The following code example is taken from the book
Object-Oriented Programming in C++
by Nicolai M. Josuttis, Wiley, 2002
© Copyright Nicolai M. Josuttis 2002
#include <iostream>
#include <list>
#include <deque>
#include <algorithm>
#include "countptr.hpp"
using namespace std;
void printCountedPtr(CountedPtr<int> elem)
{
cout << *elem << ' ';
}
int main()
{
// type for smart pointer for this purpose
typedef CountedPtr<int> IntPtr;
// two different sets
deque<IntPtr> coll1;
list<IntPtr> coll2;
// array of initial ints
static int values[] = { 3, 5, 9, 1, 6, 4 };
/* insert newly created ints in the sets with reference semantics
* - same sequence in coll1
* - reversed sequence in coll2
*/
for (unsigned i=0; i<sizeof(values)/sizeof(values[0]); ++i) {
IntPtr ptr(new int(values[i]));
coll1.push_back(ptr);
coll2.push_front(ptr);
}
// output content of both sets
for_each(coll1.begin(), coll1.end(), printCountedPtr);
cout << endl;
for_each(coll2.begin(), coll2.end(), printCountedPtr);
cout << endl << endl;
/* modify elements of the sets in different places
* - square third value in coll1
* - negate first value in coll1
* - set first value in coll2 to 0
*/
*coll1[2] *= *coll1[2];
(**coll1.begin()) *= -1;
(**coll2.begin()) = 0;
// output content of both sets again
for_each(coll1.begin(), coll1.end(), printCountedPtr);
cout << endl;
for_each(coll2.begin(), coll2.end(), printCountedPtr);
cout << endl;
}