父类接收子类new出来的变量为什么错啊，求救
class MakeSound {
public:
virtual void makeSound() {};
};
class Bark : public MakeSound {
public:
void makeSound() {
cout << "bark" << endl;
}
};
class Canine {
public:
MakeSound a;
};
class Retriever : public Canine {
public:
a = new Bark();
//a.makeSound();
};
