#include <iostream>

using namespace std;

void squared (double &x);

int main123333() {

	double x = 3.14;

	//x = squared(x);
	squared(x);  /// has side-effect (from call-by-ref)

	cout << "Square that value is: " << x << endl;

	return 0;

}


void squared (double &x) {
	x = x * x;
}