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-rw-r--r--src/test/ui/issues/issue-28498-ugeh-ex1.rs27
1 files changed, 27 insertions, 0 deletions
diff --git a/src/test/ui/issues/issue-28498-ugeh-ex1.rs b/src/test/ui/issues/issue-28498-ugeh-ex1.rs
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index 000000000..24bf706ce
--- /dev/null
+++ b/src/test/ui/issues/issue-28498-ugeh-ex1.rs
@@ -0,0 +1,27 @@
+// run-pass
+
+// Example taken from RFC 1238 text
+
+// https://github.com/rust-lang/rfcs/blob/master/text/1238-nonparametric-dropck.md
+// #example-of-the-unguarded-escape-hatch
+
+#![feature(dropck_eyepatch)]
+use std::cell::Cell;
+
+struct Concrete<'a>(#[allow(unused_tuple_struct_fields)] u32, Cell<Option<&'a Concrete<'a>>>);
+
+struct Foo<T> { data: Vec<T> }
+
+// Below is the UGEH attribute
+unsafe impl<#[may_dangle] T> Drop for Foo<T> {
+ fn drop(&mut self) { }
+}
+
+fn main() {
+ let mut foo = Foo { data: Vec::new() };
+ foo.data.push(Concrete(0, Cell::new(None)));
+ foo.data.push(Concrete(0, Cell::new(None)));
+
+ foo.data[0].1.set(Some(&foo.data[1]));
+ foo.data[1].1.set(Some(&foo.data[0]));
+}