含有虚继承的多继承构造函数执行顺序

 1 #include<iostream>
 2 using namespace std;
 3
 4 class Base1
 5 {
 6 public:
 7     Base1()
 8     {
 9         cout << "class Base1" << endl;
10     }
11 };
12
13 class Base2
14 {
15 public:
16     Base2()
17     {
18         cout << "class Base2" << endl;
19     }
20 };
21
22 class Level1:public Base2,virtual public Base1
23 {
24 public:
25     Level1()
26     {
27         cout << "class Level1" << endl;
28     }
29 };
30
31 class Level2:public Base2,virtual public Base1
32 {
33 public:
34     Level2()
35     {
36         cout << "class Level2" << endl;
37     }
38 };
39
40 class TopLevel:public Level1,virtual public Level2
41 {
42 public:
43     TopLevel()
44     {
45         cout << "class TopLevel" << endl;
46     }
47 };
48
49 int main()
50 {
51     TopLevel obj;
52 }

执行结果 

class Base1class Base2class Level2class Base2class Level1class TopLevel

结论：虚基类的构造函数优先执行