From 967ebb9c3d21d1692b0fa51112eee71c1b4668c4 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Wed, 15 Feb 2023 11:41:33 +0100
Subject: [PATCH] add test for may_dangle and ManuallyDrop

---
 tests/ui/drop/dropck-eyepatch-manuallydrop.rs | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 tests/ui/drop/dropck-eyepatch-manuallydrop.rs

diff --git a/tests/ui/drop/dropck-eyepatch-manuallydrop.rs b/tests/ui/drop/dropck-eyepatch-manuallydrop.rs
new file mode 100644
index 00000000000..ff100cd941f
--- /dev/null
+++ b/tests/ui/drop/dropck-eyepatch-manuallydrop.rs
@@ -0,0 +1,22 @@
+// check-pass
+//! This test checks that dropck knows that ManuallyDrop does not drop its field.
+#![feature(dropck_eyepatch)]
+
+use std::mem::ManuallyDrop;
+
+struct S<T>(ManuallyDrop<T>);
+
+unsafe impl<#[may_dangle] T> Drop for S<T> {
+    fn drop(&mut self) {}
+}
+
+struct NonTrivialDrop<'a>(&'a str);
+impl<'a> Drop for NonTrivialDrop<'a> {
+    fn drop(&mut self) {}
+}
+
+fn main() {
+    let s = String::from("string");
+    let _t = S(ManuallyDrop::new(NonTrivialDrop(&s)));
+    drop(s);
+}