執行環境：macOS shell
程式碼：

#include <iostream>
#include <iomanip>
#include <string>
using namespace std;

class base
{
protected:
    int x;
public:
    base(int x1)
    {
        x = x1;
        cout<<"constructing base, x = "<<x<<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;
    }
};

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;
    }
};

int main ()
{
    derived obj(1
 
,2,3,4);
    return 0;
}

執行結果：