虚继承的作用的疑问
class A
{
public:
A(){cout<<"A构造"<<endl;}
int a;
};

class B:virtual public A
{
public:
B(){cout<<"B构造"<<endl;}
};

class C: public A
{
public:
C(){cout<<"C构造"<<endl;}
};

class D:public B,public C
{
public:
D(){cout<<"D构造"<<endl;}
};

这里B是通过虚继承A的，而C是直接继承A，这样的话会是什么情况？
D里面有几个int a啊？

[解决办法]