c++11 shared_ptr example

ptr.cpp

//g++ -std=c++0x ptr.cpp

#include <cstdio>
#include <cstring>
#include <vector>

#include <memory>


using namespace std;

class Integer {
	int n;
public:
	Integer(int n) : n(n) {}
	~Integer() { printf("deleting %d\n", n); }
	int get() const { return n; }
};

typedef shared_ptr<Integer> IntegerPtr;
vector<IntegerPtr> v;

int foo()
{
	
	shared_ptr<Integer> a(new Integer{ 10 });
	v.push_back(a);
	shared_ptr<Integer> b(new Integer{ 20 });
	v.push_back(b);
	shared_ptr<Integer> c = a;

	shared_ptr<Integer> d(new Integer{ 30 });

	v.push_back(d);
	shared_ptr<Integer> e = b;
	a = d;

	b = shared_ptr<Integer>(new Integer(40));
	v.push_back(b);
	shared_ptr<Integer> f = c;
	b = f;
}

void clear()
{
	vector<IntegerPtr>::iterator i;
	for (i = v.begin(); i != v.end();) {
		
		printf("erase %d\n", (*i)->get());
		i = v.erase(i);
	}
}

int main()
{
	printf("hello\n");
	foo();
	printf("hi\n");
	clear();
	printf("bye\n");
	return 0;
}