解决浅层复制中容易出现迷途指针的方法

#include <iostream>

using namespace std;

class A

{

public:

A()

{

pa = new int;

*pa = 5;

cout<<"A 被创建"<<endl;

}

A(const A& a)

{

pa = new int;

*pa = *(a.pa);------------》避免被复制的和之前的都指向同一个地址，这里开辟一个新地址，把值丢到新地址里面去。你该干嘛干嘛去

cout<<"A 被复制:"<<*pa<<endl;

}

~A()

{

delete pa;

pa =NULL;

cout<<"A 被销毁"<<endl;

}

void print()

{

cout<<"pa:"<<*pa<<endl;

}

void set(int i)

{

*pa = i;

}

private:

int *pa;

};

int main()

{

A *pa = new A();

pa->print();

//cout<<"a:"<<<<endl;

A b =*pa;

b.print();

pa->set(21);

pa->print();

b.print();

delete pa;

return 0;

}