在定义属性或者函数中使用
#include <iostream>
using namespace std;
class Parent//父类
{
private:
int a;
public:
Parent(int _a):a(_a)
{
cout<<"Pareant的有参构造函数"<<endl;
Parent_show();
}
Parent()
{
cout<<"Pareant的无参构造函数"<<endl;
}
void Parent_show()
{
cout<<"parent value = "<<a<<endl;
}
virtual void same_fun()
{
cout<<"same_fun() -parent " ;
Parent_show();
}
};
class Son
{
private:
int a;
public:
Son(int _a,Parent _p):a(_a),p(_p)
{
cout<<"Son的有参构造函数"<<endl;
Son_show();
}
Son()
{
cout<<"Son的无参构造函数"<<endl;
}
void Son_show()
{
cout<<"Son value = "<<a<<endl;
}
void same_fun()
{
cout<<"same_fun() - son " ;
Son_show();
}
Parent p;
};
int main()
{
Parent p1(3);
Son s(4,p1);
s.p.same_fun();
}
------------------------------------------------------改为引用（指针更加可以）-----------------------------------------------------------------------------------------------
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>深度拷贝构造函数时候<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
---------------------------------------------------------------传类值，构造----------------------------------------------------------------------------------------------
结论:
传值构造不允许的，提示用引用来完成深度拷贝构造函数
-------------------------------------------------------------传引用，构造---------------------------------------------------------------------------------------------------
主函数和上面的一样
---------------------------------------------------------传地址,构造------------------------------------------------------------------------------------------------------
结论,可以使用