代码部分

#include "iostream"
using namespace std;
//讨论初始化构造函数
//主要讨论在有虚函数情况下的初始化构造函数问题
//含有虚函数的类对象维护一个vptr指向类中的vtbl
class ZoolAnimal
{
public:
	ZoolAnimal(){}
	~ZoolAnimal(){}
	virtual void animates(){
		cout << "ZoolAnimal::animates()" << endl;
	}
	virtual void draw(){
		cout << "ZoolAnimal::draw()" << endl;
	}
private:	
};

class Bear : public ZoolAnimal{
public:
	Bear(){}
	~Bear(){}
	virtual void animates(){
		cout << "Bear::animates()" << endl;
	}
	virtual void draw(){
		cout << "Bear::draw()" << endl;
	}
	virtual void dance(){
		cout << "Bear::dance()" << endl;
	}
private:
};
int main()
{
	/*bear类型的数据初始化bear数据*/
	Bear yogi;
	Bear carp = yogi;
	carp.animates();
	carp.dance();
	carp.draw();
	/*bear数据初始化ZoolAnimal类型*/
	ZoolAnimal zAnimal = carp;
	zAnimal.animates();
	zAnimal.draw();
	return 0;
}

运行结果

分析和讨论

有关初始化构造函数何时由编译器生成的讨论？