Question

麻烦看下下面的C++map容器代码，我想问的是["TOM"]元素的地址，为什么第一个到第三个都不是？

#include<utility>
#include<iostream>
#include<map>
#include<string>
using namespace std;
void main(){
map<string,int>a;
map<string,int>b;
map<string,int>::iterator c;
map<string,int>::iterator d;
a["TOM"]=1;
}

Answer 1

Map的实现并非线性的，是通过红黑树来实现的.所以它的地址并非连续

Answer 2

If I remember correctly, map is built on red-black tree where memory alignment could be different from a linear one.