) = err.downcast_ref::<&str>() {
+        assert_eq!(elem, &$msg);
+      }
+      else {
+        panic!("assert!( ... ) should return a string");
+      }
+    }
+  }
+}