#include <iostream>
using namespace std;

int main()
{
    /*
     *All code can compile and work.
    */
    /*Semantic Issue
     *main.cpp:12:19: error: no matching constructor for initialization of 'pair<int, int>'
     *utility:271:5: note: candidate constructor template not viable: requires 3 arguments, but 2 were provided
     *utility:212:5: note: candidate constructor not viable: requires 1 argument, but 2 were provided
     *utility:129:8: note: candidate constructor (the implicit copy constructor) not viable: requires 1 argument, but 2 were provided
    */
    pair<int,int> p1(10,25);
    pair<int,float> p2(20,50.5f);
    pair<double,string> p3(2.0e5,"cd");
    cout<<p1.first<<" "<<p1.second<<endl;//output is right.
    cout<<p2.first<<" "<<p2.second<<endl;//output is right.
    cout<<p3.first<<" "<<p3.second<<endl;//output is right.
    return 0;
}