Function operator co_await

tests/EduCoroutineCoAwaitOperatorTest.cpp:32–47

template<class Rep, class Period>
auto operator co_await(std::chrono::duration<Rep, Period> d)
{
    struct awaiter
    {
        std::chrono::system_clock::duration duration;
        awaiter(std::chrono::system_clock::duration d)
        : duration(d)
        {}

        bool await_ready() const { return duration.count() <= 0; }
        void await_resume() {}
        void await_suspend(std::coroutine_handle<> h) {  }
    };
    
    return awaiter{d};
}
using namespace std::chrono;

my_future<int>  h();