add opaque type member constraint tests

1 files changed, 4 insertions, 1 deletions

diff --git a/tests/ui/impl-trait/member-constraints/nested-impl-trait-pass.rs b/tests/ui/impl-trait/member-constraints/nested-impl-trait-pass.rs
index 4633ad68230..6860fc5e6a5 100644
--- a/tests/ui/impl-trait/member-constraints/nested-impl-trait-pass.rs
+++ b/tests/ui/impl-trait/member-constraints/nested-impl-trait-pass.rs
@@ -1,6 +1,7 @@
 // Nested impl-traits can impose different member constraints on the same region variable.
 
 //@ check-pass
+// FIXME(-Znext-solver): enable this test
 
 trait Cap<'a> {}
 impl<T> Cap<'_> for T {}
@@ -8,7 +9,9 @@ impl<T> Cap<'_> for T {}
 // Assuming the hidden type is `[&'?15 u8; 1]`, we have two distinct member constraints:
 // - '?15 member ['static, 'a, 'b] // from outer impl-trait
 // - '?15 member ['static, 'a]     // from inner impl-trait
-// To satisfy both we can only choose 'a.
+// To satisfy both we can only choose 'a. Concretely, first member constraint requires ?15
+// to outlive at least 'b while the second requires ?15 to outlive 'a. As 'a outlives 'b we
+// end up with 'a as the final member region.
 fn pass_early_bound<'s, 'a, 'b>(a: &'s u8) -> impl IntoIterator<Item = impl Cap<'a>> + Cap<'b>
 where
     's: 'a,