1 # include <iostream>
 2 # include <tr1/memory>
 3 using namespace std;
 4 class A {
 5 public:
 6     A() {
 7         cout << "construct A!!!" << endl;
 8     }
 9     ;
10     ~A() {
11         cout << "destruct A!!!" << endl;
12     }
13     ;
14 };
15 class B: public A {
16 public:
17     B() {
18         cout << "construct B!!!" << endl;
19     }
20     ;
21     ~B() {
22         cout << "destruct B!!!" << endl;
23     }
24     ;
25 };
26 int main() {
27 //    B* ptrB0 = new B();
28     std::tr1::shared_ptr<B> ptrB1(new B);
29 }