1 files changed, 25 insertions, 0 deletions
diff --git a/src/test/ui/generic-associated-types/issue-87258_a.rs b/src/test/ui/generic-associated-types/issue-87258_a.rs
new file mode 100644
index 000000000..c65f3fb2a
--- /dev/null
+++ b/src/test/ui/generic-associated-types/issue-87258_a.rs
@@ -0,0 +1,25 @@
+#![feature(type_alias_impl_trait)]
+#![feature(generic_associated_types)]
+
+// See https://github.com/rust-lang/rust/issues/87258#issuecomment-883293367
+
+trait Trait1 {}
+
+struct Struct<'b>(&'b ());
+
+impl<'d> Trait1 for Struct<'d> {}
+
+pub trait Trait2 {
+    type FooFuture<'a>: Trait1;
+    fn foo<'a>() -> Self::FooFuture<'a>;
+}
+
+impl<'c, S: Trait2> Trait2 for &'c mut S {
+    type FooFuture<'a> = impl Trait1;
+    //~^ ERROR unconstrained opaque type
+    fn foo<'a>() -> Self::FooFuture<'a> {
+        Struct(unimplemented!())
+    }
+}
+
+fn main() {}