C++ 构造和析构的顺序

直接用代码说明问题：

1#include <iostream>
2using namespace std;
3
4class A {
5public:
6  A(int a = 0) : _a(a) { cout << "Constructor A!" << _a << endl; }
7  ~A() { cout << "Destrucotr A!" << _a << endl; }
8
9private:
10  int _a;
11};
12
13class B : public A {
14public:
15  B(int a = 0, int b = 0) : A(a), _b(b) {
16    cout << "Constructor B!" << _b << endl;
17  }
18  ~B() { cout << "Destrucotr B!" << _b << endl; }
19
20private:
21  int _b;
22};
23
24class D {
25public:
26  D(int d = 0) : _d(d) { cout << "Constructor D!" << _d << endl; }
27  ~D() { cout << "Destrucotr D!" << _d << endl; }
28
29private:
30  int _d;
31};
32class C : public B, public D {
33public:
34  C(int a = 0, int b = 0, int c = 0, int d = 0) : B(a, b), D(d), _c(c) {
35    cout << "Constructor C!" << _c << endl;
36  }
37  ~C() { cout << "Destrucotr C!" << _c << endl; }
38
39private:
40  int _c;
41};
42int _tmain(int argc, _TCHAR *argv[]) {
43  B a(6), b(7, 8);
44  C c(1, 2, 3), d(12, 13, 14, 15);
45  return 0;
46}
47
48// OUtput:
49// Constructor A!6// Constructor B!0// Constructor A!7// Constructor
50// B!8// Constructor A!1// Constructor B!2// Constructor D!0// Constructor C!3//
51// Constructor A!12// Constructor B!13// Constructor D!15// Constructor C!14//
52// Destrucotr C!14// Destrucotr D!15// Destrucotr B!13// Destrucotr A!12//
53// Destrucotr C!3// Destrucotr D!0// Destrucotr B!2// Destrucotr A!1//
54// Destrucotr B!8// Destrucotr A!7// Destrucotr B!0// Destrucotr A!6