#include <iostream>
#include <cstdlib>
using namespace std;

void f(ostream ost);

int main()
{
	cout << "hello";
	ostream another = cout;   //won't compile
	f(cout);                  //won't compile: attempt to pass cout by value
	return EXIT_SUCCESS;
}

void f(ostream ost)
{
	ost << "goodbye";
}