c++ pass vector by pointer

// C++ program to demonstrate how vectors 
// can be passed by reference. 
#include<bits/stdc++.h> 
using namespace std; 
   
// The vect is passed by reference and changes 
// made here reflect in main() 
void func(vector<int> &vect) 
{ 
   vect.push_back(30); 
} 
   
int main() 
{ 
    vector<int> vect; 
    vect.push_back(10); 
    vect.push_back(20); 
   
    func(vect); 
  
    for (int i=0; i<vect.size(); i++) 
       cout << vect[i] << " "; 
   
    return 0; 
}