虚基类构造函数的调用

#include <iostream>


using namespace std;
class base
{
protected:
  int x;
public:
  base(int x1)
  {
    x=x1;
    cout<<"constructing base,x="<<x<<endl;
  }
  ~base()
  {
    cout<<"disconstructing base"<<endl;
  }

};
class base1:virtual public base
{
  int y;
public:
  base1(int x1,int y1):base(x1)
  {
   y=y1;
   cout<<"constructing base1,y="<<y<<endl;
  }
};
class base2:virtual public base
{
  int z;
public:
  base2(int x1,int z1):base(x1)
  {
    z=z1;
    cout<<"constructing base2,z="<<z<<endl;
  }
  ~base2()
  {
    cout<<"disconstructing base2"<<endl;
  }
};
class derived:public base1,public base2
{
  int xyz;
public:
  derived(int x1,int y1,int z1,int xyz1):base(x1),base1(x1,y1),base2(x1,z1)
  {
    xyz=xyz1;
    cout<<"constructing derived xyz="<<xyz<<endl;
  }
  ~derived()
  {
    cout<<"disconstructing derived"<<endl;
  }
};

int main()
{
  derived obj(1,2,3,4);
  return 0;
}
以上代码,简要概括虚基类构造函数的调用   结果如下

d
 
派生类的构造函数首先直接调用base的构造函数,而base1,base2,不再去调用,
(c++未调用不分配内存空间)

posted @ 2013-12-14 22:40  Android开发8585  阅读(642)  评论(0编辑  收藏  举报