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-rw-r--r--src/test/ui/dropck/issue-28498-ugeh-with-lifetime-param.rs38
1 files changed, 38 insertions, 0 deletions
diff --git a/src/test/ui/dropck/issue-28498-ugeh-with-lifetime-param.rs b/src/test/ui/dropck/issue-28498-ugeh-with-lifetime-param.rs
new file mode 100644
index 000000000..43c0bfb26
--- /dev/null
+++ b/src/test/ui/dropck/issue-28498-ugeh-with-lifetime-param.rs
@@ -0,0 +1,38 @@
+// run-pass
+
+// Demonstrate the use of the unguarded escape hatch with a lifetime param
+// to assert that destructor will not access any dead data.
+//
+// Compare with ui/span/issue28498-reject-lifetime-param.rs
+
+#![feature(dropck_eyepatch)]
+
+#[derive(Debug)]
+struct ScribbleOnDrop(String);
+
+impl Drop for ScribbleOnDrop {
+ fn drop(&mut self) {
+ self.0 = format!("DROPPED");
+ }
+}
+
+struct Foo<'a>(u32, &'a ScribbleOnDrop);
+
+unsafe impl<#[may_dangle] 'a> Drop for Foo<'a> {
+ fn drop(&mut self) {
+ // Use of `may_dangle` is sound, because destructor never accesses `self.1`.
+ println!("Dropping Foo({}, _)", self.0);
+ }
+}
+
+fn main() {
+ let (last_dropped, foo0);
+ let (foo1, first_dropped);
+
+ last_dropped = ScribbleOnDrop(format!("last"));
+ first_dropped = ScribbleOnDrop(format!("first"));
+ foo0 = Foo(0, &last_dropped);
+ foo1 = Foo(1, &first_dropped);
+
+ println!("foo0.1: {:?} foo1.1: {:?}", foo0.1, foo1.1);
+}