From 402644f72f61a28b3690a565be82d2178cd44800 Mon Sep 17 00:00:00 2001
From: Jack Wrenn <jack@wrenn.fyi>
Date: Thu, 21 Jul 2022 17:43:25 +0000
Subject: [PATCH] safe transmute: test to ensure that trait is correctly
 feature-gated

ref: https://github.com/rust-lang/rust/pull/92268#discussion_r925265476
---
 .../malformed-program-gracefulness/feature-missing.rs |  6 ++++++
 .../feature-missing.stderr                            | 11 +++++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 src/test/ui/transmutability/malformed-program-gracefulness/feature-missing.rs
 create mode 100644 src/test/ui/transmutability/malformed-program-gracefulness/feature-missing.stderr

diff --git a/src/test/ui/transmutability/malformed-program-gracefulness/feature-missing.rs b/src/test/ui/transmutability/malformed-program-gracefulness/feature-missing.rs
new file mode 100644
index 00000000000..12018f3161a
--- /dev/null
+++ b/src/test/ui/transmutability/malformed-program-gracefulness/feature-missing.rs
@@ -0,0 +1,6 @@
+// The trait must not be available if its feature flag is absent.
+
+#![crate_type = "lib"]
+
+use std::mem::BikeshedIntrinsicFrom;
+//~^ ERROR use of unstable library feature 'transmutability' [E0658]
diff --git a/src/test/ui/transmutability/malformed-program-gracefulness/feature-missing.stderr b/src/test/ui/transmutability/malformed-program-gracefulness/feature-missing.stderr
new file mode 100644
index 00000000000..4b51850634a
--- /dev/null
+++ b/src/test/ui/transmutability/malformed-program-gracefulness/feature-missing.stderr
@@ -0,0 +1,11 @@
+error[E0658]: use of unstable library feature 'transmutability'
+  --> $DIR/feature-missing.rs:5:5
+   |
+LL | use std::mem::BikeshedIntrinsicFrom;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add `#![feature(transmutability)]` to the crate attributes to enable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0658`.