c++ - boost 元组的排序双端队列

Question

不确定我是否在某处有一个简单的拼写错误，但我在对元组的双端队列进行排序时遇到了问题。

所以，我的双端队列看起来像这样:

std::deque<boost::tuple<unsigned int, unsigned int> > messages;

然后我有电话要排序:

sort(messages.begin(), messages.end(), msg_sort_criteria);

还有我的排序函数:

bool msg_sort_criteria(boost::tuple<unsigned int, unsigned int> lhs, boost::tuple<unsigned int, unsigned int> rhs)
{
  return boost::get<1>(lhs) < boost::get<1>(rhs);
}

我在 STL_heap.h 和 STL_algo.h 中遇到错误。例如，

Called object type '<bound member function type>' is not a function or function parameter.

---

编辑:

澄清一下，这一切都发生在类的私有(private)成员中。

class Messages::MessageImpl{
private:
  std::deque<boost::tuple<unsigned int, unsigned int> > messages;

  bool msg_sort_criteria(boost::tuple<unsigned int, unsigned int> lhs, boost::tuple<unsigned int, unsigned int> rhs)
  {
    return boost::get<1>(lhs) < boost::get<1>(rhs);
  }

  void fn()
  {
    sort(msg_queue_.begin(), msg_queue_.end(), msg_sort_criteria);
  }
}

Answer 1

^{主要是从评论中转发。}

将您的实现更改为:

class Messages::MessageImpl{
private:
  std::deque<boost::tuple<unsigned int, unsigned int> > messages;

  static bool msg_sort_criteria(boost::tuple<unsigned int, unsigned int> lhs,
                                boost::tuple<unsigned int, unsigned int> rhs)
  {
    return boost::get<1>(lhs) < boost::get<1>(rhs);
  }

  void fn()
  {
    sort(msg_queue_.begin(), msg_queue_.end(), &MessageImpl::msg_sort_criteria);
  }
};