[转载]析构函数的虚析构和非虚析构调用的差别

 

 

代码示例:

非虚析构的情况下.

#include <stdio.h>
#include <iostream>using namespace std;class A
{
public:A(){std::cout << "A is created." << std::endl;}~A(){std::cout << "A is deleted." << std::endl;}
};class B : public A
{
public:B(){std::cout << "B is created." << std::endl;}~B(){std::cout << "B is deleted." << std::endl;}
};int main()
{A* pA = new B();delete pA;return 0;
}

虚析构的情况下.

#include <stdio.h>
#include <iostream>using namespace std;class A
{
public:A(){std::cout << "A is created." << std::endl;}virtual ~A(){std::cout << "A is deleted." << std::endl;}
};class B : public A
{
public:B(){std::cout << "B is created." << std::endl;}~B(){std::cout << "B is deleted." << std::endl;}
};int main()
{A* pA = new B();delete pA;return 0;
}

 

如果在类型B中创建了一些资源，比如文件句柄、内存等，在这种情况下都得不到释放，从而导致资源泄漏。