From d864edc349f2548d9b05c7fa99f1387946e18f8b Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Thu, 23 Aug 2018 16:49:00 +0200
Subject: [PATCH] improve the run-pass test

---
 .../run-pass/panic-uninitialized-zeroed.rs    | 38 +++++++++++++++++--
 1 file changed, 34 insertions(+), 4 deletions(-)

diff --git a/src/test/run-pass/panic-uninitialized-zeroed.rs b/src/test/run-pass/panic-uninitialized-zeroed.rs
index a4115f8fa1d..fd88bba49c4 100644
--- a/src/test/run-pass/panic-uninitialized-zeroed.rs
+++ b/src/test/run-pass/panic-uninitialized-zeroed.rs
@@ -22,10 +22,40 @@ struct Foo {
 
 fn main() {
     unsafe {
-        panic::catch_unwind(|| mem::uninitialized::<!>()).is_err();
-        panic::catch_unwind(|| mem::zeroed::<!>()).is_err();
+        assert_eq!(
+            panic::catch_unwind(|| {
+                mem::uninitialized::<!>()
+            }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
+                s == "Attempted to instantiate uninhabited type ! using mem::uninitialized"
+            })),
+            Some(true)
+        );
 
-        panic::catch_unwind(|| mem::uninitialized::<Foo>()).is_err();
-        panic::catch_unwind(|| mem::zeroed::<Foo>()).is_err();
+        assert_eq!(
+            panic::catch_unwind(|| {
+                mem::zeroed::<!>()
+            }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
+                s == "Attempted to instantiate uninhabited type ! using mem::zeroed"
+            })),
+            Some(true)
+        );
+
+        assert_eq!(
+            panic::catch_unwind(|| {
+                mem::uninitialized::<Foo>()
+            }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
+                s == "Attempted to instantiate uninhabited type Foo using mem::uninitialized"
+            })),
+            Some(true)
+        );
+
+        assert_eq!(
+            panic::catch_unwind(|| {
+                mem::zeroed::<Foo>()
+            }).err().and_then(|a| a.downcast_ref::<String>().map(|s| {
+                s == "Attempted to instantiate uninhabited type Foo using mem::zeroed"
+            })),
+            Some(true)
+        );
     }
 }