C++运行出现 Debug Assertion Failed？

zzouc

在小甲鱼C++快速入门视频第36讲，我 按着视频写的代码出现下面错误

                               
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源码：
#include <iostream>
#include <string>

class MyClass
{
public:
MyClass(int *p);
MyClass(const MyClass &rhs);
~MyClass();
MyClass &operator=(const MyClass &rhs);
void print();
private:
int *ptr;
};
MyClass::MyClass(int *p)
{
std::cout << "进入主构造器\n";
ptr = p;
std::cout << "离开主构造器\n";
}
MyClass::MyClass(const MyClass &rhs)
{
std::cout << "进入副本构造器\n";
*this = rhs;
std::cout << "离开副本构造器\n";
}
MyClass::~MyClass()
{
std::cout << "进入析构器\n";
delete ptr;
std::cout << "离开析构器\n";
}
MyClass &MyClass::operator =(const MyClass &rhs)
{
std::cout << "进入赋值语句重载\n";
if (this != &rhs )
{
  delete ptr;
  ptr = new int;
  *ptr = *rhs.ptr;
}
else
{
  std::cout << "赋值号两边为同个对象，不做处理!\n"; //obj1=obj1;
}
std::cout << "离开赋值语句重载\n";
return *this;
}
void MyClass::print()
{
std::cout << *ptr << std::endl;
}
int main()
{
MyClass obj1(new int(1));
MyClass obj2(new int(2));
obj2=obj1;
obj1.print();
obj2.print();
std::cout << "---------------------------\n";
MyClass obj3(new int(3));
MyClass obj4 =obj3;
obj3.print();
obj4.print();
std::cout << "---------------------------\n";
MyClass obj5(new int(5));
obj5 = obj5;
obj5.print();
return 0;
}

补充内容 (2012-10-12 16:34):
:L搞个图真不容易 小木虫地址http://emuch.net/bbs/viewthread.php?tid=5052446

补充内容 (2012-10-12 20:09):
我的是VC++6.0编译器

zzouc

小木虫源地址http://emuch.net/bbs/viewthread.php?tid=5052446