// RUN: %clang_cc1 -triple x86_64-apple-darwin9 %s -std=c++20 -fsyntax-only -Wignored-qualifiers -Wno-error=return-type -verify -fblocks -Wno-unreachable-code -Wno-unused-value
#ifndef STD_COROUTINE_H
#define STD_COROUTINE_H

namespace std {

template <class Ret, typename... T>
struct coroutine_traits { using promise_type = typename Ret::promise_type; };

template <class Promise = void>
struct coroutine_handle {
  static coroutine_handle from_address(void *) noexcept;
};
template <>
struct coroutine_handle<void> {
  template <class PromiseType>
  coroutine_handle(coroutine_handle<PromiseType>) noexcept;
  static coroutine_handle from_address(void *);
};

struct suspend_always {
  bool await_ready() noexcept { return false; }
  void await_suspend(coroutine_handle<>) noexcept {}
  void await_resume() noexcept {}
};

struct suspend_never {
  bool await_ready() noexcept { return true; }
  void await_suspend(coroutine_handle<>) noexcept {}
  void await_resume() noexcept {}
};

} // namespace std

#endif // STD_COROUTINE_H