如何为地图创建自己的比较器？ - How can I create my own comparator for a map?

问题：

typedef map<string, string> myMap;

When inserting a new pair to myMap , it will use the key string to compare by its own string comparator.向myMap插入新对时，它将使用键string通过其自己的字符串比较器进行比较。 Is it possible to override that comparator?是否可以覆盖该比较器？ For example, I'd like to compare the key string by its length, not by the alphabet.例如，我想通过长度而不是字母来比较键string 。 Or is there any other way to sort the map?或者有没有其他方法可以对地图进行排序？

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解决方案：

参考： https://stackoom.com/en/question/O3Tq