1 files changed, 49 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/coroutines/pr105301.C b/gcc/testsuite/g++.dg/coroutines/pr105301.C
new file mode 100644
index 00000000000..33a0b03cf5d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/coroutines/pr105301.C
@@ -0,0 +1,49 @@
+// { dg-additional-options "-fsyntax-only" }
+namespace std {
+template <class T, class = void>
+struct traits_sfinae_base {};
+
+template <class Ret, class... Args>
+struct coroutine_traits : public traits_sfinae_base<Ret> {};
+}
+
+template<typename Promise> struct coro {};
+template <typename Promise, typename... Ps>
+struct std::coroutine_traits<coro<Promise>, Ps...> {
+  using promise_type = Promise;
+};
+
+struct awaitable {
+  bool await_ready() noexcept;
+  template <typename F>
+  void await_suspend(F) noexcept;
+  void await_resume() noexcept;
+} a;
+
+struct suspend_always {
+  bool await_ready() noexcept { return false; }
+  template <typename F>
+  void await_suspend(F) noexcept;
+  void await_resume() noexcept {}
+};
+
+namespace std {
+template <class PromiseType = void>
+struct coroutine_handle {};
+}
+
+struct bad_promise_6 {
+  coro<bad_promise_6> get_return_object();
+  suspend_always initial_suspend();
+  suspend_always final_suspend() noexcept;
+  void unhandled_exception();
+  void return_void();
+  void return_value(int) const;
+  void return_value(int);
+};
+
+coro<bad_promise_6>
+bad_implicit_return() // { dg-error {.aka 'bad_promise_6'. declares both 'return_value' and 'return_void'} }
+{
+  co_await a;
+}