// RUN: %clang_cc1 -verify -std=c++20 -fsyntax-only %s #include "Inputs/std-coroutine.h" namespace std::experimental { using std::coroutine_handle; using std::coroutine_traits; // expected-note{{declared here}} } // namespace std::experimental struct my_awaitable { bool await_ready() noexcept; void await_suspend(std::coroutine_handle<> coro) noexcept; void await_resume() noexcept; }; struct promise_void { void get_return_object(); my_awaitable initial_suspend(); my_awaitable final_suspend() noexcept; void return_void(); void unhandled_exception(); }; template <> struct std::coroutine_traits<void> { using promise_type = promise_void; }; void test() { co_return; // expected-warning@-1{{support for std::experimental::coroutine_traits will be removed}} }