Auto merge of #80558 - lcnr:gat-variance, r=matthewjasper

require gat substs to be invariant

fixes #69184, fixes #80766

r? `@matthewjasper` probably

1 files changed, 24 insertions, 0 deletions

diff --git a/src/test/ui/generic-associated-types/variance_constraints.rs b/src/test/ui/generic-associated-types/variance_constraints.rs
new file mode 100644
index 00000000000..36db80706b4
--- /dev/null
+++ b/src/test/ui/generic-associated-types/variance_constraints.rs
@@ -0,0 +1,24 @@
+// check-pass
+// issue #69184
+#![feature(generic_associated_types)]
+#![allow(incomplete_features)]
+
+trait A {
+    type B<'a>;
+
+    fn make_b<'a>(&'a self) -> Self::B<'a>;
+}
+
+struct S {}
+impl A for S {
+    type B<'a> = &'a S;
+    fn make_b<'a>(&'a self) -> &'a Self {
+        self
+    }
+}
+
+enum E<'a> {
+    S(<S as A>::B<'a>),
+}
+
+fn main() {}