std::execution::env-promise(C++26)

namespace std::execution {
  template<class Env>
  struct env-promise : with-await-transform<env-promise<Env>> {  // exposition only
    unspecified get_return_object() noexcept;
    unspecified initial_suspend() noexcept;
    unspecified final_suspend() noexcept;
    void unhandled_exception() noexcept;
    void return_void() noexcept;
    coroutine_handle<> unhandled_stopped() noexcept;

    const Env& get_env() const noexcept;
  };
}