map基础

program2050 2014-05-27 10:13:11

用map::iterator指向了一个元素，然后其他地方操作了这个map，但是不动这个iterator，这个iterator的指向没有变。
难道map里面的红黑树左旋右旋的时候，不会影响这个iterator。没看过map的源码。呵呵。。。
是因为我的代码片面，具有偶然性，还是map的iterator的实现就是如此？

linux g++



#include <iostream>

#include <map>



using namespace std;

 

int main(int argc, char** argv)

{

    map<int32_t, string> testMap;

    testMap.insert(make_pair(1, "one"));

    testMap.insert(make_pair(2, "two"));

    map<int32_t, string>::iterator iter = testMap.begin();

    for (; iter != testMap.end(); iter++) {

      cout << "iter = (" << iter->first << " --> " << iter->second << ")." << endl; 

    }



    map<int32_t, string>::iterator it = testMap.find(1);

    cout << "it = (" << it->first << " --> " << it->second << ")." << endl; 

    map<int32_t, string>::iterator jt = testMap.find(2);

    cout << "jt = (" << jt->first << " --> " << jt->second << ")." << endl;



    /*testMap.erase(jt);

    cout << "it = (" << it->first << " --> " << it->second << ")." << endl;*/

    testMap.erase(it);

    cout << "jt = (" << jt->first << " --> " << jt->second << ")." << endl;



    testMap.insert(make_pair(3, "three"));

    testMap.insert(make_pair(4, "four"));

    testMap.insert(make_pair(5, "five"));

    iter = testMap.begin();

    for (; iter != testMap.end(); iter++) {

      cout << "iter = (" << iter->first << " --> " << iter->second << ")." << endl; 

    }



    it = testMap.find(4);

    cout << "it = (" << it->first << " --> " << it->second << ")." << endl; 



    testMap.erase(it);

    cout << "jt = (" << jt->first << " --> " << jt->second << ")." << endl;



    return 0;



  }