--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/coroutines/torture/co-await-17-capture-comp-ref.C	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,99 @@
+//  { dg-do run { target c++17 } }
+
+#include "../coro.h"
+
+class resumable {
+public:
+  struct promise_type;
+  using coro_handle = std::coroutine_handle<promise_type>;
+  resumable(coro_handle handle) : handle_(handle) { }
+  resumable(resumable&) = delete;
+  resumable(resumable&&) = delete;
+  ~resumable() { handle_.destroy(); }
+  coro_handle handle_;
+};
+
+struct resumable::promise_type {
+  using coro_handle = std::coroutine_handle<promise_type>;
+  int used;
+  auto get_return_object() {
+    return coro_handle::from_promise(*this);
+  }
+  auto initial_suspend() { return std::suspend_never(); }
+  auto final_suspend() { return std::suspend_always(); }
+  void return_value(int x) {used = x;}
+  void unhandled_exception() {}
+
+  struct TestAwaiter {
+    int recent_test;
+    TestAwaiter(int test) : recent_test{test} {}
+    bool await_ready() { return false; }
+    void await_suspend(std::coroutine_handle<promise_type>) {}
+    int await_resume() {
+      return recent_test;
+    }
+    auto operator co_await() {
+      return *this;
+    }
+  };
+
+  struct TestAwaiterCH :TestAwaiter { 
+    TestAwaiterCH(int test) : TestAwaiter(test) {};
+  };
+
+  struct TestAwaiterCHCH :TestAwaiterCH {
+    TestAwaiterCHCH(int test) : TestAwaiterCH(test) {};
+
+    resumable foo(){
+    int x = co_await *this;
+    co_return x;
+    }
+  };
+};
+
+struct TestP {
+ resumable::promise_type::TestAwaiterCHCH  tp = resumable::promise_type::TestAwaiterCHCH(6);
+};
+
+resumable foo1(int t){
+  int x = co_await resumable::promise_type::TestAwaiterCH(t);
+  co_return x;
+}
+
+resumable foo2(){
+  struct TestP  TP;
+  int x = co_await TP.tp;
+  co_return x;
+}
+
+resumable foo3(){
+  int x = co_await TestP{}.tp;
+  co_return x;
+}
+
+int main(){
+  auto t = resumable::promise_type::TestAwaiterCHCH(4);
+  resumable res = t.foo();
+  while (!res.handle_.done())
+    res.handle_.resume();
+  if (res.handle_.promise().used != 4)
+    abort();
+
+  resumable res1 = foo1(5);
+  while (!res1.handle_.done())
+    res1.handle_.resume();
+  if (res1.handle_.promise().used != 5)
+    abort();
+
+  resumable res2 = foo2();
+  while (!res2.handle_.done())
+    res2.handle_.resume();
+  if (res2.handle_.promise().used != 6)
+    abort();
+  
+  resumable res3 = foo2();
+  while (!res3.handle_.done())
+    res3.handle_.resume();
+  if (res3.handle_.promise().used != 6)
+    abort();
+}