#include<bits/stdc++.h> using namespace std; struct node{ int x,y; bool operator <(const node &temp)const{ if(x<temp.x)return true; return false; } }; int main() { map<node,int>Map; node temp; temp.x=1,temp.y=1; Map[temp]=1; cout<<Map[temp]<<endl; temp.x=2; cout<<Map[temp]<<endl; return 0; 输出:1 :0 }