析构函数的用法

要注意，vector对象指针能够自动析构，所以不需要再调用 delete ,否则会造成两次析构对象


#include <iostream>
#include <vector>
using namespace std;


int i=0;
int j=0;


class CDemo
{
public:
CDemo():str(NULL)
{
cout << "constructor:" << i++ << endl;
}
CDemo(const CDemo &cd)
{
cout <<"copy constructor:" << i++ <<endl;
this->str=new char[strlen(cd.str)+1];
strcpy(str,cd.str);
}
~CDemo()
{
if (str)
{
cout << "destructor:" << j++ << endl;
delete [] str;
}
}


char * str;
};


int main()
{
CDemo d1;
d1.str=new char[32];
strcpy(d1.str,"trend micro");


vector <CDemo> *a1 = new vector <CDemo>();
a1->push_back(d1);
delete a1;


return 0;
}