代码示例:

非虚析构的情况下.

#include 
     
      #include 
      
       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 
     
      #include 
      
       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。