#include <iostream>
#include <cstdlib>   //for EXIT_SUCCESS, size_t
using namespace std;

int main()
{
	double d {3.14159265358979};

	double *p {&d};            //p holds the address of d.
			           //In other words, p "points to" d.

	cout << "The value of d is " << d << "\n";
	cout << "The address of d is " << &d << "\n";
	cout << "The address of d is " << p << "\n";

	//If you want to make sure that p does not hold the address of anything,
        p = nullptr;

	return EXIT_SUCCESS;
}