flushing output in c++

// C++ program to demonstrate the  
// use of flush function 
#include <iostream> 
#include <thread> 
#include <chrono> 
using namespace std; 
int main() 
{ 
   for (int i = 1; i <= 5; ++i) 
   { 
      cout << i << " " << flush; 
      this_thread::sleep_for(chrono::seconds(1)); 
   } 
   return 0; 
}