c++ map插入。覆盖

#include<map>int main(void) {map<int, string>temp;map<int, string>::iterator m1_Iter;//不可覆盖插入temp.insert( pair <int, string>  ( 1, "hello" ));temp[2] = "hello";//可覆盖插入//遍历for ( m1_Iter = temp.begin( ); m1_Iter != temp.end( ); m1_Iter++ ){cout<< m1_Iter->first<< " " << m1_Iter->second << " ";}return 0;}