From b6ba4ecdbb82e6dfe69b8a47e0f6db7dd88ce095 Mon Sep 17 00:00:00 2001
From: Dana Jansens <danakj@orodu.net>
Date: Wed, 2 Sep 2026 21:56:12 +0000
Subject: [PATCH] Use `match_first` to make the
 impl_recurse_with_simpler_type_in_generic_param_bidirectional_no_cycle.carbon
 test pass again (#7712)

---
 .../testdata/impl/lookup/impl_cycle.carbon    | 21 ++++---------------
 1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/toolchain/check/testdata/impl/lookup/impl_cycle.carbon b/toolchain/check/testdata/impl/lookup/impl_cycle.carbon
index 1df01a1a2942..4d8c0c686ff8 100644
--- a/toolchain/check/testdata/impl/lookup/impl_cycle.carbon
+++ b/toolchain/check/testdata/impl/lookup/impl_cycle.carbon
@@ -246,7 +246,7 @@ fn F() {
   ({} as Wraps(C)) as (Wraps(C) as ComparableTo(Wraps(D)));
 }
 
-// --- fail_todo_impl_recurse_with_simpler_type_in_generic_param_bidirectional_no_cycle.carbon
+// --- impl_recurse_with_simpler_type_in_generic_param_bidirectional_no_cycle.carbon
 library "[[@TEST_NAME]]";
 
 // Implement this for a type in one direction.
@@ -262,30 +262,17 @@ class D {}
 // - D is ComparableWith(C).
 impl C as ComparableTo(D) {}
 
-// TODO: These three `impl`s need to be placed in a match_first as they
-// overlap.
+match_first {
 
 // T is always ComparableWith(T).
 impl forall [T: type] T as ComparableWith(T) {}
 // If U is ComparableTo(T), U is ComparableWith(T).
-// CHECK:STDERR: fail_todo_impl_recurse_with_simpler_type_in_generic_param_bidirectional_no_cycle.carbon:[[@LINE+7]]:1: error: found non-final `impl` with the same type structure as another non-final `impl` [ImplNonFinalSameTypeStructure]
-// CHECK:STDERR: impl forall [T: type, U: ComparableTo(T)] U as ComparableWith(T) {}
-// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_todo_impl_recurse_with_simpler_type_in_generic_param_bidirectional_no_cycle.carbon:[[@LINE-5]]:1: note: other `impl` here [ImplNonFinalSameTypeStructureNote]
-// CHECK:STDERR: impl forall [T: type] T as ComparableWith(T) {}
-// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR:
 impl forall [T: type, U: ComparableTo(T)] U as ComparableWith(T) {}
 // If U is ComparableTo(T), T is ComparableWith(U).
-// CHECK:STDERR: fail_todo_impl_recurse_with_simpler_type_in_generic_param_bidirectional_no_cycle.carbon:[[@LINE+7]]:1: error: found non-final `impl` with the same type structure as another non-final `impl` [ImplNonFinalSameTypeStructure]
-// CHECK:STDERR: impl forall [T: type, U: ComparableTo(T)] T as ComparableWith(U) {}
-// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR: fail_todo_impl_recurse_with_simpler_type_in_generic_param_bidirectional_no_cycle.carbon:[[@LINE-14]]:1: note: other `impl` here [ImplNonFinalSameTypeStructureNote]
-// CHECK:STDERR: impl forall [T: type] T as ComparableWith(T) {}
-// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// CHECK:STDERR:
 impl forall [T: type, U: ComparableTo(T)] T as ComparableWith(U) {}
 
+}
+
 fn Compare[T: type, U: ComparableWith(T)](unused t: T, unused u: U) {}
 
 fn F() {