STL——pair

#include <bits/stdc++.h>
using namespace std;
int main()
{

    pair< int,double > p1;
    pair< int,pair< int, int> > p2;
    pair< string,int > p3;
    
    p2.first = 1;
    p2.second.first=2;
    p2.second.second=3;
    cout<<p2.first<<" "<<p2.second.first<<" "<<p2.second.second<<endl;
    
    p3 = make_pair("abc",6);
    cout<<p3.first<<" "<<p3.second<<endl;
    
    return 0;
}