Method schedule

tests/EduCoroutineStaticVarTest.cpp:40–48

  std::list<std::coroutine_handle<>> _tasks{};

  bool schedule()
  {
    auto task = _tasks.front();
    _tasks.pop_front();

    if(not task.done()) { task.resume(); }

    return not _tasks.empty();
  }

  auto suspend() { return awaiter{*this}; }
};