基类指针赋值兼容规则

/*
 
 

     赋值兼容规则
 
 

     作者：qpz
 
 

   */
 
 

  #include <iostream>
 
 

  #include <vector>
 
 

  using namespace std;
 
 

  class Base{
 
 

  private:
 
 
 int x;
 
 
 int y;
 
 

  public:
 
 
 Base(int x,int y)
 
 
 {
 
 
 this->x=x;
 
 
 this->y=y;
 
 
 }
 
 

  };
 
 

  class Derived:public Base{
 
 

  private:
 
 
 int z;
 
 

  public:
 
 
 Derived(int z):Base(z-1,z+1)
 
 
 {
 
 
 this->z=z;
 
 
 }
 
 

  };
 
 

  int main(void)
 
 

  {
 
 
 //Derived *p=new Base(2,1);//因为派生类指针映射范围大
 
 
 
 
 
 
 return 0;
 
 

  }